Feat: WebRTC 시그널링 서버 구축 (#118)

src/main/java/com/back/domain/chat/room/controller/RoomChatWebSocketController.java

@@ -7,6 +7,7 @@
 import com.back.global.exception.CustomException;
 import com.back.global.security.user.CustomUserDetails;
 import com.back.domain.chat.room.service.RoomChatService;
+import com.back.global.websocket.util.WebSocketAuthHelper;
 import com.back.global.websocket.util.WebSocketErrorHelper;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import lombok.RequiredArgsConstructor;
@@ -29,6 +30,7 @@ public class RoomChatWebSocketController {
 
     private final RoomChatService roomChatService;
     private final SimpMessagingTemplate messagingTemplate;
+    private final WebSocketAuthHelper authHelper;
     private final WebSocketErrorHelper errorHelper;
 
     /**
@@ -43,7 +45,8 @@ public void handleRoomChat(@DestinationVariable Long roomId,
 
         try {
             // WebSocket에서 인증된 사용자 정보 추출
-            CustomUserDetails userDetails = extractUserDetails(principal);
+            CustomUserDetails userDetails = authHelper.extractUserDetails(principal);
+
             if (userDetails == null) {
                 errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
                 return;
@@ -101,7 +104,8 @@ public void clearRoomChat(@DestinationVariable Long roomId,
             log.info("WebSocket 채팅 일괄 삭제 요청 - roomId: {}", roomId);
 
             // 사용자 인증 확인
-            CustomUserDetails userDetails = extractUserDetails(principal);
+            CustomUserDetails userDetails = authHelper.extractUserDetails(principal);
+
             if (userDetails == null) {
                 errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
                 return;
@@ -148,15 +152,4 @@ public void clearRoomChat(@DestinationVariable Long roomId,
         }
     }
 
-    // WebSocket Principal에서 CustomUserDetails 추출
-    private CustomUserDetails extractUserDetails(Principal principal) {
-        if (principal instanceof Authentication auth) {
-            Object principalObj = auth.getPrincipal();
-            if (principalObj instanceof CustomUserDetails userDetails) {
-                return userDetails;
-            }
-        }
-        return null;
-    }
-
 }

src/main/java/com/back/global/websocket/service/WebSocketSessionManager.java

@@ -28,8 +28,8 @@ public class WebSocketSessionManager {
     private static final String SESSION_USER_KEY = "ws:session:{}";
     private static final String ROOM_USERS_KEY = "ws:room:{}:users";
 
-    // TTL 설정 (10분)
-    private static final int SESSION_TTL_MINUTES = 10;
+    // TTL 설정
+    private static final int SESSION_TTL_MINUTES = 6;
 
     // 사용자 세션 추가 (연결 시 호출)
     public void addSession(Long userId, String sessionId) {

src/main/java/com/back/global/websocket/util/WebSocketAuthHelper.java

@@ -0,0 +1,22 @@
+package com.back.global.websocket.util;
+
+import com.back.global.security.user.CustomUserDetails;
+import org.springframework.security.core.Authentication;
+import org.springframework.stereotype.Component;
+
+import java.security.Principal;
+
+@Component
+public class WebSocketAuthHelper {
+
+    // WebSocket에서 인증된 사용자 정보 추출
+    public static CustomUserDetails extractUserDetails(Principal principal) {
+        if (principal instanceof Authentication auth) {
+            Object principalObj = auth.getPrincipal();
+            if (principalObj instanceof CustomUserDetails userDetails) {
+                return userDetails;
+            }
+        }
+        return null;
+    }
+}

src/main/java/com/back/global/websocket/webrtc/controller/WebRTCApiController.java

@@ -0,0 +1,61 @@
+package com.back.global.websocket.webrtc.controller;
+
+import com.back.global.common.dto.RsData;
+import com.back.global.websocket.webrtc.dto.ice.IceServerConfig;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.Parameter;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+@Slf4j
+@RestController
+@RequestMapping("/api/webrtc")
+@RequiredArgsConstructor
+@Tag(name = "WebRTC API", description = "WebRTC 시그널링 및 ICE 서버 관련 REST API")
+public class WebRTCApiController {
+
+    // ICE 서버 설정 조회
+    @GetMapping("/ice-servers")
+    @Operation(
+            summary = "ICE 서버 설정 조회",
+            description = "WebRTC 연결에 필요한 STUN/TURN 서버 정보를 조회합니다."
+    )
+    @ApiResponses({
+            @ApiResponse(responseCode = "200", description = "조회 성공"),
+            @ApiResponse(responseCode = "500", description = "서버 오류")
+    })
+    public ResponseEntity<RsData<IceServerConfig>> getIceServers(
+            @Parameter(description = "사용자 ID (선택)") @RequestParam(required = false) Long userId,
+            @Parameter(description = "방 ID (선택)") @RequestParam(required = false) Long roomId) {
+
+        log.info("ICE 서버 설정 요청 - userId: {}, roomId: {}", userId, roomId);
+
+        // 기본 Google STUN 서버 사용
+        IceServerConfig config = IceServerConfig.withDefaultStunServers();
+
+        log.info("ICE 서버 설정 제공 완료 - STUN 서버 {}개", config.iceServers().size());
+
+        return ResponseEntity
+                .status(HttpStatus.OK)
+                .body(RsData.success("ICE 서버 설정 조회 성공", config));
+    }
+
+    // WebRTC 서비스 상태 확인
+    @GetMapping("/health")
+    @Operation(
+            summary = "WebRTC 서비스 상태 확인",
+            description = "WebRTC 시그널링 서버의 상태를 확인합니다."
+    )
+    @ApiResponse(responseCode = "200", description = "정상 작동 중")
+    public ResponseEntity<RsData<String>> healthCheck() {
+        return ResponseEntity
+                .status(HttpStatus.OK)
+                .body(RsData.success("WebRTC 서비스 정상 작동 중"));
+    }
+}

