Draft generic audio manifest admission and public media adapter

2026-10-07 01:05:33 -04:00
parent 30b5975534
commit f1fb388ded
9 changed files with 251 additions and 14 deletions
@@ -0,0 +1,58 @@
+// Independently authored reference adapter for the public archipelago-v1 protocol.
+// No application authentication, signing keys or stream URLs cross this bridge.
+export function attachAudioBridge({ parentOrigin, snapshot, actions, unlocked = () => true, host = window }) {
+  const parsed = new URL(parentOrigin)
+  if (!['http:', 'https:'].includes(parsed.protocol) || parsed.origin !== parentOrigin || parsed.username || parsed.password) throw new Error('Configure an exact trusted dashboard origin')
+  if (host.parent === host) return { publish() {}, dispose() {} }
+  let session = null, closed = false, queue = Promise.resolve()
+  const send = data => host.parent.postMessage({ version: 1, ...data }, parentOrigin)
+  function publish() {
+    if (closed || !session) return
+    const state = unlocked() ? snapshot() : null
+    if (!state || typeof state.title !== 'string' || typeof state.artist !== 'string'
+      || typeof state.playing !== 'boolean' || typeof state.shuffle !== 'boolean'
+      || !Number.isFinite(state.position) || !Number.isFinite(state.duration) || state.position < 0 || state.duration < 0) {
+      send({type:'archipelago:media-state',session,available:false}); return
+    }
+    send({type:'archipelago:media-state',session,available:true,title:state.title.slice(0,256),artist:state.artist.slice(0,256),
+      playing:state.playing,shuffle:state.shuffle,position:Math.min(state.position,state.duration),duration:state.duration,
+      artwork:typeof state.artwork === 'string' ? state.artwork.slice(0,2048) : ''})
+  }
+  function message(event) {
+    if (closed || event.source !== host.parent || event.origin !== parentOrigin || event.data?.version !== 1) return
+    const data = event.data
+    if (data.type === 'archipelago:media-connect') {
+      if (typeof data.session !== 'string' || !/^[0-9a-f]{32}$/.test(data.session)) return
+      session = data.session; publish(); return
+    }
+    if (data.type !== 'archipelago:media-control' || !session || data.session !== session || !unlocked()) return
+    if (!['play','pause','seek','next','previous','shuffle','snapshot'].includes(data.command)) return
+    if (data.command === 'seek' && (!Number.isFinite(data.position) || data.position < 0)) return
+    const expected = session
+    queue = queue.catch(() => {}).then(async () => {
+      if (closed || session !== expected || !unlocked()) return
+      if (data.command !== 'snapshot') {
+        const action = actions[data.command]
+        if (typeof action !== 'function') return
+        const state = snapshot()
+        if (data.command === 'seek') {
+          if (!Number.isFinite(state?.duration) || state.duration < 0) return
+          await action(Math.min(data.position, state.duration))
+        } else await action()
+      }
+      if (!closed && session === expected) publish()
+    }).catch(() => { if (!closed && session === expected) publish() })
+  }
+  const ready = () => { if (!closed) send({type:'archipelago:media-ready'}) }
+  function dispose() {
+    if (closed) return
+    if (session) send({type:'archipelago:media-state',session,available:false})
+    closed = true; session = null
+    host.removeEventListener('message',message); host.removeEventListener('pageshow',ready); host.removeEventListener('pagehide',leave)
+    actions.pause?.()
+  }
+  function leave(event) { if (!event.persisted) dispose() }
+  host.addEventListener('message',message); host.addEventListener('pageshow',ready); host.addEventListener('pagehide',leave)
+  ready()
+  return { publish, dispose }
+}