const rateLimit = require('express-rate-limit');

/**
 * Strict rate limiter for authentication endpoints
 * 5 requests per 15 minutes
 */
const authLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 5,
  message: { error: 'Too many authentication attempts, please try again later' },
  standardHeaders: true,
  legacyHeaders: false,
});

/**
 * Moderate rate limiter for data modification endpoints
 * (Create, Update, Delete operations)
 * 30 requests per 15 minutes
 */
const modifyLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 30,
  message: { error: 'Too many modification requests, please slow down' },
  standardHeaders: true,
  legacyHeaders: false,
});

/**
 * Lenient rate limiter for read operations
 * 100 requests per 15 minutes
 */
const readLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100,
  message: { error: 'Too many requests, please slow down' },
  standardHeaders: true,
  legacyHeaders: false,
});

/**
 * Moderate rate limiter for resource-intensive operations
 * (Streaming, backup, file uploads)
 * Increased to 1000/min to support HLS streaming which makes many segment requests
 */
const heavyLimiter = rateLimit({
  windowMs: 60 * 1000, // 1 minute
  max: 1000,
  message: { error: 'Too many resource-intensive requests, please wait' },
  standardHeaders: true,
  legacyHeaders: false,
});

/**
 * Very strict limiter for backup/restore operations
 * 3 requests per hour
 */
const backupLimiter = rateLimit({
  windowMs: 60 * 60 * 1000, // 1 hour
  max: 3,
  message: { error: 'Too many backup operations, please wait before trying again' },
  standardHeaders: true,
  legacyHeaders: false,
});

/**
 * General API rate limiter
 * 200 requests per 15 minutes
 */
const apiLimiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 200,
  message: { error: 'Too many API requests, please try again later' },
  standardHeaders: true,
  legacyHeaders: false,
});

module.exports = {
  authLimiter,
  modifyLimiter,
  readLimiter,
  heavyLimiter,
  backupLimiter,
  apiLimiter
};