"""
Document Management API endpoints - QDROs, Templates, and General Documents
"""
from typing import List, Optional, Dict, Any
from fastapi import APIRouter, Depends, HTTPException, status, Query, UploadFile, File
from sqlalchemy.orm import Session, joinedload
from sqlalchemy import or_, func, and_, desc, asc, text
from datetime import date, datetime
import os
import uuid
import shutil

from app.database.base import get_db
from app.models.qdro import QDRO
from app.models.files import File as FileModel
from app.models.rolodex import Rolodex
from app.models.lookups import FormIndex, FormList, Footer, Employee
from app.models.user import User
from app.auth.security import get_current_user

router = APIRouter()


# Pydantic schemas
from pydantic import BaseModel


class QDROBase(BaseModel):
    file_no: str
    version: str = "01"
    title: Optional[str] = None
    content: Optional[str] = None
    status: str = "DRAFT"
    created_date: Optional[date] = None
    approved_date: Optional[date] = None
    filed_date: Optional[date] = None
    participant_name: Optional[str] = None
    spouse_name: Optional[str] = None
    plan_name: Optional[str] = None
    plan_administrator: Optional[str] = None
    notes: Optional[str] = None


class QDROCreate(QDROBase):
    pass


class QDROUpdate(BaseModel):
    version: Optional[str] = None
    title: Optional[str] = None
    content: Optional[str] = None
    status: Optional[str] = None
    created_date: Optional[date] = None
    approved_date: Optional[date] = None
    filed_date: Optional[date] = None
    participant_name: Optional[str] = None
    spouse_name: Optional[str] = None
    plan_name: Optional[str] = None
    plan_administrator: Optional[str] = None
    notes: Optional[str] = None


class QDROResponse(QDROBase):
    id: int
    
    class Config:
        from_attributes = True


@router.get("/qdros/{file_no}", response_model=List[QDROResponse])
async def get_file_qdros(
    file_no: str,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Get QDROs for specific file"""
    qdros = db.query(QDRO).filter(QDRO.file_no == file_no).order_by(QDRO.version).all()
    return qdros


@router.get("/qdros/", response_model=List[QDROResponse])
async def list_qdros(
    skip: int = Query(0, ge=0),
    limit: int = Query(50, ge=1, le=200),
    status_filter: Optional[str] = Query(None),
    search: Optional[str] = Query(None),
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """List all QDROs with filtering"""
    query = db.query(QDRO)
    
    if status_filter:
        query = query.filter(QDRO.status == status_filter)
    
    if search:
        query = query.filter(
            or_(
                QDRO.file_no.contains(search),
                QDRO.title.contains(search),
                QDRO.participant_name.contains(search),
                QDRO.spouse_name.contains(search),
                QDRO.plan_name.contains(search)
            )
        )
    
    qdros = query.offset(skip).limit(limit).all()
    return qdros


@router.post("/qdros/", response_model=QDROResponse)
async def create_qdro(
    qdro_data: QDROCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Create new QDRO"""
    qdro = QDRO(**qdro_data.model_dump())
    
    if not qdro.created_date:
        qdro.created_date = date.today()
    
    db.add(qdro)
    db.commit()
    db.refresh(qdro)
    
    return qdro


@router.get("/qdros/{file_no}/{qdro_id}", response_model=QDROResponse)
async def get_qdro(
    file_no: str,
    qdro_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Get specific QDRO"""
    qdro = db.query(QDRO).filter(
        QDRO.id == qdro_id,
        QDRO.file_no == file_no
    ).first()
    
    if not qdro:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="QDRO not found"
        )
    
    return qdro


@router.put("/qdros/{file_no}/{qdro_id}", response_model=QDROResponse)
async def update_qdro(
    file_no: str,
    qdro_id: int,
    qdro_data: QDROUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Update QDRO"""
    qdro = db.query(QDRO).filter(
        QDRO.id == qdro_id,
        QDRO.file_no == file_no
    ).first()
    
    if not qdro:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="QDRO not found"
        )
    