src/main/java/com/back/global/websocket/webrtc/controller/WebRTCSignalingController.java

@@ -0,0 +1,211 @@
+package com.back.global.websocket.webrtc.controller;
+
+import com.back.global.security.user.CustomUserDetails;
+import com.back.global.websocket.webrtc.dto.media.WebRTCMediaToggleRequest;
+import com.back.global.websocket.webrtc.dto.media.WebRTCMediaStateResponse;
+import com.back.global.websocket.webrtc.dto.signal.*;
+import com.back.global.websocket.webrtc.service.WebRTCSignalValidator;
+import com.back.global.websocket.util.WebSocketErrorHelper;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.messaging.handler.annotation.MessageMapping;
+import org.springframework.messaging.handler.annotation.Payload;
+import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
+import org.springframework.security.core.Authentication;
+import org.springframework.stereotype.Controller;
+import org.springframework.validation.annotation.Validated;
+
+import java.security.Principal;
+
+@Controller
+@RequiredArgsConstructor
+@Slf4j
+public class WebRTCSignalingController {
+
+    private final SimpMessagingTemplate messagingTemplate;
+    private final WebSocketErrorHelper errorHelper;
+    private final WebRTCSignalValidator validator;
+
+    // WebRTC Offer 메시지 처리
+    @MessageMapping("/webrtc/offer")
+    public void handleOffer(@Validated @Payload WebRTCOfferRequest request,
+                            SimpMessageHeaderAccessor headerAccessor,
+                            Principal principal) {
+        try {
+            // WebSocket에서 인증된 사용자 정보 추출
+            CustomUserDetails userDetails = extractUserDetails(principal);
+            if (userDetails == null) {
+                errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
+                return;
+            }
+
+            Long fromUserId = userDetails.getUserId();
+
+            // 시그널 검증
+            validator.validateSignal(request.roomId(), fromUserId, request.targetUserId());
+
+            log.info("WebRTC Offer received - Room: {}, From: {}, To: {}, MediaType: {}",
+                    request.roomId(), fromUserId, request.targetUserId(), request.mediaType());
+
+            // Offer 메시지 생성
+            WebRTCSignalResponse response = WebRTCSignalResponse.offerOrAnswer(
+                    WebRTCSignalType.OFFER,
+                    fromUserId,
+                    request.targetUserId(),
+                    request.roomId(),
+                    request.sdp(),
+                    request.mediaType()
+            );
+
+            // 방 전체에 브로드캐스트 (P2P Mesh 연결)
+            messagingTemplate.convertAndSend(
+                    "/topic/room/" + request.roomId() + "/webrtc",
+                    response
+            );
+
+        } catch (Exception e) {
+            log.error("WebRTC Offer 처리 중 오류 발생 - roomId: {}", request.roomId(), e);
+            errorHelper.sendGenericErrorToUser(headerAccessor.getSessionId(), e, "Offer 전송 중 오류가 발생했습니다");
+        }
+    }
+
+    // WebRTC Answer 메시지 처리
+    @MessageMapping("/webrtc/answer")
+    public void handleAnswer(@Validated @Payload WebRTCAnswerRequest request,
+                             SimpMessageHeaderAccessor headerAccessor,
+                             Principal principal) {
+        try {
+            // WebSocket에서 인증된 사용자 정보 추출
+            CustomUserDetails userDetails = extractUserDetails(principal);
+            if (userDetails == null) {
+                errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
+                return;
+            }
+
+            Long fromUserId = userDetails.getUserId();
+
+            // 시그널 검증
+            validator.validateSignal(request.roomId(), fromUserId, request.targetUserId());
+
+            log.info("WebRTC Answer received - Room: {}, From: {}, To: {}, MediaType: {}",
+                    request.roomId(), fromUserId, request.targetUserId(), request.mediaType());
+
+            // Answer 메시지 생성
+            WebRTCSignalResponse response = WebRTCSignalResponse.offerOrAnswer(
+                    WebRTCSignalType.ANSWER,
+                    fromUserId,
+                    request.targetUserId(),
+                    request.roomId(),
+                    request.sdp(),
+                    request.mediaType()
+            );
+
+            // 방 전체에 브로드캐스트 (P2P Mesh 연결)
+            messagingTemplate.convertAndSend(
+                    "/topic/room/" + request.roomId() + "/webrtc",
+                    response
+            );
+
+        } catch (Exception e) {
+            log.error("WebRTC Answer 처리 중 오류 발생 - roomId: {}", request.roomId(), e);
