Added branch endpoints and some minor logic updates.

src/main/java/nl/andrewl/railsignalapi/dao/BranchRepository.java

@@ -11,6 +11,8 @@ import java.util.Optional;
 @Repository
 public interface BranchRepository extends JpaRepository<Branch, Long> {
 	Optional<Branch> findByIdAndRailSystem(long id, RailSystem railSystem);
+	Optional<Branch> findByIdAndRailSystemId(long id, long railSystemId);
 	Optional<Branch> findByNameAndRailSystem(String name, RailSystem railSystem);
+	List<Branch> findAllByRailSystemOrderByName(RailSystem railSystem);
 	List<Branch> findAllByNameAndRailSystem(String name, RailSystem railSystem);
 }

src/main/java/nl/andrewl/railsignalapi/rest/BranchesController.java

@@ -0,0 +1,27 @@
+package nl.andrewl.railsignalapi.rest;
+
+import lombok.RequiredArgsConstructor;
+import nl.andrewl.railsignalapi.rest.dto.BranchResponse;
+import nl.andrewl.railsignalapi.service.BranchService;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping(path = "/api/railSystems/{rsId}/branches")
+@RequiredArgsConstructor
+public class BranchesController {
+	private final BranchService branchService;
+
+	@GetMapping
+	public List<BranchResponse> getAllBranches(@PathVariable long rsId) {
+		return branchService.getAllBranches(rsId);
+	}
+
+	@DeleteMapping(path = "/{branchId}")
+	public ResponseEntity<?> deleteBranch(@PathVariable long rsId, @PathVariable long branchId) {
+		branchService.deleteBranch(rsId, branchId);
+		return ResponseEntity.noContent().build();
+	}
+}

src/main/java/nl/andrewl/railsignalapi/rest/SignalsApiController.java

@@ -4,6 +4,7 @@ import lombok.RequiredArgsConstructor;
 import nl.andrewl.railsignalapi.rest.dto.SignalCreationPayload;
 import nl.andrewl.railsignalapi.rest.dto.SignalResponse;
 import nl.andrewl.railsignalapi.service.SignalService;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
@@ -28,4 +29,10 @@ public class SignalsApiController {
 	public SignalResponse getSignal(@PathVariable long rsId, @PathVariable long sigId) {
 		return signalService.getSignal(rsId, sigId);
 	}
+
+	@DeleteMapping(path = "/{sigId}")
+	public ResponseEntity<?> deleteSignal(@PathVariable long rsId, @PathVariable long sigId) {
+		signalService.deleteSignal(rsId, sigId);
+		return ResponseEntity.noContent().build();
+	}
 }

src/main/java/nl/andrewl/railsignalapi/service/BranchService.java

@@ -0,0 +1,38 @@
+package nl.andrewl.railsignalapi.service;
+
+import lombok.RequiredArgsConstructor;
+import nl.andrewl.railsignalapi.dao.BranchRepository;
+import nl.andrewl.railsignalapi.dao.RailSystemRepository;
+import nl.andrewl.railsignalapi.rest.dto.BranchResponse;
+import org.springframework.http.HttpStatus;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import org.springframework.web.server.ResponseStatusException;
+
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+public class BranchService {
+	private final BranchRepository branchRepository;
+	private final RailSystemRepository railSystemRepository;
+
+	@Transactional
+	public void deleteBranch(long rsId, long branchId) {
+		var branch = branchRepository.findByIdAndRailSystemId(branchId, rsId)
+				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		if (!branch.getSignalConnections().isEmpty()) {
+			throw new ResponseStatusException(HttpStatus.BAD_REQUEST, "Branch should not be connected to any signals.");
+		}
+		branchRepository.delete(branch);
+	}
+
+	@Transactional(readOnly = true)
+	public List<BranchResponse> getAllBranches(long rsId) {
+		var rs = railSystemRepository.findById(rsId)
+				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		return branchRepository.findAllByRailSystemOrderByName(rs).stream()
+				.map(BranchResponse::new)
+				.toList();
+	}
+}

src/main/java/nl/andrewl/railsignalapi/service/SignalService.java

@@ -33,7 +33,8 @@ public class SignalService {
 	private final SignalRepository signalRepository;
 	private final BranchRepository branchRepository;
 
-	private final Map<Long, WebSocketSession> signalWebSocketSessions = new ConcurrentHashMap<>();
+	private final ObjectMapper mapper = new ObjectMapper();
+	private final Map<WebSocketSession, Set<Long>> signalWebSocketSessions = new ConcurrentHashMap<>();
 
 	@Transactional
 	public SignalResponse createSignal(long rsId, SignalCreationPayload payload) {
@@ -60,17 +61,42 @@ public class SignalService {
 		return new SignalResponse(signal);
 	}
 
-	public void registerSignalWebSocketSession(long signalId, WebSocketSession session) {
+	@Transactional(readOnly = true)
-		this.signalWebSocketSessions.put(signalId, session);
+	public void registerSignalWebSocketSession(Set<Long> signalIds, WebSocketSession session) {
+		this.signalWebSocketSessions.put(session, signalIds);
+		// Instantly send a data packet so that the signals are up-to-date.
+		for (var signalId : signalIds) {
+			var signal = signalRepository.findById(signalId)
+					.orElseThrow(() -> new ResponseStatusException(HttpStatus.BAD_REQUEST, "Invalid signal id."));
+			for (var branchConnection : signal.getBranchConnections()) {
+				try {
+					session.sendMessage(new TextMessage(mapper.writeValueAsString(
+							new BranchUpdateMessage(
+									branchConnection.getBranch().getId(),
+									branchConnection.getBranch().getStatus().name()
+							)
+					)));
+				} catch (IOException e) {
+					e.printStackTrace();
+				}
+			}
+		}
 	}
 
