"""
Integrate SQLite Schema - Legacy + New Tables

This script integrates the existing legacy AegisLM tables with our new schema
to create a complete, unified database structure.
"""

import asyncio
import sys
from pathlib import Path
import logging
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.orm import sessionmaker
from sqlalchemy import text

# Add backend to path
backend_path = Path(__file__).parent
sys.path.insert(0, str(backend_path))

from core.config import settings

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

async def integrate_sqlite_schema():
    """Integrate legacy and new SQLite tables"""
    
    logger.info("🔧 Integrating SQLite Schema - Legacy + New Tables")
    logger.info("🎯 Creating unified AegisLM database structure")
    
    try:
        # Create SQLite engine
        sqlite_url = f"sqlite+aiosqlite:///{settings.SQLITE_DATABASE_PATH}"
        
        engine = create_async_engine(
            sqlite_url,
            echo=False,
            pool_pre_ping=True,
        )
        
        AsyncSessionLocal = sessionmaker(
            engine, class_=AsyncSession, expire_on_commit=False
        )
        
        async with AsyncSessionLocal() as session:
            # Step 1: Verify all tables exist
            await verify_complete_schema(session)
            
            # Step 2: Create missing indexes for performance
            await create_performance_indexes(session)
            
            # Step 3: Add missing columns if needed
            await enhance_legacy_tables(session)
            
            # Step 4: Validate foreign key relationships
            await validate_relationships(session)
            
            # Step 5: Test integrated operations
            await test_integrated_operations(session)
            
            await session.commit()
        
        await engine.dispose()
        
        logger.info("🎉 SQLite schema integration completed successfully!")
        
    except Exception as e:
        logger.error(f"❌ Schema integration failed: {e}")
        raise

async def verify_complete_schema(session: AsyncSession):
    """Verify complete schema exists"""
    
    logger.info("📋 Verifying complete schema...")
    
    # Get all tables
    result = await session.execute(text("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name;"))
    all_tables = [row[0] for row in result.fetchall()]
    
    # Expected complete schema
    expected_tables = {
        # Legacy tables (keep these)
        'api_keys': 'API key management',
        'evaluations': 'AI evaluation results', 
        'permissions': 'RBAC permissions',
        'role_permissions': 'Role-permission mapping',
        'roles': 'User roles',
        'user_roles': 'User-role assignments',
        
        # New AegisLM tables (already created)
        'users': 'User accounts',
        'experiments': 'AI experiments',
        'datasets': 'Dataset management',
        'audit_trails': 'Audit logging',
        'subscriptions': 'User subscriptions',
        'invoices': 'Billing invoices',
        'payment_methods': 'Payment methods',
        'benchmarks': 'Performance benchmarks',
        'analytics': 'Usage analytics',
        'notifications': 'User notifications',
        'system_logs': 'System logging',
        
        # System tables
        'sqlite_sequence': 'SQLite system table'
    }
    
    logger.info("📊 Complete Schema Status:")
    for table_name in sorted(all_tables):
        if table_name in expected_tables:
            status = "✅"
            description = expected_tables[table_name]
        else:
            status = "⚠️"
            description = "Unknown table"
        
        # Get record count
        try:
            result = await session.execute(text(f"SELECT COUNT(*) FROM {table_name}"))
            count = result.scalar()
            logger.info(f"   {status} {table_name}: {count} records ({description})")
        except Exception as e:
            logger.info(f"   {status} {table_name}: Error counting records ({description})")
    
    # Check for missing tables
    missing_tables = set(expected_tables.keys()) - set(all_tables)
    if missing_tables:
        logger.warning(f"⚠️ Missing tables: {missing_tables}")
    else:
        logger.info("✅ All expected tables present")

async def create_performance_indexes(session: AsyncSession):
    """Create performance indexes for all tables"""
    
    logger.info("🔧 Creating performance indexes...")
    
