Cast: receiver position and pause/play on both clients

The player's remote mode reads where the television is instead of the
local playhead, which drifts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 55 insertions, 0 deletions

diff --git a/packages/meshbay-client/src/cast-chromecast.js b/packages/meshbay-client/src/cast-chromecast.js
index 7fc8079..55deb5b 100644
--- a/packages/meshbay-client/src/cast-chromecast.js
+++ b/packages/meshbay-client/src/cast-chromecast.js
@@ -174,6 +174,7 @@ class CastChromecast {
 
     player.on('status', (status) => {
       debug(`[cast-chromecast] player status: ${status.playerState}`);
+      this._noteStatus(status);
     });
 
     debug(`[cast-chromecast] loading with ${subtitle?.url ? 'subtitles' : 'no subtitles'}`);
@@ -185,6 +186,7 @@ class CastChromecast {
         });
     });
 
+    this._noteStatus(status);
     debug(`[cast-chromecast] loaded on "${device.name}", state: ${status.playerState}`);
     return { deviceName: device.name, playerState: status.playerState };
   }
@@ -200,6 +202,7 @@ class CastChromecast {
           resolve(s);
         });
     });
+    this._noteStatus(status);
     debug(`[cast-chromecast] reloaded, state: ${status.playerState}`);
     return { playerState: status.playerState };
   }
@@ -215,10 +218,55 @@ class CastChromecast {
     this._cleanup();
   }
 
+  /**
+   * What the receiver last said, kept so the page can show where the
+   * *television* is: its playhead is not the local one, which started earlier
+   * and drifts. `currentTime` is on the stream's timeline — zero at the point
+   * the relay started — and the page adds that start.
+   */
+  _noteStatus(status) {
+    if (!status) return;
+    this._lastStatus = {
+      playerState: status.playerState || null,
+      idleReason: status.idleReason || null,
+      position: Number(status.currentTime) || 0,
+      at: Date.now(),
+    };
+  }
+
+  /** The receiver's position now: extrapolated while it plays, as its own clock does. */
+  _position() {
+    const s = this._lastStatus;
+    if (!s) return null;
+    return s.playerState === 'PLAYING' ? s.position + (Date.now() - s.at) / 1000 : s.position;
+  }
+
+  async pause() {
+    if (!this._player) throw new Error('Not connected');
+    const status = await new Promise((resolve, reject) => {
+      this._player.pause((err, s) => (err ? reject(err) : resolve(s)));
+    });
+    this._noteStatus(status);
+    return { playerState: status && status.playerState };
+  }
+
+  async play() {
+    if (!this._player) throw new Error('Not connected');
+    const status = await new Promise((resolve, reject) => {
+      this._player.play((err, s) => (err ? reject(err) : resolve(s)));
+    });
+    this._noteStatus(status);
+    return { playerState: status && status.playerState };
+  }
+
   getStatus() {
+    const s = this._lastStatus;
     return {
       connected: this._client !== null,
       deviceName: this._connectedDevice?.name || null,
+      playerState: s ? s.playerState : null,
+      idleReason: s ? s.idleReason : null,
+      position: this._client !== null ? this._position() : null,
     };
   }
 
@@ -229,6 +277,7 @@ class CastChromecast {
     this._client = null;
     this._player = null;
     this._connectedDevice = null;
+    this._lastStatus = null;
   }
 }
 
diff --git a/packages/meshbay-client/src/main.js b/packages/meshbay-client/src/main.js
index 0ad7e71..4c8707c 100644
--- a/packages/meshbay-client/src/main.js
+++ b/packages/meshbay-client/src/main.js
@@ -2330,6 +2330,10 @@ function registerBridge() {
       subtitle === undefined ? castRelay.subtitle : subtitle);
   });
 
+  // The player becomes a remote while casting: these drive the receiver.
+  handle('cast:chromecast:pause', async () => castChromecast.pause());
+  handle('cast:chromecast:play', async () => castChromecast.play());
+
   handle('cast:chromecast:disconnect', async () => {
     await castChromecast.disconnect();
     return true;
diff --git a/packages/meshbay-client/src/preload.js b/packages/meshbay-client/src/preload.js
index 665ec1f..43cf317 100644
--- a/packages/meshbay-client/src/preload.js
+++ b/packages/meshbay-client/src/preload.js
@@ -180,6 +180,8 @@ contextBridge.exposeInMainWorld('meshbay', {
     chromecastConnect: (opts) => ipcRenderer.invoke('cast:chromecast:connect', opts),
     chromecastReload: (opts) => ipcRenderer.invoke('cast:chromecast:reload', opts),
     chromecastDisconnect: () => ipcRenderer.invoke('cast:chromecast:disconnect'),
+    chromecastPause: () => ipcRenderer.invoke('cast:chromecast:pause'),
+    chromecastPlay: () => ipcRenderer.invoke('cast:chromecast:play'),
   },
 
   // A sink that writes to disk as chunks arrive, never a buffer handed over at