/**
 * Audit Log Usage Examples
 *
 * This file demonstrates how to use the audit_logs table
 * in the Telegram Bot Workers codebase.
 */

import { Env } from './types';

// =============================================================================
// Helper Function: Create Audit Log Entry
// =============================================================================

async function createAuditLog(
  env: Env,
  params: {
    userId?: number;
    telegramId?: string;
    action: string;
    resourceType?: string;
    resourceId?: number;
    details?: object;
    ipAddress?: string;
    userAgent?: string;
  }
): Promise<void> {
  const detailsJson = params.details ? JSON.stringify(params.details) : null;

  await env.DB.prepare(`
    INSERT INTO audit_logs (
      user_id, telegram_id, action, resource_type, resource_id, details, ip_address, user_agent
    ) VALUES (?, ?, ?, ?, ?, ?, ?, ?)
  `).bind(
    params.userId ?? null,
    params.telegramId ?? null,
    params.action,
    params.resourceType ?? null,
    params.resourceId ?? null,
    detailsJson,
    params.ipAddress ?? null,
    params.userAgent ?? null
  ).run();
}

// =============================================================================
// Example 1: Deposit Confirmation Logging
// =============================================================================

async function logDepositConfirmation(
  env: Env,
  userId: number,
  telegramId: string,
  transactionId: number,
  amount: number,
  depositorName: string,
  bankNotificationId?: number
): Promise<void> {
  await createAuditLog(env, {
    userId,
    telegramId,
    action: 'deposit_confirmed',
    resourceType: 'deposit_transaction',
    resourceId: transactionId,
    details: {
      amount,
      depositor_name: depositorName,
      matched_bank_notification_id: bankNotificationId,
      balance_change: amount
    }
  });

  console.log(`[AuditLog] Deposit confirmed: ${amount}원 for user ${telegramId}`);
}

// Usage in deposit-agent.ts or index.ts:
/*
// After confirming deposit
await logDepositConfirmation(
  env,
  userId,
  telegramId,
  transactionId,
  5000,
  '홍길동',
  bankNotificationId
);
*/

// =============================================================================
// Example 2: Domain Registration Logging
// =============================================================================

async function logDomainRegistration(
  env: Env,
  userId: number,
  telegramId: string,
  domainId: number,
  domain: string,
  price: number,
  balanceBefore: number,
  balanceAfter: number
): Promise<void> {
  await createAuditLog(env, {
    userId,
    telegramId,
    action: 'domain_registered',
    resourceType: 'user_domains',
    resourceId: domainId,
    details: {
      domain,
      price,
      balance_before: balanceBefore,
      balance_after: balanceAfter,
      balance_change: -price
    }
  });

  console.log(`[AuditLog] Domain registered: ${domain} for ${price}원`);
}

// Usage in domain-register.ts:
/*
// After successful registration
await logDomainRegistration(
  env,
  userId,
  telegramId,
  domainId,
  'example.com',
  15000,
  50000,
  35000
);
*/

// =============================================================================
// Example 3: Balance Change Logging
// =============================================================================

async function logBalanceChange(
  env: Env,
  userId: number,
  telegramId: string,
  changeType: 'deposit' | 'withdrawal' | 'refund',
  amount: number,
  balanceBefore: number,
  balanceAfter: number,
  reason: string,
  relatedResourceType?: string,
  relatedResourceId?: number
): Promise<void> {
  await createAuditLog(env, {
    userId,
    telegramId,
    action: `balance_${changeType}`,
    resourceType: relatedResourceType,
    resourceId: relatedResourceId,
    details: {
      amount,
      balance_before: balanceBefore,
      balance_after: balanceAfter,
      balance_change: changeType === 'withdrawal' ? -amount : amount,
      reason
    }
  });

  console.log(`[AuditLog] Balance ${changeType}: ${amount}원, new balance: ${balanceAfter}원`);
}

// Usage example:
/*
// After domain registration (withdrawal)
await logBalanceChange(
  env,
  userId,
  telegramId,
  'withdrawal',
  15000,
  50000,
  35000,
  'Domain registration: example.com',
  'user_domains',
  domainId
);
*/

// =============================================================================
// Example 4: Failed Operations Logging
// =============================================================================

async function logFailedOperation(
  env: Env,
  telegramId: string,
  action: string,
  reason: string,
  details?: object
): Promise<void> {
  await createAuditLog(env, {
    telegramId,
    action: `${action}_failed`,
    details: {
      reason,
      ...details
    }
  });

  console.error(`[AuditLog] Operation failed: ${action} - ${reason}`);
}

// Usage example:
/*
// When deposit confirmation fails
await logFailedOperation(
  env,
  telegramId,
  'deposit_confirm',
  'Transaction not found',
  { transaction_id: 123 }
);
*/

// =============================================================================
// Example 5: Admin Actions Logging
// =============================================================================

async function logAdminAction(
  env: Env,
  adminTelegramId: string,
  action: string,
  targetUserId?: number,
  targetTelegramId?: string,
  details?: object
): Promise<void> {
  await createAuditLog(env, {
    telegramId: adminTelegramId,
    action: `admin_${action}`,
    details: {
      target_user_id: targetUserId,
      target_telegram_id: targetTelegramId,
      admin_telegram_id: adminTelegramId,
      ...details
    }
  });

  console.log(`[AuditLog] Admin action: ${action} by ${adminTelegramId}`);
}

// Usage example:
/*
// When admin manually confirms deposit
await logAdminAction(
  env,
  adminTelegramId,
  'manual_deposit_confirm',
  userId,
  userTelegramId,
  {
    transaction_id: transactionId,
    amount: 5000,
    reason: 'Manual verification'
  }
);
*/

