"""
FastAPI application entry point for Delphi Database.

This module initializes the FastAPI application, sets up database connections,
and provides the main application instance.
"""

import os
import time
import csv
import json
import uuid
from contextlib import asynccontextmanager
from datetime import datetime
from typing import Optional, List, Dict, Any
from io import StringIO

from fastapi import FastAPI, Depends, Request, Query, HTTPException, UploadFile, File, Form
from fastapi.responses import RedirectResponse, Response, JSONResponse
from starlette.middleware.sessions import SessionMiddleware
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
from sqlalchemy.orm import Session, joinedload
from sqlalchemy import or_, and_, func as sa_func
from dotenv import load_dotenv
from starlette.middleware.base import BaseHTTPMiddleware
import structlog
from structlog import contextvars as structlog_contextvars

from .database import create_tables, get_db, get_database_url
from .models import User, Case, Client, Phone, Transaction, Document, Payment, ImportLog
from .auth import authenticate_user, get_current_user_from_session
from .reporting import (
    build_phone_book_pdf,
    build_payments_detailed_pdf,
    build_envelope_pdf,
    build_phone_book_address_pdf,
    build_rolodex_info_pdf,
)
from .logging_config import setup_logging
from .schemas import (
    ClientOut,
    PhoneOut,
    CaseOut,
    TransactionOut,
    Pagination,
    RolodexListResponse,
    FilesListResponse,
    LedgerListResponse,
)

# Load environment variables
load_dotenv()

# Get SECRET_KEY from environment variables
SECRET_KEY = os.getenv("SECRET_KEY")
if not SECRET_KEY:
    raise ValueError("SECRET_KEY environment variable must be set")

# Configure structured logging
setup_logging()
logger = structlog.get_logger(__name__)
def open_text_with_fallbacks(file_path: str):
    """
    Open a text file trying multiple encodings commonly seen in legacy CSVs.

    Attempts in order: utf-8, utf-8-sig, cp1252, latin-1.

    Returns a tuple of (file_object, encoding_used). Caller is responsible to close file.
    """
    encodings = ["utf-8", "utf-8-sig", "cp1252", "latin-1"]
    last_error = None
    for enc in encodings:
        try:
            f = open(file_path, 'r', encoding=enc, errors='strict', newline='')
            # Try reading a tiny chunk to force decoding errors early
            _ = f.read(1024)
            f.seek(0)
            logger.info("csv_open_encoding_selected", file=file_path, encoding=enc)
            return f, enc
        except Exception as e:
            last_error = e
            continue
    raise last_error if last_error else RuntimeError("Unable to open file with known encodings")


# Configure Jinja2 templates
templates = Jinja2Templates(directory="app/templates")


class AuthMiddleware(BaseHTTPMiddleware):
    """
    Simple session-based authentication middleware.

    Redirects unauthenticated users to /login for protected routes.
    """

    def __init__(self, app, exempt_paths: list[str] | None = None):
        super().__init__(app)
        self.exempt_paths = exempt_paths or []

    async def dispatch(self, request, call_next):
        path = request.url.path

        # Allow exempt paths and static assets
        if (
            path in self.exempt_paths
            or path.startswith("/static")
            or path.startswith("/favicon")
        ):
            return await call_next(request)

        # Enforce authentication for other paths
        if not request.session.get("user_id"):
            # Return JSON 401 for API routes, redirect for HTML routes
            if path.startswith("/api/"):
                return JSONResponse(status_code=401, content={"detail": "Unauthorized"})
            return RedirectResponse(url="/login", status_code=302)

        return await call_next(request)


class RequestIdMiddleware(BaseHTTPMiddleware):
    """
    Middleware that assigns a request_id and binds request context for logging.

    Adds: request_id, http.method, http.path, user.id to the structlog context.
    Emits a JSON access log with status_code and duration_ms after response.
    """

    async def dispatch(self, request: Request, call_next):
        start_time = time.perf_counter()

        request_id = request.headers.get("X-Request-ID") or str(uuid.uuid4())
        method = request.method
        path = request.url.path

        # user id from session if available (SessionMiddleware runs first)
        user_id = request.session.get("user_id") if hasattr(request, "session") else None

        structlog_contextvars.bind_contextvars(
            request_id=request_id,
            **{"http.method": method, "http.path": path, "user.id": user_id},
        )

        try:
            response = await call_next(request)
            status_code = response.status_code
        except Exception as exc:  # noqa: BLE001 - we re-raise after logging
            status_code = 500
            duration_ms = int((time.perf_counter() - start_time) * 1000)
            logger.error(
                "request",
                status_code=status_code,
                duration_ms=duration_ms,
                exc_info=True,
            )
            structlog_contextvars.unbind_contextvars("request_id", "http.method", "http.path", "user.id")
            raise

        # Ensure response header has request id
        try:
            response.headers["X-Request-ID"] = request_id
        except Exception:
            pass

        duration_ms = int((time.perf_counter() - start_time) * 1000)
        logger.info(
            "request",
            status_code=status_code,
            duration_ms=duration_ms,
        )

        structlog_contextvars.unbind_contextvars("request_id", "http.method", "http.path", "user.id")
        return response

@asynccontextmanager
async def lifespan(app: FastAPI):
    """
    Lifespan context manager for FastAPI application.

    Handles startup and shutdown events:
    - Creates database tables on startup
    - Logs database connection info
    """
    # Startup
    logger.info("app_start")

    # Create database tables
    create_tables()
    logger.info("db_tables_verified")

    # Log database connection info
    db_url = get_database_url()
    logger.info("db_connected", database_url=db_url)

    yield

    # Shutdown
    logger.info("app_shutdown")


# Create FastAPI application with lifespan management
app = FastAPI(
    title="Delphi Database",
    description="Legal case management database application",
    version="1.0.0",
    lifespan=lifespan
)

# Add CORS middleware for cross-origin requests
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # In production, specify allowed origins
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Register request logging and authentication middleware with exempt paths
EXEMPT_PATHS = ["/", "/health", "/login", "/logout"]
app.add_middleware(RequestIdMiddleware)
app.add_middleware(AuthMiddleware, exempt_paths=EXEMPT_PATHS)

# Add SessionMiddleware for session management (must be added LAST so it runs FIRST)
app.add_middleware(SessionMiddleware, secret_key=SECRET_KEY)

# Mount static files directory
app.mount("/static", StaticFiles(directory="static"), name="static")


def get_import_type_from_filename(filename: str) -> str:
    """
    Determine import type based on filename pattern.

    Args:
        filename: Name of the uploaded CSV file

    Returns:
        Import type string (client, phone, case, transaction, document, payment)
    """
    filename_upper = filename.upper()
    # Strip extension and normalize
    base = filename_upper.rsplit('.', 1)[0]

    # Support files saved with explicit type prefixes (e.g., CLIENT_<uuid>.csv)
    if base.startswith('CLIENT_'):
        return 'client'
    if base.startswith('PHONE_'):
        return 'phone'
    if base.startswith('CASE_'):
        return 'case'
    if base.startswith('TRANSACTION_'):
        return 'transaction'
    if base.startswith('DOCUMENT_'):
        return 'document'
    if base.startswith('PAYMENT_'):
        return 'payment'

    # Legacy/real file name patterns
    if base.startswith('ROLODEX') or base.startswith('ROLEX') or 'ROLODEX' in base or 'ROLEX' in base:
        return 'client'
    if base.startswith('PHONE') or 'PHONE' in base:
        return 'phone'
    if base.startswith('FILES') or base.startswith('FILE') or 'FILES' in base:
        return 'case'
    if base.startswith('LEDGER') or 'LEDGER' in base or base.startswith('TRNSACTN') or 'TRNSACTN' in base:
        return 'transaction'
    if base.startswith('QDROS') or base.startswith('QDRO') or 'QDRO' in base:
        return 'document'
    if base.startswith('PAYMENTS') or base.startswith('DEPOSITS') or 'PAYMENT' in base or 'DEPOSIT' in base:
        return 'payment'

    raise ValueError(f"Unknown file type for filename: {filename}")


def validate_csv_headers(headers: List[str], expected_fields: Dict[str, str]) -> Dict[str, Any]:
    """
    Validate CSV headers against expected model fields.

    Args:
        headers: List of CSV column headers
        expected_fields: Dict mapping field names to descriptions

    Returns:
        Dict with validation results and field mapping
    """
    result = {
        'valid': True,
        'missing_fields': [],
        'field_mapping': {},
        'errors': []
    }

    # Create mapping from CSV headers to model fields (case-insensitive)
    for csv_header in headers:
        csv_header_clean = csv_header.strip().lower()
        matched = False

        for model_field, description in expected_fields.items():
            if csv_header_clean == model_field.lower():
                result['field_mapping'][model_field] = csv_header
                matched = True
                break

        if not matched:
            # Try partial matches for common variations
            for model_field, description in expected_fields.items():
                if model_field.lower() in csv_header_clean or csv_header_clean in model_field.lower():
                    result['field_mapping'][model_field] = csv_header
                    matched = True
                    break

        if not matched:
            result['errors'].append(f"Unknown header: '{csv_header}'")

    # Check for required fields (case-insensitive)
    required_fields = ['id']  # Most imports need some form of ID
    for required in required_fields:
        found = False
        for mapped_field in result['field_mapping']:
            if mapped_field.lower() == required.lower():
                found = True
                break
        if not found:
            result['missing_fields'].append(required)

    if result['missing_fields'] or result['errors']:
        result['valid'] = False

    return result


def parse_date(date_str: str) -> Optional[datetime]:
    """Parse date string into datetime object."""
    if not date_str or date_str.strip() in ('', 'NULL', 'N/A'):
        return None

    # Try common date formats
    formats = ['%Y-%m-%d', '%m/%d/%Y', '%Y/%m/%d', '%d-%m-%Y']

    for fmt in formats:
        try:
            return datetime.strptime(date_str.strip(), fmt)
        except ValueError:
            continue

    logger.warning("parse_date_failed", value=date_str)
    return None


def parse_float(value: str) -> Optional[float]:
    """Parse string value into float."""
    if not value or value.strip() in ('', 'NULL', 'N/A'):
        return None

    try:
        return float(value.strip())
    except ValueError:
        logger.warning("parse_float_failed", value=value)
        return None


def parse_int(value: str) -> Optional[int]:
    """Parse string value into int."""
    if not value or value.strip() in ('', 'NULL', 'N/A'):
        return None

    try:
        return int(value.strip())
    except ValueError:
        logger.warning("parse_int_failed", value=value)
        return None


def import_rolodex_data(db: Session, file_path: str) -> Dict[str, Any]:
    """
    Import ROLODEX CSV data into Client model.