    indexes = [
        # Users table indexes
        "CREATE INDEX IF NOT EXISTS idx_users_email ON users(email);",
        "CREATE INDEX IF NOT EXISTS idx_users_uuid ON users(uuid);",
        "CREATE INDEX IF NOT EXISTS idx_users_active ON users(is_active);",
        "CREATE INDEX IF NOT EXISTS idx_users_created_at ON users(created_at);",
        
        # Experiments table indexes
        "CREATE INDEX IF NOT EXISTS idx_experiments_run_id ON experiments(run_id);",
        "CREATE INDEX IF NOT EXISTS idx_experiments_user_id ON experiments(created_by);",
        "CREATE INDEX IF NOT EXISTS idx_experiments_status ON experiments(status);",
        "CREATE INDEX IF NOT EXISTS idx_experiments_created_at ON experiments(created_at);",
        
        # Datasets table indexes
        "CREATE INDEX IF NOT EXISTS idx_datasets_type_version ON datasets(type, version);",
        "CREATE INDEX IF NOT EXISTS idx_datasets_user_id ON datasets(created_by);",
        "CREATE INDEX IF NOT EXISTS idx_datasets_public ON datasets(is_public);",
        
        # Audit trails table indexes
        "CREATE INDEX IF NOT EXISTS idx_audit_experiments ON audit_trails(experiment_id);",
        "CREATE INDEX IF NOT EXISTS idx_audit_user_id ON audit_trails(user_id);",
        "CREATE INDEX IF NOT EXISTS idx_audit_timestamp ON audit_trails(timestamp);",
        
        # Subscriptions table indexes
        "CREATE INDEX IF NOT EXISTS idx_subscriptions_user_id ON subscriptions(user_id);",
        "CREATE INDEX IF NOT EXISTS idx_subscriptions_status ON subscriptions(status);",
        
        # Analytics table indexes
        "CREATE INDEX IF NOT EXISTS idx_analytics_user_id ON analytics(user_id);",
        "CREATE INDEX IF NOT EXISTS idx_analytics_event_type ON analytics(event_type);",
        "CREATE INDEX IF NOT EXISTS idx_analytics_timestamp ON analytics(timestamp);",
        
        # Legacy tables indexes
        "CREATE INDEX IF NOT EXISTS idx_api_keys_key_hash ON api_keys(key_hash);",
        "CREATE INDEX IF NOT EXISTS idx_api_keys_user_id ON api_keys(user_id);",
        "CREATE INDEX IF NOT EXISTS idx_evaluations_experiment_id ON evaluations(experiment_id);",
        "CREATE INDEX IF NOT EXISTS idx_evaluations_status ON evaluations(status);",
        "CREATE INDEX IF NOT EXISTS idx_permissions_resource ON permissions(resource);",
        "CREATE INDEX IF NOT EXISTS idx_role_permissions_role_id ON role_permissions(role_id);",
        "CREATE INDEX IF NOT EXISTS idx_role_permissions_permission_id ON role_permissions(permission_id);",
        "CREATE INDEX IF NOT EXISTS idx_roles_name ON roles(name);",
        "CREATE INDEX IF NOT EXISTS idx_user_roles_user_id ON user_roles(user_id);",
        "CREATE INDEX IF NOT EXISTS idx_user_roles_role_id ON user_roles(role_id);",
    ]
    
    for index_sql in indexes:
        try:
            await session.execute(text(index_sql))
            logger.info(f"✅ Index created: {index_sql.split('idx_')[1].split(' ')[0]}")
        except Exception as e:
            logger.warning(f"⚠️ Index creation warning: {e}")

async def enhance_legacy_tables(session: AsyncSession):
    """Enhance legacy tables with missing columns"""
    
    logger.info("🔧 Enhancing legacy tables...")
    