    # Update fields
    for field, value in qdro_data.model_dump(exclude_unset=True).items():
        setattr(qdro, field, value)
    
    db.commit()
    db.refresh(qdro)
    
    return qdro


@router.delete("/qdros/{file_no}/{qdro_id}")
async def delete_qdro(
    file_no: str,
    qdro_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Delete QDRO"""
    qdro = db.query(QDRO).filter(
        QDRO.id == qdro_id,
        QDRO.file_no == file_no
    ).first()
    
    if not qdro:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="QDRO not found"
        )
    
    db.delete(qdro)
    db.commit()
    
    return {"message": "QDRO deleted successfully"}


# Enhanced Document Management Endpoints

# Template Management Schemas
class TemplateBase(BaseModel):
    """Base template schema"""
    form_id: str
    form_name: str
    category: str = "GENERAL"
    content: str = ""
    variables: Optional[Dict[str, str]] = None

class TemplateCreate(TemplateBase):
    pass

class TemplateUpdate(BaseModel):
    form_name: Optional[str] = None
    category: Optional[str] = None
    content: Optional[str] = None
    variables: Optional[Dict[str, str]] = None

class TemplateResponse(TemplateBase):
    active: bool = True
    created_at: Optional[datetime] = None
    
    class Config:
        from_attributes = True

# Document Generation Schema
class DocumentGenerateRequest(BaseModel):
    """Request to generate document from template"""
    template_id: str
    file_no: str
    output_format: str = "PDF"  # PDF, DOCX, HTML
    variables: Optional[Dict[str, Any]] = None

class DocumentResponse(BaseModel):
    """Generated document response"""
    document_id: str
    file_name: str
    file_path: str
    size: int
    created_at: datetime

# Document Statistics
class DocumentStats(BaseModel):
    """Document system statistics"""
    total_templates: int
    total_qdros: int
    templates_by_category: Dict[str, int]
    recent_activity: List[Dict[str, Any]]


@router.get("/templates/", response_model=List[TemplateResponse])
async def list_templates(
    skip: int = Query(0, ge=0),
    limit: int = Query(50, ge=1, le=200),
    category: Optional[str] = Query(None),
    search: Optional[str] = Query(None),
    active_only: bool = Query(True),
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """List available document templates"""
    query = db.query(FormIndex)
    
    if active_only:
        query = query.filter(FormIndex.active == True)
    
    if category:
        query = query.filter(FormIndex.category == category)
    
    if search:
        query = query.filter(
            or_(
                FormIndex.form_name.contains(search),
                FormIndex.form_id.contains(search)
            )
        )
    
    templates = query.offset(skip).limit(limit).all()
    
    # Enhanced response with template content
    results = []
    for template in templates:
        template_lines = db.query(FormList).filter(
            FormList.form_id == template.form_id
        ).order_by(FormList.line_number).all()
        
        content = "\n".join([line.content or "" for line in template_lines])
        
        results.append({
            "form_id": template.form_id,
            "form_name": template.form_name,
            "category": template.category,
            "content": content,
            "active": template.active,
            "created_at": template.created_at,
            "variables": _extract_variables_from_content(content)
        })
    
    return results


@router.post("/templates/", response_model=TemplateResponse)
async def create_template(
    template_data: TemplateCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Create new document template"""
    # Check if template already exists
    existing = db.query(FormIndex).filter(FormIndex.form_id == template_data.form_id).first()
    if existing:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Template with this ID already exists"
        )
    
    # Create form index entry
    form_index = FormIndex(
        form_id=template_data.form_id,
        form_name=template_data.form_name,
        category=template_data.category,
        active=True
    )
    db.add(form_index)
    
    # Create form content lines
    content_lines = template_data.content.split('\n')
    for i, line in enumerate(content_lines, 1):
        form_line = FormList(
            form_id=template_data.form_id,
            line_number=i,
            content=line
        )
        db.add(form_line)
    
    db.commit()
    db.refresh(form_index)
    
    return {
        "form_id": form_index.form_id,
        "form_name": form_index.form_name,
        "category": form_index.category,
        "content": template_data.content,
        "active": form_index.active,
        "created_at": form_index.created_at,
        "variables": template_data.variables or {}
    }


@router.get("/templates/{template_id}", response_model=TemplateResponse)
async def get_template(
    template_id: str,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Get specific template with content"""
    template = db.query(FormIndex).filter(FormIndex.form_id == template_id).first()
    
    if not template:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Template not found"
        )
    