    Expected CSV format: Id,Prefix,First,Middle,Last,Suffix,Title,A1,A2,A3,City,Abrev,St,Zip,Email,DOB,SS#,Legal_Status,Group,Memo
    """
    result = {
        'success': 0,
        'errors': [],
        'total_rows': 0
    }

    expected_fields = {
        'Id': 'Client ID',
        'Prefix': 'Name Prefix',
        'First': 'First Name',
        'Middle': 'Middle Initial',
        'Last': 'Last Name',
        'Suffix': 'Name Suffix',
        'Title': 'Company/Organization',
        'A1': 'Address Line 1',
        'A2': 'Address Line 2',
        'A3': 'Address Line 3',
        'City': 'City',
        'Abrev': 'State Abbreviation',
        'St': 'State',
        'Zip': 'ZIP Code',
        'Email': 'Email Address',
        'DOB': 'Date of Birth',
        'SS#': 'Social Security Number',
        'Legal_Status': 'Legal Status',
        'Group': 'Group',
        'Memo': 'Memo/Notes'
    }

    try:
        f, used_encoding = open_text_with_fallbacks(file_path)
        with f as file:
            reader = csv.DictReader(file)

            # Validate headers
            headers = reader.fieldnames or []
            validation = validate_csv_headers(headers, expected_fields)

            if not validation['valid']:
                result['errors'].append(f"Header validation failed: {validation['errors']}")
                return result

            for row_num, row in enumerate(reader, start=2):  # Start at 2 (header is row 1)
                result['total_rows'] += 1

                try:
                    # Extract and clean data
                    rolodex_id = row.get('Id', '').strip()
                    if not rolodex_id:
                        result['errors'].append(f"Row {row_num}: Missing client ID")
                        continue

                    # Check for existing client
                    existing = db.query(Client).filter(Client.rolodex_id == rolodex_id).first()
                    if existing:
                        result['errors'].append(f"Row {row_num}: Client with ID '{rolodex_id}' already exists")
                        continue

                    client = Client(
                        rolodex_id=rolodex_id,
                        first_name=row.get('First', '').strip() or None,
                        middle_initial=row.get('Middle', '').strip() or None,
                        last_name=row.get('Last', '').strip() or None,
                        company=row.get('Title', '').strip() or None,
                        address=row.get('A1', '').strip() or None,
                        city=row.get('City', '').strip() or None,
                        state=row.get('St', '').strip() or None,
                        zip_code=row.get('Zip', '').strip() or None
                    )

                    db.add(client)
                    result['success'] += 1

                except Exception as e:
                    result['errors'].append(f"Row {row_num}: {str(e)}")

        db.commit()

    except Exception as e:
        logger.error("rolodex_import_failed", file=file_path, error=str(e))
        result['errors'].append(f"Import failed: {str(e)}")
        db.rollback()

    return result


def import_phone_data(db: Session, file_path: str) -> Dict[str, Any]:
    """
    Import PHONE CSV data into Phone model.

    Expected CSV format: Id,Phone,Location
    """
    result = {
        'success': 0,
        'errors': [],
        'total_rows': 0
    }

    f = None
    try:
        f, used_encoding = open_text_with_fallbacks(file_path)
        reader = csv.DictReader(f)

        headers = reader.fieldnames or []
        if len(headers) < 2:
            result['errors'].append("Invalid CSV format: expected at least 2 columns")
            return result

        for row_num, row in enumerate(reader, start=2):
            result['total_rows'] += 1

            try:
                client_id = row.get('Id', '').strip()
                if not client_id:
                    result['errors'].append(f"Row {row_num}: Missing client ID")
                    continue

                # Find the client
                client = db.query(Client).filter(Client.rolodex_id == client_id).first()
                if not client:
                    result['errors'].append(f"Row {row_num}: Client with ID '{client_id}' not found")
                    continue

                phone_number = row.get('Phone', '').strip()
                if not phone_number:
                    result['errors'].append(f"Row {row_num}: Missing phone number")
                    continue

                phone = Phone(
                    client_id=client.id,
                    phone_type=row.get('Location', '').strip() or 'primary',
                    phone_number=phone_number
                )

                db.add(phone)
                result['success'] += 1

            except Exception as e:
                result['errors'].append(f"Row {row_num}: {str(e)}")

        db.commit()

    except Exception as e:
        result['errors'].append(f"Import failed: {str(e)}")
        db.rollback()
    finally:
        if f:
            f.close()

    return result


def import_files_data(db: Session, file_path: str) -> Dict[str, Any]:
    """
    Import FILES CSV data into Case model.

    Expected CSV format: File_No,Id,File_Type,Regarding,Opened,Closed,Empl_Num,Rate_Per_Hour,Status,Footer_Code,Opposing,Hours,Hours_P,Trust_Bal,Trust_Bal_P,Hourly_Fees,Hourly_Fees_P,Flat_Fees,Flat_Fees_P,Disbursements,Disbursements_P,Credit_Bal,Credit_Bal_P,Total_Charges,Total_Charges_P,Amount_Owing,Amount_Owing_P,Transferable,Memo
    """
    result = {
        'success': 0,
        'errors': [],
        'total_rows': 0
    }

    expected_fields = {
        'File_No': 'File Number',
        'Status': 'Status',
        'File_Type': 'File Type',
        'Regarding': 'Regarding',
        'Opened': 'Opened Date',
        'Closed': 'Closed Date',
        'Id': 'Client ID',
        'Empl_Num': 'Employee Number',
        'Rate_Per_Hour': 'Rate Per Hour',
        'Footer_Code': 'Footer Code',
        'Opposing': 'Opposing Party',
        'Hours': 'Hours',
        'Hours_P': 'Hours (Previous)',
        'Trust_Bal': 'Trust Balance',
        'Trust_Bal_P': 'Trust Balance (Previous)',
        'Hourly_Fees': 'Hourly Fees',
        'Hourly_Fees_P': 'Hourly Fees (Previous)',
        'Flat_Fees': 'Flat Fees',
        'Flat_Fees_P': 'Flat Fees (Previous)',
        'Disbursements': 'Disbursements',
        'Disbursements_P': 'Disbursements (Previous)',
        'Credit_Bal': 'Credit Balance',
        'Credit_Bal_P': 'Credit Balance (Previous)',
        'Total_Charges': 'Total Charges',
        'Total_Charges_P': 'Total Charges (Previous)',
        'Amount_Owing': 'Amount Owing',
        'Amount_Owing_P': 'Amount Owing (Previous)',
        'Transferable': 'Transferable',
        'Memo': 'Memo'
    }

    f = None
    try:
        f, used_encoding = open_text_with_fallbacks(file_path)
        reader = csv.DictReader(f)

        headers = reader.fieldnames or []
        validation = validate_csv_headers(headers, expected_fields)

        if not validation['valid']:
            result['errors'].append(f"Header validation failed: {validation['errors']}")
            return result

        for row_num, row in enumerate(reader, start=2):
            result['total_rows'] += 1

            try:
                file_no = row.get('File_No', '').strip()
                if not file_no:
                    result['errors'].append(f"Row {row_num}: Missing file number")
                    continue

                # Check for existing case
                existing = db.query(Case).filter(Case.file_no == file_no).first()
                if existing:
                    result['errors'].append(f"Row {row_num}: Case with file number '{file_no}' already exists")
                    continue

                # Find client by ID
                client_id = row.get('Id', '').strip()
                client = None
                if client_id:
                    client = db.query(Client).filter(Client.rolodex_id == client_id).first()
                    if not client:
                        result['errors'].append(f"Row {row_num}: Client with ID '{client_id}' not found")
                        continue

                case = Case(
                    file_no=file_no,
                    client_id=client.id if client else None,
                    status=row.get('Status', '').strip() or 'active',
                    case_type=row.get('File_Type', '').strip() or None,
                    description=row.get('Regarding', '').strip() or None,
                    open_date=parse_date(row.get('Opened', '')),
                    close_date=parse_date(row.get('Closed', ''))
                )

                db.add(case)
                result['success'] += 1

            except Exception as e:
                result['errors'].append(f"Row {row_num}: {str(e)}")

        db.commit()

    except Exception as e:
        result['errors'].append(f"Import failed: {str(e)}")
        db.rollback()
    finally:
        if f:
            f.close()

    return result


def import_ledger_data(db: Session, file_path: str) -> Dict[str, Any]:
    """
    Import LEDGER CSV data into Transaction model.

    Expected CSV format: File_No,Date,Item_No,Empl_Num,T_Code,T_Type,T_Type_L,Quantity,Rate,Amount,Billed,Note
    """
    result = {
        'success': 0,
        'errors': [],
        'total_rows': 0
    }

    f = None
    try:
        f, used_encoding = open_text_with_fallbacks(file_path)
        reader = csv.DictReader(f)

        headers = reader.fieldnames or []
        if len(headers) < 3:
            result['errors'].append("Invalid CSV format: expected at least 3 columns")
            return result

        for row_num, row in enumerate(reader, start=2):
            result['total_rows'] += 1

            try:
                file_no = row.get('File_No', '').strip()
                if not file_no:
                    result['errors'].append(f"Row {row_num}: Missing file number")
                    continue

                # Find the case
                case = db.query(Case).filter(Case.file_no == file_no).first()
                if not case:
                    result['errors'].append(f"Row {row_num}: Case with file number '{file_no}' not found")
                    continue

                amount = parse_float(row.get('Amount', '0'))
                if amount is None:
                    result['errors'].append(f"Row {row_num}: Invalid amount")
                    continue

                tx_date = parse_date(row.get('Date', ''))
                item_no = parse_int(row.get('Item_No', '') or '')
                # ensure unique item_no per date by increment
                # temp session-less check via while loop
                desired_item_no = item_no if item_no is not None else 1
                while True:
                    exists = (
                        db.query(Transaction)
                        .filter(
                            Transaction.case_id == case.id,
                            Transaction.transaction_date == tx_date,
                            Transaction.item_no == desired_item_no,
                        )
                        .first()
                    )
                    if not exists:
                        break
                    desired_item_no += 1

                transaction = Transaction(
                    case_id=case.id,
                    transaction_date=tx_date,
                    transaction_type=(row.get('T_Type', '').strip() or None),
                    t_type_l=(row.get('T_Type_L', '').strip().upper() or None),
                    amount=amount,
                    description=(row.get('Note', '').strip() or None),
                    reference=(row.get('Item_No', '').strip() or None),
                    item_no=desired_item_no,
                    employee_number=(row.get('Empl_Num', '').strip() or None),
                    t_code=(row.get('T_Code', '').strip().upper() or None),
                    quantity=parse_float(row.get('Quantity', '')),
                    rate=parse_float(row.get('Rate', '')),
                    billed=((row.get('Billed', '') or '').strip().upper() or None),
                )

                db.add(transaction)
                result['success'] += 1

            except Exception as e:
                result['errors'].append(f"Row {row_num}: {str(e)}")

        db.commit()

    except Exception as e:
        result['errors'].append(f"Import failed: {str(e)}")
        db.rollback()
    finally:
        if f:
            f.close()

    return result


def import_qdros_data(db: Session, file_path: str) -> Dict[str, Any]:
    """
    Import QDROS CSV data into Document model.

