"""
Database migration script to add multi-cloud storage fields to site_deployments table
Story 6.3: Database Schema Updates for Multi-Cloud

Adds:
- storage_provider (String(20), Not Null, Default: 'bunny', Indexed)
- s3_bucket_name (String(255), Nullable)
- s3_bucket_region (String(50), Nullable)
- s3_custom_domain (String(255), Nullable)
- s3_endpoint_url (String(500), Nullable)

Usage:
    python scripts/migrate_add_multi_cloud_storage_fields.py
"""

import sys
from pathlib import Path

project_root = Path(__file__).parent.parent
sys.path.insert(0, str(project_root))

from sqlalchemy import text
from src.database.session import db_manager
from src.core.config import get_config


def migrate():
    """Add multi-cloud storage fields to site_deployments table"""
    print("Starting migration: add multi-cloud storage fields to site_deployments...")
    
    try:
        config = get_config()
        print(f"Database URL: {config.database.url}")
    except Exception as e:
        print(f"Error loading configuration: {e}")
        sys.exit(1)
    
    try:
        db_manager.initialize()
        engine = db_manager.get_engine()
        
        with engine.connect() as conn:
            print("Checking for existing columns...")
            
            result = conn.execute(text("PRAGMA table_info(site_deployments)"))
            existing_columns = [row[1] for row in result]
            print(f"Existing columns: {', '.join(existing_columns)}")
            
            migrations_applied = []
            
            if "storage_provider" not in existing_columns:
                print("Adding storage_provider column...")
                conn.execute(text("""
                    ALTER TABLE site_deployments 
                    ADD COLUMN storage_provider VARCHAR(20) NOT NULL DEFAULT 'bunny'
                """))
                conn.commit()
                
                print("Setting storage_provider='bunny' for all existing records...")
                conn.execute(text("""
                    UPDATE site_deployments 
                    SET storage_provider = 'bunny'
                """))
                conn.commit()
                
                print("Creating index on storage_provider...")
                conn.execute(text("""
                    CREATE INDEX IF NOT EXISTS idx_site_deployments_storage_provider 
                    ON site_deployments(storage_provider)
                """))
                conn.commit()
                migrations_applied.append("storage_provider")
            else:
                print("storage_provider column already exists, skipping")
            
            if "s3_bucket_name" not in existing_columns:
                print("Adding s3_bucket_name column...")
                conn.execute(text("""
                    ALTER TABLE site_deployments 
                    ADD COLUMN s3_bucket_name VARCHAR(255)
                """))
                conn.commit()
                migrations_applied.append("s3_bucket_name")
            else:
                print("s3_bucket_name column already exists, skipping")
            
            if "s3_bucket_region" not in existing_columns:
                print("Adding s3_bucket_region column...")
                conn.execute(text("""
                    ALTER TABLE site_deployments 
                    ADD COLUMN s3_bucket_region VARCHAR(50)
                """))
                conn.commit()
                migrations_applied.append("s3_bucket_region")
            else:
                print("s3_bucket_region column already exists, skipping")
            
            if "s3_custom_domain" not in existing_columns:
                print("Adding s3_custom_domain column...")
                conn.execute(text("""
                    ALTER TABLE site_deployments 
                    ADD COLUMN s3_custom_domain VARCHAR(255)
                """))
                conn.commit()
                migrations_applied.append("s3_custom_domain")
            else:
                print("s3_custom_domain column already exists, skipping")
            
            if "s3_endpoint_url" not in existing_columns:
                print("Adding s3_endpoint_url column...")
                conn.execute(text("""
                    ALTER TABLE site_deployments 
                    ADD COLUMN s3_endpoint_url VARCHAR(500)
                """))
                conn.commit()
                migrations_applied.append("s3_endpoint_url")
            else:
                print("s3_endpoint_url column already exists, skipping")
            
            if migrations_applied:
                print(f"\nMigration complete! Added columns: {', '.join(migrations_applied)}")
                print("\nNew fields added:")
                print("  - storage_provider (VARCHAR(20), NOT NULL, DEFAULT 'bunny', indexed)")
                print("  - s3_bucket_name (VARCHAR(255), nullable)")
                print("  - s3_bucket_region (VARCHAR(50), nullable)")
                print("  - s3_custom_domain (VARCHAR(255), nullable)")
                print("  - s3_endpoint_url (VARCHAR(500), nullable)")
            else:
                print("\nNo migrations needed - all columns already exist")
        
    except Exception as e:
        print(f"Error during migration: {e}")
        import traceback
        traceback.print_exc()
        sys.exit(1)
    finally:
        db_manager.close()


if __name__ == "__main__":
    migrate()