RawCastClient.kt
1076 lines · 49.1 KB
Changed in: 0.5.0
| 1 | package dev.stave.cast.raw |
| 2 | |
| 3 | import kotlinx.coroutines.CoroutineScope |
| 4 | import kotlinx.coroutines.Dispatchers |
| 5 | import kotlinx.coroutines.SupervisorJob |
| 6 | import kotlinx.coroutines.cancel |
| 7 | import kotlinx.coroutines.currentCoroutineContext |
| 8 | import kotlinx.coroutines.delay |
| 9 | import kotlinx.coroutines.flow.MutableSharedFlow |
| 10 | import kotlinx.coroutines.flow.MutableStateFlow |
| 11 | import kotlinx.coroutines.flow.SharedFlow |
| 12 | import kotlinx.coroutines.flow.StateFlow |
| 13 | import kotlinx.coroutines.flow.asSharedFlow |
| 14 | import kotlinx.coroutines.flow.asStateFlow |
| 15 | import kotlinx.coroutines.isActive |
| 16 | import kotlinx.coroutines.launch |
| 17 | import kotlinx.coroutines.withContext |
| 18 | import org.json.JSONObject |
| 19 | import java.io.BufferedInputStream |
| 20 | import java.io.BufferedOutputStream |
| 21 | import java.io.ByteArrayOutputStream |
| 22 | import java.io.IOException |
| 23 | import java.io.InputStream |
| 24 | import java.io.OutputStream |
| 25 | import java.net.InetSocketAddress |
| 26 | import javax.net.ssl.SSLContext |
| 27 | import javax.net.ssl.SSLSocket |
| 28 | import javax.net.ssl.TrustManager |
| 29 | import javax.net.ssl.X509TrustManager |
| 30 | |
| 31 | /** |
| 32 | * Raw Cast protocol client for observing Chromecast sessions without the Cast SDK. |
| 33 | * |
| 34 | * Connects via TLS to port 8009 on any Chromecast/Chromecast Audio/group leader, |
| 35 | * discovers the active media session, and streams [MediaStatus] updates. Transport |
| 36 | * commands (play/pause/stop/seek/next/previous) are sent as JSON over the media |
| 37 | * namespace. |
| 38 | * |
| 39 | * This bypasses Google Play Services entirely and works on libre builds, the |
| 40 | * GNU/Linux desktop, or anywhere with a JDK and a TLS-capable socket. Ported |
| 41 | * from the Android TV implementation: the protocol code is identical, only the |
| 42 | * logging surface differs (`android.util.Log` → stderr in the |
| 43 | * `[EarhornCast/Raw]` channel matching the existing `CastIntegration` style). |
| 44 | * |
| 45 | * Protocol references: |
| 46 | * - github.com/thibauts/node-castv2 |
| 47 | * - github.com/home-assistant-libs/pychromecast |
| 48 | * - chromium.googlesource.com/.../cast_channel.proto |
| 49 | */ |
| 50 | class RawCastClient( |
| 51 | private val host: String, |
| 52 | private val port: Int = 8009, |
| 53 | ) { |
| 54 | companion object { |
| 55 | // Cast protocol namespaces |
| 56 | private const val NS_CONNECTION = "urn:x-cast:com.google.cast.tp.connection" |
| 57 | private const val NS_HEARTBEAT = "urn:x-cast:com.google.cast.tp.heartbeat" |
| 58 | private const val NS_RECEIVER = "urn:x-cast:com.google.cast.receiver" |
| 59 | private const val NS_MEDIA = "urn:x-cast:com.google.cast.media" |
| 60 | |
| 61 | private const val SENDER_ID = "sender-earhorn" |
| 62 | private const val RECEIVER_ID = "receiver-0" |
| 63 | |
| 64 | private const val HEARTBEAT_INTERVAL_MS = 5_000L |
| 65 | |
| 66 | /** No bytes from the receiver for this long = the socket is dead. |
| 67 | * Receivers answer every PING with a PONG (and send their own PINGs), |
| 68 | * so a live connection never goes quiet this long. Without it a |
| 69 | * speaker that lost power or Wi-Fi (no FIN) kept `connected` true |
| 70 | * until the kernel gave up on TCP retransmits, about 15 minutes, and |
| 71 | * the observer's reconnect never ran. Same budget as pychromecast |
| 72 | * (10 s ping + 10 s pong wait). */ |
| 73 | private const val RX_TIMEOUT_MS = 20_000L |
| 74 | private const val CONNECT_TIMEOUT_MS = 10_000 |
| 75 | |
| 76 | /** How long after a local [setVolume] incoming RECEIVER_STATUS volume |
| 77 | * readings are ignored. Long enough to outlive any status response |
| 78 | * that was already on the wire when the user clicked; short enough |
| 79 | * that genuine external changes (another sender's slider) surface |
| 80 | * within a poll cycle. */ |
| 81 | private const val VOLUME_ECHO_SUPPRESS_MS = 1_500L |
| 82 | |
| 83 | /** Diagnostic tag prefix. Matches `[EarhornCast]` from the sender-side |
| 84 | * integration so all cast-related output sits in one mental bucket. */ |
| 85 | private const val TAG = "[EarhornCast/Raw]" |
| 86 | } |
| 87 | |
| 88 | data class MediaStatus( |
| 89 | val title: String? = null, |
| 90 | val artist: String? = null, |
| 91 | val album: String? = null, |
| 92 | val albumArtUrl: String? = null, |
| 93 | val contentId: String? = null, |
| 94 | val duration: Double = 0.0, |
| 95 | val currentTime: Double = 0.0, |
| 96 | val playerState: String = "UNKNOWN", // PLAYING, PAUSED, IDLE, BUFFERING |
| 97 | val mediaSessionId: Int = 0, |
| 98 | val volume: Double = 1.0, |
| 99 | val isMuted: Boolean = false, |
| 100 | /** False until we have an authoritative DEVICE volume — from a |
| 101 | * RECEIVER_STATUS `volume` block, or latched by our own [setVolume]. |
| 102 | * (MEDIA_STATUS never contributes: its `volume` is the media STREAM |
| 103 | * volume, a different knob — see [handleMediaStatus].) UI |
| 104 | * surfaces use this to distinguish "we don't know what the device |
| 105 | * is at" (do not display the slider as if it's the truth, do not |
| 106 | * apply optimistic updates) from "device reported 100%." |
| 107 | * |
| 108 | * The default volume of 1.0 above is a placeholder used until the |
| 109 | * first authoritative value arrives; without this flag the slider |
| 110 | * would sit at 100% on attach and a user click anywhere below |
| 111 | * that — say at 30% on a device actually at 5% — would jump the |
| 112 | * audible level by 6x in a single command, feeling like a |
| 113 | * "volume blast" even though the new value is correct. */ |
| 114 | val volumeKnown: Boolean = false, |
| 115 | /** The receiver's authoritative "which queue item is playing" pointer — |
| 116 | * the `currentItemId` top-level field of MEDIA_STATUS. Cross-referenced |
| 117 | * against the QUEUE_ITEM_IDS order to derive the queue index. NEVER |
| 118 | * count the index locally; this value cannot drift from what's audible. |
| 119 | * Null until the receiver first reports it (or when the session has no |