    Expected CSV format: File_No,Document_Type,Description,File_Name,Date
    """
    result = {
        'success': 0,
        'errors': [],
        'total_rows': 0
    }

    f = None
    try:
        f, used_encoding = open_text_with_fallbacks(file_path)
        reader = csv.DictReader(f)

        headers = reader.fieldnames or []
        if len(headers) < 2:
            result['errors'].append("Invalid CSV format: expected at least 2 columns")
            return result

        for row_num, row in enumerate(reader, start=2):
            result['total_rows'] += 1

            try:
                file_no = row.get('File_No', '').strip()
                if not file_no:
                    result['errors'].append(f"Row {row_num}: Missing file number")
                    continue

                # Find the case
                case = db.query(Case).filter(Case.file_no == file_no).first()
                if not case:
                    result['errors'].append(f"Row {row_num}: Case with file number '{file_no}' not found")
                    continue

                document = Document(
                    case_id=case.id,
                    document_type=row.get('Document_Type', '').strip() or 'QDRO',
                    file_name=row.get('File_Name', '').strip() or None,
                    description=row.get('Description', '').strip() or None,
                    uploaded_date=parse_date(row.get('Date', ''))
                )

                db.add(document)
                result['success'] += 1

            except Exception as e:
                result['errors'].append(f"Row {row_num}: {str(e)}")

        db.commit()

    except Exception as e:
        result['errors'].append(f"Import failed: {str(e)}")
        db.rollback()
    finally:
        if f:
            f.close()

    return result


def import_payments_data(db: Session, file_path: str) -> Dict[str, Any]:
    """
    Import PAYMENTS CSV data into Payment model.

    Expected CSV format: File_No,Date,Amount,Type,Description,Check_Number
    """
    result = {
        'success': 0,
        'errors': [],
        'total_rows': 0
    }

    f = None
    try:
        f, used_encoding = open_text_with_fallbacks(file_path)
        reader = csv.DictReader(f)

        headers = reader.fieldnames or []
        if len(headers) < 2:
            result['errors'].append("Invalid CSV format: expected at least 2 columns")
            return result

        for row_num, row in enumerate(reader, start=2):
            result['total_rows'] += 1

            try:
                file_no = row.get('File_No', '').strip()
                if not file_no:
                    result['errors'].append(f"Row {row_num}: Missing file number")
                    continue

                # Find the case
                case = db.query(Case).filter(Case.file_no == file_no).first()
                if not case:
                    result['errors'].append(f"Row {row_num}: Case with file number '{file_no}' not found")
                    continue

                amount = parse_float(row.get('Amount', '0'))
                if amount is None:
                    result['errors'].append(f"Row {row_num}: Invalid amount")
                    continue

                payment = Payment(
                    case_id=case.id,
                    payment_date=parse_date(row.get('Date', '')),
                    payment_type=row.get('Type', '').strip() or None,
                    amount=amount,
                    description=row.get('Description', '').strip() or None,
                    check_number=row.get('Check_Number', '').strip() or None
                )

                db.add(payment)
                result['success'] += 1

            except Exception as e:
                result['errors'].append(f"Row {row_num}: {str(e)}")

        db.commit()

    except Exception as e:
        result['errors'].append(f"Import failed: {str(e)}")
        db.rollback()
    finally:
        if f:
            f.close()

    return result


def process_csv_import(db: Session, import_type: str, file_path: str) -> Dict[str, Any]:
    """
    Process CSV import based on type.

    Args:
        db: Database session
        import_type: Type of import (client, phone, case, transaction, document, payment)
        file_path: Path to CSV file

    Returns:
        Dict with import results
    """
    import_functions = {
        'client': import_rolodex_data,
        'phone': import_phone_data,
        'case': import_files_data,
        'transaction': import_ledger_data,
        'document': import_qdros_data,
        'payment': import_payments_data
    }

    import_func = import_functions.get(import_type)
    if not import_func:
        return {
            'success': 0,
            'errors': [f"Unknown import type: {import_type}"],
            'total_rows': 0
        }

    return import_func(db, file_path)


# ------------------------------
# Ledger CRUD and helpers
# ------------------------------

def validate_ledger_fields(
    *,
    transaction_date: Optional[str],
    t_code: Optional[str],
    employee_number: Optional[str],
    quantity: Optional[str],
    rate: Optional[str],
    amount: Optional[str],
    billed: Optional[str],
) -> tuple[list[str], dict[str, Any]]:
    """Validate incoming ledger form fields and return (errors, parsed_values)."""
    errors: list[str] = []
    parsed: dict[str, Any] = {}

    # Date
    tx_dt = parse_date(transaction_date or "") if transaction_date is not None else None
    if tx_dt is None:
        errors.append("Date is required and must be valid")
    else:
        parsed["transaction_date"] = tx_dt

    # T_Code
    if t_code is None or not t_code.strip():
        errors.append("T_Code is required")
    else:
        parsed["t_code"] = t_code.strip().upper()

    # Employee number
    if employee_number is None or not employee_number.strip():
        errors.append("Empl_Num is required")
    else:
        parsed["employee_number"] = employee_number.strip()

    # Quantity, Rate, Amount
    qty = parse_float(quantity or "") if quantity is not None else None
    rt = parse_float(rate or "") if rate is not None else None
    amt = parse_float(amount or "") if amount is not None else None

    if qty is not None:
        parsed["quantity"] = qty
    if rt is not None:
        parsed["rate"] = rt

    # Auto-compute amount if missing but quantity and rate present
    if amt is None and qty is not None and rt is not None:
        amt = round(qty * rt, 2)
    if amt is None:
        errors.append("Amount is required or derivable from Quantity × Rate")
    else:
        parsed["amount"] = amt

    # Billed flag
    billed_flag = (billed or "").strip().upper() if billed is not None else ""
    if billed_flag not in ("Y", "N"):
        errors.append("Billed must be 'Y' or 'N'")
    else:
        parsed["billed"] = billed_flag

    return errors, parsed


def next_unique_item_no(db: Session, case_id: int, tx_date: datetime, desired_item_no: Optional[int]) -> int:
    """Ensure (transaction_date, item_no) uniqueness per case by incrementing if needed."""
    # Start at provided item_no or at 1 if missing
    item_no = int(desired_item_no) if desired_item_no is not None else 1
    while True:
        exists = (
            db.query(Transaction)
            .filter(
                Transaction.case_id == case_id,
                Transaction.transaction_date == tx_date,
                Transaction.item_no == item_no,
            )
            .first()
        )
        if not exists:
            return item_no
        item_no += 1


def compute_case_totals_from_case(case_obj: Case) -> Dict[str, float]:
    """
    Compute simple totals for a case from its transactions.

    Returns billed, unbilled, and total sums. Amounts are treated as positive;
    future enhancement could apply sign based on t_type_l.
    """
    billed_total = 0.0
    unbilled_total = 0.0
    overall_total = 0.0

    for t in (case_obj.transactions or []):
        amt = float(t.amount) if t.amount is not None else 0.0
        overall_total += amt
        if (t.billed or '').upper() == 'Y':
            billed_total += amt
        else:
            unbilled_total += amt

    return {
        'billed_total': round(billed_total, 2),
        'unbilled_total': round(unbilled_total, 2),
        'overall_total': round(overall_total, 2),
    }


def compute_case_totals_for_case_id(db: Session, case_id: int) -> Dict[str, float]:
    """
    Compute billed, unbilled, and overall totals for a case by ID.

    This uses a simple in-Python aggregation over the case's transactions to
    avoid SQL portability issues and to keep the logic consistent with
    compute_case_totals_from_case.
    """
    billed_total = 0.0
    unbilled_total = 0.0
    overall_total = 0.0

    transactions: List[Transaction] = (
        db.query(Transaction).filter(Transaction.case_id == case_id).all()
    )
    for t in transactions:
        amt = float(t.amount) if t.amount is not None else 0.0
        overall_total += amt
        if ((t.billed or '').upper()) == 'Y':
            billed_total += amt
        else:
            unbilled_total += amt

    return {
        'billed_total': round(billed_total, 2),
        'unbilled_total': round(unbilled_total, 2),
        'overall_total': round(overall_total, 2),
    }


def _ledger_keys_from_tx(tx: Optional["Transaction"]) -> Dict[str, Any]:
    """
    Extract identifying keys for a ledger transaction for audit logs.
    """
    if tx is None:
        return {}
    return {
        'transaction_id': getattr(tx, 'id', None),
        'case_id': getattr(tx, 'case_id', None),
        'item_no': getattr(tx, 'item_no', None),
        'transaction_date': getattr(tx, 'transaction_date', None),
        't_code': getattr(tx, 't_code', None),
        't_type_l': getattr(tx, 't_type_l', None),
        'employee_number': getattr(tx, 'employee_number', None),
        'billed': getattr(tx, 'billed', None),
        'amount': getattr(tx, 'amount', None),
    }


def _log_ledger_audit(
    *,
    action: str,
    user: "User",
    case_id: int,
    keys: Dict[str, Any],
    pre: Dict[str, float],
    post: Dict[str, float],
) -> None:
    """
    Emit a structured audit log line for ledger mutations including user, action,
    identifiers, and pre/post balances with deltas.
    """
    delta = {
        'billed_total': round((post.get('billed_total', 0.0) - pre.get('billed_total', 0.0)), 2),
        'unbilled_total': round((post.get('unbilled_total', 0.0) - pre.get('unbilled_total', 0.0)), 2),
        'overall_total': round((post.get('overall_total', 0.0) - pre.get('overall_total', 0.0)), 2),
    }

    logger.info(
        "ledger_audit",
        action=action,
        user_id=getattr(user, 'id', None),
        user_username=getattr(user, 'username', None),
        case_id=case_id,
        keys=keys,
        pre_balances=pre,
        post_balances=post,
        delta_balances=delta,
    )


@app.post("/case/{case_id}/ledger")
async def ledger_create(
    request: Request,
    case_id: int,
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    form = await request.form()

