const winston = require('winston');
const DailyRotateFile = require('winston-daily-rotate-file');
const path = require('path');

// Define log format
const logFormat = winston.format.combine(
  winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
  winston.format.errors({ stack: true }),
  winston.format.splat(),
  winston.format.json()
);

// Console format for development
const consoleFormat = winston.format.combine(
  winston.format.colorize(),
  winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
  winston.format.printf(({ timestamp, level, message, stack }) => {
    return stack
      ? `${timestamp} [${level}]: ${message}\n${stack}`
      : `${timestamp} [${level}]: ${message}`;
  })
);

// Create logs directory if it doesn't exist
const fs = require('fs');
const logsDir = path.join(__dirname, '../logs');
if (!fs.existsSync(logsDir)) {
  fs.mkdirSync(logsDir);
}

// Daily rotate file transport for error logs
const errorRotateTransport = new DailyRotateFile({
  filename: path.join(logsDir, 'error-%DATE%.log'),
  datePattern: 'YYYY-MM-DD',
  level: 'error',
  maxSize: '20m',
  maxFiles: '14d',
  format: logFormat
});

// Daily rotate file transport for combined logs
const combinedRotateTransport = new DailyRotateFile({
  filename: path.join(logsDir, 'combined-%DATE%.log'),
  datePattern: 'YYYY-MM-DD',
  maxSize: '20m',
  maxFiles: '30d',
  format: logFormat
});

// Daily rotate file transport for HTTP logs
const httpRotateTransport = new DailyRotateFile({
  filename: path.join(logsDir, 'http-%DATE%.log'),
  datePattern: 'YYYY-MM-DD',
  maxSize: '20m',
  maxFiles: '7d',
  format: logFormat
});

// Create the Winston logger
const logger = winston.createLogger({
  level: process.env.LOG_LEVEL || 'info',
  format: logFormat,
  defaultMeta: { service: 'interview-quiz-api' },
  transports: [
    errorRotateTransport,
    combinedRotateTransport
  ],
  exceptionHandlers: [
    new winston.transports.File({ 
      filename: path.join(logsDir, 'exceptions.log') 
    })
  ],
  rejectionHandlers: [
    new winston.transports.File({ 
      filename: path.join(logsDir, 'rejections.log') 
    })
  ]
});

// Add console transport in development
if (process.env.NODE_ENV !== 'production') {
  logger.add(new winston.transports.Console({
    format: consoleFormat
  }));
}

// HTTP logger for request logging
const httpLogger = winston.createLogger({
  level: 'http',
  format: logFormat,
  defaultMeta: { service: 'interview-quiz-api' },
  transports: [httpRotateTransport]
});

// Stream for Morgan middleware
logger.stream = {
  write: (message) => {
    httpLogger.http(message.trim());
  }
};

// Helper functions for structured logging
logger.logRequest = (req, message) => {
  logger.info(message, {
    method: req.method,
    url: req.originalUrl,
    ip: req.ip,
    userId: req.user?.id,
    userAgent: req.get('user-agent')
  });
};

logger.logError = (error, req = null) => {
  const errorLog = {
    message: error.message,
    stack: error.stack,
    statusCode: error.statusCode || 500
  };

  if (req) {
    errorLog.method = req.method;
    errorLog.url = req.originalUrl;
    errorLog.ip = req.ip;
    errorLog.userId = req.user?.id;
    errorLog.body = req.body;
  }

  logger.error('Application Error', errorLog);
};

logger.logDatabaseQuery = (query, duration) => {
  logger.debug('Database Query', {
    query,
    duration: `${duration}ms`
  });
};

logger.logSecurityEvent = (event, req) => {
  logger.warn('Security Event', {
    event,
    method: req.method,
    url: req.originalUrl,
    ip: req.ip,
    userAgent: req.get('user-agent')
  });
};

module.exports = logger;