| 120 | * receiver-side queue at all — e.g. a single-item load). Sticky across |
| 121 | * transport-only pushes that omit it, same as the metadata fields. */ |
| 122 | val currentItemId: Int? = null, |
| 123 | /** Advances by one for every MEDIA_STATUS the receiver sends, and for |
| 124 | * nothing else. RECEIVER_STATUS (device volume) copies keep it. The |
| 125 | * observer keys "is this a new playback report?" on this number |
| 126 | * (ported from Android, 2026-09-04: a volume report used to count as |
| 127 | * "same position twice" and hold the bar). */ |
| 128 | val statusSeq: Long = 0L, |
| 129 | /** Receiver queue repeat mode: REPEAT_OFF, REPEAT_ALL, REPEAT_SINGLE, |
| 130 | * REPEAT_ALL_AND_SHUFFLE; "" until reported. */ |
| 131 | val repeatMode: String = "", |
| 132 | ) |
| 133 | |
| 134 | // ── Receiver-queue introspection (follower queue) ──────────── |
| 135 | // |
| 136 | // The receiver is the source of truth for its queue and answers |
| 137 | // introspection requests from any connected peer — the same mechanism |
| 138 | // Google's own MediaQueue sender class uses. We expose the wire traffic |
| 139 | // as a stream of [QueueEvent]s; RawCastObserver owns the assembled |
| 140 | // queue state (ordering, item buffer, batching, debouncing). |
| 141 | |
| 142 | /** One queue entry as it appears in a QUEUE_ITEMS response (or the `items` |
| 143 | * array some receivers piggyback on MEDIA_STATUS pushes). Blank strings |
| 144 | * from lax JSON parsers are normalised to null before this is built. */ |
| 145 | data class QueueItemLite( |
| 146 | val itemId: Int, |
| 147 | val contentId: String?, |
| 148 | val title: String?, |
| 149 | val artist: String?, |
| 150 | val album: String?, |
| 151 | val albumArtUrl: String?, |
| 152 | val durationSeconds: Double?, |
| 153 | ) |
| 154 | |
| 155 | sealed interface QueueEvent { |
| 156 | /** QUEUE_ITEM_IDS response: the receiver's full ordered id list. */ |
| 157 | data class ItemIds(val itemIds: List<Int>) : QueueEvent |
| 158 | |
| 159 | /** QUEUE_ITEMS response batch — or items piggybacked on a MEDIA_STATUS |
| 160 | * push ([fromStatusPush] = true). Piggybacked payloads carry only the |
| 161 | * current (and sometimes preloaded) item; merge them opportunistically |
| 162 | * so the now-playing row has metadata before the batched fetch lands, |
| 163 | * but never treat them as a complete queue. */ |
| 164 | data class Items( |
| 165 | val items: List<QueueItemLite>, |
| 166 | val fromStatusPush: Boolean = false, |
| 167 | ) : QueueEvent |
| 168 | |
| 169 | /** QUEUE_CHANGE broadcast — the receiver announcing that *some* sender |
| 170 | * edited the queue. [changeType] is ITEMS_CHANGED|INSERT|REMOVE|UPDATE. |
| 171 | * The correct reaction is a (debounced) refetch of the id list. */ |
| 172 | data class Change(val changeType: String, val itemIds: List<Int>) : QueueEvent |
| 173 | |
| 174 | /** mediaSessionId transitioned to a new non-zero value — a new load, |
| 175 | * which means a new receiver-side queue. Everything buffered for the |
| 176 | * old session is invalid. */ |
| 177 | data class SessionChanged(val mediaSessionId: Int) : QueueEvent |
| 178 | } |
| 179 | |
| 180 | private val _queueEvents = MutableSharedFlow<QueueEvent>( |
| 181 | // Queue traffic is bursty (batched QUEUE_ITEMS during a refetch) and |
| 182 | // every event is recoverable by a fresh refetch, so a bounded buffer |
| 183 | // with drop-oldest is the right failure mode — never suspend the read |
| 184 | // loop on a slow collector. |
| 185 | extraBufferCapacity = 256, |
| 186 | onBufferOverflow = kotlinx.coroutines.channels.BufferOverflow.DROP_OLDEST, |
| 187 | ) |
| 188 | /** Wire-level queue traffic. Collected by [RawCastObserver]'s queue manager. */ |
| 189 | val queueEvents: SharedFlow<QueueEvent> = _queueEvents.asSharedFlow() |
| 190 | |
| 191 | private val _mediaStatus = MutableStateFlow(MediaStatus()) |
| 192 | val mediaStatus: StateFlow<MediaStatus> = _mediaStatus.asStateFlow() |
| 193 | |
| 194 | private val _connected = MutableStateFlow(false) |
| 195 | val connected: StateFlow<Boolean> = _connected.asStateFlow() |
| 196 | |
| 197 | // Written by connect()/disconnect() and the reader thread, read by command |
| 198 | // callers on other threads, hence @Volatile. |
| 199 | @Volatile private var socket: SSLSocket? = null |
| 200 | @Volatile private var output: OutputStream? = null |
| 201 | @Volatile private var input: InputStream? = null |
| 202 | @Volatile private var scope: CoroutineScope? = null |
| 203 | @Volatile private var transportId: String? = null |
| 204 | /** Wall-clock of the last frame read from the socket (any namespace). */ |
| 205 | @Volatile private var lastRxAt: Long = 0L |
| 206 | private var requestId = 1 |
| 207 | /** Wall-clock of the last RECEIVER_STATUS, idle or not (ported from Android). */ |
| 208 | @Volatile var lastReceiverStatusAt: Long = 0L |
| 209 | private set |
| 210 | /** Log every non-heartbeat message with a payload preview. Off by default: |
| 211 | * one line per status, every few seconds, forever, on every desktop. */ |
| 212 | @Volatile var verboseWireLog: Boolean = false |
| 213 | |
| 214 | /** Wallclock of the most recent local [setVolume]. RECEIVER_STATUS volume |
| 215 | * ingest is suppressed for [VOLUME_ECHO_SUPPRESS_MS] after this so a |
| 216 | * status that was already in flight when the user clicked (carrying the |
| 217 | * OLD device level) can't briefly bounce the slider back before the |
| 218 | * post-set broadcast confirms the new value. Written on the caller's |
| 219 | * coroutine, read on the socket-reader coroutine — hence @Volatile. */ |
| 220 | @Volatile |
| 221 | private var localVolumeSetAtMs = 0L |
| 222 | |
| 223 | // ── Connect / Disconnect ───────────────────────────────────── |
| 224 | |
| 225 | suspend fun connect() = withContext(Dispatchers.IO) { |
| 226 | disconnect() |
| 227 | val sc = CoroutineScope(SupervisorJob() + Dispatchers.IO) |
| 228 | scope = sc |
| 229 | |
| 230 | System.err.println("$TAG connecting to $host:$port") |
| 231 | // TLS with permissive trust (Chromecast uses self-signed certs) |
| 232 | val sslContext = SSLContext.getInstance("TLS") |
