feat(call): integrate LiveKit for voice and video calling

Replace the manual WebRTC signaling implementation with LiveKit SFU. This includes:
- Adding LiveKit service, handler, and configuration.
- Updating Docker Compose to include LiveKit server, Redis, and PostgreSQL.
- Refactoring `CallService` and `WSHandler` to support LiveKit room readiness instead of raw SDP/ICE relaying.
- Adding new API endpoints for LiveKit token generation and webhooks.
- Removing deprecated WebRTC configuration and manual signaling DTOs.

internal/service/call_service.go

@@ -59,8 +59,6 @@ type ActiveCall struct {
 	Duration       int64 // 通话时长（秒）
 	// 参与者状态
 	Participants map[string]*ActiveParticipant
-	// ICE Servers
-	ICEServers []config.ICEServerConfig
 }
 
 // ActiveParticipant 内存中的活跃参与者
@@ -77,10 +75,10 @@ type CallService interface {
 	Reject(ctx context.Context, callID, userID string) error
 	Busy(ctx context.Context, callID, userID string) error
 	End(ctx context.Context, callID, userID string, reason string) (*ActiveCall, error)
-	RelaySignal(ctx context.Context, callID, fromUserID string, signalType string, payload json.RawMessage) error
 	SetMuted(ctx context.Context, callID, userID string, muted bool) error
+	Ready(ctx context.Context, callID, userID string) error
+	GetActiveCall(ctx context.Context, callID string) *ActiveCall
 	GetCallHistory(ctx context.Context, userID string, page, pageSize int) ([]model.CallSession, int64, error)
-	GetICEServers() []config.ICEServerConfig
 	StartCleanupTicker()
 }
 
@@ -217,8 +215,7 @@ func (s *callService) redisGetCall(callID string) *ActiveCall {
 		CallType:       model.CallType(data.CallType),
 		Status:         model.CallStatus(data.Status),
 		MediaType:      data.MediaType,
-		ICEServers:     s.config.WebRTC.ICEServers,
-		Participants: map[string]*ActiveParticipant{
+				Participants: map[string]*ActiveParticipant{
 			data.CallerID: {UserID: data.CallerID, Status: model.ParticipantStatusJoined},
 			data.CalleeID: {UserID: data.CalleeID, Status: model.ParticipantStatusInvited},
 		},
@@ -390,8 +387,7 @@ func (s *callService) Invite(ctx context.Context, callerID, calleeID, conversati
 			callerID: {UserID: callerID, Status: model.ParticipantStatusJoined, JoinedAt: &now},
 			calleeID: {UserID: calleeID, Status: model.ParticipantStatusInvited},
 		},
-		ICEServers: s.config.WebRTC.ICEServers,
-	}
+			}
 
 	// 存储到内存
 	s.storeActiveCall(call)
@@ -411,8 +407,7 @@ func (s *callService) Invite(ctx context.Context, callerID, calleeID, conversati
 		"media_type":      mediaType,
 		"created_at":      now.UnixMilli(),
 		"lifetime":        CallLifetimeMs,
-		"ice_servers":     s.config.WebRTC.ICEServers,
-	}
+			}
 
 	online := s.hub.PublishToUserOnline(calleeID, "call_incoming", payload)
 
@@ -473,8 +468,7 @@ func (s *callService) Accept(ctx context.Context, callID, userID string) (*Activ
 	s.hub.PublishToUserOnline(call.CallerID, "call_accepted", map[string]any{
 		"call_id":     callID,
 		"started_at":  now.UnixMilli(),
-		"ice_servers": s.config.WebRTC.ICEServers,
-	})
+			})
 
 	// 通知被叫方其他设备
 	s.hub.PublishToUserOnline(userID, "call_answered_elsewhere", map[string]any{
@@ -626,35 +620,6 @@ func (s *callService) End(ctx context.Context, callID, userID string, reason str
 	return call, nil
 }
 
