Change conversation during call

- Add `CallManagerProvider` to manage calls when the user navigates away from the call interface.
- Delete `NotificationManager`. Move its logic to `CallManagerProvider`.
- Rework routing
- Rework `ConversationProvider` and `useConversationQuery` to remove
  unecessary states

GitLab: #172
Change-Id: I4a786a3dd52159680e5712e598d9b831525fb63f
diff --git a/client/src/contexts/CallManagerProvider.tsx b/client/src/contexts/CallManagerProvider.tsx
new file mode 100644
index 0000000..4261f07
--- /dev/null
+++ b/client/src/contexts/CallManagerProvider.tsx
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2022 Savoir-faire Linux Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation; either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this program.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+import { CallBegin, WebSocketMessageType } from 'jami-web-common';
+import { createContext, useCallback, useContext, useEffect, useState } from 'react';
+import { useNavigate } from 'react-router-dom';
+
+import { Conversation } from '../models/conversation';
+import { useConversationQuery } from '../services/conversationQueries';
+import { SetState, WithChildren } from '../utils/utils';
+import CallProvider, { CallRole } from './CallProvider';
+import WebRtcProvider from './WebRtcProvider';
+import { WebSocketContext } from './WebSocketProvider';
+
+type CallData = {
+  conversationId: string;
+  role: CallRole;
+  withVideoOn?: boolean;
+};
+
+type ICallManagerContext = {
+  callData: CallData | undefined;
+  callConversation: Conversation | undefined;
+
+  startCall: SetState<CallData | undefined>;
+  exitCall: () => void;
+};
+
+export const CallManagerContext = createContext<ICallManagerContext>(undefined!);
+CallManagerContext.displayName = 'CallManagerContext';
+
+export default ({ children }: WithChildren) => {
+  const [callData, setCallData] = useState<CallData>();
+  const webSocket = useContext(WebSocketContext);
+  const navigate = useNavigate();
+  const conversationId = callData?.conversationId;
+  const { conversation } = useConversationQuery(conversationId);
+
+  const failStartCall = useCallback(() => {
+    throw new Error('Cannot start call: Already in a call');
+  }, []);
+
+  const startCall = !callData ? setCallData : failStartCall;
+
+  const exitCall = useCallback(() => {
+    if (!callData) {
+      return;
+    }
+
+    setCallData(undefined);
+    // TODO: write in chat that the call ended
+  }, [callData]);
+
+  useEffect(() => {
+    if (callData) {
+      // TODO: Currently, we simply do not bind the CallBegin listener if already in a call.
+      //       In the future, we should handle receiving a call while already in another.
+      return;
+    }
+    if (!webSocket) {
+      return;
+    }
+
+    const callBeginListener = ({ conversationId, withVideoOn }: CallBegin) => {
+      startCall({ conversationId: conversationId, role: 'receiver', withVideoOn });
+      navigate(`/conversation/${conversationId}`);
+    };
+
+    webSocket.bind(WebSocketMessageType.CallBegin, callBeginListener);
+
+    return () => {
+      webSocket.unbind(WebSocketMessageType.CallBegin, callBeginListener);
+    };
+  }, [webSocket, navigate, startCall, callData]);
+
+  return (
+    <CallManagerContext.Provider
+      value={{
+        startCall,
+        callData,
+        callConversation: conversation,
+        exitCall,
+      }}
+    >
+      <CallManagerProvider>{children}</CallManagerProvider>
+    </CallManagerContext.Provider>
+  );
+};
+
+const CallManagerProvider = ({ children }: WithChildren) => {
+  const { callData } = useContext(CallManagerContext);
+
+  if (!callData) {
+    return <>{children}</>;
+  }
+
+  return (
+    <WebRtcProvider>
+      <CallProvider>{children}</CallProvider>
+    </WebRtcProvider>
+  );
+};