    # Pre-mutation totals for audit
    pre_totals = compute_case_totals_for_case_id(db, case_id)

    # Validate
    errors, parsed = validate_ledger_fields(
        transaction_date=form.get("transaction_date"),
        t_code=form.get("t_code"),
        employee_number=form.get("employee_number"),
        quantity=form.get("quantity"),
        rate=form.get("rate"),
        amount=form.get("amount"),
        billed=form.get("billed"),
    )

    if errors:
        request.session["case_update_errors"] = errors
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Ensure case exists
    case_obj = db.query(Case).filter(Case.id == case_id).first()
    if not case_obj:
        request.session["case_update_errors"] = ["Case not found"]
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Assign optional fields
    t_type = (form.get("transaction_type") or "").strip() or None
    t_type_l = (form.get("t_type_l") or "").strip().upper() or None
    reference = (form.get("reference") or "").strip() or None
    desc = (form.get("description") or "").strip() or None

    desired_item_no = parse_int(form.get("item_no") or "")
    item_no = next_unique_item_no(db, case_id, parsed["transaction_date"], desired_item_no)

    try:
        tx = Transaction(
            case_id=case_id,
            transaction_date=parsed["transaction_date"],
            transaction_type=t_type,
            t_type_l=t_type_l,
            amount=parsed["amount"],
            description=desc,
            reference=reference,
            item_no=item_no,
            employee_number=parsed["employee_number"],
            t_code=parsed["t_code"],
            quantity=parsed.get("quantity"),
            rate=parsed.get("rate"),
            billed=parsed["billed"],
        )
        db.add(tx)
        db.commit()
        # Post-mutation totals and audit log
        post_totals = compute_case_totals_for_case_id(db, case_id)
        _log_ledger_audit(
            action="create",
            user=user,
            case_id=case_id,
            keys=_ledger_keys_from_tx(tx),
            pre=pre_totals,
            post=post_totals,
        )
        logger.info("ledger_create", case_id=case_id, transaction_id=tx.id)
        return RedirectResponse(url=f"/case/{case_id}?saved=1", status_code=302)
    except Exception as e:
        db.rollback()
        logger.error("ledger_create_failed", case_id=case_id, error=str(e))
        request.session["case_update_errors"] = ["Failed to create ledger entry"]
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)


@app.post("/case/{case_id}/ledger/{tx_id}")
async def ledger_update(
    request: Request,
    case_id: int,
    tx_id: int,
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    form = await request.form()

    tx = db.query(Transaction).filter(Transaction.id == tx_id, Transaction.case_id == case_id).first()
    if not tx:
        request.session["case_update_errors"] = ["Ledger entry not found"]
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Pre-mutation totals for audit
    pre_totals = compute_case_totals_for_case_id(db, case_id)

    errors, parsed = validate_ledger_fields(
        transaction_date=form.get("transaction_date"),
        t_code=form.get("t_code"),
        employee_number=form.get("employee_number"),
        quantity=form.get("quantity"),
        rate=form.get("rate"),
        amount=form.get("amount"),
        billed=form.get("billed"),
    )
    if errors:
        request.session["case_update_errors"] = errors
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    try:
        tx.transaction_date = parsed["transaction_date"]
        # Ensure uniqueness of (date, item_no)
        desired_item_no = parse_int(form.get("item_no") or "") or tx.item_no
        tx.item_no = next_unique_item_no(db, case_id, parsed["transaction_date"], desired_item_no)

        tx.t_code = parsed["t_code"]
        tx.employee_number = parsed["employee_number"]
        tx.quantity = parsed.get("quantity")
        tx.rate = parsed.get("rate")
        tx.amount = parsed["amount"]
        tx.billed = parsed["billed"]
        tx.transaction_type = (form.get("transaction_type") or "").strip() or None
        tx.t_type_l = (form.get("t_type_l") or "").strip().upper() or None
        tx.reference = (form.get("reference") or "").strip() or None
        tx.description = (form.get("description") or "").strip() or None

        db.commit()
        # Post-mutation totals and audit log
        post_totals = compute_case_totals_for_case_id(db, case_id)
        _log_ledger_audit(
            action="update",
            user=user,
            case_id=case_id,
            keys=_ledger_keys_from_tx(tx),
            pre=pre_totals,
            post=post_totals,
        )
        logger.info("ledger_update", case_id=case_id, transaction_id=tx.id)
        return RedirectResponse(url=f"/case/{case_id}?saved=1", status_code=302)
    except Exception as e:
        db.rollback()
        logger.error("ledger_update_failed", case_id=case_id, tx_id=tx_id, error=str(e))
        request.session["case_update_errors"] = ["Failed to update ledger entry"]
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)


@app.post("/case/{case_id}/ledger/{tx_id}/delete")
async def ledger_delete(
    request: Request,
    case_id: int,
    tx_id: int,
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    tx = db.query(Transaction).filter(Transaction.id == tx_id, Transaction.case_id == case_id).first()
    if not tx:
        request.session["case_update_errors"] = ["Ledger entry not found"]
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    try:
        # Capture pre-mutation totals and keys for audit before deletion
        pre_totals = compute_case_totals_for_case_id(db, case_id)
        tx_keys = _ledger_keys_from_tx(tx)
        db.delete(tx)
        db.commit()
        # Post-mutation totals and audit log
        post_totals = compute_case_totals_for_case_id(db, case_id)
        _log_ledger_audit(
            action="delete",
            user=user,
            case_id=case_id,
            keys=tx_keys,
            pre=pre_totals,
            post=post_totals,
        )
        logger.info("ledger_delete", case_id=case_id, transaction_id=tx_id)
        return RedirectResponse(url=f"/case/{case_id}?saved=1", status_code=302)
    except Exception as e:
        db.rollback()
        logger.error("ledger_delete_failed", case_id=case_id, tx_id=tx_id, error=str(e))
        request.session["case_update_errors"] = ["Failed to delete ledger entry"]
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)


@app.get("/")
async def root():
    """
    Root endpoint - serves login form for web interface.
    """
    return RedirectResponse(url="/login", status_code=302)


@app.get("/health")
async def health_check(db: Session = Depends(get_db)):
    """
    Health check endpoint that verifies database connectivity.
    """
    try:
        # Test database connection by querying user count
        user_count = db.query(User).count()
        return {
            "status": "healthy",
            "database": "connected",
            "users": user_count
        }
    except Exception as e:
        logger.error("health_check_failed", error=str(e))
        return {
            "status": "unhealthy",
            "database": "error",
            "error": str(e)
        }


@app.get("/login")
async def login_form(request: Request):
    """
    Display login form.

    If user is already logged in, redirect to dashboard.
    """
    # Check if user is already logged in
    user = get_current_user_from_session(request.session)
    if user:
        return RedirectResponse(url="/dashboard", status_code=302)

    return templates.TemplateResponse("login.html", {"request": request})


@app.post("/login")
async def login_submit(request: Request, db: Session = Depends(get_db)):
    """
    Handle login form submission.

    Authenticates user credentials and sets up session.
    """
    form = await request.form()
    username = form.get("username")
    password = form.get("password")

    if not username or not password:
        error_message = "Username and password are required"
        logger.warning("login_failed", username=username, reason="missing_credentials")
        return templates.TemplateResponse("login.html", {
            "request": request,
            "error": error_message
        })

    # Authenticate user
    user = authenticate_user(username, password)
    if not user:
        error_message = "Invalid username or password"
        logger.warning("login_failed", username=username, reason="invalid_credentials")
        return templates.TemplateResponse("login.html", {
            "request": request,
            "error": error_message
        })

    # Set up user session
    request.session["user_id"] = user.id
    request.session["user"] = {"id": user.id, "username": user.username}

    # Update bound context with authenticated user id
    structlog_contextvars.bind_contextvars(**{"user.id": user.id})
    logger.info("login_success", username=username, **{"user.id": user.id})

    # Redirect to dashboard after successful login
    return RedirectResponse(url="/dashboard", status_code=302)


@app.get("/logout")
async def logout(request: Request):
    """
    Handle user logout.

    Clears user session and redirects to home page.
    """
    username = request.session.get("user", {}).get("username", "unknown")
    request.session.clear()
    logger.info("logout", username=username)

    return RedirectResponse(url="/", status_code=302)


@app.get("/dashboard")
async def dashboard(
    request: Request,
    q: str | None = Query(None, description="Search by file number or client name"),
    page: int = Query(1, ge=1, description="Page number (1-indexed)"),
    page_size: int = Query(20, ge=1, le=100, description="Results per page"),
    db: Session = Depends(get_db),
):
    """
    Dashboard page - lists recent cases with search and pagination.

    - Optional query param `q` filters by case file number or client name/company
    - `page` and `page_size` control pagination
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Base query: join clients for name/company access
    query = db.query(Case).join(Client).order_by(
        Case.open_date.desc(),
        Case.created_at.desc(),
    )

    # Apply search filter if provided
    if q:
        like_term = f"%{q}%"
        query = query.filter(
            or_(
                Case.file_no.ilike(like_term),
                Client.first_name.ilike(like_term),
                Client.last_name.ilike(like_term),
                Client.company.ilike(like_term),
            )
        )

    # Total count for pagination
    total: int = query.count()

    # Clamp page to valid range when total is known
    total_pages: int = (total + page_size - 1) // page_size if total > 0 else 1
    if page > total_pages:
        page = total_pages

    # Pagination window
    offset = (page - 1) * page_size
    cases = query.offset(offset).limit(page_size).all()

    # Page number window for UI (current +/- 2)
    start_page = max(1, page - 2)
    end_page = min(total_pages, page + 2)
    page_numbers = list(range(start_page, end_page + 1))

    logger.info(
        "dashboard_render",
        query=q,
        page=page,
        page_size=page_size,
        total=total,
    )

    return templates.TemplateResponse(
        "dashboard.html",
        {
            "request": request,
            "user": user,
            "cases": cases,
            "q": q,
            "page": page,
            "page_size": page_size,
            "total": total,
            "total_pages": total_pages,
            "page_numbers": page_numbers,
            "start_index": (offset + 1) if total > 0 else 0,
            "end_index": min(offset + len(cases), total),
        },
    )


@app.post("/admin/upload")
async def admin_upload_files(
    request: Request,
    files: List[UploadFile] = File(...),
    db: Session = Depends(get_db)
):
    """
    Handle CSV file uploads for admin panel.

    Validates uploaded files are CSV format and stores them in data-import directory.
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    results = []
    errors = []

    # Ensure data-import directory exists
    import_dir = "data-import"
    os.makedirs(import_dir, exist_ok=True)

    for file in files:
        try:
            # Validate file type
            if not file.filename.lower().endswith('.csv'):
                errors.append(f"File '{file.filename}' is not a CSV file")
                continue

            # Generate unique filename to avoid conflicts
            file_id = str(uuid.uuid4())
            file_ext = os.path.splitext(file.filename)[1]
            # Determine import type from original filename for better categorization later
            try:
                detected_type = get_import_type_from_filename(file.filename)
            except ValueError:
                detected_type = 'unknown'

            # Prefix stored filename with detected type to preserve context
            stored_filename = f"{detected_type}_{file_id}{file_ext}"
            file_path = os.path.join(import_dir, stored_filename)

            # Save file
            contents = await file.read()
            with open(file_path, "wb") as f:
                f.write(contents)

            # Use detected type (already derived from original name)
            import_type = detected_type

            results.append({
                'filename': file.filename,
                'stored_filename': stored_filename,
                'import_type': import_type,
                'file_path': file_path,
                'size': len(contents)
            })

        except Exception as e:
            errors.append(f"Error processing '{file.filename}': {str(e)}")
            continue

    # Log the upload operation
    logger.info(
        "admin_upload",
        uploaded_count=len(results),
        error_count=len(errors),
        username=user.username,
    )

    return templates.TemplateResponse("admin.html", {
        "request": request,
        "user": user,
        "upload_results": results,
        "upload_errors": errors,
        "show_upload_results": True
    })


@app.post("/admin/import/{data_type}")
async def admin_import_data(
    request: Request,
    data_type: str,
    db: Session = Depends(get_db)
):
    """
    Process CSV import for specified data type.