| 233 | sslContext.init(null, arrayOf<TrustManager>(PermissiveTrustManager), null) |
| 234 | val factory = sslContext.socketFactory |
| 235 | |
| 236 | val sock = factory.createSocket() as SSLSocket |
| 237 | // Published before connecting so a disconnect() from another thread |
| 238 | // (the user stops following mid-connect) closes it and aborts the |
| 239 | // blocking connect/handshake instead of waiting for the timeouts. |
| 240 | socket = sock |
| 241 | try { |
| 242 | sock.connect(InetSocketAddress(host, port), CONNECT_TIMEOUT_MS) |
| 243 | // The handshake had no timeout: a receiver that accepts and stalls |
| 244 | // pinned this thread until it let go. Reset after — the read loop |
| 245 | // blocks on purpose. |
| 246 | sock.soTimeout = CONNECT_TIMEOUT_MS |
| 247 | sock.startHandshake() |
| 248 | sock.soTimeout = 0 |
| 249 | output = BufferedOutputStream(sock.outputStream) |
| 250 | input = BufferedInputStream(sock.inputStream) |
| 251 | } catch (t: Throwable) { |
| 252 | // A timeout or TLS failure used to leave the socket's fd open, |
| 253 | // once per reconnect attempt. |
| 254 | runCatching { sock.close() } |
| 255 | if (socket === sock) socket = null |
| 256 | sc.cancel() |
| 257 | if (scope === sc) scope = null |
| 258 | throw t |
| 259 | } |
| 260 | lastRxAt = System.currentTimeMillis() |
| 261 | _connected.value = true |
| 262 | System.err.println("$TAG TLS handshake OK — sending CONNECT + GET_STATUS") |
| 263 | |
| 264 | // Start reader + heartbeat |
| 265 | sc.launch { readLoop(sock) } |
| 266 | sc.launch { heartbeatLoop(sock) } |
| 267 | |
| 268 | // Connect to receiver platform |
| 269 | sendJson(RECEIVER_ID, NS_CONNECTION, """{"type":"CONNECT","origin":{}}""") |
| 270 | // Get receiver status to discover active app/session |
| 271 | sendJson( |
| 272 | RECEIVER_ID, NS_RECEIVER, |
| 273 | """{"type":"GET_STATUS","requestId":${nextRequestId()}}""", |
| 274 | ) |
| 275 | } |
| 276 | |
| 277 | fun disconnect() { |
| 278 | if (_connected.value || socket != null) { |
| 279 | System.err.println("$TAG disconnecting from $host:$port") |
| 280 | } |
| 281 | scope?.cancel() |
| 282 | scope = null |
| 283 | runCatching { socket?.close() } |
| 284 | socket = null |
| 285 | output = null |
| 286 | input = null |
| 287 | transportId = null |
| 288 | _connected.value = false |
| 289 | } |
| 290 | |
| 291 | // ── Transport commands ─────────────────────────────────────── |
| 292 | |
| 293 | suspend fun play() = sendMediaCommand("PLAY") |
| 294 | suspend fun pause() = sendMediaCommand("PAUSE") |
| 295 | suspend fun stop() = sendMediaCommand("STOP") |
| 296 | |
| 297 | suspend fun seek(positionSeconds: Double) { |
| 298 | val tid = transportId ?: return |
| 299 | val msid = _mediaStatus.value.mediaSessionId |
| 300 | if (msid == 0) return |
| 301 | sendJson( |
| 302 | tid, NS_MEDIA, |
| 303 | """{"type":"SEEK","mediaSessionId":$msid,"currentTime":$positionSeconds,"requestId":${nextRequestId()}}""", |
| 304 | ) |
| 305 | } |
| 306 | |
| 307 | suspend fun next() { |
| 308 | val tid = transportId ?: return |
| 309 | val msid = _mediaStatus.value.mediaSessionId |
| 310 | if (msid == 0) return |
| 311 | sendJson( |
| 312 | tid, NS_MEDIA, |
| 313 | """{"type":"QUEUE_NEXT","mediaSessionId":$msid,"requestId":${nextRequestId()}}""", |
| 314 | ) |
| 315 | } |
| 316 | |
| 317 | suspend fun previous() { |
| 318 | val tid = transportId ?: return |
| 319 | val msid = _mediaStatus.value.mediaSessionId |
| 320 | if (msid == 0) return |
| 321 | sendJson( |
| 322 | tid, NS_MEDIA, |
| 323 | """{"type":"QUEUE_PREV","mediaSessionId":$msid,"requestId":${nextRequestId()}}""", |
| 324 | ) |
| 325 | } |
| 326 | |
| 327 | suspend fun setVolume(level: Double) { |
| 328 | // Optimistically reflect the new level in our own MediaStatus BEFORE |
| 329 | // sending. The observer bridges _mediaStatus → PlaybackState on every |
| 330 | // emission; MEDIA_STATUS payloads never contribute volume (their |
| 331 | // `volume` field is the media STREAM volume — see the note in |
| 332 | // [handleMediaStatus]), so this optimistic write is the baseline every |
| 333 | // subsequent media update preserves. An authoritative RECEIVER_STATUS |
| 334 | // still wins if the device reports something different — but only |
| 335 | // after [VOLUME_ECHO_SUPPRESS_MS], so a status already in flight with |
| 336 | // the OLD level can't bounce the slider before the post-set broadcast |
| 337 | // lands (see [handleReceiverStatus]). |
| 338 | val clamped = level.coerceIn(0.0, 1.0) |
| 339 | localVolumeSetAtMs = System.currentTimeMillis() |
| 340 | _mediaStatus.value = _mediaStatus.value.copy(volume = clamped, volumeKnown = true) |
| 341 | sendJson( |
| 342 | RECEIVER_ID, NS_RECEIVER, |
| 343 | """{"type":"SET_VOLUME","volume":{"level":$clamped},"requestId":${nextRequestId()}}""", |
| 344 | ) |
| 345 | } |
| 346 | |
| 347 | /** Re-request current media status from the Chromecast. Called periodically |
| 348 | * to catch any MEDIA_STATUS broadcasts that were missed. */ |
| 349 | suspend fun requestMediaStatus() { |
| 350 | val tid = transportId ?: return |
| 351 | sendJson( |
| 352 | tid, NS_MEDIA, |
| 353 | """{"type":"GET_STATUS","requestId":${nextRequestId()}}""", |
| 354 | ) |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * Re-request the device's RECEIVER_STATUS. Unlike [requestMediaStatus], this |
| 359 | * goes to the receiver-platform namespace and reliably returns a payload |
| 360 | * with the `volume` sub-object — MEDIA_STATUS broadcasts often omit it |
| 361 | * after the initial connect because volume changes are infrequent. The |
| 362 | * observer uses this on attach (with backoff) to bootstrap an |
| 363 | * authoritative volume reading; without it the slider sits on the |
| 364 | * default 100% until something happens to make the receiver re-broadcast, |
| 365 | * which on a steady-state PLAYING session may never happen. |
| 366 | */ |
| 367 | suspend fun requestReceiverStatus() { |
| 368 | sendJson( |
| 369 | RECEIVER_ID, NS_RECEIVER, |
| 370 | """{"type":"GET_STATUS","requestId":${nextRequestId()}}""", |
| 371 | ) |
| 372 | } |
| 373 | |
| 374 | // ── Queue introspection commands ───────────────────────────── |
| 375 | // |
| 376 | // All three go to the app transportId (NOT receiver-0) on the media |
