package web

import (
	"net/http"
	"strconv"
	"time"

	"hearthforge/internal/ratelimit"
)

// Rate limits. The window is one minute unless noted.
var (
	loginLimiter        = ratelimit.New(10, time.Minute)
	registrationLimiter = ratelimit.New(3, time.Hour)
	gitAuthLimiter      = ratelimit.New(10, time.Minute)
	commentLimiter      = ratelimit.New(30, time.Minute)
	reactionLimiter     = ratelimit.New(60, time.Minute)
	issueCreateLimiter  = ratelimit.New(10, time.Minute)
	patchCreateLimiter  = ratelimit.New(10, time.Minute)
	labelWriteLimiter   = ratelimit.New(30, time.Minute)
	uploadLimiter       = ratelimit.New(10, time.Minute)
	passwordLimiter     = ratelimit.New(10, time.Minute)
)

// limitKey is "u<id>" for logged-in users, else the client IP.
func (s *Server) limitKey(r *http.Request) string {
	if u := User(r); u != nil {
		return "u" + strconv.FormatInt(u.ID, 10)
	}
	return ratelimit.ClientIP(r, s.Cfg.TrustedProxy)
}

// allowed reports whether the request may proceed under l. byIP keys on the
// client address instead of the session, for endpoints reachable logged out.
// Handlers that answer in JSON call this and write their own 429.
func (s *Server) allowed(r *http.Request, l *ratelimit.Limiter, byIP bool) bool {
	if s.Cfg.RateLimitDisabled {
		return true
	}
	key := s.limitKey(r)
	if byIP {
		key = ratelimit.ClientIP(r, s.Cfg.TrustedProxy)
	}
	return l.Allow(key)
}

// limited writes a plain-text 429 when the request exceeded l. Callers return
// immediately when it reports true.
func (s *Server) limited(w http.ResponseWriter, r *http.Request, l *ratelimit.Limiter, byIP bool) bool {
	if s.allowed(r, l, byIP) {
		return false
	}
	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
	w.WriteHeader(http.StatusTooManyRequests)
	w.Write([]byte("Too many requests. Please slow down."))
	return true
}