--- a/libervia/web/pages/calls/_browser/webrtc.py	Wed Aug 09 00:48:21 2023 +0200
+++ b/libervia/web/pages/calls/_browser/webrtc.py	Mon Aug 14 16:49:02 2023 +0200
@@ -3,8 +3,10 @@
 
 from bridge import AsyncBridge as Bridge
 from browser import aio, console as log, document, timer, window
+import dialog
 import errors
-import  jid
+from javascript import JSObject
+import jid
 
 log.warning = log.warn
 profile = window.profile or ""
@@ -13,15 +15,27 @@
 
 
 class WebRTC:
-
     def __init__(self):
         self.reset_instance()
         bridge.register_signal("ice_candidates_new", self._on_ice_candidates_new)
         self.is_audio_muted = None
         self.is_video_muted = None
+        self._is_sharing_screen = False
+        self.screen_sharing_cb = None
         self.local_video_elt = document["local_video"]
         self.remote_video_elt = document["remote_video"]
 
+    @property
+    def is_sharing_screen(self) -> bool:
+        return self._is_sharing_screen
+
+    @is_sharing_screen.setter
+    def is_sharing_screen(self, sharing: bool) -> None:
+        if sharing != self._is_sharing_screen:
+            self._is_sharing_screen = sharing
+            if self.screen_sharing_cb is not None:
+                self.screen_sharing_cb(sharing)
+
     def reset_instance(self):
         """Inits or resets the instance variables to their default state."""
         self._peer_connection = None
@@ -47,7 +61,7 @@
     @media_types.setter
     def media_types(self, new_media_types: dict) -> None:
         self._media_types = new_media_types
-        self._media_types_inv = {v:k for k,v in new_media_types.items()}
+        self._media_types_inv = {v: k for k, v in new_media_types.items()}
 
     @property
     def media_types_inv(self) -> dict:
@@ -88,10 +102,7 @@
         fingerprint_line = re.search(r"a=fingerprint:(\S+)\s+(\S+)", sdp)
         if fingerprint_line:
             algorithm, fingerprint = fingerprint_line.groups()
-            fingerprint_data = {
-                "hash": algorithm,
-                "fingerprint": fingerprint
-            }
+            fingerprint_data = {"hash": algorithm, "fingerprint": fingerprint}
 
             setup_line = re.search(r"a=setup:(\S+)", sdp)
             if setup_line:
@@ -144,11 +155,10 @@
             "{address} {port} typ {type}"
         )
 
-        if ((parsed_candidate.get('rel_addr')
-             and parsed_candidate.get('rel_port'))):
+        if parsed_candidate.get("rel_addr") and parsed_candidate.get("rel_port"):
             base_format += " raddr {rel_addr} rport {rel_port}"
 
-        if parsed_candidate.get('generation'):
+        if parsed_candidate.get("generation"):
             base_format += " generation {generation}"
 
         return base_format.format(**parsed_candidate)
@@ -187,7 +197,7 @@
 
         for line in sdp_lines:
             if line.startswith("m="):
-                media_types[mline_index] = line[2:line.find(" ")]
+                media_types[mline_index] = line[2 : line.find(" ")]
                 mline_index += 1
 
         self.media_types = media_types
@@ -218,9 +228,9 @@
             if server["type"] == "stun":
                 ice_server["urls"] = f"stun:{server['host']}:{server['port']}"
             elif server["type"] == "turn":
-                ice_server["urls"] = (
-                    f"turn:{server['host']}:{server['port']}?transport={server['transport']}"
-                )
+                ice_server[
+                    "urls"
+                ] = f"turn:{server['host']}:{server['port']}?transport={server['transport']}"
                 ice_server["username"] = server["username"]
                 ice_server["credential"] = server["password"]
             ice_servers.append(ice_server)
@@ -231,28 +241,102 @@
         peer_connection.addEventListener("track", self.on_track)
         peer_connection.addEventListener("negotiationneeded", self.on_negotiation_needed)
         peer_connection.addEventListener("icecandidate", self.on_ice_candidate)
-        peer_connection.addEventListener("icegatheringstatechange", self.on_ice_gathering_state_change)
+        peer_connection.addEventListener(
+            "icegatheringstatechange", self.on_ice_gathering_state_change
+        )
 
         self._peer_connection = peer_connection
         window.pc = self._peer_connection
 
-    async def _get_user_media(
-        self,
-        audio: bool = True,
-        video: bool = True
-    ):
-        """Gets user media
+    async def _get_user_media(self, audio: bool = True, video: bool = True) -> None:
+        """
+        Gets user media (camera and microphone).
 
