import { GELFLogger } from '@walsys/cloudflare_worker-gelf_logger';

export default {
  async fetch(request, env, ctx) {
    // Initialize logger with env and request
    const logger = new GELFLogger({ env, request });

    // Log at different levels
    logger.info('User login successful');
    logger.error('Database connection failed');
    logger.debug('Cache miss for key: user-123');

    // Ensure logs are sent before worker terminates
    ctx.waitUntil(logger.flush());

    return new Response('OK');
  }
};

const logger = new GELFLogger({
  // Required: Cloudflare env object
  env: env,

  // Optional: Cloudflare Request object (extracts colo, IP, geo data)
  request: request,

  // Optional: Override GELF endpoint
  endpoint: 'https://custom-graylog.com/gelf',

  // Optional: Override host identifier
  host: 'custom-worker-name',

  // Optional: Facility name
  facility: 'worker',

  // Optional: Global fields added to all logs
  globalFields: {
    app_version: '1.2.3',
    team: 'backend'
  },

  // Optional: Minimum log level (default: INFO)
  minLevel: GELFLogger.LEVELS.DEBUG,

  // Optional: Also log to console (default: true)
  consoleLog: true,

  // Optional: Request timeout in milliseconds (default: 5000)
  timeout: 3000,

  // Optional: Max failed messages to track (default: 50)
  maxFailedMessages: 100
});

logger.emergency('System is down');        // Level 0 - System unusable
logger.alert('Immediate action required'); // Level 1 - Take action immediately
logger.critical('Critical database error'); // Level 2 - Critical conditions
logger.error('Failed to process payment');  // Level 3 - Error conditions
logger.warning('High memory usage');        // Level 4 - Warning conditions
logger.notice('Config file reloaded');      // Level 5 - Normal but significant
logger.info('User logged in');              // Level 6 - Informational
logger.debug('Cache lookup: user-123');     // Level 7 - Debug messages

// Aliases
logger.warn('Same as warning');             // Alias for warning
logger.log('Same as info');                 // Alias for info

logger.info('User authenticated successfully');
logger.error('Payment processing failed', null, {
  user_id: '12345',
  amount: 99.99,
  payment_method: 'stripe'
});

logger.warning(
  'High memory usage detected',
  'Memory usage is above 80% threshold. Consider scaling.',
  { memory_percent: 85, threshold: 80 }
);

try {
  await processPayment();
} catch (error) {
  logger.exception(error, {
    user_id: userId,
    context: 'payment-processing'
  });
}

// Create a child logger with additional context
const requestLogger = logger.child({
  request_id: crypto.randomUUID(),
  user_id: '12345'
});

// All logs from this child include request_id and user_id
requestLogger.info('Processing user request');
requestLogger.debug('Fetching user data from database');

logger.info('API request completed', null, {
  method: 'POST',
  path: '/api/users',
  status_code: 201,
  duration_ms: 145,
  user_agent: request.headers.get('user-agent')
});

// Only logs at INFO level and below
const logger = new GELFLogger({
  env,
  minLevel: GELFLogger.LEVELS.INFO
});

logger.debug('This will be skipped');  // Skipped
logger.info('This will be logged');     // Logged

const childLogger = logger.child({ request_id: '12345' });

ctx.waitUntil(logger.flush());

const stats = logger.getStats();
// { sent: 150, failed: 2, skipped: 10, failedMessagesCount: 2 }

const failures = logger.getFailedMessages(5); // Last 5 failures

const summary = logger.getFailureSummary();
// { no_endpoint: 0, http_error: 1, timeout: 1, network_error: 0, other: 0 }

export default {
  async fetch(request, env, ctx) {
    const logger = new GELFLogger({ env, request });

    // Your code here
    logger.info('Processing request');

    // Critical: Ensure logs are sent
    ctx.waitUntil(logger.flush());

    return new Response('OK');
  }
};

const requestLogger = logger.child({
  request_id: crypto.randomUUID(),
  path: new URL(request.url).pathname
});

const logger = new GELFLogger({
  env,
  minLevel: env.ENVIRONMENT === 'production'
    ? GELFLogger.LEVELS.INFO
    : GELFLogger.LEVELS.DEBUG
});

logger.error('Database query failed', null, {
  query: 'SELECT * FROM users',
  table: 'users',
  error_code: 'ER_NO_SUCH_TABLE',
  duration_ms: 150
});

try {
  await riskyOperation();
} catch (error) {
  logger.exception(error, { operation: 'user-update' });
  throw error; // Re-throw if needed
}

const logger = new GELFLogger({ env, request });
// Logs automatically include _colo field (e.g., "SFO", "LAX", "LHR")

const logger = new GELFLogger({ env, request });
// Logs include _latitude and _longitude from request.cf

const logger = new GELFLogger({ env, request });
// Logs include _client_ip from cf-connecting-ip header

const stats = logger.getStats();
const summary = logger.getFailureSummary();
console.log('Stats:', stats);
console.log('Failure reasons:', summary);

const logger = new GELFLogger({
  env,
  minLevel: GELFLogger.LEVELS.DEBUG // Include debug logs
});