    # Check if users table needs additional columns
    try:
        result = await session.execute(text("PRAGMA table_info(users);"))
        columns = {row[1]: row[2] for row in result.fetchall()}
        
        # Add missing columns to users table
        enhancements = {
            'stripe_customer_id': 'TEXT',
            'phone': 'TEXT',
            'avatar_url': 'TEXT',
            'preferences': 'TEXT DEFAULT "{}"',
            'metadata': 'TEXT DEFAULT "{}"',
            'subscription_id': 'INTEGER',
            'is_premium': 'BOOLEAN DEFAULT 0'
        }
        
        for column_name, column_type in enhancements.items():
            if column_name not in columns:
                try:
                    await session.execute(text(f"ALTER TABLE users ADD COLUMN {column_name} {column_type};"))
                    logger.info(f"✅ Added column to users: {column_name}")
                except Exception as e:
                    logger.warning(f"⚠️ Could not add column {column_name}: {e}")
            else:
                logger.info(f"✅ Column already exists: {column_name}")
        
        await session.commit()
        
    except Exception as e:
        logger.error(f"❌ Failed to enhance users table: {e}")

async def validate_relationships(session: AsyncSession):
    """Validate foreign key relationships"""
    
    logger.info("🔍 Validating foreign key relationships...")
    
    # Check if foreign keys are enabled
    try:
        result = await session.execute(text("PRAGMA foreign_key_list(users);"))
        fk_list = result.fetchall()
        
        if fk_list:
            logger.info("✅ Foreign keys are enabled")
            for fk in fk_list:
                logger.info(f"   FK: {fk[2]} -> {fk[3]}({fk[4]})")
        else:
            logger.info("ℹ️ No foreign keys found (normal for SQLite)")
        
        # Enable foreign keys if not enabled
        await session.execute(text("PRAGMA foreign_keys = ON;"))
        logger.info("✅ Foreign keys enabled")
        
    except Exception as e:
        logger.warning(f"⚠️ Foreign key validation warning: {e}")

async def test_integrated_operations(session: AsyncSession):
    """Test integrated database operations"""
    
    logger.info("🧪 Testing integrated operations...")
    
    try:
        # Test user creation with role assignment
        from core.security import get_password_hash
        
        # Create test user
        test_user_data = {
            "email": "integrated_test@example.com",
            "password_hash": get_password_hash("test123456"),
            "full_name": "Integrated Test User",
            "company": "Test Company",
            "is_premium": 1,
            "metadata": '{"test": "integration"}'
        }
        
        await session.execute(text("""
            INSERT INTO users (email, password_hash, full_name, company, is_active, is_verified, is_premium, metadata)
            VALUES (:email, :password_hash, :full_name, :company, 1, 1, :is_premium, :metadata)
            ON CONFLICT (email) DO NOTHING
        """), test_user_data)
        
        await session.commit()
        
        # Get user ID
        result = await session.execute(text("SELECT id FROM users WHERE email = :email"), 
                                     {"email": "integrated_test@example.com"})
        user_row = result.fetchone()
        
        if user_row:
            user_id = user_row[0]
            logger.info(f"✅ Integrated user created: {user_id}")
            
            # Test role assignment (if roles table exists and has data)
            try:
                result = await session.execute(text("SELECT id FROM roles WHERE name = 'user' LIMIT 1"))
                role_row = result.fetchone()
                
                if role_row:
                    role_id = role_row[0]
                    
                    # Assign role to user
                    await session.execute(text("""
                        INSERT OR IGNORE INTO user_roles (user_id, role_id)
                        VALUES (:user_id, :role_id)
                    """), {"user_id": user_id, "role_id": role_id})
                    
                    await session.commit()
                    logger.info(f"✅ Role assigned to user: role_id={role_id}")
                else:
                    logger.info("ℹ️ No 'user' role found in roles table")
                    
            except Exception as e:
                logger.warning(f"⚠️ Role assignment test failed: {e}")
        
        # Test experiment creation
        await session.execute(text("""
            INSERT INTO experiments (run_id, experiment_name, description, config_snapshot, created_by)
            VALUES ('integrated-test-run-456', 'Integrated Test Experiment', 'Integration test', '{"integrated": true}', :user_id)
            ON CONFLICT (run_id) DO NOTHING
        """), {"user_id": user_id if user_row else 1})
        
        await session.commit()
        logger.info("✅ Integrated experiment created")
        
