package server

import (
	"bytes"
	"embed"
	"io/fs"
	"net"
	"net/http"
	"time"

	"google.golang.org/grpc"
	"gospeak-live-sfu-demo/gen"
	"gospeak-live-sfu-demo/internal/config"
	"gospeak-live-sfu-demo/internal/sfu/cloudflare"
	"gospeak-live-sfu-demo/internal/sfu/srs"
)

//go:embed static
var staticFS embed.FS

// Server 聚合控制面（gRPC + JSON 网关）、媒体面反向代理与静态 UI。
type Server struct {
	cfg      *config.Config
	svc      *Service
	hub      *roomHub
	srsProxy http.Handler
	cfProxy  http.Handler
}

func New(cfg *config.Config) *Server {
	hub := newRoomHub()
	cf := cloudflare.NewProvider(cfg.CFAppID, cfg.CFAppSecret, cfg.CFBaseURL, cfg.CFStunURL)
	srsP := srs.NewProvider(cfg.SRSBaseURL, cfg.SRSApp, cfg.SRSSecret, cfg.SRSCandidate)
	svc := NewService(cfg, cf, srsP, hub)
	s := &Server{cfg: cfg, svc: svc, hub: hub}
	s.srsProxy = s.srsProxyHandler()
	s.cfProxy = s.cfProxyHandler()
	return s
}

// StartGRPC 启动 gRPC 控制面（protobuf 契约的服务端实现）。
func (s *Server) StartGRPC() error {
	lis, err := net.Listen("tcp", ":"+s.cfg.GRPCPort)
	if err != nil {
		return err
	}
	gs := grpc.NewServer()
	gen.RegisterLiveSFUServer(gs, NewGRPCServer(s.svc))
	go func() { _ = gs.Serve(lis) }()
	return nil
}

// Handler 返回 HTTP 路由：静态 UI、JSON 网关、SSE、SRS/Cloudflare 媒体反代。
func (s *Server) Handler() http.Handler {
	mux := http.NewServeMux()
	sub, _ := fs.Sub(staticFS, "static")
	mux.Handle("GET /", s.fileServer("static/index.html"))
	mux.Handle("GET /publish", s.fileServer("static/publish.html"))
	mux.Handle("GET /watch", s.fileServer("static/watch.html"))
	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.FS(sub))))

	mux.HandleFunc("GET /api/config", s.handleConfig)
	mux.HandleFunc("GET /api/rooms", s.handleRooms)
	mux.HandleFunc("POST /api/publish", s.handlePublish)
	mux.HandleFunc("POST /api/subscribe", s.handleSubscribe)
	mux.HandleFunc("POST /api/stop", s.handleStop)
	mux.HandleFunc("GET /api/srs/streams", s.handleSRSStreams)
	mux.Handle("GET /api/room/{room}/events", http.HandlerFunc(s.handleRoomEvents))

	mux.Handle("GET /rtc/v1/", s.srsProxy)
	mux.Handle("POST /rtc/v1/", s.srsProxy)
	mux.Handle("PUT /rtc/v1/", s.srsProxy)
	mux.Handle("DELETE /rtc/v1/", s.srsProxy)

	mux.Handle("GET /api/cf/", s.cfProxy)
	mux.Handle("POST /api/cf/", s.cfProxy)
	mux.Handle("PUT /api/cf/", s.cfProxy)
	mux.Handle("DELETE /api/cf/", s.cfProxy)
	return mux
}

func (s *Server) fileServer(name string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		data, err := staticFS.ReadFile(name)
		if err != nil {
			http.Error(w, "not found", http.StatusNotFound)
			return
		}
		http.ServeContent(w, r, name, time.Time{}, bytes.NewReader(data))
	}
}