"""Database migration utility for adding loading status fields.

This script adds the loading status fields to existing anime_series tables
without Alembic. For new databases, these fields are created automatically
via create_all().

Run this after updating the models.py file.
"""
import asyncio
import logging
import sys
from pathlib import Path

# Add project root to Python path
project_root = Path(__file__).parent.parent
sys.path.insert(0, str(project_root))

from sqlalchemy import text
from sqlalchemy.exc import OperationalError

from src.config.settings import settings
from src.server.database.connection import get_engine, init_db

logger = logging.getLogger(__name__)
logging.basicConfig(level=logging.INFO)


async def migrate_add_loading_status_fields():
    """Add loading status fields to anime_series table if they don't exist."""
    
    # Initialize database connection
    await init_db()
    engine = get_engine()
    
    if not engine:
        logger.error("Failed to get database engine")
        return
    
    # Define the migrations
    migrations = [
        ("loading_status", "ALTER TABLE anime_series ADD COLUMN loading_status VARCHAR(50) NOT NULL DEFAULT 'completed'"),
        ("episodes_loaded", "ALTER TABLE anime_series ADD COLUMN episodes_loaded BOOLEAN NOT NULL DEFAULT 1"),
        ("logo_loaded", "ALTER TABLE anime_series ADD COLUMN logo_loaded BOOLEAN NOT NULL DEFAULT 0"),
        ("images_loaded", "ALTER TABLE anime_series ADD COLUMN images_loaded BOOLEAN NOT NULL DEFAULT 0"),
        ("loading_started_at", "ALTER TABLE anime_series ADD COLUMN loading_started_at TIMESTAMP"),
        ("loading_completed_at", "ALTER TABLE anime_series ADD COLUMN loading_completed_at TIMESTAMP"),
        ("loading_error", "ALTER TABLE anime_series ADD COLUMN loading_error VARCHAR(1000)"),
    ]
    
    async with engine.begin() as conn:
        for column_name, sql in migrations:
            try:
                logger.info(f"Adding column: {column_name}")
                await conn.execute(text(sql))
                logger.info(f"✅ Successfully added column: {column_name}")
            except OperationalError as e:
                if "duplicate column name" in str(e).lower() or "already exists" in str(e).lower():
                    logger.info(f"⏭️  Column {column_name} already exists, skipping")
                else:
                    logger.error(f"❌ Error adding column {column_name}: {e}")
                    raise
    
    logger.info("Migration completed successfully!")
    logger.info("All loading status fields are now available in anime_series table")


async def rollback_loading_status_fields():
    """Remove loading status fields from anime_series table."""
    
    await init_db()
    engine = get_engine()
    
    if not engine:
        logger.error("Failed to get database engine")
        return
    
    # SQLite doesn't support DROP COLUMN easily, so we'd need to recreate the table
    # For now, just log a warning
    logger.warning("Rollback not implemented for SQLite")
    logger.warning("To rollback, you would need to:")
    logger.warning("1. Create a new table without the loading fields")
    logger.warning("2. Copy data from old table")
    logger.warning("3. Drop old table and rename new table")


def main():
    """Run the migration."""
    import sys
    
    if len(sys.argv) > 1 and sys.argv[1] == "rollback":
        asyncio.run(rollback_loading_status_fields())
    else:
        asyncio.run(migrate_add_loading_status_fields())


if __name__ == "__main__":
    main()