-        @param audio: True if an audio flux is required
-        @param video: True if a video flux is required
+        @param audio: True if an audio flux is required.
+        @param video: True if a video flux is required.
         """
-        media_constraints = {'audio': audio, 'video': video}
+        media_constraints = {"audio": audio, "video": video}
         local_stream = await window.navigator.mediaDevices.getUserMedia(media_constraints)
+
+        if not local_stream:
+            log.error("Failed to get the media stream.")
+            return
+
         self.local_video_elt.srcObject = local_stream
 
         for track in local_stream.getTracks():
             self._peer_connection.addTrack(track)
 
+    async def _replace_user_video(
+        self,
+        screen: bool = False,
+    ) -> JSObject | None:
+        """Replaces the user video track with either a camera or desktop sharing track.
+
+        @param screen: True if desktop sharing is required. False will use the camera.
+        @return: The local media stream or None if failed.
+        """
+        if screen:
+            media_constraints = {"video": {"cursor": "always"}}
+            new_stream = await window.navigator.mediaDevices.getDisplayMedia(
+                media_constraints
+            )
+        else:
+            if self.local_video_elt.srcObject:
+                for track in self.local_video_elt.srcObject.getTracks():
+                    if track.kind == "video":
+                        track.stop()
+            media_constraints = {"video": True}
+            new_stream = await window.navigator.mediaDevices.getUserMedia(
+                media_constraints
+            )
+
+        if not new_stream:
+            log.error("Failed to get the media stream.")
+            return None
+
+        new_video_tracks = [
+            track for track in new_stream.getTracks() if track.kind == "video"
+        ]
+
+        if not new_video_tracks:
+            log.error("Failed to retrieve the video track from the new stream.")
+            return None
+
+        # Retrieve the current local stream's video track.
+        local_stream = self.local_video_elt.srcObject
+        if local_stream:
+            local_video_tracks = [
+                track for track in local_stream.getTracks() if track.kind == "video"
+            ]
+            if local_video_tracks:
+                # Remove the old video track and add the new one to the local stream.
+                local_stream.removeTrack(local_video_tracks[0])
+                local_stream.addTrack(new_video_tracks[0])
+
+        video_sender = next(
+            (
+                sender
+                for sender in self._peer_connection.getSenders()
+                if sender.track and sender.track.kind == "video"
+            ),
+            None,
+        )
+        if video_sender:
+            await video_sender.replaceTrack(new_video_tracks[0])
+
+            if screen:
+                # For screen sharing, we track the end event to properly stop the sharing when
+                # the user clicks on the browser's stop sharing dialog.
+                def on_track_ended(event):
+                    aio.run(self.toggle_screen_sharing())
+
+                new_video_tracks[0].bind("ended", on_track_ended)
+
+        self.is_sharing_screen = screen
+
+        return local_stream
+
     async def _gather_ice_candidates(self, is_initiator: bool, remote_candidates=None):
         """Get ICE candidates and wait to have them all before returning them
 
@@ -260,14 +344,16 @@
         @param remote_candidates: Remote ICE candidates, if any
         """
         if self._peer_connection is None:
-            raise Exception("The peer connection must be created before gathering ICE candidates!")
+            raise Exception(
+                "The peer connection must be created before gathering ICE candidates!"
+            )
 
         self.media_candidates.clear()
         gather_timeout = timer.set_timeout(
             lambda: self.candidates_gathered.set_exception(
                 errors.TimeoutError("ICE gathering time out")
             ),
-            GATHER_TIMEOUT
+            GATHER_TIMEOUT,
         )
 
         if is_initiator:
@@ -298,10 +384,7 @@
         @param sdp: Session Description Protocol data
         @param profile: Profile associated
         """
-        await self._peer_connection.setRemoteDescription({
-            "type": "answer",
-            "sdp": sdp
-        })
+        await self._peer_connection.setRemoteDescription({"type": "answer", "sdp": sdp})
         await self.on_ice_candidates_new(self.candidates_buffer)
         self.candidates_buffer.clear()
 