    # Get template content
    template_lines = db.query(FormList).filter(
        FormList.form_id == template_id
    ).order_by(FormList.line_number).all()
    
    content = "\n".join([line.content or "" for line in template_lines])
    
    return {
        "form_id": template.form_id,
        "form_name": template.form_name,
        "category": template.category,
        "content": content,
        "active": template.active,
        "created_at": template.created_at,
        "variables": _extract_variables_from_content(content)
    }


@router.put("/templates/{template_id}", response_model=TemplateResponse)
async def update_template(
    template_id: str,
    template_data: TemplateUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Update document template"""
    template = db.query(FormIndex).filter(FormIndex.form_id == template_id).first()
    
    if not template:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Template not found"
        )
    
    # Update form index
    if template_data.form_name:
        template.form_name = template_data.form_name
    if template_data.category:
        template.category = template_data.category
    
    # Update content if provided
    if template_data.content is not None:
        # Delete existing content lines
        db.query(FormList).filter(FormList.form_id == template_id).delete()
        
        # Add new content lines
        content_lines = template_data.content.split('\n')
        for i, line in enumerate(content_lines, 1):
            form_line = FormList(
                form_id=template_id,
                line_number=i,
                content=line
            )
            db.add(form_line)
    
    db.commit()
    db.refresh(template)
    
    # Get updated content
    template_lines = db.query(FormList).filter(
        FormList.form_id == template_id
    ).order_by(FormList.line_number).all()
    
    content = "\n".join([line.content or "" for line in template_lines])
    
    return {
        "form_id": template.form_id,
        "form_name": template.form_name,
        "category": template.category,
        "content": content,
        "active": template.active,
        "created_at": template.created_at,
        "variables": _extract_variables_from_content(content)
    }


@router.delete("/templates/{template_id}")
async def delete_template(
    template_id: str,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Delete document template"""
    template = db.query(FormIndex).filter(FormIndex.form_id == template_id).first()
    
    if not template:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Template not found"
        )
    
    # Delete content lines
    db.query(FormList).filter(FormList.form_id == template_id).delete()
    
    # Delete template
    db.delete(template)
    db.commit()
    
    return {"message": "Template deleted successfully"}


@router.post("/generate/{template_id}")
async def generate_document(
    template_id: str,
    request: DocumentGenerateRequest,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Generate document from template"""
    # Get template
    template = db.query(FormIndex).filter(FormIndex.form_id == template_id).first()
    if not template:
        raise HTTPException(status_code=404, detail="Template not found")
    
    # Get file information
    file_obj = db.query(FileModel).options(
        joinedload(FileModel.owner)
    ).filter(FileModel.file_no == request.file_no).first()
    
    if not file_obj:
        raise HTTPException(status_code=404, detail="File not found")
    
    # Get template content
    template_lines = db.query(FormList).filter(
        FormList.form_id == template_id
    ).order_by(FormList.line_number).all()
    
    template_content = "\n".join([line.content or "" for line in template_lines])
    
    # Prepare merge variables
    merge_vars = {
        "FILE_NO": file_obj.file_no,
        "CLIENT_FIRST": file_obj.owner.first if file_obj.owner else "",
        "CLIENT_LAST": file_obj.owner.last if file_obj.owner else "",
        "CLIENT_FULL": f"{file_obj.owner.first or ''} {file_obj.owner.last}".strip() if file_obj.owner else "",
        "MATTER": file_obj.regarding or "",
        "OPENED": file_obj.opened.strftime("%B %d, %Y") if file_obj.opened else "",
        "ATTORNEY": file_obj.empl_num or "",
        "TODAY": date.today().strftime("%B %d, %Y")
    }
    
