Start to implement intents for DM calls.

Author: Half-Shot

src/models/Call.ts

@@ -45,6 +45,7 @@ import { type JitsiCallMemberContent, JitsiCallMemberEventType } from "../call-t
 import SdkConfig from "../SdkConfig.ts";
 import RoomListStore from "../stores/room-list/RoomListStore.ts";
 import { DefaultTagID } from "../stores/room-list/models.ts";
+import { getJoinedNonFunctionalMembers } from "../utils/room/getJoinedNonFunctionalMembers.ts";
 
 const TIMEOUT_MS = 16000;
 
@@ -542,6 +543,13 @@ export class JitsiCall extends Call {
     };
 }
 
+export enum ElementCallIntent {
+    StartCall = 'start_call',
+    JoinExisting = 'join_existing',
+    StartCallDM = 'start_call_dm',
+    JoinExistingDM = 'join_existing_dm',
+}
+
 /**
  * A group call using MSC3401 and Element Call as a backend.
  * (somewhat cheekily named)
@@ -560,7 +568,7 @@ export class ElementCall extends Call {
         this.checkDestroy();
     }
 
-    private static generateWidgetUrl(client: MatrixClient, roomId: string): URL {
+    private static generateWidgetUrl(client: MatrixClient, roomId: string, intent?: ElementCallIntent): URL {
         const baseUrl = window.location.href;
         let url = new URL("./widgets/element-call/index.html#", baseUrl); // this strips hash fragment from baseUrl
 
@@ -582,6 +590,7 @@ export class ElementCall extends Call {
             lang: getCurrentLanguage().replace("_", "-"),
             fontScale: (FontWatcher.getRootFontSize() / FontWatcher.getBrowserDefaultFontSize()).toString(),
             theme: "$org.matrix.msc2873.client_theme",
+            ...(intent && { intent })
         });
 
         const room = client.getRoom(roomId);
@@ -672,9 +681,24 @@ export class ElementCall extends Call {
             return ecWidget;
         }
 
+        let intent: ElementCallIntent|undefined;
+        const room = client.getRoom(roomId);
+        const functionalMembers = room && getJoinedNonFunctionalMembers(room);
+        const isDm = functionalMembers ? functionalMembers.length === 2 : false;
+        
+        if (room && isDm) {
+            const oldestMembership = client.matrixRTC.getRoomSession(room).getOldestMembership();
+            if (!oldestMembership) {
+                // We are starting a call
+                intent = ElementCallIntent.StartCallDM;
+            } else if (oldestMembership.sender !== client.getSafeUserId()) {
+                intent = ElementCallIntent.JoinExistingDM;
+            } // else, the call is ongoing but it was from us so just handle as normal.
+        }
+
         // To use Element Call without touching room state, we create a virtual
         // widget (one that doesn't have a corresponding state event)
-        const url = ElementCall.generateWidgetUrl(client, roomId);
+        const url = ElementCall.generateWidgetUrl(client, roomId, intent);
         const createdWidget = WidgetStore.instance.addVirtualWidget(
             {
                 id: secureRandomString(24), // So that it's globally unique