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

// Define log levels
const levels = {
  error: 0,
  warn: 1,
  info: 2,
  http: 3,
  debug: 4,
};

// Define colors for each level
const colors = {
  error: 'red',
  warn: 'yellow',
  info: 'green',
  http: 'magenta',
  debug: 'white',
};

// Tell winston about our colors
winston.addColors(colors);

// Define which level to log based on environment
const level = () => {
  const env = process.env.NODE_ENV || 'development';
  const isDevelopment = env === 'development';
  return isDevelopment ? 'debug' : 'info';
};

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

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

// Define transports
const transports = [
  // Console output
  new winston.transports.Console({
    format: consoleFormat,
    handleExceptions: true,
  }),
  
  // Error logs - rotate daily
  new DailyRotateFile({
    filename: path.join(__dirname, '../../logs/error-%DATE%.log'),
    datePattern: 'YYYY-MM-DD',
    level: 'error',
    format: logFormat,
    maxSize: '20m',
    maxFiles: '14d',
    handleExceptions: true,
  }),
  
  // Combined logs - rotate daily
  new DailyRotateFile({
    filename: path.join(__dirname, '../../logs/combined-%DATE%.log'),
    datePattern: 'YYYY-MM-DD',
    format: logFormat,
    maxSize: '20m',
    maxFiles: '14d',
  }),
  
  // HTTP logs - rotate daily
  new DailyRotateFile({
    filename: path.join(__dirname, '../../logs/http-%DATE%.log'),
    datePattern: 'YYYY-MM-DD',
    level: 'http',
    format: logFormat,
    maxSize: '20m',
    maxFiles: '7d',
  }),
];

// Create the logger
const logger = winston.createLogger({
  level: level(),
  levels,
  format: logFormat,
  transports,
  exitOnError: false,
});

// Create a stream object for Morgan HTTP logger
logger.stream = {
  write: (message) => {
    logger.http(message.trim());
  },
};

// Helper methods for common logging patterns
logger.logRequest = (req, res, duration) => {
  const logData = {
    method: req.method,
    url: req.url,
    status: res.statusCode,
    duration: `${duration}ms`,
    ip: req.ip,
    userAgent: req.get('user-agent'),
  };
  
  if (res.statusCode >= 500) {
    logger.error('Request failed', logData);
  } else if (res.statusCode >= 400) {
    logger.warn('Request error', logData);
  } else {
    logger.http('Request completed', logData);
  }
};

logger.logEmailSent = (recipient, campaign, status) => {
  logger.info('Email sent', {
    event: 'email_sent',
    recipient,
    campaign,
    status,
    timestamp: new Date().toISOString(),
  });
};

logger.logEmailFailed = (recipient, campaign, error) => {
  logger.error('Email failed', {
    event: 'email_failed',
    recipient,
    campaign,
    error: error.message,
    stack: error.stack,
    timestamp: new Date().toISOString(),
  });
};

logger.logAuth = (action, username, success, ip) => {
  const level = success ? 'info' : 'warn';
  logger[level]('Auth action', {
    event: 'auth',
    action,
    username,
    success,
    ip,
    timestamp: new Date().toISOString(),
  });
};

logger.logCampaignAction = (action, campaignId, userId, ip) => {
  logger.info('Campaign action', {
    event: 'campaign_action',
    action,
    campaignId,
    userId,
    ip,
    timestamp: new Date().toISOString(),
  });
};

logger.logRateLimitHit = (endpoint, ip, limit) => {
  logger.warn('Rate limit hit', {
    event: 'rate_limit',
    endpoint,
    ip,
    limit,
    timestamp: new Date().toISOString(),
  });
};

logger.logHealthCheck = (service, status, details = {}) => {
  const level = status === 'healthy' ? 'info' : 'error';
  logger[level]('Health check', {
    event: 'health_check',
    service,
    status,
    ...details,
    timestamp: new Date().toISOString(),
  });
};

module.exports = logger;