import { RateLimiterMemory } from 'rate-limiter-flexible'

// Strict rate limit for auth endpoints
const authLimiter = new RateLimiterMemory({
  points: 5,     // 5 requests
  duration: 300, // per 5 minutes
  keyPrefix: 'rl_auth'
})

// Moderate rate limit for payment endpoints
const paymentLimiter = new RateLimiterMemory({
  points: 10,
  duration: 60,
  keyPrefix: 'rl_payment'
})

// Light rate limit for upload endpoints
const uploadLimiter = new RateLimiterMemory({
  points: 10,
  duration: 60,
  keyPrefix: 'rl_upload'
})

// General API rate limit
const generalLimiter = new RateLimiterMemory({
  points: 100,
  duration: 60,
  keyPrefix: 'rl_general'
})

function getClientIp(event) {
  return getHeader(event, 'x-forwarded-for')?.split(',')[0]?.trim()
    || getHeader(event, 'x-real-ip')
    || event.node.req.socket.remoteAddress
    || 'unknown'
}

const AUTH_PATHS = new Set(['/api/auth/login', '/api/auth/verify'])
const PAYMENT_PREFIXES = ['/api/helcim/']
const UPLOAD_PATHS = new Set(['/api/upload/image'])

export default defineEventHandler(async (event) => {
  const path = getRequestURL(event).pathname
  if (!path.startsWith('/api/')) return

  const ip = getClientIp(event)

  try {
    if (AUTH_PATHS.has(path)) {
      await authLimiter.consume(ip)
    } else if (PAYMENT_PREFIXES.some(p => path.startsWith(p))) {
      await paymentLimiter.consume(ip)
    } else if (UPLOAD_PATHS.has(path)) {
      await uploadLimiter.consume(ip)
    } else {
      await generalLimiter.consume(ip)
    }
  } catch (rateLimiterRes) {
    setHeader(event, 'Retry-After', Math.ceil(rateLimiterRes.msBeforeNext / 1000))
    throw createError({
      statusCode: 429,
      statusMessage: 'Too many requests. Please try again later.'
    })
  }
})