| 377 | // namespace, and all require a live mediaSessionId from MEDIA_STATUS — |
| 378 | // the guards below silently no-op until both are known, which matches |
| 379 | // how transport commands already behave. |
| 380 | |
| 381 | /** Ask the receiver for its ordered queue-item id list. The response |
| 382 | * arrives asynchronously as a [QueueEvent.ItemIds]. */ |
| 383 | suspend fun requestQueueItemIds() { |
| 384 | val tid = transportId ?: return |
| 385 | val msid = _mediaStatus.value.mediaSessionId |
| 386 | if (msid == 0) return |
| 387 | sendJson( |
| 388 | tid, NS_MEDIA, |
| 389 | """{"type":"QUEUE_GET_ITEM_IDS","mediaSessionId":$msid,"requestId":${nextRequestId()}}""", |
| 390 | ) |
| 391 | } |
| 392 | |
| 393 | /** Fetch metadata for a batch of queue item ids. Callers chunk to the |
| 394 | * shared batch size (20); the response arrives as [QueueEvent.Items]. */ |
| 395 | suspend fun requestQueueItems(itemIds: List<Int>) { |
| 396 | if (itemIds.isEmpty()) return |
| 397 | val tid = transportId ?: return |
| 398 | val msid = _mediaStatus.value.mediaSessionId |
| 399 | if (msid == 0) return |
| 400 | val ids = itemIds.joinToString(",") |
| 401 | sendJson( |
| 402 | tid, NS_MEDIA, |
| 403 | """{"type":"QUEUE_GET_ITEMS","mediaSessionId":$msid,"itemIds":[$ids],"requestId":${nextRequestId()}}""", |
| 404 | ) |
| 405 | } |
| 406 | |
| 407 | /** |
| 408 | * Jump the receiver's playback position to [itemId] — position-only, |
| 409 | * queue contents untouched. This is the ONLY queue mutation a follower |
| 410 | * is allowed to send: the driving sender's local queue is authoritative |
| 411 | * and (on Android at least) it full-reloads the receiver queue on its |
| 412 | * own edits, so a follower REMOVE/REORDER would be silently clobbered |
| 413 | * and desync the sender in the interim. QUEUE_UPDATE with currentItemId |
| 414 | * is safe because the sender's index tracker follows the receiver via |
| 415 | * its own status callbacks. |
| 416 | */ |
| 417 | /** Set the receiver queue's repeat mode (QUEUE_UPDATE.repeatMode). */ |
| 418 | suspend fun setRepeatMode(mode: String) { |
| 419 | val tid = transportId ?: return |
| 420 | val msid = _mediaStatus.value.mediaSessionId |
| 421 | if (msid == 0) return |
| 422 | sendJson( |
| 423 | tid, NS_MEDIA, |
| 424 | """{"type":"QUEUE_UPDATE","mediaSessionId":$msid,"repeatMode":"$mode","requestId":${nextRequestId()}}""", |
| 425 | ) |
| 426 | } |
| 427 | |
| 428 | /** Shuffle the receiver queue (QUEUE_UPDATE.shuffle). */ |
| 429 | suspend fun setShuffle(on: Boolean) { |
| 430 | val tid = transportId ?: return |
| 431 | val msid = _mediaStatus.value.mediaSessionId |
| 432 | if (msid == 0) return |
| 433 | sendJson( |
| 434 | tid, NS_MEDIA, |
| 435 | """{"type":"QUEUE_UPDATE","mediaSessionId":$msid,"shuffle":$on,"requestId":${nextRequestId()}}""", |
| 436 | ) |
| 437 | } |
| 438 | |
| 439 | suspend fun queueJumpTo(itemId: Int) { |
| 440 | val tid = transportId ?: return |
| 441 | val msid = _mediaStatus.value.mediaSessionId |
| 442 | if (msid == 0) return |
| 443 | sendJson( |
| 444 | tid, NS_MEDIA, |
| 445 | """{"type":"QUEUE_UPDATE","mediaSessionId":$msid,"currentItemId":$itemId,"requestId":${nextRequestId()}}""", |
| 446 | ) |
| 447 | } |
| 448 | |
| 449 | private suspend fun sendMediaCommand(type: String) { |
| 450 | val tid = transportId ?: return |
| 451 | val msid = _mediaStatus.value.mediaSessionId |
| 452 | if (msid == 0) return |
| 453 | sendJson( |
| 454 | tid, NS_MEDIA, |
| 455 | """{"type":"$type","mediaSessionId":$msid,"requestId":${nextRequestId()}}""", |
| 456 | ) |
| 457 | } |
| 458 | |
| 459 | // ── Message I/O ───────────────────────────────────────────── |
| 460 | |
| 461 | private suspend fun sendJson( |
| 462 | destinationId: String, |
| 463 | namespace: String, |
| 464 | json: String, |
| 465 | ) = withContext(Dispatchers.IO) { |
| 466 | val msg = CastMessageCodec.encode( |
| 467 | sourceId = SENDER_ID, |
| 468 | destinationId = destinationId, |
| 469 | namespace = namespace, |
| 470 | payloadUtf8 = json, |
| 471 | ) |
| 472 | val lenBuf = ByteArray(4) |
| 473 | lenBuf[0] = (msg.size shr 24 and 0xFF).toByte() |
| 474 | lenBuf[1] = (msg.size shr 16 and 0xFF).toByte() |
| 475 | lenBuf[2] = (msg.size shr 8 and 0xFF).toByte() |
| 476 | lenBuf[3] = (msg.size and 0xFF).toByte() |
| 477 | val sock = socket |
| 478 | val out = output ?: return@withContext |
| 479 | // Ported from Android: a write on a dead socket (receiver rebooted, |
| 480 | // network drop) is the earliest sign the connection is gone, since |
| 481 | // the read loop may block forever on a half-open socket. Mark the |
| 482 | // connection lost so the observer's reconnect supervisor runs, and |
| 483 | // don't throw into the caller (commands are fire-and-forget). |
| 484 | try { |
| 485 | synchronized(out) { |
| 486 | out.write(lenBuf) |
| 487 | out.write(msg) |
| 488 | out.flush() |
| 489 | } |
| 490 | } catch (e: IOException) { |
| 491 | System.err.println("$TAG send failed (${e.message}) — marking connection lost") |
| 492 | markLost(sock) |
| 493 | } |
| 494 | } |
| 495 | |
| 496 | /** Flag the connection lost, but only if [sock] is still the current |
| 497 | * socket: a reader or writer of a socket that a reconnect has already |
| 498 | * replaced must not knock the new connection's flag back to false. */ |
| 499 | private fun markLost(sock: SSLSocket?) { |
| 500 | if (sock != null && socket === sock) _connected.value = false |
| 501 | } |
| 502 | |
| 503 | private suspend fun readLoop(sock: SSLSocket) { |
| 504 | try { |
| 505 | val inp = input ?: return |
| 506 | val lenBuf = ByteArray(4) |
| 507 | while (currentCoroutineContext().isActive) { |
| 508 | // Read 4-byte length prefix |
| 509 | readFully(inp, lenBuf) |
| 510 | val len = (lenBuf[0].toInt() and 0xFF shl 24) or |
| 511 | (lenBuf[1].toInt() and 0xFF shl 16) or |
| 512 | (lenBuf[2].toInt() and 0xFF shl 8) or |
| 513 | (lenBuf[3].toInt() and 0xFF) |
| 514 | if (len <= 0 || len > 1_000_000) { |
| 515 | // Desynchronised stream: skipping the prefix would parse |
| 516 | // payload bytes as the next length. Drop the connection. |
| 517 | System.err.println("$TAG bad length prefix $len — marking connection lost") |
