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WebApp/src/class/websockethandler.ts

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+import Offer from './offer';
+import Answer from './answer';
+import Candidate from './candidate';
+
+let isPrivate: boolean;
+
+// [{sessonId:[connectionId,...]}]
+const clients: Map<WebSocket, Set<string>> = new Map<WebSocket, Set<string>>();
+
+// [{connectionId:[sessionId1, sessionId2]}]
+const connectionPair: Map<string, [WebSocket, WebSocket]> = new Map<string, [WebSocket, WebSocket]>();
+
+function getOrCreateConnectionIds(session: WebSocket): Set<string> {
+  let connectionIds = null;
+  if (!clients.has(session)) {
+    connectionIds = new Set<string>();
+    clients.set(session, connectionIds);
+  }
+  connectionIds = clients.get(session);
+  return connectionIds;
+}
+
+function reset(mode: string): void {
+  isPrivate = mode == "private";
+}
+
+function add(ws: WebSocket): void {
+  clients.set(ws, new Set<string>());
+}
+
+function remove(ws: WebSocket): void {
+  const connectionIds = clients.get(ws);
+  connectionIds.forEach(connectionId => {
+    const pair = connectionPair.get(connectionId);
+    if (pair) {
+      const otherSessionWs = pair[0] == ws ? pair[1] : pair[0];
+      if (otherSessionWs) {
+        otherSessionWs.send(JSON.stringify({ type: "disconnect", connectionId: connectionId }));
+      }
+    }
+    connectionPair.delete(connectionId);
+  });
+
+  clients.delete(ws);
+}
+
+function onConnect(ws: WebSocket, connectionId: string): void {
+  let polite = true;
+  if (isPrivate) {
+    if (connectionPair.has(connectionId)) {
+      const pair = connectionPair.get(connectionId);
+
+      if (pair[0] != null && pair[1] != null) {
+        ws.send(JSON.stringify({ type: "error", message: `${connectionId}: This connection id is already used.` }));
+        return;
+      } else if (pair[0] != null) {
+        connectionPair.set(connectionId, [pair[0], ws]);
+      }
+    } else {
+      connectionPair.set(connectionId, [ws, null]);
+      polite = false;
+    }
+  }
+
+  const connectionIds = getOrCreateConnectionIds(ws);
+  connectionIds.add(connectionId);
+  ws.send(JSON.stringify({ type: "connect", connectionId: connectionId, polite: polite }));
+}
+
+function onDisconnect(ws: WebSocket, connectionId: string): void {
+  const connectionIds = clients.get(ws);
+  connectionIds.delete(connectionId);
+
+  if (connectionPair.has(connectionId)) {
+    const pair = connectionPair.get(connectionId);
+    const otherSessionWs = pair[0] == ws ? pair[1] : pair[0];
+    if (otherSessionWs) {
+      otherSessionWs.send(JSON.stringify({ type: "disconnect", connectionId: connectionId }));
+    }
+  }
+  connectionPair.delete(connectionId);
+  ws.send(JSON.stringify({ type: "disconnect", connectionId: connectionId }));
+}
+
+function onOffer(ws: WebSocket, message: any): void {
+  const connectionId = message.connectionId as string;
+  const newOffer = new Offer(message.sdp, Date.now(), false);
+
+  if (isPrivate) {
+    if (connectionPair.has(connectionId)) {
+      const pair = connectionPair.get(connectionId);
+      const otherSessionWs = pair[0] == ws ? pair[1] : pair[0];
+      if (otherSessionWs) {
+        newOffer.polite = true;
+        otherSessionWs.send(JSON.stringify({ from: connectionId, to: "", type: "offer", data: newOffer }));
+      }
+    }
+    return;
+  }
+
+  connectionPair.set(connectionId, [ws, null]);
+  clients.forEach((_v, k) => {
+    if (k == ws) {
+      return;
+    }
+    k.send(JSON.stringify({ from: connectionId, to: "", type: "offer", data: newOffer }));
+  });
+}
+
+function onAnswer(ws: WebSocket, message: any): void {
+  const connectionId = message.connectionId as string;
+  const connectionIds = getOrCreateConnectionIds(ws);
+  connectionIds.add(connectionId);
+  const newAnswer = new Answer(message.sdp, Date.now());
+
+  if (!connectionPair.has(connectionId)) {
+    return;
+  }
+
+  const pair = connectionPair.get(connectionId);
+  const otherSessionWs = pair[0] == ws ? pair[1] : pair[0];
+
+  if (!isPrivate) {
+    connectionPair.set(connectionId, [otherSessionWs, ws]);
+  }
+
+  otherSessionWs.send(JSON.stringify({ from: connectionId, to: "", type: "answer", data: newAnswer }));
+}
+
+function onCandidate(ws: WebSocket, message: any): void {
+  const connectionId = message.connectionId;
+  const candidate = new Candidate(message.candidate, message.sdpMLineIndex, message.sdpMid, Date.now());
+
+  if (isPrivate) {
+    if (connectionPair.has(connectionId)) {
+      const pair = connectionPair.get(connectionId);
+      const otherSessionWs = pair[0] == ws ? pair[1] : pair[0];
+      if (otherSessionWs) {
+        otherSessionWs.send(JSON.stringify({ from: connectionId, to: "", type: "candidate", data: candidate }));
+      }
+    }
+    return;
+  }
+
+  clients.forEach((_v, k) => {
+    if (k === ws) {
+      return;
+    }
+    k.send(JSON.stringify({ from: connectionId, to: "", type: "candidate", data: candidate }));
+  });
+}
+
+export { reset, add, remove, onConnect, onDisconnect, onOffer, onAnswer, onCandidate };