    Creates import log entry and processes the import in the background.
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Validate data type
    valid_types = ['client', 'phone', 'case', 'transaction', 'document', 'payment']
    if data_type not in valid_types:
        return templates.TemplateResponse("admin.html", {
            "request": request,
            "user": user,
            "error": f"Invalid data type: {data_type}"
        })

    # Get form data for file selection
    form = await request.form()
    selected_files = form.getlist("selected_files")

    if not selected_files:
        return templates.TemplateResponse("admin.html", {
            "request": request,
            "user": user,
            "error": "No files selected for import"
        })

    import_results = []
    total_success = 0
    total_errors = 0

    for stored_filename in selected_files:
        file_path = os.path.join("data-import", stored_filename)

        if not os.path.exists(file_path):
            import_results.append({
                'filename': stored_filename,
                'status': 'error',
                'message': 'File not found'
            })
            total_errors += 1
            continue

        # Create import log entry
        import_log = ImportLog(
            import_type=data_type,
            file_name=stored_filename,
            file_path=file_path,
            status="running"
        )
        db.add(import_log)
        db.commit()

        try:
            # Process the import
            result = process_csv_import(db, data_type, file_path)

            # Update import log
            import_log.status = "completed" if result['errors'] else "failed"
            import_log.total_rows = result['total_rows']
            import_log.success_count = result['success']
            import_log.error_count = len(result['errors'])
            import_log.error_details = json.dumps(result['errors'])
            import_log.completed_at = datetime.now()

            db.commit()

            import_results.append({
                'filename': stored_filename,
                'status': 'success' if result['success'] > 0 else 'error',
                'total_rows': result['total_rows'],
                'success_count': result['success'],
                'error_count': len(result['errors']),
                'errors': result['errors'][:10]  # Show first 10 errors
            })

            total_success += result['success']
            total_errors += len(result['errors'])

        except Exception as e:
            # Update import log on error
            import_log.status = "failed"
            import_log.error_details = json.dumps([str(e)])
            import_log.completed_at = datetime.now()
            db.commit()

            import_results.append({
                'filename': stored_filename,
                'status': 'error',
                'message': str(e)
            })
            total_errors += 1

    # Log the import operation
    logger.info(
        "admin_import",
        import_type=data_type,
        success_count=total_success,
        error_count=total_errors,
        username=user.username,
    )

    return templates.TemplateResponse("admin.html", {
        "request": request,
        "user": user,
        "import_results": import_results,
        "total_success": total_success,
        "total_errors": total_errors,
        "show_import_results": True
    })


@app.get("/admin")
async def admin_panel(request: Request, db: Session = Depends(get_db)):
    """
    Admin panel - requires authentication.

    Provides administrative functions like data import and system management.
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Get recent import history
    recent_imports = db.query(ImportLog).order_by(ImportLog.created_at.desc()).limit(10).all()

    # Get available files for import
    import_dir = "data-import"
    available_files = []
    if os.path.exists(import_dir):
        for filename in os.listdir(import_dir):
            if filename.endswith('.csv'):
                file_path = os.path.join(import_dir, filename)
                file_size = os.path.getsize(file_path)
                try:
                    import_type = get_import_type_from_filename(filename)
                except ValueError:
                    import_type = 'unknown'

                available_files.append({
                    'filename': filename,
                    'import_type': import_type,
                    'size': file_size,
                    'modified': datetime.fromtimestamp(os.path.getmtime(file_path))
                })

    # Group files by import type
    files_by_type = {}
    for file_info in available_files:
        import_type = file_info['import_type']
        if import_type not in files_by_type:
            files_by_type[import_type] = []
        files_by_type[import_type].append(file_info)

    return templates.TemplateResponse("admin.html", {
        "request": request,
        "user": user,
        "recent_imports": recent_imports,
        "available_files": available_files,
        "files_by_type": files_by_type
    })


@app.get("/case/{case_id}")
async def case_detail(
    request: Request,
    case_id: int,
    saved: bool = Query(False, description="Whether to show success message"),
    db: Session = Depends(get_db),
):
    """
    Case detail view.

    Displays detailed information for a single case and its related client and
    associated records (transactions, documents, payments).
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Fetch case with related entities eagerly loaded to avoid lazy-load issues
    case_obj = (
        db.query(Case)
        .options(
            joinedload(Case.client),
            joinedload(Case.transactions),
            joinedload(Case.documents),
            joinedload(Case.payments),
        )
        .filter(Case.id == case_id)
        .first()
    )

    if not case_obj:
        logger.warning("case_not_found", case_id=case_id)
        # Get any errors from session and clear them
        errors = request.session.pop("case_update_errors", None)

        return templates.TemplateResponse(
            "case.html",
            {
                "request": request,
                "user": user,
                "case": None,
                "error": "Case not found",
                "saved": False,
                "errors": errors or [],
            },
            status_code=404,
        )

    logger.info("case_detail", case_id=case_obj.id, file_no=case_obj.file_no)

    # Get any errors from session and clear them
    errors = request.session.pop("case_update_errors", None)

    # Sort transactions by date then item_no for stable display
    sorted_transactions = sorted(
        case_obj.transactions or [],
        key=lambda t: (
            t.transaction_date or datetime.min,
            t.item_no or 0,
        )
    )
    case_obj.transactions = sorted_transactions

    totals = compute_case_totals_from_case(case_obj)

    return templates.TemplateResponse(
        "case.html",
        {
            "request": request,
            "user": user,
            "case": case_obj,
            "saved": saved,
            "errors": errors or [],
            "totals": totals,
        },
    )


@app.post("/case/{case_id}/update")
async def case_update(
    request: Request,
    case_id: int,
    db: Session = Depends(get_db),
) -> RedirectResponse:
    """
    Update case details.

    Updates the specified fields on a case and redirects back to the case detail view.
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Get form data
    form = await request.form()

    # Fetch the case
    case_obj = db.query(Case).filter(Case.id == case_id).first()
    if not case_obj:
        logger.warning("case_not_found_update", case_id=case_id)
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Validate and process fields
    errors = []
    update_data = {}

    # Status validation
    status = form.get("status")
    if status is not None:
        if status not in ["active", "closed"]:
            errors.append("Status must be 'active' or 'closed'")
        else:
            update_data["status"] = status

    # Case type and description (optional)
    case_type = form.get("case_type")
    if case_type is not None:
        update_data["case_type"] = case_type.strip() if case_type.strip() else None

    description = form.get("description")
    if description is not None:
        update_data["description"] = description.strip() if description.strip() else None

    # Date validation and parsing
    open_date = form.get("open_date")
    if open_date is not None:
        if open_date.strip():
            try:
                update_data["open_date"] = datetime.strptime(open_date.strip(), "%Y-%m-%d")
            except ValueError:
                errors.append("Open date must be in YYYY-MM-DD format")
        else:
            update_data["open_date"] = None

    close_date = form.get("close_date")
    if close_date is not None:
        if close_date.strip():
            try:
                update_data["close_date"] = datetime.strptime(close_date.strip(), "%Y-%m-%d")
            except ValueError:
                errors.append("Close date must be in YYYY-MM-DD format")
        else:
            update_data["close_date"] = None

    # If there are validation errors, redirect back with errors
    if errors:
        # Store errors in session for display on the case page
        request.session["case_update_errors"] = errors
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Apply updates
    try:
        changed_fields = {}
        for field, value in update_data.items():
            old_value = getattr(case_obj, field)
            if old_value != value:
                changed_fields[field] = {"old": old_value, "new": value}
            setattr(case_obj, field, value)

        db.commit()
        logger.info(
            "case_update",
            case_id=case_id,
            changed_fields=list(update_data.keys()),
            changed_details=changed_fields,
        )

        # Clear any previous errors from session
        request.session.pop("case_update_errors", None)

        return RedirectResponse(url=f"/case/{case_id}?saved=1", status_code=302)

    except Exception as e:
        db.rollback()
        logger.error("case_update_failed", case_id=case_id, error=str(e))

        # Store error in session for display
        request.session["case_update_errors"] = ["Failed to save changes. Please try again."]

        return RedirectResponse(url=f"/case/{case_id}", status_code=302)


@app.post("/case/{case_id}/close")
async def case_close(
    request: Request,
    case_id: int,
    db: Session = Depends(get_db),
) -> RedirectResponse:
    """
    Close a case.

    Sets the case status to 'closed' and sets close_date to current date if not already set.
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Fetch the case
    case_obj = db.query(Case).filter(Case.id == case_id).first()
    if not case_obj:
        logger.warning("case_not_found_close", case_id=case_id)
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Update case
    try:
        case_obj.status = "closed"
        # Only set close_date if it's not already set
        if not case_obj.close_date:
            case_obj.close_date = datetime.now()

        db.commit()
        logger.info("case_closed", case_id=case_id, close_date=case_obj.close_date.isoformat() if case_obj.close_date else None)

        return RedirectResponse(url=f"/case/{case_id}?saved=1", status_code=302)

    except Exception as e:
        db.rollback()
        logger.error("case_close_failed", case_id=case_id, error=str(e))

        # Store error in session for display
        request.session["case_update_errors"] = ["Failed to close case. Please try again."]

        return RedirectResponse(url=f"/case/{case_id}", status_code=302)


@app.post("/case/{case_id}/reopen")
async def case_reopen(
    request: Request,
    case_id: int,
    db: Session = Depends(get_db),
) -> RedirectResponse:
    """
    Reopen a case.

    Sets the case status to 'active' and clears the close_date.
    """
    # Check authentication
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Fetch the case
    case_obj = db.query(Case).filter(Case.id == case_id).first()
    if not case_obj:
        logger.warning("case_not_found_reopen", case_id=case_id)
        return RedirectResponse(url=f"/case/{case_id}", status_code=302)

    # Update case
    try:
        case_obj.status = "active"
        case_obj.close_date = None

        db.commit()
        logger.info("case_reopened", case_id=case_id)

        return RedirectResponse(url=f"/case/{case_id}?saved=1", status_code=302)

    except Exception as e:
        db.rollback()
        logger.error("case_reopen_failed", case_id=case_id, error=str(e))

        # Store error in session for display
        request.session["case_update_errors"] = ["Failed to reopen case. Please try again."]

        return RedirectResponse(url=f"/case/{case_id}", status_code=302)


@app.get("/rolodex")
async def rolodex_list(
    request: Request,
    q: str | None = Query(None, description="Search by name or company"),
    phone: str | None = Query(None, description="Search by phone contains"),
    page: int = Query(1, ge=1, description="Page number (1-indexed)"),
    page_size: int = Query(20, ge=1, le=100, description="Results per page"),
    db: Session = Depends(get_db),
):
    """
    Rolodex list with simple search and pagination.

