"""
Migration script: Generate PDFs for existing performance check records

This script:
1. Finds all CarPerformanceCheck records that have check_number but no pdf_path
2. Generates PDF for each using Playwright
3. Updates the pdf_path in the database

Usage:
    cd backend
    python scripts/migrate_performance_check_to_pdf.py

Requirements:
    pip install playwright
    playwright install chromium
"""

import asyncio
import sys
import os

# Add parent directory to path for imports
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from app.database import Base
from app.models import CarPerformanceCheck
from app.services.pdf_service import capture_performance_check_pdf, PLAYWRIGHT_AVAILABLE

# Database connection
DATABASE_URL = os.getenv("DATABASE_URL", "sqlite:///./autonetsellcar.db")


async def migrate_performance_checks():
    """Migrate existing performance checks to PDF format"""

    if not PLAYWRIGHT_AVAILABLE:
        print("ERROR: Playwright is not installed. Please run:")
        print("  pip install playwright")
        print("  playwright install chromium")
        return

    # Create database session
    engine = create_engine(DATABASE_URL)
    SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
    db = SessionLocal()

    try:
        # Find all performance checks without PDF
        records = db.query(CarPerformanceCheck).filter(
            CarPerformanceCheck.check_number.isnot(None),
            CarPerformanceCheck.check_number != "",
            (CarPerformanceCheck.pdf_path.is_(None)) | (CarPerformanceCheck.pdf_path == "")
        ).all()

        total = len(records)
        print(f"Found {total} performance check records to migrate")

        if total == 0:
            print("No records to migrate. Done.")
            return

        success_count = 0
        error_count = 0

        for i, record in enumerate(records, 1):
            print(f"\n[{i}/{total}] Processing car_id={record.car_id}, check_number={record.check_number}")

            try:
                pdf_path = await capture_performance_check_pdf(
                    record.check_number,
                    record.car_id
                )

                if pdf_path:
                    record.pdf_path = pdf_path
                    db.commit()
                    print(f"  SUCCESS: {pdf_path}")
                    success_count += 1
                else:
                    print(f"  FAILED: PDF generation returned None")
                    error_count += 1

            except Exception as e:
                print(f"  ERROR: {e}")
                error_count += 1
                db.rollback()

            # Small delay to avoid overwhelming the server
            await asyncio.sleep(1)

        print(f"\n{'='*50}")
        print(f"Migration completed!")
        print(f"  Total: {total}")
        print(f"  Success: {success_count}")
        print(f"  Errors: {error_count}")

    finally:
        db.close()


async def check_status():
    """Check current migration status"""

    engine = create_engine(DATABASE_URL)
    SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
    db = SessionLocal()

    try:
        total = db.query(CarPerformanceCheck).count()
        with_check_num = db.query(CarPerformanceCheck).filter(
            CarPerformanceCheck.check_number.isnot(None),
            CarPerformanceCheck.check_number != ""
        ).count()
        with_pdf = db.query(CarPerformanceCheck).filter(
            CarPerformanceCheck.pdf_path.isnot(None),
            CarPerformanceCheck.pdf_path != ""
        ).count()

        print(f"Performance Check Status:")
        print(f"  Total records: {total}")
        print(f"  With check_number: {with_check_num}")
        print(f"  With PDF: {with_pdf}")
        print(f"  Pending migration: {with_check_num - with_pdf}")

    finally:
        db.close()


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description="Migrate performance checks to PDF")
    parser.add_argument("--status", action="store_true", help="Show current status only")
    parser.add_argument("--dry-run", action="store_true", help="Show what would be done without making changes")
    args = parser.parse_args()

    if args.status:
        asyncio.run(check_status())
    else:
        print("Starting performance check PDF migration...")
        print("This will generate PDFs for all existing performance check records.")
        print()

        if args.dry_run:
            print("DRY RUN - No changes will be made")
            asyncio.run(check_status())
        else:
            confirm = input("Continue? (y/n): ")
            if confirm.lower() == 'y':
                asyncio.run(migrate_performance_checks())
            else:
                print("Cancelled.")