-func (s *callService) RelaySignal(ctx context.Context, callID, fromUserID string, signalType string, payload json.RawMessage) error {
-	call := s.getActiveCall(callID)
-	if call == nil {
-		return apperrors.ErrCallNotFound
-	}
-
-	s.mu.RLock()
-	if call.Status != model.CallStatusCalling && call.Status != model.CallStatusConnected {
-		s.mu.RUnlock()
-		return apperrors.ErrCallNotActive
-	}
-	if !isParticipant(call, fromUserID) {
-		s.mu.RUnlock()
-		return apperrors.ErrNotCallParticipant
-	}
-	s.mu.RUnlock()
-
-	for pUserID := range call.Participants {
-		if pUserID != fromUserID {
-			s.hub.PublishToUserOnlineReliable(pUserID, signalType, map[string]any{
-				"call_id": callID,
-				"from_id": fromUserID,
-				"payload": json.RawMessage(payload),
-			})
-		}
-	}
-	return nil
-}
-
 func (s *callService) SetMuted(ctx context.Context, callID, userID string, muted bool) error {
 	call := s.getActiveCall(callID)
 	if call == nil {
@@ -684,13 +649,41 @@ func (s *callService) SetMuted(ctx context.Context, callID, userID string, muted
 	return nil
 }
 
+// GetActiveCall 获取活跃通话（公开方法，供 LiveKit handler 调用）
+func (s *callService) GetActiveCall(ctx context.Context, callID string) *ActiveCall {
+	return s.getActiveCall(callID)
+}
+
+// Ready 标记参与者已加入 LiveKit 房间
+func (s *callService) Ready(ctx context.Context, callID, userID string) error {
+	call := s.getActiveCall(callID)
+	if call == nil {
+		return apperrors.ErrCallNotFound
+	}
+
+	s.mu.RLock()
+	if !isParticipant(call, userID) {
+		s.mu.RUnlock()
+		return apperrors.ErrNotCallParticipant
+	}
+	s.mu.RUnlock()
+
+	// 通知其他参与者该用户已就绪
+	for pUserID := range call.Participants {
+		if pUserID != userID {
+			s.hub.PublishToUserOnline(pUserID, "call_ready", map[string]any{
+				"call_id": callID,
+				"user_id": userID,
+			})
+		}
+	}
+	return nil
+}
+
 func (s *callService) GetCallHistory(ctx context.Context, userID string, page, pageSize int) ([]model.CallSession, int64, error) {
 	return s.callRepo.GetCallHistory(userID, page, pageSize)
 }
 
-func (s *callService) GetICEServers() []config.ICEServerConfig {
-	return s.config.WebRTC.ICEServers
-}
 
 // saveCallHistory 保存通话历史到数据库
 func (s *callService) saveCallHistory(call *ActiveCall, status model.CallStatus, duration int64) {