-	public void deregisterSignalWebSocketSession(long signalId) {
+	public void deregisterSignalWebSocketSession(WebSocketSession session) {
-		this.signalWebSocketSessions.remove(signalId);
+		this.signalWebSocketSessions.remove(session);
+	}
+
+	public WebSocketSession getSignalWebSocketSession(long signalId) {
+		for (var entry : signalWebSocketSessions.entrySet()) {
+			if (entry.getValue().contains(signalId)) return entry.getKey();
+		}
+		return null;
 	}
 
 	@Transactional
-	public void handleSignalUpdate(long signalId, SignalUpdateMessage updateMessage) {
+	public void handleSignalUpdate(SignalUpdateMessage updateMessage) {
-		var signal = signalRepository.findById(signalId)
+		var signal = signalRepository.findById(updateMessage.signalId())
 				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
 		Branch fromBranch = null;
 		Branch toBranch = null;
@@ -102,15 +128,21 @@ public class SignalService {
 				branchRepository.save(fromBranch);
 				broadcastToConnectedSignals(fromBranch);
 			}
+		} else if (updateType == SignalUpdateType.BEGIN) {
+			if (fromBranch.getStatus() != BranchStatus.OCCUPIED) {
+				log.info("Updating branch {} status from {} to {}.", fromBranch.getName(), fromBranch.getStatus(), BranchStatus.OCCUPIED);
+				fromBranch.setStatus(BranchStatus.OCCUPIED);
+				branchRepository.save(fromBranch);
+				broadcastToConnectedSignals(fromBranch);
+			}
 		}
 	}
 
 	private void broadcastToConnectedSignals(Branch branch) {
-		ObjectMapper mapper = new ObjectMapper();
 		try {
 			WebSocketMessage<String> msg = new TextMessage(mapper.writeValueAsString(new BranchUpdateMessage(branch.getId(), branch.getStatus().name())));
 			signalRepository.findAllConnectedToBranch(branch).stream()
-					.map(s -> signalWebSocketSessions.get(s.getId()))
+					.map(s -> getSignalWebSocketSession(s.getId()))
 					.filter(Objects::nonNull)
 					.forEach(session -> {
 						try {
@@ -140,4 +172,11 @@ public class SignalService {
 				.map(SignalResponse::new)
 				.toList();
 	}
+
+	@Transactional
+	public void deleteSignal(long rsId, long sigId) {
+		var s = signalRepository.findByIdAndRailSystemId(sigId, rsId)
+				.orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND));
+		signalRepository.delete(s);
+	}
 }

src/main/java/nl/andrewl/railsignalapi/websocket/SignalUpdateMessage.java

@@ -1,6 +1,7 @@
 package nl.andrewl.railsignalapi.websocket;
 
 public record SignalUpdateMessage(
+		long signalId,
 		long fromBranchId,
 		long toBranchId,
 		String type

src/main/java/nl/andrewl/railsignalapi/websocket/SignalWebSocketHandler.java

@@ -10,6 +10,9 @@ import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 import org.springframework.web.socket.handler.TextWebSocketHandler;
 
+import java.util.HashSet;
+import java.util.Set;
+
 @Component
 @RequiredArgsConstructor
 @Slf4j
@@ -24,27 +27,23 @@ public class SignalWebSocketHandler extends TextWebSocketHandler {
 			session.close(CloseStatus.PROTOCOL_ERROR);
 			return;
 		}
-		long signalId = Long.parseLong(signalIdHeader);
+		Set<Long> ids = new HashSet<>();
-		session.getAttributes().put("signalId", signalId);
+		for (var idStr : signalIdHeader.split(",")) {
-		signalService.registerSignalWebSocketSession(signalId, session);
+			ids.add(Long.parseLong(idStr.trim()));
-		log.info("Connection established with signal {}.", signalId);
+		}
+		signalService.registerSignalWebSocketSession(ids, session);
+		log.info("Connection established with signals {}.", ids);
 	}
 
 	@Override
 	protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
 		var msg = mapper.readValue(message.getPayload(), SignalUpdateMessage.class);
-		Long signalId = (Long) session.getAttributes().get("signalId");
+		signalService.handleSignalUpdate(msg);
-		if (signalId == null) {
-			log.warn("Got text message from a websocket session that did not establish a signalId session attribute.");
-		} else {
-			log.info("Received update from signal {}.", signalId);
-			signalService.handleSignalUpdate(signalId, msg);
-		}
 	}
 
 	@Override
-	public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
+	public void afterConnectionClosed(WebSocketSession session, CloseStatus status) {
-		signalService.deregisterSignalWebSocketSession((Long) session.getAttributes().get("signalId"));
+		signalService.deregisterSignalWebSocketSession(session);
-		log.info("Closed connection to signal {}. Status: {}", session.getAttributes().get("signalId"), status.toString());
+		log.info("Closed connection {}. Status: {}", session.getId(), status.toString());
 	}
 }