| 518 | markLost(sock) |
| 519 | return |
| 520 | } |
| 521 | |
| 522 | val msgBuf = ByteArray(len) |
| 523 | readFully(inp, msgBuf) |
| 524 | lastRxAt = System.currentTimeMillis() |
| 525 | |
| 526 | val decoded = CastMessageCodec.decode(msgBuf) ?: continue |
| 527 | handleMessage(decoded) |
| 528 | } |
| 529 | } catch (e: IOException) { |
| 530 | // Connection lost (or closed by disconnect(); markLost ignores |
| 531 | // a socket that has already been replaced). |
| 532 | markLost(sock) |
| 533 | } catch (e: kotlinx.coroutines.CancellationException) { |
| 534 | throw e |
| 535 | } catch (t: Throwable) { |
| 536 | // Anything else used to kill this coroutine silently while the |
| 537 | // heartbeat kept the socket "connected" — a mute socket. |
| 538 | System.err.println("$TAG read loop died (${t.javaClass.simpleName}: ${t.message}) — marking connection lost") |
| 539 | markLost(sock) |
| 540 | } |
| 541 | } |
| 542 | |
| 543 | private fun readFully(inp: InputStream, buf: ByteArray) { |
| 544 | var offset = 0 |
| 545 | while (offset < buf.size) { |
| 546 | val n = inp.read(buf, offset, buf.size - offset) |
| 547 | if (n < 0) throw IOException("End of stream") |
| 548 | offset += n |
| 549 | } |
| 550 | } |
| 551 | |
| 552 | private suspend fun heartbeatLoop(sock: SSLSocket) { |
| 553 | while (currentCoroutineContext().isActive) { |
| 554 | delay(HEARTBEAT_INTERVAL_MS) |
| 555 | if (socket !== sock) return |
| 556 | // Rx watchdog: a socket that has gone silent past RX_TIMEOUT_MS is |
| 557 | // dead even though nothing has told us so (no FIN, read blocked). |
| 558 | // Closing it unblocks the read loop; marking it lost starts the |
| 559 | // observer's reconnect supervisor now rather than in ~15 minutes. |
| 560 | val quietMs = System.currentTimeMillis() - lastRxAt |
| 561 | if (quietMs > RX_TIMEOUT_MS) { |
| 562 | System.err.println("$TAG nothing received for ${quietMs / 1000}s — marking connection lost") |
| 563 | markLost(sock) |
| 564 | runCatching { sock.close() } |
| 565 | return |
| 566 | } |
| 567 | // sendJson handles IOException itself (marks the connection lost). |
| 568 | sendJson(RECEIVER_ID, NS_HEARTBEAT, """{"type":"PING"}""") |
| 569 | } |
| 570 | } |
| 571 | |
| 572 | // ── Message handling ──────────────────────────────────────── |
| 573 | |
| 574 | private suspend fun handleMessage(msg: CastMessageCodec.DecodedMessage) { |
| 575 | val json = runCatching { JSONObject(msg.payloadUtf8) }.getOrNull() |
| 576 | ?: return |
| 577 | val type = json.optString("type", "") |
| 578 | |
| 579 | // Diagnostic — skip heartbeat to keep output readable; log everything |
| 580 | // else with a truncated payload preview. Filter on "[EarhornCast/Raw]" |
| 581 | // in stderr to see the receiver's message flow during a session. Useful |
| 582 | // when a device gets stuck on "Waiting for…" — the output will show |
| 583 | // whether MEDIA_STATUS is arriving at all, and what it contains. |
| 584 | if (verboseWireLog && msg.namespace != NS_HEARTBEAT) { |
| 585 | val preview = msg.payloadUtf8.take(280) + |
| 586 | if (msg.payloadUtf8.length > 280) "…" else "" |
| 587 | System.err.println( |
| 588 | "$TAG rx ns=${msg.namespace.removePrefix("urn:x-cast:com.google.cast.")} " + |
| 589 | "type=$type payload=$preview", |
| 590 | ) |
| 591 | } |
| 592 | |
| 593 | when (msg.namespace) { |
| 594 | NS_HEARTBEAT -> { |
| 595 | if (type == "PING") { |
| 596 | sendJson(msg.sourceId, NS_HEARTBEAT, """{"type":"PONG"}""") |
| 597 | } |
| 598 | } |
| 599 | |
| 600 | NS_RECEIVER -> { |
| 601 | if (type == "RECEIVER_STATUS") { |
| 602 | handleReceiverStatus(json) |
| 603 | } |
| 604 | } |
| 605 | |
| 606 | NS_MEDIA -> { |
| 607 | when (type) { |
| 608 | "MEDIA_STATUS" -> handleMediaStatus(json) |
| 609 | |
| 610 | "QUEUE_ITEM_IDS" -> { |
| 611 | val arr = json.optJSONArray("itemIds") |
| 612 | val ids = if (arr == null) emptyList() else { |
| 613 | (0 until arr.length()).mapNotNull { i -> |
| 614 | arr.optInt(i, -1).takeIf { it > 0 } |
| 615 | } |
| 616 | } |
| 617 | _queueEvents.tryEmit(QueueEvent.ItemIds(ids)) |
| 618 | } |
| 619 | |
| 620 | "QUEUE_ITEMS" -> { |
| 621 | val arr = json.optJSONArray("items") |
| 622 | if (arr != null) { |
| 623 | val items = (0 until arr.length()).mapNotNull { i -> |
| 624 | parseQueueItem(arr.optJSONObject(i)) |
| 625 | } |
| 626 | if (items.isNotEmpty()) { |
| 627 | _queueEvents.tryEmit(QueueEvent.Items(items)) |
| 628 | } |
| 629 | } |
| 630 | } |
| 631 | |
| 632 | "QUEUE_CHANGE" -> { |
| 633 | val changeType = json.optString("changeType", "ITEMS_CHANGED") |
| 634 | val arr = json.optJSONArray("itemIds") |
| 635 | val ids = if (arr == null) emptyList() else { |
| 636 | (0 until arr.length()).mapNotNull { i -> |
| 637 | arr.optInt(i, -1).takeIf { it > 0 } |
| 638 | } |
| 639 | } |
| 640 | _queueEvents.tryEmit(QueueEvent.Change(changeType, ids)) |
| 641 | } |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | NS_CONNECTION -> { |
| 646 | if (type == "CLOSE") { |
| 647 | // Session ended |
| 648 | System.err.println("$TAG transport session CLOSE from ${msg.sourceId}") |
| 649 | transportId = null |
| 650 | // Keep the DEVICE volume reading: it belongs to the |
| 651 | // receiver, not the session that just ended. Resetting it |
| 652 | // locked the follower's volume slider (volumeKnown=false) |
| 653 | // until the next RECEIVER_STATUS with a volume block. |
| 654 | val prev = _mediaStatus.value |
| 655 | _mediaStatus.value = MediaStatus( |
| 656 | volume = prev.volume, |
| 657 | isMuted = prev.isMuted, |
| 658 | volumeKnown = prev.volumeKnown, |
| 659 | statusSeq = prev.statusSeq + 1, |
| 660 | ) |
| 661 | } |
| 662 | } |
| 663 | } |
| 664 | } |
| 665 | |
| 666 | private suspend fun handleReceiverStatus(json: JSONObject) { |
| 667 | val status = json.optJSONObject("status") ?: return |
| 668 | lastReceiverStatusAt = System.currentTimeMillis() |
| 669 | val apps = status.optJSONArray("applications") |
| 670 | if (apps == null || apps.length() == 0) { |
| 671 | // No media app running. Now that the observer polls NS_RECEIVER |
| 672 | // every 3s (for device volume), this branch fires continuously on |
| 673 | // an idle device — so it logs and tears down only on the |