    # Add any custom variables from the request
    if request.variables:
        merge_vars.update(request.variables)
    
    # Perform variable substitution
    merged_content = _merge_template_variables(template_content, merge_vars)
    
    # Generate document file
    document_id = str(uuid.uuid4())
    file_name = f"{template.form_name}_{file_obj.file_no}_{date.today().isoformat()}"
    
    if request.output_format.upper() == "PDF":
        file_path = f"/app/exports/{document_id}.pdf"
        file_name += ".pdf"
        # Here you would implement PDF generation
        # For now, create a simple text file
        with open(f"/app/exports/{document_id}.txt", "w") as f:
            f.write(merged_content)
        file_path = f"/app/exports/{document_id}.txt"
    elif request.output_format.upper() == "DOCX":
        file_path = f"/app/exports/{document_id}.docx"
        file_name += ".docx"
        # Implement DOCX generation
        with open(f"/app/exports/{document_id}.txt", "w") as f:
            f.write(merged_content)
        file_path = f"/app/exports/{document_id}.txt"
    else:  # HTML
        file_path = f"/app/exports/{document_id}.html"
        file_name += ".html"
        html_content = f"<html><body><pre>{merged_content}</pre></body></html>"
        with open(file_path, "w") as f:
            f.write(html_content)
    
    file_size = os.path.getsize(file_path) if os.path.exists(file_path) else 0
    
    return {
        "document_id": document_id,
        "file_name": file_name,
        "file_path": file_path,
        "size": file_size,
        "created_at": datetime.now()
    }


@router.get("/categories/")
async def get_template_categories(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Get available template categories"""
    categories = db.query(FormIndex.category).distinct().all()
    return [cat[0] for cat in categories if cat[0]]


@router.get("/stats/summary")
async def get_document_stats(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Get document system statistics"""
    # Template statistics
    total_templates = db.query(FormIndex).filter(FormIndex.active == True).count()
    total_qdros = db.query(QDRO).count()
    
    # Templates by category
    category_stats = db.query(
        FormIndex.category,
        func.count(FormIndex.form_id)
    ).filter(FormIndex.active == True).group_by(FormIndex.category).all()
    
    categories_dict = {cat[0] or "Uncategorized": cat[1] for cat in category_stats}
    
    # Recent QDRO activity
    recent_qdros = db.query(QDRO).order_by(desc(QDRO.updated_at)).limit(5).all()
    recent_activity = [
        {
            "type": "QDRO",
            "file_no": qdro.file_no,
            "status": qdro.status,
            "updated_at": qdro.updated_at.isoformat() if qdro.updated_at else None
        }
        for qdro in recent_qdros
    ]
    
    return {
        "total_templates": total_templates,
        "total_qdros": total_qdros,
        "templates_by_category": categories_dict,
        "recent_activity": recent_activity
    }


@router.get("/file/{file_no}/documents")
async def get_file_documents(
    file_no: str,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user)
):
    """Get all documents associated with a specific file"""
    # Get QDROs for this file
    qdros = db.query(QDRO).filter(QDRO.file_no == file_no).order_by(desc(QDRO.updated_at)).all()
    
    # Format response
    documents = [
        {
            "id": qdro.id,
            "type": "QDRO",
            "title": f"QDRO v{qdro.version}",
            "status": qdro.status,
            "created_date": qdro.created_date.isoformat() if qdro.created_date else None,
            "updated_at": qdro.updated_at.isoformat() if qdro.updated_at else None,
            "file_no": qdro.file_no
        }
        for qdro in qdros
    ]
    
    return {
        "file_no": file_no,
        "documents": documents,
        "total_count": len(documents)
    }


def _extract_variables_from_content(content: str) -> Dict[str, str]:
    """Extract variable placeholders from template content"""
    import re
    variables = {}
    
    # Find variables in format {{VARIABLE_NAME}}
    matches = re.findall(r'\{\{([^}]+)\}\}', content)
    for match in matches:
        var_name = match.strip()
        variables[var_name] = f"Placeholder for {var_name}"
    
    # Find variables in format ^VARIABLE
    matches = re.findall(r'\^([A-Z_]+)', content)
    for match in matches:
        variables[match] = f"Placeholder for {match}"
    
    return variables


def _merge_template_variables(content: str, variables: Dict[str, Any]) -> str:
    """Replace template variables with actual values"""
    merged = content
    
    # Replace {{VARIABLE}} format
    for var_name, value in variables.items():
        merged = merged.replace(f"{{{{{var_name}}}}}", str(value or ""))
        merged = merged.replace(f"^{var_name}", str(value or ""))
    
    return merged