From b74b03024c116e711a8b287ffe58b97e6d761fc7 Mon Sep 17 00:00:00 2001
From: cnderrauber <zengjie9004@gmail.com>
Date: Thu, 25 Jul 2024 11:11:46 +0800
Subject: [PATCH] WIP

---
 pkg/service/server.go |   1 +
 pkg/whep/handler.go   |   1 +
 pkg/whep/server.go    | 125 ++++++++++++++++++++++++++++++++++++++++++
 pkg/whep/session.go   |  24 ++++++++
 4 files changed, 151 insertions(+)
 create mode 100644 pkg/whep/handler.go
 create mode 100644 pkg/whep/server.go
 create mode 100644 pkg/whep/session.go

diff --git a/pkg/service/server.go b/pkg/service/server.go
index 88498518e..3bbbd712a 100644
--- a/pkg/service/server.go
+++ b/pkg/service/server.go
@@ -132,6 +132,7 @@ func NewLivekitServer(conf *config.Config,
 	mux.Handle(sipServer.PathPrefix(), sipServer)
 	mux.Handle("/rtc", rtcService)
 	mux.Handle("/agent", agentService)
+	mux.Handle("/whep/", http.StripPrefix("/whep", whepServer))
 	mux.HandleFunc("/rtc/validate", rtcService.Validate)
 	mux.HandleFunc("/", s.defaultHandler)
 
diff --git a/pkg/whep/handler.go b/pkg/whep/handler.go
new file mode 100644
index 000000000..5712989af
--- /dev/null
+++ b/pkg/whep/handler.go
@@ -0,0 +1 @@
+package whep
diff --git a/pkg/whep/server.go b/pkg/whep/server.go
new file mode 100644
index 000000000..70a53248c
--- /dev/null
+++ b/pkg/whep/server.go
@@ -0,0 +1,125 @@
+package whep
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"hash/crc32"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/livekit/mediatransportutil/pkg/rtcconfig"
+	"github.com/livekit/protocol/logger"
+	"github.com/livekit/protocol/utils"
+	"github.com/livekit/psrpc"
+)
+
+const (
+	authorizationHeader = "Authorization"
+	bearerPrefix        = "Bearer "
+)
+
+type Server struct {
+	*http.ServeMux
+
+	sessions map[string]*Session
+}
+
+func (s *Server) Start() error {
+	s.ctx, s.cancel = context.WithCancel(context.Background())
+
+	logger.Infow("starting WHEP server")
+
+	if onPublish == nil {
+		return psrpc.NewErrorf(psrpc.Internal, "no onPublish callback provided")
+	}
+
+	s.onPublish = onPublish
+
+	var err error
+	s.webRTCConfig, err = rtcconfig.NewWebRTCConfig(&conf.RTCConfig, conf.Development)
+	if err != nil {
+		return err
+	}
+
+	r := http.NewServeMux()
+	r.HandleFunc("POST /{room}/{participant}", s.handleNewSession)
+
+	r.HandleFunc("PATCH /{room}/{participant}/{resource_id}", s.handleICE)
+	r.HandleFunc("DELETE /{room}/{participant}/{resource_id}", s.handleDeleteSession)
+
+	hs := &http.Server{
+		Addr:         fmt.Sprintf(":%d", conf.WHIPPort),
+		Handler:      r,
+		ReadTimeout:  10 * time.Second,
+		WriteTimeout: 10 * time.Second,
+	}
+
+	go func() {
+		err := hs.ListenAndServe()
+		if err != http.ErrServerClosed {
+			logger.Errorw("WHIP server start failed", err)
+		}
+	}()
+
+	return nil
+}
+
+func (s *Server) Stop() {
+
+}
+
+func (s *Server) handleNewSession(w http.ResponseWriter, r *http.Request) {
+	authHeader := r.Header.Get(authorizationHeader)
+	var authToken string
+
+	if authHeader != "" {
+		if !strings.HasPrefix(authHeader, bearerPrefix) {
+			handleError(w, r, http.StatusUnauthorized, ErrMissingAuthorization)
+			return
+		}
+
+		authToken = authHeader[len(bearerPrefix):]
+	}
+
+	room := r.PathValue("room")
+	participant := r.PathValue("participant")
+
+	offer := bytes.Buffer{}
+
+	_, err := io.Copy(&offer, r.Body)
+	if err != nil {
+		return err
+	}
+
+	resourceID := utils.NewGuid(utils.WHIPResourcePrefix)
+	session := NewSession(room, participant, authToken, offer)
+
+	answer := session.CreateAnswer()
+
+	s.sessions[resourceID] = session
+
+	go session.Run()
+
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+	w.Header().Set("Access-Control-Expose-Headers", "Location")
+	w.Header().Set("Content-Type", "application/sdp")
+	w.Header().Set("Location", fmt.Sprintf("/%s/%s/%s", room, participant, resourceID))
+	w.Header().Set("ETag", fmt.Sprintf("%08x", crc32.ChecksumIEEE(offer.Bytes())))
+	w.WriteHeader(http.StatusCreated)
+	_, _ = w.Write([]byte(answer))
+}
+
+func (s *Server) handleICE(w http.ResponseWriter, r *http.Request) {
+	// TODO: trickle ice and ice restart
+	w.WriteHeader(http.StatusNotImplemented)
+}
+
+func (s *Server) handleDeleteSession(w http.ResponseWriter, r *http.Request) {
+	resourceID := r.PathValue("resource_id")
+	if session, ok := s.sessions[resourceID]; ok {
+		session.Close()
+	}
+}
diff --git a/pkg/whep/session.go b/pkg/whep/session.go
new file mode 100644
index 000000000..735e50525
--- /dev/null
+++ b/pkg/whep/session.go
@@ -0,0 +1,24 @@
+package whep
+
+type Session struct {
+}
+
+func NewSession() *Session {
+
+}
+
+func (s *Session) CreateAnswer() {
+
+}
+
+func (s *Session) Run() {
+
+}
+
+func (s *Session) HandleICERequest() {
+
+}
+
+func (s *Session) Close() {
+
+}