internal/service/livekit_service.go

@@ -0,0 +1,191 @@
+package service
+
+import (
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"with_you/internal/config"
+
+	"github.com/livekit/protocol/auth"
+	"github.com/livekit/protocol/livekit"
+	"go.uber.org/zap"
+	"google.golang.org/protobuf/encoding/protojson"
+)
+
+// LiveKitService LiveKit 令牌生成和 Webhook 处理服务
+type LiveKitService interface {
+	GenerateToken(roomName, userID string, canPublish, canSubscribe bool) (string, error)
+	ProcessWebhook(ctx context.Context, body []byte, authHeader string) (*livekit.WebhookEvent, error)
+}
+
+type liveKitService struct {
+	config *config.LiveKitConfig
+	logger *zap.Logger
+}
+
+// NewLiveKitService 创建 LiveKit 服务
+func NewLiveKitService(cfg *config.Config, logger *zap.Logger) LiveKitService {
+	return &liveKitService{
+		config: &cfg.LiveKit,
+		logger: logger,
+	}
+}
+
+// GenerateToken 为指定 room 和 user 生成 LiveKit 访问令牌
+func (s *liveKitService) GenerateToken(roomName, userID string, canPublish, canSubscribe bool) (string, error) {
+	if !s.config.Enabled {
+		return "", fmt.Errorf("livekit is not enabled")
+	}
+
+	ttl := s.config.TokenTTL
+	if ttl <= 0 {
+		ttl = 600 // 默认 10 分钟
+	}
+
+	at := auth.NewAccessToken(s.config.APIKey, s.config.APISecret)
+	at.SetName(userID)
+	at.SetIdentity(userID)
+	at.SetValidFor(time.Duration(ttl) * time.Second)
+
+	grant := &auth.VideoGrant{
+		RoomJoin:       true,
+		Room:           roomName,
+		CanPublish:     &canPublish,
+		CanSubscribe:   &canSubscribe,
+		CanPublishData: &canSubscribe,
+	}
+	at.SetVideoGrant(grant)
+
+	token, err := at.ToJWT()
+	if err != nil {
+		s.logger.Error("failed to generate livekit token", zap.Error(err))
+		return "", fmt.Errorf("generate token: %w", err)
+	}
+
+	return token, nil
+}
+
+// ProcessWebhook 验证并解析 LiveKit Webhook 事件
+func (s *liveKitService) ProcessWebhook(ctx context.Context, body []byte, authHeader string) (*livekit.WebhookEvent, error) {
+	if s.config.WebhookSecret != "" {
+		if err := s.verifyWebhookSignature(body, authHeader); err != nil {
+			return nil, fmt.Errorf("webhook signature verification failed: %w", err)
+		}
+	}
+
+	var event livekit.WebhookEvent
+	if err := protojson.Unmarshal(body, &event); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal webhook event: %w", err)
+	}
+
+	s.logger.Info("received livekit webhook",
+		zap.String("event", event.Event),
+		zap.String("room_name", event.Room.GetName()),
+	)
+
+	return &event, nil
+}
+
+// verifyWebhookSignature 验证 Webhook 签名
+func (s *liveKitService) verifyWebhookSignature(body []byte, authHeader string) error {
+	// LiveKit webhook 使用 SHA256 HMAC 签名
+	// Authorization header 格式: "sha256=<base64 encoded signature>"
+	if authHeader == "" {
+		return fmt.Errorf("missing authorization header")
+	}
+
+	expectedPrefix := "sha256="
+	if len(authHeader) < len(expectedPrefix) || authHeader[:len(expectedPrefix)] != expectedPrefix {
+		return fmt.Errorf("invalid authorization header format")
+	}
+
+	expectedSig, err := base64.StdEncoding.DecodeString(authHeader[len(expectedPrefix):])
+	if err != nil {
+		return fmt.Errorf("failed to decode signature: %w", err)
+	}
+
+	mac := hmac.New(sha256.New, []byte(s.config.WebhookSecret))
+	mac.Write(body)
+	actualSig := mac.Sum(nil)
+
+	if !hmac.Equal(actualSig, expectedSig) {
+		return fmt.Errorf("signature mismatch")
+	}
+
+	return nil
+}
+
+// WebhookRoomFinished 处理 room_finished 事件的负载
+type WebhookRoomFinished struct {
+	RoomName   string `json:"room_name"`
+	Duration   int64  `json:"duration"`
+	StartedAt  int64  `json:"started_at"`
+	EndedAt    int64  `json:"ended_at"`
+}
+
+// ParseRoomFinished 从 webhook event 中解析 room_finished 数据
+func ParseRoomFinished(event *livekit.WebhookEvent) (*WebhookRoomFinished, error) {
+	if event.Event != "room_finished" {
+		return nil, fmt.Errorf("not a room_finished event: %s", event.Event)
+	}
+
+	room := event.Room
+	if room == nil {
+		return nil, fmt.Errorf("room is nil in webhook event")
+	}
+
+	duration := int64(0)
+	startedAt := int64(0)
+	endedAt := int64(0)
+
+	if room.CreationTime > 0 {
+		startedAt = room.CreationTime
+	}
+
+	endedAt = time.Now().Unix()
+	if startedAt > 0 {
+		duration = endedAt - startedAt
+	}
+
+	return &WebhookRoomFinished{
+		RoomName:  room.Name,
+		Duration:  duration,
+		StartedAt: startedAt,
+		EndedAt:   endedAt,
+	}, nil
+}
+
+// WebhookEventJSON 用于 JSON 序列化的 webhook 事件
+type WebhookEventJSON struct {
+	Event    string               `json:"event"`
+	Room     *WebhookRoomJSON     `json:"room,omitempty"`
+	RoomName string               `json:"room_name,omitempty"`
+}
+
+// WebhookRoomJSON webhook 房间信息 JSON
+type WebhookRoomJSON struct {
+	Sid          string `json:"sid,omitempty"`
+	Name         string `json:"name,omitempty"`
+	CreationTime int64  `json:"creation_time,omitempty"`
+	NumParticipants uint32 `json:"num_participants,omitempty"`
+}
+
+// WebhookEventToJSON 将 webhook event 转为自定义 JSON 结构（避免 protobuf 内部字段）
+func WebhookEventToJSON(event *livekit.WebhookEvent) (*WebhookEventJSON, error) {
+	data, err := protojson.Marshal(event)
+	if err != nil {
+		return nil, err
+	}
+
+	var result WebhookEventJSON
+	if err := json.Unmarshal(data, &result); err != nil {
+		return nil, err
+	}
+
+	return &result, nil
+}