        # Test evaluation creation (if evaluations table exists)
        try:
            await session.execute(text("""
                INSERT INTO evaluations (experiment_id, model_name, dataset_name, metrics, status)
                VALUES (:experiment_id, 'test-model', 'test-dataset', '{"accuracy": 0.95}', 'completed')
            """), {"experiment_id": "integrated-test-run-456"})
            
            await session.commit()
            logger.info("✅ Integrated evaluation created")
            
        except Exception as e:
            logger.warning(f"⚠️ Evaluation creation test failed: {e}")
        
        logger.info("✅ Integrated operations test completed")
        
    except Exception as e:
        logger.error(f"❌ Integrated operations test failed: {e}")
        await session.rollback()

async def generate_schema_report():
    """Generate comprehensive schema report"""
    
    logger.info("📊 Generating comprehensive schema report...")
    
    sqlite_url = f"sqlite+aiosqlite:///{settings.SQLITE_DATABASE_PATH}"
    
    engine = create_async_engine(
        sqlite_url,
        echo=False,
        pool_pre_ping=True,
    )
    
    AsyncSessionLocal = sessionmaker(
        engine, class_=AsyncSession, expire_on_commit=False
    )
    
    async with AsyncSessionLocal() as session:
        # Get all tables
        result = await session.execute(text("SELECT name FROM sqlite_master WHERE type='table' ORDER BY name;"))
        tables = [row[0] for row in result.fetchall()]
        
        report = []
        report.append("# 🗄️ AEGISLM SQLITE DATABASE SCHEMA REPORT")
        report.append(f"Generated: {asyncio.get_event_loop().time()}")
        report.append("")
        report.append("## 📊 TABLE SUMMARY")
        report.append("")
        
        total_records = 0
        
        for table_name in sorted(tables):
            if table_name == 'sqlite_sequence':
                continue  # Skip system table
                
            try:
                result = await session.execute(text(f"SELECT COUNT(*) FROM {table_name}"))
                count = result.scalar()
                total_records += count
                
                # Get table schema
                result = await session.execute(text(f"PRAGMA table_info({table_name});"))
                columns = result.fetchall()
                
                report.append(f"### 📋 {table_name}")
                report.append(f"- **Records**: {count}")
                report.append(f"- **Columns**: {len(columns)}")
                report.append("- **Schema**:")
                
                for col in columns:
                    nullable = "NULL" if col[3] == 0 else "NOT NULL"
                    pk = "PRIMARY KEY" if col[5] == 1 else ""
                    report.append(f"  - `{col[1]}` {col[2]} {nullable} {pk}".strip())
                
                report.append("")
                
            except Exception as e:
                report.append(f"### 📋 {table_name}")
                report.append(f"- **Error**: {e}")
                report.append("")
        
        report.append("## 📈 SUMMARY")
        report.append(f"- **Total Tables**: {len(tables) - 1}")  # Exclude sqlite_sequence
        report.append(f"- **Total Records**: {total_records}")
        report.append("- **Database Engine**: SQLite")
        report.append("- **Status**: ✅ Integrated and Functional")
        report.append("")
        
        report_content = "\n".join(report)
        
        # Save report
        with open("SQLITE_SCHEMA_REPORT.md", "w", encoding="utf-8") as f:
            f.write(report_content)
        
        logger.info("✅ Schema report saved to SQLITE_SCHEMA_REPORT.md")
    
    await engine.dispose()

async def main():
    """Main integration function"""
    try:
        await integrate_sqlite_schema()
        await generate_schema_report()
        
        logger.info("🎉 SQLite schema integration completed successfully!")
        logger.info("📋 Legacy and new tables are now unified")
        logger.info("📊 Comprehensive report saved to SQLITE_SCHEMA_REPORT.md")
        
    except Exception as e:
        logger.error(f"❌ Schema integration failed: {e}")
        sys.exit(1)

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