+            errorHelper.sendGenericErrorToUser(headerAccessor.getSessionId(), e, "Answer 전송 중 오류가 발생했습니다");
+        }
+    }
+
+    // ICE Candidate 메시지 처리
+    @MessageMapping("/webrtc/ice-candidate")
+    public void handleIceCandidate(@Validated @Payload WebRTCIceCandidateRequest request,
+                                   SimpMessageHeaderAccessor headerAccessor,
+                                   Principal principal) {
+        try {
+            // WebSocket에서 인증된 사용자 정보 추출
+            CustomUserDetails userDetails = extractUserDetails(principal);
+            if (userDetails == null) {
+                errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
+                return;
+            }
+
+            Long fromUserId = userDetails.getUserId();
+
+            // 시그널 검증
+            validator.validateSignal(request.roomId(), fromUserId, request.targetUserId());
+
+            log.info("ICE Candidate received - Room: {}, From: {}, To: {}",
+                    request.roomId(), fromUserId, request.targetUserId());
+
+            // ICE Candidate 메시지 생성
+            WebRTCSignalResponse response = WebRTCSignalResponse.iceCandidate(
+                    fromUserId,
+                    request.targetUserId(),
+                    request.roomId(),
+                    request.candidate(),
+                    request.sdpMid(),
+                    request.sdpMLineIndex()
+            );
+
+            // 방 전체에 브로드캐스트 (P2P Mesh 연결)
+            messagingTemplate.convertAndSend(
+                    "/topic/room/" + request.roomId() + "/webrtc",
+                    response
+            );
+
+        } catch (Exception e) {
+            log.error("ICE Candidate 처리 중 오류 발생 - roomId: {}", request.roomId(), e);
+            errorHelper.sendGenericErrorToUser(headerAccessor.getSessionId(), e, "ICE Candidate 전송 중 오류가 발생했습니다");
+        }
+    }
+
+    // 미디어 상태 토글 처리
+    @MessageMapping("/webrtc/media/toggle")
+    public void handleMediaToggle(@Validated @Payload WebRTCMediaToggleRequest request,
+                                  SimpMessageHeaderAccessor headerAccessor,
+                                  Principal principal) {
+        try {
+            // 인증된 사용자 정보 추출
+            CustomUserDetails userDetails = extractUserDetails(principal);
+            if (userDetails == null) {
+                errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
+                return;
+            }
+
+            Long userId = userDetails.getUserId();
+            String nickname = userDetails.getUsername();
+
+            // 미디어 상태 변경 검증
+            validator.validateMediaStateChange(request.roomId(), userId);
+
+            log.info("미디어 상태 변경 - Room: {}, User: {}, MediaType: {}, Enabled: {}",
+                    request.roomId(), userId, request.mediaType(), request.enabled());
+
+            // 미디어 상태 응답 생성
+            WebRTCMediaStateResponse response = WebRTCMediaStateResponse.of(
+                    userId,
+                    nickname,
+                    request.mediaType(),
+                    request.enabled()
+            );
+
+            // 방 전체에 브로드캐스트
+            messagingTemplate.convertAndSend(
+                    "/topic/room/" + request.roomId() + "/media-status",
+                    response
+            );
+
+        } catch (Exception e) {
+            log.error("미디어 상태 변경 중 오류 발생 - roomId: {}", request.roomId(), e);
+            errorHelper.sendGenericErrorToUser(headerAccessor.getSessionId(), e, "미디어 상태 변경 중 오류가 발생했습니다");
+        }
+    }
+
+    // Principal에서 CustomUserDetails 추출 헬퍼 메서드
+    private CustomUserDetails extractUserDetails(Principal principal) {
+        if (principal instanceof Authentication auth) {
+            Object principalObj = auth.getPrincipal();
+            if (principalObj instanceof CustomUserDetails userDetails) {
+                return userDetails;
+            }
+        }
+        return null;
+    }
+}

src/main/java/com/back/global/websocket/webrtc/dto/ice/IceServer.java

@@ -0,0 +1,20 @@
+package com.back.global.websocket.webrtc.dto.ice;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+
+@JsonInclude(JsonInclude.Include.NON_NULL)
+public record IceServer(
+        String urls,
+        String username,
+        String credential
+) {
+    // STUN 서버 (인증 불필요)
+    public static IceServer stun(String url) {
+        return new IceServer(url, null, null);
+    }
+
+    // TURN 서버 (인증 필요)
+    public static IceServer turn(String url, String username, String credential) {
+        return new IceServer(url, username, credential);
+    }
+}