#!/usr/bin/env python3
"""
Migration runner for requirement processor service
Run migrations in order to set up database schema
"""

import os
import sys
import asyncio
import asyncpg
from pathlib import Path
from loguru import logger

# Database connection settings
DATABASE_URL = os.getenv('DATABASE_URL', 'postgresql://postgres:password@localhost:5432/dev_pipeline')

SCHEMA_MIGRATIONS_TABLE_SQL = """
CREATE TABLE IF NOT EXISTS schema_migrations (
  id SERIAL PRIMARY KEY,
  version VARCHAR(255) NOT NULL UNIQUE,
  service VARCHAR(100) NOT NULL,
  applied_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  description TEXT
);
"""

async def ensure_migrations_table(pool) -> None:
    async with pool.acquire() as conn:
        await conn.execute(SCHEMA_MIGRATIONS_TABLE_SQL)

async def is_applied(pool, version: str, service: str = "requirement-processor") -> bool:
    async with pool.acquire() as conn:
        row = await conn.fetchrow("SELECT 1 FROM schema_migrations WHERE version = $1 AND service = $2", version, service)
        return row is not None

async def mark_applied(pool, version: str, service: str = "requirement-processor", description: str = None) -> None:
    async with pool.acquire() as conn:
        await conn.execute(
            "INSERT INTO schema_migrations(version, service, description) VALUES($1, $2, $3) ON CONFLICT (version) DO NOTHING", 
            version, service, description
        )

async def run_migration(pool, migration_file):
    """Run a single migration file if not applied"""
    version = migration_file.name
    service = "requirement-processor"
    try:
        if await is_applied(pool, version, service):
            logger.info(f"⏭️  Skipping already applied migration: {version}")
            return True

        with open(migration_file, 'r') as f:
            sql_content = f.read()

        async with pool.acquire() as conn:
            await conn.execute(sql_content)

        await mark_applied(pool, version, service, f"Requirement processor migration: {version}")
        logger.info(f"✅ Migration completed: {version}")
        return True
    except Exception as e:
        logger.error(f"❌ Migration failed: {version} - {e}")
        return False

async def run_migrations():
    """Run all migrations in order"""
    try:
        # Connect to database
        pool = await asyncpg.create_pool(DATABASE_URL)
        logger.info("Connected to database")
        
        # Ensure tracking table exists
        await ensure_migrations_table(pool)

        # Get migration files
        migrations_dir = Path(__file__).parent
        migration_files = sorted(migrations_dir.glob("*.sql"))
        
        if not migration_files:
            logger.info("No migration files found")
            return
        
        logger.info(f"Found {len(migration_files)} migration files")
        
        # Run migrations
        for migration_file in migration_files:
            success = await run_migration(pool, migration_file)
            if not success:
                logger.error("Migration failed, stopping")
                break
        
        await pool.close()
        logger.info("All migrations completed successfully")
        
    except Exception as e:
        logger.error(f"Migration runner failed: {e}")
        sys.exit(1)

if __name__ == "__main__":
    asyncio.run(run_migrations())