| 674 | // TRANSITION (we previously had a transport, now the app is |
| 675 | // gone), and stays silent while already idle. Clearing |
| 676 | // [transportId] mirrors the CLOSE handler: the old transport is |
| 677 | // dead, and nulling it turns subsequent media polls/commands |
| 678 | // into no-ops instead of writes to a defunct session. Track |
| 679 | // metadata stays sticky (art/title shouldn't vanish); only the |
| 680 | // transport state drops to IDLE, same as the empty-status-array |
| 681 | // branch of [handleMediaStatus]. |
| 682 | // Also when transportId is already null but the last status still |
| 683 | // claims a live session: after a reconnect, connect() has cleared |
| 684 | // transportId, and a recovered device that reports no app is the |
| 685 | // only evidence the old session is gone (ported from Android's |
| 686 | // 2026-08-28 fix). Without this a stale PLAYING state stuck until |
| 687 | // the observer's 150 s silence watchdog. |
| 688 | val ms0 = _mediaStatus.value |
| 689 | if (transportId != null || (ms0.mediaSessionId != 0 && ms0.playerState != "IDLE")) { |
| 690 | System.err.println( |
| 691 | "$TAG RECEIVER_STATUS reports no running media app — session ended; detaching transport", |
| 692 | ) |
| 693 | transportId = null |
| 694 | _mediaStatus.value = _mediaStatus.value.let { |
| 695 | it.copy(playerState = "IDLE", currentTime = 0.0, statusSeq = it.statusSeq + 1) |
| 696 | } |
| 697 | } |
| 698 | return |
| 699 | } |
| 700 | |
| 701 | // Pick the app that actually owns the media namespace, not just apps[0]. |
| 702 | // CCA groups in particular run TWO apps simultaneously when a session is |
| 703 | // active: the "Multizone Leader" (managing audio sync across followers, |
| 704 | // exposes its own namespaces but NOT media), and the sender's actual |
| 705 | // receiver app (Default Media Receiver, Spotify, etc — exposes |
| 706 | // urn:x-cast:com.google.cast.media). Attaching to the leader gives us a |
| 707 | // working channel that never delivers MEDIA_STATUS payloads, which is |
| 708 | // why the UI was sitting at "Nothing playing" while the user could hear |
| 709 | // music: transport state was syncing via the receiver's other channels, |
| 710 | // but media metadata only rides on the media namespace. |
| 711 | // |
| 712 | // Fallback to apps[0] if no app exposes the media namespace (e.g., the |
| 713 | // device is showing only a leader or a non-media app) — preserves the |
| 714 | // pre-fix behavior in the unlikely edge case rather than silently doing |
| 715 | // nothing. |
| 716 | val app = (0 until apps.length()).map { apps.getJSONObject(it) } |
| 717 | .firstOrNull { candidate -> |
| 718 | val ns = candidate.optJSONArray("namespaces") ?: return@firstOrNull false |
| 719 | (0 until ns.length()).any { i -> |
| 720 | ns.getJSONObject(i).optString("name") == NS_MEDIA |
| 721 | } |
| 722 | } ?: apps.getJSONObject(0) |
| 723 | |
| 724 | val tid = app.optString("transportId", "") |
| 725 | val appId = app.optString("appId", "") |
| 726 | val displayName = app.optString("displayName", "") |
| 727 | if (tid.isBlank()) { |
| 728 | System.err.println( |
| 729 | "$TAG RECEIVER_STATUS app has no transportId — appId=$appId displayName=$displayName", |
| 730 | ) |
| 731 | return |
| 732 | } |
| 733 | |
| 734 | // Extract DEVICE volume. RECEIVER_STATUS is the one place the real |
| 735 | // device/group level lives (MEDIA_STATUS only ever carries the media |
| 736 | // STREAM volume — see [handleMediaStatus]). Skip the copy inside the |
| 737 | // short post-[setVolume] window: a GET_STATUS response that was |
| 738 | // already in flight when the user clicked still reports the OLD |
| 739 | // level, and ingesting it would bounce the slider back for a beat |
| 740 | // before the volume-change broadcast confirms the new value. After |
| 741 | // the window the receiver is authoritative again, which is what lets |
| 742 | // volume changes made by OTHER senders (the phone's slider) track. |
| 743 | val vol = status.optJSONObject("volume") |
| 744 | val sinceLocalSet = System.currentTimeMillis() - localVolumeSetAtMs |
| 745 | if (vol != null && sinceLocalSet > VOLUME_ECHO_SUPPRESS_MS) { |
| 746 | _mediaStatus.value = _mediaStatus.value.copy( |
| 747 | volume = vol.optDouble("level", 1.0), |
| 748 | isMuted = vol.optBoolean("muted", false), |
| 749 | volumeKnown = true, |
| 750 | ) |
| 751 | } |
| 752 | |
| 753 | if (tid != transportId) { |
| 754 | System.err.println( |
| 755 | "$TAG attaching to media-app transport tid=$tid appId=$appId displayName=$displayName", |
| 756 | ) |
| 757 | transportId = tid |
| 758 | // Connect to the app's transport and get media status |
| 759 | sendJson(tid, NS_CONNECTION, """{"type":"CONNECT","origin":{}}""") |
| 760 | sendJson( |
| 761 | tid, NS_MEDIA, |
| 762 | """{"type":"GET_STATUS","requestId":${nextRequestId()}}""", |
| 763 | ) |
| 764 | } |
| 765 | } |
| 766 | |
| 767 | private fun handleMediaStatus(json: JSONObject) { |
| 768 | val statusArray = json.optJSONArray("status") ?: return |
| 769 | if (statusArray.length() == 0) { |
| 770 | // Empty status = idle. Don't wipe the previously-seen track metadata — |
| 771 | // a tap of "stop" briefly returns an empty status array before the next |
| 772 | // track loads, and the user shouldn't see the album art / title vanish |
| 773 | // for the millisecond between broadcasts. |
| 774 | _mediaStatus.value = _mediaStatus.value.let { |
| 775 | it.copy(playerState = "IDLE", currentTime = 0.0, statusSeq = it.statusSeq + 1) |
| 776 | } |
| 777 | return |
| 778 | } |
| 779 | |
| 780 | val previous = _mediaStatus.value |
| 781 | val s = statusArray.getJSONObject(0) |
| 782 | |
| 783 | // Always-present transport fields. Fall back to previous when the receiver |
| 784 | // omits a field rather than to a hardcoded default — receivers do send |
| 785 | // partial updates and we don't want a missing field to overwrite a known |
| 786 | // value with garbage. |
| 787 | val playerState = s.optString("playerState", previous.playerState) |
| 788 | .ifBlank { previous.playerState } |
| 789 | val currentTime = s.optDouble("currentTime", previous.currentTime) |
| 790 | val mediaSessionId = s.optInt("mediaSessionId", previous.mediaSessionId) |
