"""
Migration script to convert is_admin boolean field to role string field
"""
import sqlite3
import os
from pathlib import Path
from sqlalchemy.engine.url import make_url

def migrate_users_table():
    """Add role column to users table and migrate data from is_admin"""
    
    # Get database path from environment or use default
    db_url = os.getenv("DATABASE_URL", "sqlite:///./data/drugs.db")
    
    # Parse SQLite URL to get the file path
    if db_url.startswith("sqlite:///"):
        db_path = db_url.replace("sqlite:///", "")
        # Handle relative paths
        if not db_path.startswith("/"):
            db_path = Path("/app/data") / "drugs.db"
        else:
            db_path = Path(db_path)
    else:
        print(f"Unsupported database URL: {db_url}")
        return
    
    if not db_path.exists():
        print(f"Database does not exist at {db_path}, skipping migration")
        return
    
    print(f"Connecting to database at {db_path}")
    conn = sqlite3.connect(str(db_path))
    cursor = conn.cursor()
    
    try:
        # Check if role column already exists
        cursor.execute("PRAGMA table_info(users)")
        columns = [col[1] for col in cursor.fetchall()]
        
        if "role" in columns:
            print("Role column already exists, skipping migration")
            conn.close()
            return
        
        if not columns:
            print("Users table does not exist yet, skipping migration")
            conn.close()
            return
        
        print("Migrating users table: adding role column...")
        
        # Add role column with default value
        cursor.execute("ALTER TABLE users ADD COLUMN role VARCHAR DEFAULT 'user'")
        
        # Migrate data from is_admin to role
        if "is_admin" in columns:
            print("Migrating data from is_admin to role...")
            cursor.execute("""
                UPDATE users 
                SET role = CASE 
                    WHEN is_admin = 1 THEN 'admin'
                    ELSE 'user'
                END
            """)
            
            # Drop the old is_admin column
            # SQLite doesn't support DROP COLUMN directly in older versions,
            # so we use a workaround
            cursor.execute("ALTER TABLE users RENAME TO users_old")
            cursor.execute("""
                CREATE TABLE users (
                    id INTEGER PRIMARY KEY,
                    username VARCHAR UNIQUE NOT NULL,
                    hashed_password VARCHAR NOT NULL,
                    role VARCHAR NOT NULL DEFAULT 'user',
                    created_at DATETIME
                )
            """)
            cursor.execute("""
                INSERT INTO users (id, username, hashed_password, role, created_at)
                SELECT id, username, hashed_password, role, created_at FROM users_old
            """)
            cursor.execute("DROP TABLE users_old")
            print("Successfully migrated is_admin to role and cleaned up old column")
        
        conn.commit()
        print("Migration completed successfully!")
        
    except sqlite3.OperationalError as e:
        print(f"Migration error: {e}")
        conn.rollback()
        raise
    finally:
        conn.close()

if __name__ == "__main__":
    migrate_users_table()