    Filters clients by name/company and optional phone substring.
    """
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    # Eager-load phones to avoid N+1 in template
    query = db.query(Client).options(joinedload(Client.phones))

    if q:
        like = f"%{q}%"
        query = query.filter(
            or_(
                Client.first_name.ilike(like),
                Client.last_name.ilike(like),
                Client.company.ilike(like),
            )
        )

    if phone:
        like_phone = f"%{phone}%"
        # Use EXISTS over join to avoid duplicate rows
        query = query.filter(Client.phones.any(Phone.phone_number.ilike(like_phone)))

    # Order by last then first for stable display
    query = query.order_by(Client.last_name.asc().nulls_last(), Client.first_name.asc().nulls_last())

    total: int = query.count()
    total_pages: int = (total + page_size - 1) // page_size if total > 0 else 1
    if page > total_pages:
        page = total_pages

    offset = (page - 1) * page_size
    clients = query.offset(offset).limit(page_size).all()

    start_page = max(1, page - 2)
    end_page = min(total_pages, page + 2)
    page_numbers = list(range(start_page, end_page + 1))

    logger.info(
        "rolodex_render",
        query=q,
        phone=phone,
        page=page,
        page_size=page_size,
        total=total,
    )

    return templates.TemplateResponse(
        "rolodex.html",
        {
            "request": request,
            "user": user,
            "clients": clients,
            "q": q,
            "phone": phone,
            "page": page,
            "page_size": page_size,
            "total": total,
            "total_pages": total_pages,
            "page_numbers": page_numbers,
            "start_index": (offset + 1) if total > 0 else 0,
            "end_index": min(offset + len(clients), total),
            "enable_bulk": True,
        },
    )


@app.get("/rolodex/new")
async def rolodex_new(request: Request):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    return templates.TemplateResponse("rolodex_edit.html", {"request": request, "user": user, "client": None})


@app.get("/rolodex/{client_id}")
async def rolodex_view(client_id: int, request: Request, db: Session = Depends(get_db)):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    client = (
        db.query(Client)
        .options(joinedload(Client.phones), joinedload(Client.cases))
        .filter(Client.id == client_id)
        .first()
    )
    if not client:
        raise HTTPException(status_code=404, detail="Client not found")

    return templates.TemplateResponse("rolodex_view.html", {"request": request, "user": user, "client": client})


@app.post("/rolodex/create")
async def rolodex_create(
    request: Request,
    first_name: str = Form(None),
    last_name: str = Form(None),
    company: str = Form(None),
    address: str = Form(None),
    city: str = Form(None),
    state: str = Form(None),
    zip_code: str = Form(None),
    rolodex_id: str = Form(None),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    client = Client(
        first_name=(first_name or "").strip() or None,
        last_name=(last_name or "").strip() or None,
        company=(company or "").strip() or None,
        address=(address or "").strip() or None,
        city=(city or "").strip() or None,
        state=(state or "").strip() or None,
        zip_code=(zip_code or "").strip() or None,
        rolodex_id=(rolodex_id or "").strip() or None,
    )
    db.add(client)
    db.commit()
    db.refresh(client)
    logger.info("rolodex_create", client_id=client.id, rolodex_id=client.rolodex_id)
    return RedirectResponse(url=f"/rolodex/{client.id}", status_code=302)


@app.post("/rolodex/{client_id}/update")
async def rolodex_update(
    client_id: int,
    request: Request,
    first_name: str = Form(None),
    last_name: str = Form(None),
    company: str = Form(None),
    address: str = Form(None),
    city: str = Form(None),
    state: str = Form(None),
    zip_code: str = Form(None),
    rolodex_id: str = Form(None),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    client = db.query(Client).filter(Client.id == client_id).first()
    if not client:
        raise HTTPException(status_code=404, detail="Client not found")

    client.first_name = (first_name or "").strip() or None
    client.last_name = (last_name or "").strip() or None
    client.company = (company or "").strip() or None
    client.address = (address or "").strip() or None
    client.city = (city or "").strip() or None
    client.state = (state or "").strip() or None
    client.zip_code = (zip_code or "").strip() or None
    client.rolodex_id = (rolodex_id or "").strip() or None

    db.commit()
    logger.info(
        "rolodex_update",
        client_id=client.id,
        fields={
            "first_name": client.first_name,
            "last_name": client.last_name,
            "company": client.company,
            "rolodex_id": client.rolodex_id,
        },
    )
    return RedirectResponse(url=f"/rolodex/{client.id}", status_code=302)


@app.post("/rolodex/{client_id}/delete")
async def rolodex_delete(client_id: int, request: Request, db: Session = Depends(get_db)):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    client = db.query(Client).filter(Client.id == client_id).first()
    if not client:
        raise HTTPException(status_code=404, detail="Client not found")

    db.delete(client)
    db.commit()
    logger.info("rolodex_delete", client_id=client_id)
    return RedirectResponse(url="/rolodex", status_code=302)


@app.post("/rolodex/{client_id}/phone/add")
async def rolodex_add_phone(
    client_id: int,
    request: Request,
    phone_number: str = Form(...),
    phone_type: str = Form(None),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    client = db.query(Client).filter(Client.id == client_id).first()
    if not client:
        raise HTTPException(status_code=404, detail="Client not found")

    phone = Phone(
        client_id=client.id,
        phone_number=(phone_number or "").strip(),
        phone_type=(phone_type or "").strip() or None,
    )
    db.add(phone)
    db.commit()
    logger.info("rolodex_phone_add", client_id=client.id, phone_id=phone.id, number=phone.phone_number)
    return RedirectResponse(url=f"/rolodex/{client.id}", status_code=302)


@app.post("/rolodex/{client_id}/phone/{phone_id}/delete")
async def rolodex_delete_phone(client_id: int, phone_id: int, request: Request, db: Session = Depends(get_db)):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    phone = db.query(Phone).filter(Phone.id == phone_id, Phone.client_id == client_id).first()
    if not phone:
        raise HTTPException(status_code=404, detail="Phone not found")

    db.delete(phone)
    db.commit()
    logger.info("rolodex_phone_delete", client_id=client_id, phone_id=phone_id)
    return RedirectResponse(url=f"/rolodex/{client_id}", status_code=302)


@app.get("/payments")
async def payments_search(
    request: Request,
    from_date: str | None = Query(None, description="YYYY-MM-DD"),
    to_date: str | None = Query(None, description="YYYY-MM-DD"),
    file_no: str | None = Query(None, description="Case file number"),
    rolodex_id: str | None = Query(None, description="Legacy client Id"),
    q: str | None = Query(None, description="Description contains"),
    page: int = Query(1, ge=1),
    page_size: int = Query(50, ge=1, le=200),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    query = (
        db.query(Payment)
        .join(Case, Payment.case_id == Case.id)
        .join(Client, Case.client_id == Client.id)
        .order_by(Payment.payment_date.desc().nulls_last(), Payment.id.desc())
    )

    filters = []
    if from_date:
        try:
            dt = datetime.strptime(from_date, "%Y-%m-%d")
            filters.append(Payment.payment_date >= dt)
        except ValueError:
            pass
    if to_date:
        try:
            dt = datetime.strptime(to_date, "%Y-%m-%d")
            filters.append(Payment.payment_date <= dt)
        except ValueError:
            pass
    if file_no:
        filters.append(Case.file_no.ilike(f"%{file_no}%"))
    if rolodex_id:
        filters.append(Client.rolodex_id.ilike(f"%{rolodex_id}%"))
    if q:
        filters.append(Payment.description.ilike(f"%{q}%"))

    if filters:
        query = query.filter(and_(*filters))

    total = query.count()
    total_pages = (total + page_size - 1) // page_size if total > 0 else 1
    if page > total_pages:
        page = total_pages
    offset = (page - 1) * page_size
    payments = query.offset(offset).limit(page_size).all()

    # Totals for current result page
    page_total_amount = sum(p.amount or 0 for p in payments)

    logger.info(
        "payments_render",
        from_date=from_date,
        to_date=to_date,
        file_no=file_no,
        rolodex_id=rolodex_id,
        q=q,
        total=total,
    )

    return templates.TemplateResponse(
        "payments.html",
        {
            "request": request,
            "user": user,
            "payments": payments,
            "from_date": from_date,
            "to_date": to_date,
            "file_no": file_no,
            "rolodex_id": rolodex_id,
            "q": q,
            "page": page,
            "page_size": page_size,
            "total": total,
            "total_pages": total_pages,
            "start_index": (offset + 1) if total > 0 else 0,
            "end_index": min(offset + len(payments), total),
            "page_total_amount": page_total_amount,
        },
    )


@app.post("/reports/phone-book")
async def phone_book_report_post(request: Request):
    """Accepts selected client IDs from forms and redirects to GET for rendering."""
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    form = await request.form()
    client_ids = form.getlist("client_ids")
    if not client_ids:
        return RedirectResponse(url="/rolodex", status_code=302)

    ids_param = "&".join([f"client_ids={cid}" for cid in client_ids])
    return RedirectResponse(url=f"/reports/phone-book?{ids_param}", status_code=302)


@app.get("/reports/phone-book")
async def phone_book_report(
    request: Request,
    client_ids: List[int] | None = Query(None),
    q: str | None = Query(None, description="Filter by name/company"),
    format: str | None = Query(None, description="csv or pdf for export"),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    query = db.query(Client).options(joinedload(Client.phones))
    if client_ids:
        query = query.filter(Client.id.in_(client_ids))
    elif q:
        like = f"%{q}%"
        query = query.filter(
            or_(Client.first_name.ilike(like), Client.last_name.ilike(like), Client.company.ilike(like))
        )

    clients = query.order_by(Client.last_name.asc().nulls_last(), Client.first_name.asc().nulls_last()).all()

    if format == "csv":
        # Build CSV output
        output = StringIO()
        writer = csv.writer(output)
        writer.writerow(["Last", "First", "Company", "Phone Type", "Phone Number"])
        for c in clients:
            if c.phones:
                for p in c.phones:
                    writer.writerow([
                        c.last_name or "",
                        c.first_name or "",
                        c.company or "",
                        p.phone_type or "",
                        p.phone_number or "",
                    ])
            else:
                writer.writerow([c.last_name or "", c.first_name or "", c.company or "", "", ""])
        csv_bytes = output.getvalue().encode("utf-8")
        return Response(
            content=csv_bytes,
            media_type="text/csv",
            headers={"Content-Disposition": "attachment; filename=phone_book.csv"},
        )

    if format == "pdf":
        pdf_bytes = build_phone_book_pdf(clients)
        return Response(
            content=pdf_bytes,
            media_type="application/pdf",
            headers={"Content-Disposition": "attachment; filename=phone_book.pdf"},
        )

    logger.info("phone_book_render", count=len(clients))
    return templates.TemplateResponse(
        "report_phone_book.html",
        {"request": request, "user": user, "clients": clients, "q": q, "client_ids": client_ids or []},
    )


