#!/usr/bin/env python
"""
SQLite migration for Story 3.1
Makes custom_hostname nullable and adds unique constraint to pull_zone_bcdn_hostname
"""

import sqlite3
import sys

def migrate():
    conn = sqlite3.connect('content_automation.db')
    cursor = conn.cursor()
    
    try:
        print("Starting migration for Story 3.1...")
        
        # Check if migration already applied
        cursor.execute("PRAGMA table_info(site_deployments)")
        columns = cursor.fetchall()
        custom_hostname_col = [col for col in columns if col[1] == 'custom_hostname'][0]
        is_nullable = custom_hostname_col[3] == 0  # 0 = nullable, 1 = not null
        
        if is_nullable:
            print("✓ Migration already applied (custom_hostname is already nullable)")
            conn.close()
            return
        
        print("Step 1: Backing up existing data...")
        cursor.execute("SELECT COUNT(*) FROM site_deployments")
        count = cursor.fetchone()[0]
        print(f"  Found {count} existing site deployment(s)")
        
        print("Step 2: Creating new table with updated schema...")
        cursor.execute("""
            CREATE TABLE site_deployments_new (
                id INTEGER PRIMARY KEY AUTOINCREMENT,
                site_name VARCHAR(255) NOT NULL,
                custom_hostname VARCHAR(255) UNIQUE,
                storage_zone_id INTEGER NOT NULL,
                storage_zone_name VARCHAR(255) NOT NULL,
                storage_zone_password VARCHAR(255) NOT NULL,
                storage_zone_region VARCHAR(10) NOT NULL,
                pull_zone_id INTEGER NOT NULL,
                pull_zone_bcdn_hostname VARCHAR(255) NOT NULL UNIQUE,
                created_at DATETIME NOT NULL,
                updated_at DATETIME NOT NULL
            )
        """)
        
        print("Step 3: Copying data from old table...")
        cursor.execute("""
            INSERT INTO site_deployments_new 
            SELECT * FROM site_deployments
        """)
        
        print("Step 4: Dropping old table...")
        cursor.execute("DROP TABLE site_deployments")
        
        print("Step 5: Renaming new table...")
        cursor.execute("ALTER TABLE site_deployments_new RENAME TO site_deployments")
        
        # Create indexes
        print("Step 6: Creating indexes...")
        cursor.execute("CREATE INDEX IF NOT EXISTS ix_site_deployments_custom_hostname ON site_deployments (custom_hostname)")
        
        conn.commit()
        
        print("\n✓ Migration completed successfully!")
        print(f"  - custom_hostname is now nullable")
        print(f"  - pull_zone_bcdn_hostname has unique constraint")
        print(f"  - {count} record(s) migrated")
        
    except Exception as e:
        conn.rollback()
        print(f"\n✗ Migration failed: {e}", file=sys.stderr)
        sys.exit(1)
    finally:
        conn.close()

if __name__ == "__main__":
    migrate()