import { PrismaClient as CentralPrismaClient } from '.prisma/central';
import knex, { Knex } from 'knex';
import { createDecipheriv } from 'crypto';

// Encryption configuration
const ALGORITHM = 'aes-256-cbc';

/**
 * Decrypt a tenant's database password
 */
function decryptPassword(encryptedPassword: string): string {
  try {
    // Check if password is already plaintext (for legacy/development)
    if (!encryptedPassword.includes(':')) {
      return encryptedPassword;
    }

    const key = Buffer.from(process.env.ENCRYPTION_KEY, 'hex');
    const parts = encryptedPassword.split(':');
    if (parts.length !== 2) {
      throw new Error('Invalid encrypted password format');
    }

    const iv = Buffer.from(parts[0], 'hex');
    const encrypted = parts[1];
    
    const decipher = createDecipheriv(ALGORITHM, key, iv);
    
    let decrypted = decipher.update(encrypted, 'hex', 'utf8');
    decrypted += decipher.final('utf8');
    
    return decrypted;
  } catch (error) {
    console.error('Error decrypting password:', error);
    throw error;
  }
}

/**
 * Create a Knex connection for a specific tenant
 */
function createTenantKnexConnection(tenant: any): Knex {
  const decryptedPassword = decryptPassword(tenant.dbPassword);

  return knex({
    client: 'mysql2',
    connection: {
      host: tenant.dbHost,
      port: tenant.dbPort,
      user: tenant.dbUsername,
      password: decryptedPassword,
      database: tenant.dbName,
    },
    migrations: {
      tableName: 'knex_migrations',
      directory: './migrations/tenant',
    },
  });
}

/**
 * Get migration status for a specific tenant
 */
async function getTenantMigrationStatus(tenant: any): Promise<{
  completed: string[];
  pending: string[];
}> {
  const tenantKnex = createTenantKnexConnection(tenant);
  
  try {
    const [completed, pending] = await tenantKnex.migrate.list();
    return {
      completed: completed[1] || [],
      pending: pending || [],
    };
  } catch (error) {
    throw error;
  } finally {
    await tenantKnex.destroy();
  }
}

/**
 * Check migration status across all tenants
 */
async function checkMigrationStatus() {
  console.log('🔍 Checking migration status for all tenants...\n');
  
  const centralPrisma = new CentralPrismaClient();
  
  try {
    // Fetch all active tenants
    const tenants = await centralPrisma.tenant.findMany({
      where: {
        status: 'ACTIVE',
      },
      orderBy: {
        name: 'asc',
      },
    });

    if (tenants.length === 0) {
      console.log('⚠️  No active tenants found.');
      return;
    }

    console.log(`📋 Found ${tenants.length} active tenant(s)\n`);
    console.log('='.repeat(80));

    let allUpToDate = true;
    const tenantsWithPending: { name: string; pending: string[] }[] = [];

    // Check each tenant
    for (const tenant of tenants) {
      try {
        const status = await getTenantMigrationStatus(tenant);
        
        console.log(`\n📦 ${tenant.name} (${tenant.slug})`);
        console.log(`   Database: ${tenant.dbName}`);
        console.log(`   Completed: ${status.completed.length} migration(s)`);
        
        if (status.pending.length > 0) {
          allUpToDate = false;
          console.log(`   ⚠️  Pending: ${status.pending.length} migration(s)`);
          status.pending.forEach((migration) => {
            console.log(`      - ${migration}`);
          });
          tenantsWithPending.push({
            name: tenant.name,
            pending: status.pending,
          });
        } else {
          console.log(`   ✅ Up to date`);
        }

        // Show last 3 completed migrations
        if (status.completed.length > 0) {
          const recent = status.completed.slice(-3);
          console.log(`   Recent migrations:`);
          recent.forEach((migration) => {
            console.log(`      - ${migration}`);
          });
        }
      } catch (error) {
        console.log(`\n❌ ${tenant.name}: Failed to check status`);
        console.log(`   Error: ${error.message}`);
        allUpToDate = false;
      }
    }

    // Print summary
    console.log('\n' + '='.repeat(80));
    console.log('📊 Summary');
    console.log('='.repeat(80));

    if (allUpToDate) {
      console.log('✅ All tenants are up to date!');
    } else {
      console.log(`⚠️  ${tenantsWithPending.length} tenant(s) have pending migrations:\n`);
      tenantsWithPending.forEach(({ name, pending }) => {
        console.log(`   ${name}: ${pending.length} pending`);
      });
      console.log('\n💡 Run: npm run migrate:all-tenants');
    }
  } catch (error) {
    console.error('❌ Fatal error:', error);
    process.exit(1);
  } finally {
    await centralPrisma.$disconnect();
  }
}

// Run the status check
checkMigrationStatus()
  .then(() => {
    process.exit(0);
  })
  .catch((error) => {
    console.error('Unhandled error:', error);
    process.exit(1);
  });