# ------------------------------
# Reports: Payments - Detailed
# ------------------------------

@app.get("/reports/payments-detailed")
async def payments_detailed_report(
    request: Request,
    from_date: str | None = Query(None, description="YYYY-MM-DD"),
    to_date: str | None = Query(None, description="YYYY-MM-DD"),
    file_no: str | None = Query(None, description="Case file number"),
    format: str | None = Query(None, description="pdf for PDF output"),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    query = (
        db.query(Payment)
        .join(Case, Payment.case_id == Case.id)
        .join(Client, Case.client_id == Client.id)
    )

    filters = []
    if from_date:
        try:
            dt = datetime.strptime(from_date, "%Y-%m-%d")
            filters.append(Payment.payment_date >= dt)
        except ValueError:
            pass
    if to_date:
        try:
            dt = datetime.strptime(to_date, "%Y-%m-%d")
            filters.append(Payment.payment_date <= dt)
        except ValueError:
            pass
    if file_no:
        filters.append(Case.file_no.ilike(f"%{file_no}%"))

    if filters:
        query = query.filter(and_(*filters))

    # For grouping by deposit date, order by date then id
    payments = (
        query.options(joinedload(Payment.case).joinedload(Case.client))
        .order_by(Payment.payment_date.asc().nulls_last(), Payment.id.asc())
        .all()
    )

    if format == "pdf":
        pdf_bytes = build_payments_detailed_pdf(payments)
        return Response(
            content=pdf_bytes,
            media_type="application/pdf",
            headers={"Content-Disposition": "attachment; filename=payments_detailed.pdf"},
        )

    # Build preview groups for template: [{date, total, items}]
    groups: list[dict[str, Any]] = []
    from collections import defaultdict
    grouped: dict[str, list[Payment]] = defaultdict(list)
    for p in payments:
        key = p.payment_date.date().isoformat() if p.payment_date else "(No Date)"
        grouped[key].append(p)
    overall_total = sum((p.amount or 0.0) for p in payments)
    for key in sorted(grouped.keys()):
        items = grouped[key]
        total_amt = sum((p.amount or 0.0) for p in items)
        groups.append({"date": key, "total": total_amt, "items": items})

    logger.info(
        "payments_detailed_render",
        from_date=from_date,
        to_date=to_date,
        file_no=file_no,
        count=len(payments),
    )

    return templates.TemplateResponse(
        "payments_detailed.html",
        {
            "request": request,
            "user": user,
            "groups": groups,
            "overall_total": overall_total,
            "from_date": from_date,
            "to_date": to_date,
            "file_no": file_no,
        },
    )


# ------------------------------
# Reports: Phone Book (Address + Phone)
# ------------------------------

@app.post("/reports/phone-book-address")
async def phone_book_address_post(request: Request):
    """Accept selected client IDs from forms and redirect to GET for rendering."""
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    form = await request.form()
    client_ids = form.getlist("client_ids")
    if not client_ids:
        return RedirectResponse(url="/rolodex", status_code=302)

    ids_param = "&".join([f"client_ids={cid}" for cid in client_ids])
    return RedirectResponse(url=f"/reports/phone-book-address?{ids_param}", status_code=302)


@app.get("/reports/phone-book-address")
async def phone_book_address_report(
    request: Request,
    client_ids: List[int] | None = Query(None),
    q: str | None = Query(None, description="Filter by name/company"),
    phone: str | None = Query(None, description="Phone contains"),
    format: str | None = Query(None, description="csv or pdf for export"),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    query = db.query(Client).options(joinedload(Client.phones))
    if client_ids:
        query = query.filter(Client.id.in_(client_ids))
    else:
        if q:
            like = f"%{q}%"
            query = query.filter(
                or_(Client.first_name.ilike(like), Client.last_name.ilike(like), Client.company.ilike(like))
            )
        if phone:
            query = query.filter(Client.phones.any(Phone.phone_number.ilike(f"%{phone}%")))

    clients = query.order_by(Client.last_name.asc().nulls_last(), Client.first_name.asc().nulls_last()).all()

    if format == "csv":
        # Build CSV output
        output = StringIO()
        writer = csv.writer(output)
        writer.writerow(["Last", "First", "Company", "Address", "City", "State", "ZIP", "Phone Type", "Phone Number"])
        for c in clients:
            if c.phones:
                for p in c.phones:
                    writer.writerow([
                        c.last_name or "",
                        c.first_name or "",
                        c.company or "",
                        c.address or "",
                        c.city or "",
                        c.state or "",
                        c.zip_code or "",
                        p.phone_type or "",
                        p.phone_number or "",
                    ])
            else:
                writer.writerow([
                    c.last_name or "",
                    c.first_name or "",
                    c.company or "",
                    c.address or "",
                    c.city or "",
                    c.state or "",
                    c.zip_code or "",
                    "",
                    "",
                ])
        csv_bytes = output.getvalue().encode("utf-8")
        return Response(
            content=csv_bytes,
            media_type="text/csv",
            headers={"Content-Disposition": "attachment; filename=phone_book_address.csv"},
        )

    if format == "pdf":
        pdf_bytes = build_phone_book_address_pdf(clients)
        return Response(
            content=pdf_bytes,
            media_type="application/pdf",
            headers={"Content-Disposition": "attachment; filename=phone_book_address.pdf"},
        )

    logger.info("phone_book_address_render", count=len(clients))
    return templates.TemplateResponse(
        "report_phone_book_address.html",
        {
            "request": request,
            "user": user,
            "clients": clients,
            "q": q,
            "phone": phone,
            "client_ids": client_ids or [],
        },
    )


# ------------------------------
# Reports: Envelope (PDF)
# ------------------------------

@app.post("/reports/envelope")
async def envelope_report_post(request: Request):
    """Accept selected client IDs and redirect to GET for PDF download."""
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    form = await request.form()
    client_ids = form.getlist("client_ids")
    if not client_ids:
        return RedirectResponse(url="/rolodex", status_code=302)

    ids_param = "&".join([f"client_ids={cid}" for cid in client_ids])
    return RedirectResponse(url=f"/reports/envelope?{ids_param}&format=pdf", status_code=302)


@app.get("/reports/envelope")
async def envelope_report(
    request: Request,
    client_ids: List[int] | None = Query(None),
    q: str | None = Query(None, description="Filter by name/company"),
    phone: str | None = Query(None, description="Phone contains (optional)"),
    format: str | None = Query("pdf", description="pdf output only"),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    query = db.query(Client)
    if client_ids:
        query = query.filter(Client.id.in_(client_ids))
    else:
        if q:
            like = f"%{q}%"
            query = query.filter(
                or_(Client.first_name.ilike(like), Client.last_name.ilike(like), Client.company.ilike(like))
            )
        if phone:
            # include clients that have a matching phone
            query = query.join(Phone, isouter=True).filter(or_(Phone.phone_number.ilike(f"%{phone}%"), Phone.id == None)).distinct()  # noqa: E711

    clients = query.order_by(Client.last_name.asc().nulls_last(), Client.first_name.asc().nulls_last()).all()

    # Always produce PDF
    pdf_bytes = build_envelope_pdf(clients)
    logger.info("envelope_pdf", count=len(clients))
    return Response(
        content=pdf_bytes,
        media_type="application/pdf",
        headers={"Content-Disposition": "attachment; filename=envelopes.pdf"},
    )


# ------------------------------
# Reports: Rolodex Info (PDF)
# ------------------------------

@app.post("/reports/rolodex-info")
async def rolodex_info_post(request: Request):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    form = await request.form()
    client_ids = form.getlist("client_ids")
    if not client_ids:
        return RedirectResponse(url="/rolodex", status_code=302)

    ids_param = "&".join([f"client_ids={cid}" for cid in client_ids])
    return RedirectResponse(url=f"/reports/rolodex-info?{ids_param}&format=pdf", status_code=302)


@app.get("/reports/rolodex-info")
async def rolodex_info_report(
    request: Request,
    client_ids: List[int] | None = Query(None),
    q: str | None = Query(None, description="Filter by name/company"),
    format: str | None = Query("pdf", description="pdf output only"),
    db: Session = Depends(get_db),
):
    user = get_current_user_from_session(request.session)
    if not user:
        return RedirectResponse(url="/login", status_code=302)

    query = db.query(Client).options(joinedload(Client.phones))
    if client_ids:
        query = query.filter(Client.id.in_(client_ids))
    elif q:
        like = f"%{q}%"
        query = query.filter(
            or_(Client.first_name.ilike(like), Client.last_name.ilike(like), Client.company.ilike(like))
        )

    clients = query.order_by(Client.last_name.asc().nulls_last(), Client.first_name.asc().nulls_last()).all()

    pdf_bytes = build_rolodex_info_pdf(clients)
    logger.info("rolodex_info_pdf", count=len(clients))
    return Response(
        content=pdf_bytes,
        media_type="application/pdf",
        headers={"Content-Disposition": "attachment; filename=rolodex_info.pdf"},
    )

# ------------------------------
# JSON API: list/filter endpoints
# ------------------------------

def _apply_sorting(query, sort_by: str | None, sort_dir: str, allowed_map: dict[str, Any], default_order: list[Any]):
    """Apply validated sorting to a SQLAlchemy query.

    Args:
        query: Base SQLAlchemy query object
        sort_by: Optional requested sort field
        sort_dir: 'asc' or 'desc'
        allowed_map: Map of allowed sort_by -> SQLAlchemy column or list of columns
        default_order: Fallback order_by list when sort_by is not provided

    Returns:
        (query, applied_sort_by, applied_sort_dir)
    """
    if not sort_by:
        for col in default_order:
            query = query.order_by(col)
        return query, None, sort_dir

    column_expr = allowed_map.get(sort_by)
    if column_expr is None:
        raise HTTPException(status_code=400, detail=f"Invalid sort_by: '{sort_by}'. Allowed: {sorted(list(allowed_map.keys()))}")

    def _order(expr):
        return expr.asc().nulls_last() if sort_dir == "asc" else expr.desc().nulls_last()

    if isinstance(column_expr, (list, tuple)):
        for expr in column_expr:
            query = query.order_by(_order(expr))
    else:
        query = query.order_by(_order(column_expr))

    return query, sort_by, sort_dir

@app.get("/api/rolodex", response_model=RolodexListResponse)
async def api_list_rolodex(
    request: Request,
    q: str | None = Query(None, description="Search by first/last/company contains"),
    phone: str | None = Query(None, description="Phone number contains"),
    rolodex_id: str | None = Query(None, description="Legacy Rolodex ID contains"),
    page: int = Query(1, ge=1, description="Page number (1-indexed)"),
    page_size: int = Query(20, ge=1, le=100, description="Results per page"),
    sort_by: str | None = Query(None, description="Sort field: id, rolodex_id, last_name, first_name, company, created_at"),
    sort_dir: str = Query("asc", description="Sort direction: asc or desc"),
    db: Session = Depends(get_db),
) -> RolodexListResponse:
    """Return paginated clients with simple filters as JSON."""
    user = get_current_user_from_session(request.session)
    if not user:
        # Middleware ensures JSON 401 for /api/*, keep explicit for clarity
        raise HTTPException(status_code=401, detail="Unauthorized")

    query = db.query(Client).options(joinedload(Client.phones))

    if q:
        like = f"%{q}%"
        query = query.filter(
            or_(
                Client.first_name.ilike(like),
                Client.last_name.ilike(like),
                Client.company.ilike(like),
            )
        )
    if phone:
        query = query.filter(Client.phones.any(Phone.phone_number.ilike(f"%{phone}%")))
    if rolodex_id:
        query = query.filter(Client.rolodex_id.ilike(f"%{rolodex_id}%"))

