"""Import API endpoints for CSV file uploads."""
from fastapi import APIRouter, Depends, HTTPException, UploadFile, File, status
from sqlalchemy.orm import Session
from pathlib import Path
import tempfile
import shutil

from app.api.deps import get_db
from app.services import ImportService
from app.services.position_tracker import PositionTracker
from app.config import settings

router = APIRouter()


@router.post("/upload/{account_id}")
def upload_csv(
    account_id: int, file: UploadFile = File(...), db: Session = Depends(get_db)
):
    """
    Upload and import a CSV file for an account.

    Args:
        account_id: Account ID to import transactions for
        file: CSV file to upload
        db: Database session

    Returns:
        Import statistics

    Raises:
        HTTPException: If import fails
    """
    if not file.filename.endswith(".csv"):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST, detail="File must be a CSV"
        )

    # Save uploaded file to temporary location
    try:
        with tempfile.NamedTemporaryFile(delete=False, suffix=".csv") as tmp_file:
            shutil.copyfileobj(file.file, tmp_file)
            tmp_path = Path(tmp_file.name)

        # Import transactions
        import_service = ImportService(db)
        result = import_service.import_from_file(tmp_path, account_id)

        # Rebuild positions after import
        if result.imported > 0:
            position_tracker = PositionTracker(db)
            positions_created = position_tracker.rebuild_positions(account_id)
        else:
            positions_created = 0

        # Clean up temporary file
        tmp_path.unlink()

        return {
            "filename": file.filename,
            "imported": result.imported,
            "skipped": result.skipped,
            "errors": result.errors,
            "total_rows": result.total_rows,
            "positions_created": positions_created,
        }

    except Exception as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Import failed: {str(e)}",
        )


@router.post("/filesystem/{account_id}")
def import_from_filesystem(account_id: int, db: Session = Depends(get_db)):
    """
    Import all CSV files from the filesystem import directory.

    Args:
        account_id: Account ID to import transactions for
        db: Database session

    Returns:
        Import statistics for all files

    Raises:
        HTTPException: If import directory doesn't exist
    """
    import_dir = Path(settings.IMPORT_DIR)

    if not import_dir.exists():
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Import directory not found: {import_dir}",
        )

    try:
        import_service = ImportService(db)
        results = import_service.import_from_directory(import_dir, account_id)

        # Rebuild positions if any transactions were imported
        total_imported = sum(r.imported for r in results.values())
        if total_imported > 0:
            position_tracker = PositionTracker(db)
            positions_created = position_tracker.rebuild_positions(account_id)
        else:
            positions_created = 0

        return {
            "files": {
                filename: {
                    "imported": result.imported,
                    "skipped": result.skipped,
                    "errors": result.errors,
                    "total_rows": result.total_rows,
                }
                for filename, result in results.items()
            },
            "total_imported": total_imported,
            "positions_created": positions_created,
        }

    except Exception as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Import failed: {str(e)}",
        )