package main

import (
	"flag"
	"fmt"
	"log"
	"net/http"

	"aijianzhan/gateway/internal/config"
	"aijianzhan/gateway/internal/jwtmw"
	"aijianzhan/gateway/internal/proxy"
	"aijianzhan/gateway/internal/ratelimit"

	"github.com/zeromicro/go-zero/core/conf"
)

var configFile = flag.String("f", "etc/gateway.yaml", "config file")

func main() {
	flag.Parse()
	var c config.Config
	conf.MustLoad(*configFile, &c)

	dir, err := proxy.New(c.PlatformURL, c.AIURL, c.ProxyTimeoutSec)
	if err != nil {
		log.Fatal(err)
	}
	limiter := ratelimit.New(c.RateLimitPerMin)
	h := limiter.Middleware(dir.Handler())

	if c.JWTEnable {
		secret := c.JWTSecret
		if secret == "" {
			secret = "dev-only-change-me"
		}
		public := []string{
			"/gateway/health",
			"/api/v1/auth/login",
			"/api/v1/auth/register",
			"/api/v1/auth/token",
			"/api/v1/auth/agent/register",
			"/api/v1/meta/",
			"/api/v1/public/",
			"/ai/",
			"/ai",
		}
		h = jwtmw.Middleware(secret, public)(h)
	}

	mux := http.NewServeMux()
	mux.HandleFunc("/gateway/health", dir.Health)
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		if c.CorsEnable {
			origin := r.Header.Get("Origin")
			if origin == "" {
				origin = "*"
			}
			w.Header().Set("Access-Control-Allow-Origin", origin)
			w.Header().Set("Access-Control-Allow-Headers", "Authorization, Content-Type, X-Request-Id, X-Tenant-Id, X-User-Id, X-Role")
			w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
			w.Header().Set("Access-Control-Allow-Credentials", "true")
			if r.Method == http.MethodOptions {
				w.WriteHeader(http.StatusNoContent)
				return
			}
		}
		if r.URL.Path == "/gateway/health" {
			dir.Health(w, r)
			return
		}
		h(w, r)
	})

	addr := fmt.Sprintf("%s:%d", c.Host, c.Port)
	limitDesc := fmt.Sprintf("%d/min (loopback exempt)", c.RateLimitPerMin)
	if c.RateLimitPerMin <= 0 {
		limitDesc = "disabled"
	}
	fmt.Printf("gateway listening %s jwt=%v rate=%s → platform=%s ai=%s\n", addr, c.JWTEnable, limitDesc, c.PlatformURL, c.AIURL)
	log.Fatal(http.ListenAndServe(addr, mux))
}