| 791 | .let { if (it == 0) previous.mediaSessionId else it } |
| 792 | |
| 793 | // New load = new receiver-side queue. Tell the queue manager so it can |
| 794 | // clear everything buffered for the old session and refetch. The very |
| 795 | // first MEDIA_STATUS after connect also lands here (previous id is 0), |
| 796 | // which doubles as the initial fetch trigger. |
| 797 | if (mediaSessionId != 0 && mediaSessionId != previous.mediaSessionId) { |
| 798 | _queueEvents.tryEmit(QueueEvent.SessionChanged(mediaSessionId)) |
| 799 | } |
| 800 | |
| 801 | // Receiver-authoritative queue pointer. Sticky across pushes that omit |
| 802 | // it (transport-only refreshes drop it along with the media block). |
| 803 | val currentItemId = s.optInt("currentItemId", -1).takeIf { it > 0 } |
| 804 | ?: previous.currentItemId |
| 805 | |
| 806 | // Receivers piggyback an `items` array on some MEDIA_STATUS pushes |
| 807 | // containing the current (and sometimes preloaded) item. Merge those |
| 808 | // opportunistically so the now-playing row has metadata before the |
| 809 | // batched QUEUE_GET_ITEMS fetch lands. |
| 810 | s.optJSONArray("items")?.let { arr -> |
| 811 | val items = (0 until arr.length()).mapNotNull { i -> |
| 812 | parseQueueItem(arr.optJSONObject(i)) |
| 813 | } |
| 814 | if (items.isNotEmpty()) { |
| 815 | _queueEvents.tryEmit(QueueEvent.Items(items, fromStatusPush = true)) |
| 816 | } |
| 817 | } |
| 818 | |
| 819 | // ── Volume: deliberately IGNORED here ──────────────────────────── |
| 820 | // MEDIA_STATUS *does* sometimes carry a `volume` sub-object, but per |
| 821 | // the Cast protocol that is the media STREAM volume (the per-item |
| 822 | // attenuation a sender can apply on top of the device level), NOT the |
| 823 | // device/group volume the user hears and controls. The Default Media |
| 824 | // Receiver and CCA groups report the stream volume pegged at 1.0 |
| 825 | // essentially always. An earlier revision ingested it as if it were |
| 826 | // the device volume, which produced the "set the slider to 40, watch |
| 827 | // it snap back to 100 a few seconds later while the audio stays at |
| 828 | // 40" bug: the user's SET_VOLUME (receiver namespace → device volume) |
| 829 | // worked, then the next 3s media poll delivered volume:{level:1.0} |
| 830 | // (stream volume) and clobbered the display. |
| 831 | // |
| 832 | // Device volume flows exclusively through RECEIVER_STATUS (see |
| 833 | // [handleReceiverStatus]) plus the optimistic latch in [setVolume]. |
| 834 | // Both status constructions below carry `previous.*` forward |
| 835 | // untouched. |
| 836 | |
| 837 | val media = s.optJSONObject("media") |
| 838 | if (media == null) { |
| 839 | // Transport-state-only update — PAUSE, RESUME, SEEK, or a heartbeat-ish |
| 840 | // refresh. The receiver does NOT redeliver the media block on every |
| 841 | // status push. Preserve the track metadata we already had; only update |
| 842 | // the volatile transport fields. THIS is the fix for the symptom where |
| 843 | // the displayed album art / title flickered back to a stale local- |
| 844 | // renderer track between Cast broadcasts. |
| 845 | _mediaStatus.value = previous.copy( |
| 846 | playerState = playerState, |
| 847 | currentTime = currentTime, |
| 848 | mediaSessionId = mediaSessionId, |
| 849 | currentItemId = currentItemId, |
| 850 | repeatMode = s.optString("repeatMode").ifBlank { null } ?: previous.repeatMode, |
| 851 | statusSeq = previous.statusSeq + 1, |
| 852 | ) |
| 853 | return |
| 854 | } |
| 855 | |
| 856 | // A media block IS present. Re-derive every metadata field from it, but |
| 857 | // treat empty strings as "not provided" and keep the previous value — |
| 858 | // `JSONObject.optString` returns "" (not null) for missing keys, and we |
| 859 | // don't want a partial metadata payload to blank the artist or album. |
| 860 | val duration = media.optDouble("duration", previous.duration) |
| 861 | val contentId = media.optString("contentId").ifBlank { null } ?: previous.contentId |
| 862 | |
| 863 | val metadata = media.optJSONObject("metadata") |
| 864 | val title = metadata?.optString("title")?.ifBlank { null } ?: previous.title |
| 865 | val artist = ( |
| 866 | metadata?.optString("artist")?.ifBlank { null } |
| 867 | ?: metadata?.optString("albumArtist")?.ifBlank { null } |
| 868 | ) |
| 869 | ?: previous.artist |
| 870 | val album = metadata?.optString("albumName")?.ifBlank { null } ?: previous.album |
| 871 | |
| 872 | val images = metadata?.optJSONArray("images") |
| 873 | // Keep the previous picture only while the SAME item is loaded (a |
| 874 | // partial status). A different item with no picture gets none — a |
| 875 | // radio station used to wear the last album's cover (decision, |
| 876 | // 2026-09-07). |
| 877 | val sameItem = contentId == previous.contentId |
| 878 | val albumArtUrl = if (images != null && images.length() > 0) { |
| 879 | images.getJSONObject(0).optString("url").ifBlank { null } ?: previous.albumArtUrl.takeIf { sameItem } |
| 880 | } else { |
| 881 | previous.albumArtUrl.takeIf { sameItem } |
| 882 | } |
| 883 | |
| 884 | _mediaStatus.value = MediaStatus( |
| 885 | title = title, |
| 886 | artist = artist, |
| 887 | album = album, |
| 888 | albumArtUrl = albumArtUrl, |
| 889 | contentId = contentId, |
| 890 | duration = duration, |
| 891 | currentTime = currentTime, |
| 892 | playerState = playerState, |
| 893 | mediaSessionId = mediaSessionId, |
| 894 | volume = previous.volume, |
| 895 | isMuted = previous.isMuted, |
| 896 | volumeKnown = previous.volumeKnown, |
| 897 | currentItemId = currentItemId, |
| 898 | repeatMode = s.optString("repeatMode").ifBlank { null } ?: previous.repeatMode, |
| 899 | statusSeq = previous.statusSeq + 1, |
| 900 | ) |
| 901 | } |
| 902 | |
| 903 | /** |
| 904 | * Parse one queue item from a QUEUE_ITEMS response or a MEDIA_STATUS |
| 905 | * `items` piggyback. Per the cross-platform spec: `artist` sometimes |
| 906 | * arrives as `albumArtist` instead — check both; missing keys come back |
| 907 | * as empty strings from lax JSON parsers — treat blank as absent. |
| 908 | */ |
| 909 | private fun parseQueueItem(o: JSONObject?): QueueItemLite? { |
