Another rewrite

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/components/structures/CallEventGrouper.ts

@@ -0,0 +1,90 @@
+/*
+Copyright 2021 Šimon Brandner <simon.bra.ag@gmail.com>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+
+import { EventType } from "matrix-js-sdk/src/@types/event";
+import { MatrixEvent } from "matrix-js-sdk/src/models/event";
+import { CallEvent, CallState, MatrixCall } from "matrix-js-sdk/src/webrtc/call";
+import CallHandler from '../../CallHandler';
+import { EventEmitter } from 'events';
+
+export enum CallEventGrouperState {
+    Incoming = "incoming",
+    Ended = "ended",
+}
+
+export enum CallEventGrouperEvent {
+    StateChanged = "state_changed",
+}
+
+export default class CallEventGrouper extends EventEmitter {
+    invite: MatrixEvent;
+    call: MatrixCall;
+    state: CallEventGrouperState;
+
+    public answerCall() {
+        this.call?.answer();
+    }
+
+    public rejectCall() {
+        this.call?.reject();
+    }
+
+    public callBack() {
+
+    }
+
+    public isVoice(): boolean {
+        const invite = this.invite;
+
+        // FIXME: Find a better way to determine this from the event?
+        let isVoice = true;
+        if (
+            invite.getContent().offer && invite.getContent().offer.sdp &&
+            invite.getContent().offer.sdp.indexOf('m=video') !== -1
+        ) {
+            isVoice = false;
+        }
+
+        return isVoice;
+    }
+
+    public getState() {
+        return this.state;
+    }
+
+    private setCallListeners() {
+        this.call.addListener(CallEvent.State, this.setCallState);
+    }
+
+    private setCallState = () => {
+        if (this.call?.state === CallState.Ringing) {
+            this.state = CallEventGrouperState.Incoming;
+        }
+        this.emit(CallEventGrouperEvent.StateChanged, this.state);
+    }
+
+    public add(event: MatrixEvent) {
+        if (event.getType() === EventType.CallInvite) this.invite = event;
+
+        if (this.call) return;
+        const callId = event.getContent().call_id;
+        this.call = CallHandler.sharedInstance().getCallById(callId);
+        if (!this.call) return;
+        this.setCallListeners();
+        this.setCallState();
+    }
+}