// =============================================================================
// Query Examples: Retrieve Audit Logs
// =============================================================================

// Get user's recent activity
async function getUserActivity(
  env: Env,
  telegramId: string,
  limit: number = 10
) {
  const logs = await env.DB.prepare(`
    SELECT action, resource_type, details, created_at
    FROM audit_logs
    WHERE telegram_id = ?
    ORDER BY created_at DESC
    LIMIT ?
  `).bind(telegramId, limit).all();

  return logs.results;
}

// Get all deposit confirmations today
async function getTodayDepositConfirmations(env: Env) {
  const logs = await env.DB.prepare(`
    SELECT
      a.telegram_id,
      a.details,
      a.created_at,
      u.username
    FROM audit_logs a
    LEFT JOIN users u ON a.user_id = u.id
    WHERE a.action = 'deposit_confirmed'
      AND date(a.created_at) = date('now')
    ORDER BY a.created_at DESC
  `).all();

  return logs.results;
}

// Get suspicious activity (multiple failed attempts)
async function getSuspiciousActivity(env: Env) {
  const suspicious = await env.DB.prepare(`
    SELECT
      telegram_id,
      action,
      COUNT(*) as attempts,
      MAX(created_at) as last_attempt
    FROM audit_logs
    WHERE action LIKE '%_failed'
      AND created_at > datetime('now', '-1 hour')
    GROUP BY telegram_id, action
    HAVING attempts > 5
    ORDER BY attempts DESC
  `).all();

  return suspicious.results;
}

// Get user's balance history from audit logs
async function getBalanceHistory(
  env: Env,
  telegramId: string,
  limit: number = 20
) {
  const history = await env.DB.prepare(`
    SELECT
      action,
      json_extract(details, '$.amount') as amount,
      json_extract(details, '$.balance_before') as balance_before,
      json_extract(details, '$.balance_after') as balance_after,
      json_extract(details, '$.reason') as reason,
      created_at
    FROM audit_logs
    WHERE telegram_id = ?
      AND action LIKE 'balance_%'
    ORDER BY created_at DESC
    LIMIT ?
  `).bind(telegramId, limit).all();

  return history.results;
}

// Get all domain registrations
async function getDomainRegistrations(env: Env, days: number = 30) {
  const registrations = await env.DB.prepare(`
    SELECT
      a.telegram_id,
      u.username,
      json_extract(a.details, '$.domain') as domain,
      json_extract(a.details, '$.price') as price,
      a.created_at
    FROM audit_logs a
    LEFT JOIN users u ON a.user_id = u.id
    WHERE a.action = 'domain_registered'
      AND a.created_at > datetime('now', '-' || ? || ' days')
    ORDER BY a.created_at DESC
  `).bind(days).all();

  return registrations.results;
}

// Get admin actions
async function getAdminActions(env: Env, days: number = 7) {
  const actions = await env.DB.prepare(`
    SELECT
      action,
      details,
      created_at
    FROM audit_logs
    WHERE action LIKE 'admin_%'
      AND created_at > datetime('now', '-' || ? || ' days')
    ORDER BY created_at DESC
  `).bind(days).all();

  return actions.results;
}

// =============================================================================
// Export for use in main codebase
// =============================================================================

export {
  createAuditLog,
  logDepositConfirmation,
  logDomainRegistration,
  logBalanceChange,
  logFailedOperation,
  logAdminAction,
  getUserActivity,
  getTodayDepositConfirmations,
  getSuspiciousActivity,
  getBalanceHistory,
  getDomainRegistrations,
  getAdminActions
};

// =============================================================================
// Integration Example: Add to deposit-agent.ts
// =============================================================================

/*
// In deposit-agent.ts, after confirming deposit:

import { logDepositConfirmation, logBalanceChange } from './audit-log-helpers';

// ... existing code ...

// After updating balance
await env.DB.prepare(
  'UPDATE user_deposits SET balance = balance + ? WHERE user_id = ?'
).bind(amount, userId).run();

// Log the deposit confirmation
await logDepositConfirmation(
  env,
  userId,
  telegramId,
  transactionId,
  amount,
  depositorName,
  bankNotificationId
);

// Log the balance change
await logBalanceChange(
  env,
  userId,
  telegramId,
  'deposit',
  amount,
  balanceBefore,
  balanceBefore + amount,
  `Deposit from ${depositorName}`,
  'deposit_transaction',
  transactionId
);
*/

// =============================================================================
// Integration Example: Add to domain-register.ts
// =============================================================================

/*
// In domain-register.ts, after successful registration:

import { logDomainRegistration, logBalanceChange } from './audit-log-helpers';

// ... existing code ...

// After registering domain
await env.DB.prepare(
  'UPDATE user_deposits SET balance = balance - ? WHERE user_id = ?'
).bind(price, userId).run();

// Log the domain registration
await logDomainRegistration(
  env,
  userId,
  telegramId,
  domainId,
  domain,
  price,
  balanceBefore,
  balanceBefore - price
);

// Log the balance withdrawal
await logBalanceChange(
  env,
  userId,
  telegramId,
  'withdrawal',
  price,
  balanceBefore,
  balanceBefore - price,
  `Domain registration: ${domain}`,
  'user_domains',
  domainId
);
*/