import json
from datetime import datetime

import pytest

from app.main import run_auto_import_for_upload, ORDER_INDEX


class DummyImportLog:
    # Minimal stand-in to satisfy attribute assignments; not used by SQLAlchemy
    def __init__(self, **kwargs):
        self.import_type = kwargs.get("import_type")
        self.file_name = kwargs.get("file_name")
        self.file_path = kwargs.get("file_path")
        self.status = kwargs.get("status", "pending")
        self.total_rows = 0
        self.success_count = 0
        self.error_count = 0
        self.error_details = "[]"
        self.completed_at = None


class DummyDB:
    """Very small in-memory stub for the DB session interactions used by helper."""

    def __init__(self, import_results_by_type):
        self.import_results_by_type = import_results_by_type
        self.logs = []

    # SQLAlchemy-like API surface used by helper
    def add(self, obj):
        # record created logs
        self.logs.append(obj)

    def commit(self):
        # no-op for tests
        return None


# Monkeypatch target lookup inside the helper by patching process function in module namespace
@pytest.fixture(autouse=True)
def patch_process_csv_import(monkeypatch):
    from app import main as main_mod

    def fake_process_csv_import(db, import_type, file_path):
        # return test-configured results from DummyDB
        return db.import_results_by_type.get(import_type, {"success": 0, "errors": []})

    monkeypatch.setattr(main_mod, "process_csv_import", fake_process_csv_import)
    # Replace ImportLog class with Dummy for isolation (no DB)
    monkeypatch.setattr(main_mod, "ImportLog", DummyImportLog)


def sorted_by_order(items):
    return sorted(items, key=lambda x: (ORDER_INDEX.get(x["import_type"], 1_000_000), x.get("filename", "")))


def test_auto_import_sorts_and_runs_in_order():
    uploaded = [
        {"filename": "B.csv", "stored_filename": "files_b.csv", "file_path": "/tmp/b.csv", "import_type": "files"},
        {"filename": "A.csv", "stored_filename": "trnstype_a.csv", "file_path": "/tmp/a.csv", "import_type": "trnstype"},
        {"filename": "C.csv", "stored_filename": "payments_c.csv", "file_path": "/tmp/c.csv", "import_type": "payments"},
    ]

    # Make all succeed
    db = DummyDB({
        "trnstype": {"success": 1, "errors": [], "total_rows": 10},
        "files": {"success": 1, "errors": [], "total_rows": 20},
        "payments": {"success": 1, "errors": [], "total_rows": 5},
    })

    result = run_auto_import_for_upload(db, uploaded)

    # Should be ordered by IMPORT_ORDER
    filenames_in_result = [f["stored_filename"] for f in result["files"]]
    expected_order = [i["stored_filename"] for i in sorted_by_order(uploaded)]
    assert filenames_in_result == expected_order
    assert result["stopped"] is False
    assert result["stopped_on"] is None
    assert result["skipped_unknowns"] == []


def test_auto_import_skips_unknown_and_reports():
    uploaded = [
        {"filename": "Unknown.csv", "stored_filename": "unknown_1.csv", "file_path": "/tmp/u1.csv", "import_type": "unknown"},
        {"filename": "Rolodex.csv", "stored_filename": "rolodex_2.csv", "file_path": "/tmp/r2.csv", "import_type": "rolodex"},
    ]

    db = DummyDB({"rolodex": {"success": 1, "errors": [], "total_rows": 1}})
    result = run_auto_import_for_upload(db, uploaded)

    # Only known type processed
    assert [f["stored_filename"] for f in result["files"]] == ["rolodex_2.csv"]
    # Unknown skipped and listed
    assert result["skipped_unknowns"] == [{"filename": "Unknown.csv", "stored_filename": "unknown_1.csv"}]


def test_auto_import_stops_on_first_error_and_sets_stopped_on():
    uploaded = [
        {"filename": "A.csv", "stored_filename": "trnstype_a.csv", "file_path": "/tmp/a.csv", "import_type": "trnstype"},
        {"filename": "B.csv", "stored_filename": "files_b.csv", "file_path": "/tmp/b.csv", "import_type": "files"},
        {"filename": "C.csv", "stored_filename": "payments_c.csv", "file_path": "/tmp/c.csv", "import_type": "payments"},
    ]

    # First succeeds, second returns errors -> should stop before third
    db = DummyDB({
        "trnstype": {"success": 1, "errors": [], "total_rows": 10},
        "files": {"success": 0, "errors": ["bad row"], "total_rows": 2},
        "payments": {"success": 1, "errors": [], "total_rows": 5},
    })

    result = run_auto_import_for_upload(db, uploaded)

    processed = [f["stored_filename"] for f in result["files"]]
    # The run order starts with trnstype then files; payments should not run
    assert processed == ["trnstype_a.csv", "files_b.csv"]
    assert result["stopped"] is True
    assert result["stopped_on"] == "files_b.csv"