| 910 | if (o == null) return null |
| 911 | val itemId = o.optInt("itemId", -1) |
| 912 | if (itemId <= 0) return null |
| 913 | val media = o.optJSONObject("media") |
| 914 | val metadata = media?.optJSONObject("metadata") |
| 915 | val images = metadata?.optJSONArray("images") |
| 916 | val duration = media?.optDouble("duration", Double.NaN) |
| 917 | ?.takeIf { it.isFinite() && it > 0.0 } |
| 918 | return QueueItemLite( |
| 919 | itemId = itemId, |
| 920 | contentId = media?.optString("contentId")?.ifBlank { null }, |
| 921 | title = metadata?.optString("title")?.ifBlank { null }, |
| 922 | artist = metadata?.optString("artist")?.ifBlank { null } |
| 923 | ?: metadata?.optString("albumArtist")?.ifBlank { null }, |
| 924 | album = metadata?.optString("albumName")?.ifBlank { null }, |
| 925 | albumArtUrl = if (images != null && images.length() > 0) { |
| 926 | images.optJSONObject(0)?.optString("url")?.ifBlank { null } |
| 927 | } else null, |
| 928 | durationSeconds = duration, |
| 929 | ) |
| 930 | } |
| 931 | |
| 932 | private fun nextRequestId(): Int = synchronized(this) { requestId++ } |
| 933 | |
| 934 | // ── TLS trust (Chromecast uses self-signed certs) ─────────── |
| 935 | |
| 936 | private object PermissiveTrustManager : X509TrustManager { |
| 937 | override fun checkClientTrusted( |
| 938 | chain: Array<java.security.cert.X509Certificate>?, |
| 939 | authType: String?, |
| 940 | ) { |
| 941 | } |
| 942 | |
| 943 | override fun checkServerTrusted( |
| 944 | chain: Array<java.security.cert.X509Certificate>?, |
| 945 | authType: String?, |
| 946 | ) { |
| 947 | } |
| 948 | |
| 949 | override fun getAcceptedIssuers(): Array<java.security.cert.X509Certificate> = |
| 950 | emptyArray() |
| 951 | } |
| 952 | } |
| 953 | |
| 954 | /** |
| 955 | * Minimal hand-rolled protobuf codec for CastMessage. |
| 956 | * |
| 957 | * The CastMessage protobuf has exactly 7 fields, all simple types. Rather than |
| 958 | * pulling in the full protobuf-javalite dependency, we encode/decode the ~80 bytes |
| 959 | * of wire format directly. This keeps the client zero-dependency. |
| 960 | * |
| 961 | * Wire format reference: |
| 962 | * message CastMessage { |
| 963 | * required ProtocolVersion protocol_version = 1; // varint, always 0 |
| 964 | * required string source_id = 2; |
| 965 | * required string destination_id = 3; |
| 966 | * required string namespace = 4; |
| 967 | * required PayloadType payload_type = 5; // varint, 0=STRING 1=BINARY |
| 968 | * optional string payload_utf8 = 6; |
| 969 | * optional bytes payload_binary = 7; |
| 970 | * } |
| 971 | */ |
| 972 | object CastMessageCodec { |
| 973 | |
| 974 | data class DecodedMessage( |
| 975 | val sourceId: String, |
| 976 | val destinationId: String, |
| 977 | val namespace: String, |
| 978 | val payloadUtf8: String, |
| 979 | ) |
| 980 | |
| 981 | fun encode( |
| 982 | sourceId: String, |
| 983 | destinationId: String, |
| 984 | namespace: String, |
| 985 | payloadUtf8: String, |
| 986 | ): ByteArray { |
| 987 | val buf = ByteArrayOutputStream(256) |
| 988 | // field 1: protocol_version = 0 (CASTV2_1_0), wire type 0 (varint) |
| 989 | writeVarint(buf, (1 shl 3) or 0) |
| 990 | writeVarint(buf, 0) |
| 991 | // field 2: source_id |
| 992 | writeString(buf, 2, sourceId) |
| 993 | // field 3: destination_id |
| 994 | writeString(buf, 3, destinationId) |
| 995 | // field 4: namespace |
| 996 | writeString(buf, 4, namespace) |
| 997 | // field 5: payload_type = 0 (STRING) |
| 998 | writeVarint(buf, (5 shl 3) or 0) |
| 999 | writeVarint(buf, 0) |
| 1000 | // field 6: payload_utf8 |
| 1001 | writeString(buf, 6, payloadUtf8) |
| 1002 | return buf.toByteArray() |
| 1003 | } |
| 1004 | |
| 1005 | fun decode(data: ByteArray): DecodedMessage? { |
| 1006 | var sourceId = "" |
| 1007 | var destinationId = "" |
| 1008 | var namespace = "" |
| 1009 | var payloadUtf8 = "" |
| 1010 | |
| 1011 | var pos = 0 |
| 1012 | while (pos < data.size) { |
| 1013 | val (tag, newPos) = readVarint(data, pos) |
| 1014 | pos = newPos |
| 1015 | val fieldNumber = tag ushr 3 |
| 1016 | val wireType = tag and 0x07 |
| 1017 | |
| 1018 | when (wireType) { |
| 1019 | 0 -> { // varint — skip the value |
| 1020 | val (_, p) = readVarint(data, pos) |
| 1021 | pos = p |
| 1022 | } |
| 1023 | 2 -> { // length-delimited |
| 1024 | val (len, p) = readVarint(data, pos) |
| 1025 | pos = p |
| 1026 | // A varint that overflows to a negative length passed the |
| 1027 | // old `pos + len > size` check and threw in copyOfRange, |
| 1028 | // which dropped the connection. |
| 1029 | if (len < 0 || len > data.size - pos) return null |
| 1030 | val bytes = data.copyOfRange(pos, pos + len) |
| 1031 | pos += len |
| 1032 | when (fieldNumber) { |
| 1033 | 2 -> sourceId = String(bytes, Charsets.UTF_8) |
| 1034 | 3 -> destinationId = String(bytes, Charsets.UTF_8) |
| 1035 | 4 -> namespace = String(bytes, Charsets.UTF_8) |
| 1036 | 6 -> payloadUtf8 = String(bytes, Charsets.UTF_8) |
| 1037 | // 7 = payload_binary, ignored |
| 1038 | } |
| 1039 | } |
| 1040 | else -> return null // unexpected wire type |
| 1041 | } |
| 1042 | } |
| 1043 | |
| 1044 | return DecodedMessage(sourceId, destinationId, namespace, payloadUtf8) |
| 1045 | } |
| 1046 | |
| 1047 | private fun writeString(buf: ByteArrayOutputStream, fieldNumber: Int, value: String) { |
| 1048 | val bytes = value.toByteArray(Charsets.UTF_8) |
| 1049 | writeVarint(buf, (fieldNumber shl 3) or 2) |
| 1050 | writeVarint(buf, bytes.size) |
| 1051 | buf.write(bytes) |
| 1052 | } |
| 1053 | |
| 1054 | private fun writeVarint(buf: ByteArrayOutputStream, value: Int) { |
| 1055 | var v = value |
| 1056 | while (v > 0x7F) { |
| 1057 | buf.write((v and 0x7F) or 0x80) |
| 1058 | v = v ushr 7 |
| 1059 | } |
| 1060 | buf.write(v and 0x7F) |
| 1061 | } |
| 1062 | |
| 1063 | private fun readVarint(data: ByteArray, startPos: Int): Pair<Int, Int> { |
| 1064 | var result = 0 |
| 1065 | var shift = 0 |
| 1066 | var pos = startPos |
| 1067 | while (pos < data.size) { |
| 1068 | val b = data[pos].toInt() and 0xFF |
| 1069 | result = result or ((b and 0x7F) shl shift) |
| 1070 | pos++ |
| 1071 | if (b and 0x80 == 0) break |
| 1072 | shift += 7 |
| 1073 | } |
| 1074 | return result to pos |
| 1075 | } |
| 1076 | } |