@@ -313,9 +396,7 @@
         @param profile: Profile associated with the action
         """
         if sid != self.sid:
-            log.debug(
-                f"ignoring peer ice candidates for {sid=} ({self.sid=})."
-            )
+            log.debug(f"ignoring peer ice candidates for {sid=} ({self.sid=}).")
             return
         candidates = json.loads(candidates_s)
         aio.run(self.on_ice_candidates_new(candidates))
@@ -344,11 +425,9 @@
                 except Exception as e:
                     log.warning(e)
                     continue
-                ice_candidate = window.RTCIceCandidate.new({
-                    "candidate": candidate_sdp,
-                    "sdpMLineIndex": sdp_mline_index
-                }
-                                                           )
+                ice_candidate = window.RTCIceCandidate.new(
+                    {"candidate": candidate_sdp, "sdpMLineIndex": sdp_mline_index}
+                )
                 await self._peer_connection.addIceCandidate(ice_candidate)
 
     def on_track(self, event):
@@ -373,15 +452,12 @@
         """We respond to the call"""
         log.debug("answering call")
         if sid != self.sid:
-            raise Exception(
-                f"Internal Error: unexpected sid: {sid=} {self.sid=}"
-            )
+            raise Exception(f"Internal Error: unexpected sid: {sid=} {self.sid=}")
         await self._create_peer_connection()
 
-        await self._peer_connection.setRemoteDescription({
-            "type": "offer",
-            "sdp": offer_sdp
-        })
+        await self._peer_connection.setRemoteDescription(
+            {"type": "offer", "sdp": offer_sdp}
+        )
         await self.on_ice_candidates_new(self.candidates_buffer)
         self.candidates_buffer.clear()
         await self._get_user_media()
@@ -393,10 +469,7 @@
         await bridge.call_answer_sdp(sid, self._peer_connection.localDescription.sdp)
 
     async def make_call(
-        self,
-        callee_jid: jid.JID,
-        audio: bool = True,
-        video: bool = True
+        self, callee_jid: jid.JID, audio: bool = True, video: bool = True
     ) -> None:
         """Start a WebRTC call
 
@@ -407,14 +480,9 @@
         await self._get_user_media(audio, video)
         await self._gather_ice_candidates(True)
 
-        call_data = {
-            "sdp": self._peer_connection.localDescription.sdp
-        }
+        call_data = {"sdp": self._peer_connection.localDescription.sdp}
         log.info(f"calling {callee_jid!r}")
-        self.sid = await bridge.call_start(
-            str(callee_jid),
-            json.dumps(call_data)
-        )
+        self.sid = await bridge.call_start(str(callee_jid), json.dumps(call_data))
         log.debug(f"Call SID: {self.sid}")
 
     async def end_call(self) -> None:
@@ -423,9 +491,15 @@
             log.debug("There is currently no call to end.")
         else:
             self._peer_connection.removeEventListener("track", self.on_track)
-            self._peer_connection.removeEventListener("negotiationneeded", self.on_negotiation_needed)
-            self._peer_connection.removeEventListener("icecandidate", self.on_ice_candidate)
-            self._peer_connection.removeEventListener("icegatheringstatechange", self.on_ice_gathering_state_change)
+            self._peer_connection.removeEventListener(
+                "negotiationneeded", self.on_negotiation_needed
+            )
+            self._peer_connection.removeEventListener(
+                "icecandidate", self.on_ice_candidate
+            )
+            self._peer_connection.removeEventListener(
+                "icegatheringstatechange", self.on_ice_gathering_state_change
+            )
 
             # Base64 encoded 1x1 black pixel image
             # this is a trick to reset the image displayed, so we don't see last image of
@@ -462,8 +536,13 @@
         is_muted_attr = f"is_{media_type}_muted"
 
         if local_video.srcObject:
-            track_getter = getattr(local_video.srcObject, f"get{media_type.capitalize()}Tracks")
+            log.debug(f"{local_video.srcObject=}")
+            track_getter = getattr(
+                local_video.srcObject, f"get{media_type.capitalize()}Tracks"
+            )
+            log.debug("track go")
             for track in track_getter():
+                log.debug(f"{track=}")
                 track.enabled = not track.enabled
                 setattr(self, is_muted_attr, not track.enabled)
 
@@ -487,3 +566,11 @@
     def toggle_video_mute(self) -> bool:
         """Toggle mute/unmute for video tracks."""
         return self.toggle_media_mute("video")
+
+    async def toggle_screen_sharing(self):
+        log.debug(f"toggle_screen_sharing {self._is_sharing_screen=}")
+
+        if self._is_sharing_screen:
+            await self._replace_user_video(screen=False)
+        else:
+            await self._replace_user_video(screen=True)