    # Sorting
    sort_dir_norm = (sort_dir or "").lower()
    if sort_dir_norm not in ("asc", "desc"):
        raise HTTPException(status_code=400, detail="Invalid sort_dir. Allowed: 'asc' or 'desc'")

    allowed_sort = {
        "id": Client.id,
        "rolodex_id": Client.rolodex_id,
        "last_name": Client.last_name,
        "first_name": Client.first_name,
        "company": Client.company,
        "created_at": Client.created_at,
    }
    default_order = [Client.last_name.asc().nulls_last(), Client.first_name.asc().nulls_last(), Client.id.asc()]
    query, applied_sort_by, applied_sort_dir = _apply_sorting(query, sort_by, sort_dir_norm, allowed_sort, default_order)

    total: int = query.count()
    total_pages: int = (total + page_size - 1) // page_size if total > 0 else 1
    if page > total_pages:
        page = total_pages
    offset = (page - 1) * page_size

    clients = query.offset(offset).limit(page_size).all()

    logger.info(
        "api_rolodex_list",
        query=q,
        phone=phone,
        rolodex_id=rolodex_id,
        page=page,
        page_size=page_size,
        total=total,
        sort_by=applied_sort_by,
        sort_dir=applied_sort_dir,
    )

    items = [ClientOut.model_validate(c) for c in clients]
    return RolodexListResponse(
        items=items,
        pagination=Pagination(page=page, page_size=page_size, total=total, total_pages=total_pages),
    )


@app.get("/api/files", response_model=FilesListResponse)
async def api_list_files(
    request: Request,
    q: str | None = Query(None, description="Search file no/description/client name/company"),
    status: str | None = Query(None, description="Case status: active or closed"),
    case_type: str | None = Query(None, description="Case type contains"),
    file_no: str | None = Query(None, description="File number contains"),
    client_rolodex_id: str | None = Query(None, description="Legacy client Id contains"),
    from_open_date: str | None = Query(None, description="Opened on/after YYYY-MM-DD"),
    to_open_date: str | None = Query(None, description="Opened on/before YYYY-MM-DD"),
    page: int = Query(1, ge=1, description="Page number (1-indexed)"),
    page_size: int = Query(20, ge=1, le=100, description="Results per page"),
    sort_by: str | None = Query(None, description="Sort field: file_no, status, case_type, description, open_date, close_date, created_at, client_last_name, client_first_name, client_company"),
    sort_dir: str = Query("desc", description="Sort direction: asc or desc"),
    db: Session = Depends(get_db),
) -> FilesListResponse:
    """Return paginated cases with simple filters as JSON."""
    user = get_current_user_from_session(request.session)
    if not user:
        raise HTTPException(status_code=401, detail="Unauthorized")

    query = (
        db.query(Case)
        .join(Client, Case.client_id == Client.id)
        .options(joinedload(Case.client))
    )

    filters = []
    if q:
        like = f"%{q}%"
        filters.append(
            or_(
                Case.file_no.ilike(like),
                Case.description.ilike(like),
                Client.first_name.ilike(like),
                Client.last_name.ilike(like),
                Client.company.ilike(like),
            )
        )
    if status:
        filters.append(Case.status.ilike(f"%{status}%"))
    if case_type:
        filters.append(Case.case_type.ilike(f"%{case_type}%"))
    if file_no:
        filters.append(Case.file_no.ilike(f"%{file_no}%"))
    if client_rolodex_id:
        filters.append(Client.rolodex_id.ilike(f"%{client_rolodex_id}%"))
    if from_open_date:
        try:
            dt = datetime.strptime(from_open_date, "%Y-%m-%d")
            filters.append(Case.open_date >= dt)
        except ValueError:
            pass
    if to_open_date:
        try:
            dt = datetime.strptime(to_open_date, "%Y-%m-%d")
            filters.append(Case.open_date <= dt)
        except ValueError:
            pass

    if filters:
        query = query.filter(and_(*filters))

    # Sorting
    sort_dir_norm = (sort_dir or "").lower()
    if sort_dir_norm not in ("asc", "desc"):
        raise HTTPException(status_code=400, detail="Invalid sort_dir. Allowed: 'asc' or 'desc'")

    allowed_sort = {
        "file_no": Case.file_no,
        "status": Case.status,
        "case_type": Case.case_type,
        "description": Case.description,
        "open_date": Case.open_date,
        "close_date": Case.close_date,
        "created_at": Case.created_at,
        "client_last_name": Client.last_name,
        "client_first_name": Client.first_name,
        "client_company": Client.company,
        "id": Case.id,
    }
    default_order = [Case.open_date.desc().nulls_last(), Case.created_at.desc()]
    query, applied_sort_by, applied_sort_dir = _apply_sorting(query, sort_by, sort_dir_norm, allowed_sort, default_order)

    total: int = query.count()
    total_pages: int = (total + page_size - 1) // page_size if total > 0 else 1
    if page > total_pages:
        page = total_pages
    offset = (page - 1) * page_size

    cases = query.offset(offset).limit(page_size).all()

    logger.info(
        "api_files_list",
        query=q,
        status=status,
        case_type=case_type,
        file_no=file_no,
        client_rolodex_id=client_rolodex_id,
        page=page,
        page_size=page_size,
        total=total,
        sort_by=applied_sort_by,
        sort_dir=applied_sort_dir,
    )

    items = [CaseOut.model_validate(c) for c in cases]
    return FilesListResponse(
        items=items,
        pagination=Pagination(page=page, page_size=page_size, total=total, total_pages=total_pages),
    )


@app.get("/api/ledger", response_model=LedgerListResponse)
async def api_list_ledger(
    request: Request,
    case_id: int | None = Query(None, description="Filter by case ID"),
    file_no: str | None = Query(None, description="Filter by case file number contains"),
    from_date: str | None = Query(None, description="On/after YYYY-MM-DD"),
    to_date: str | None = Query(None, description="On/before YYYY-MM-DD"),
    billed: str | None = Query(None, description="'Y' or 'N'"),
    t_code: str | None = Query(None, description="Transaction code contains"),
    t_type_l: str | None = Query(None, description="Legacy type flag (e.g., C/D)"),
    employee_number: str | None = Query(None, description="Employee number contains"),
    q: str | None = Query(None, description="Description contains"),
    page: int = Query(1, ge=1),
    page_size: int = Query(50, ge=1, le=200),
    sort_by: str | None = Query(None, description="Sort field: transaction_date, item_no, id, amount, billed, t_code, t_type_l, employee_number, case_file_no, case_id"),
    sort_dir: str = Query("desc", description="Sort direction: asc or desc"),
    db: Session = Depends(get_db),
) -> LedgerListResponse:
    """Return paginated ledger (transactions) with simple filters as JSON."""
    user = get_current_user_from_session(request.session)
    if not user:
        raise HTTPException(status_code=401, detail="Unauthorized")

    query = (
        db.query(Transaction)
        .join(Case, Transaction.case_id == Case.id)
        .options(joinedload(Transaction.case))
    )

    filters = []
    if case_id is not None:
        filters.append(Transaction.case_id == case_id)
    if file_no:
        filters.append(Case.file_no.ilike(f"%{file_no}%"))
    if from_date:
        try:
            dt = datetime.strptime(from_date, "%Y-%m-%d")
            filters.append(Transaction.transaction_date >= dt)
        except ValueError:
            pass
    if to_date:
        try:
            dt = datetime.strptime(to_date, "%Y-%m-%d")
            filters.append(Transaction.transaction_date <= dt)
        except ValueError:
            pass
    if billed in ("Y", "N"):
        filters.append(Transaction.billed == billed)
    if t_code:
        filters.append(Transaction.t_code.ilike(f"%{t_code}%"))
    if t_type_l:
        filters.append(Transaction.t_type_l.ilike(f"%{t_type_l}%"))
    if employee_number:
        filters.append(Transaction.employee_number.ilike(f"%{employee_number}%"))
    if q:
        filters.append(Transaction.description.ilike(f"%{q}%"))

    if filters:
        query = query.filter(and_(*filters))

    # Sorting
    sort_dir_norm = (sort_dir or "").lower()
    if sort_dir_norm not in ("asc", "desc"):
        raise HTTPException(status_code=400, detail="Invalid sort_dir. Allowed: 'asc' or 'desc'")
    allowed_sort = {
        "transaction_date": Transaction.transaction_date,
        "item_no": Transaction.item_no,
        "id": Transaction.id,
        "amount": Transaction.amount,
        "billed": Transaction.billed,
        "t_code": Transaction.t_code,
        "t_type_l": Transaction.t_type_l,
        "employee_number": Transaction.employee_number,
        "case_file_no": Case.file_no,
        "case_id": Transaction.case_id,
    }
    default_order = [
        Transaction.transaction_date.desc().nulls_last(),
        Transaction.item_no.asc().nulls_last(),
        Transaction.id.desc(),
    ]
    query, applied_sort_by, applied_sort_dir = _apply_sorting(query, sort_by, sort_dir_norm, allowed_sort, default_order)

    total: int = query.count()
    total_pages: int = (total + page_size - 1) // page_size if total > 0 else 1
    if page > total_pages:
        page = total_pages
    offset = (page - 1) * page_size

    txns = query.offset(offset).limit(page_size).all()

    logger.info(
        "api_ledger_list",
        case_id=case_id,
        file_no=file_no,
        from_date=from_date,
        to_date=to_date,
        billed=billed,
        t_code=t_code,
        t_type_l=t_type_l,
        employee_number=employee_number,
        q=q,
        page=page,
        page_size=page_size,
        total=total,
        sort_by=applied_sort_by,
        sort_dir=applied_sort_dir,
    )

    items = [
        TransactionOut(
            id=t.id,
            case_id=t.case_id,
            case_file_no=t.case.file_no if t.case else None,
            transaction_date=t.transaction_date,
            item_no=t.item_no,
            amount=t.amount,
            billed=t.billed,
            t_code=t.t_code,
            t_type_l=t.t_type_l,
            quantity=t.quantity,
            rate=t.rate,
            description=t.description,
            employee_number=t.employee_number,
        )
        for t in txns
    ]

    return LedgerListResponse(
        items=items,
        pagination=Pagination(page=page, page_size=page_size, total=total, total_pages=total_pages),
    )