tauri-plugin-video 0.3.0

Native video playback for Tauri using platform media engines
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
package io.github.taurivideo.plugin

import android.app.Activity
import android.content.Context
import android.content.res.Configuration
import android.graphics.Color
import android.media.AudioAttributes
import android.media.AudioFocusRequest
import android.media.AudioManager
import android.net.Uri
import android.os.Build
import android.os.SystemClock
import android.util.Log
import android.view.View
import android.view.ViewGroup
import android.view.ViewTreeObserver
import android.view.WindowManager
import android.webkit.WebSettings
import android.webkit.WebView
import android.widget.FrameLayout
import androidx.media3.common.C
import androidx.media3.common.Format
import androidx.media3.common.MediaItem
import androidx.media3.common.MimeTypes
import androidx.media3.common.PlaybackException
import androidx.media3.common.Player
import androidx.media3.common.TrackSelectionOverride
import androidx.media3.common.Tracks
import androidx.media3.common.VideoSize
import androidx.media3.datasource.DefaultDataSource
import androidx.media3.datasource.DefaultHttpDataSource
import androidx.media3.datasource.HttpDataSource
import androidx.media3.datasource.okhttp.OkHttpDataSource
import androidx.media3.exoplayer.DefaultLoadControl
import androidx.media3.exoplayer.DefaultRenderersFactory
import androidx.media3.exoplayer.ExoPlayer
import androidx.media3.exoplayer.analytics.AnalyticsListener
import androidx.media3.exoplayer.mediacodec.MediaCodecSelector
import androidx.media3.exoplayer.source.DefaultMediaSourceFactory
import androidx.media3.exoplayer.trackselection.DefaultTrackSelector
import androidx.media3.exoplayer.upstream.DefaultAllocator
import androidx.media3.ui.AspectRatioFrameLayout
import androidx.media3.ui.PlayerView
import app.tauri.annotation.Command
import app.tauri.annotation.InvokeArg
import app.tauri.annotation.TauriPlugin
import app.tauri.plugin.Invoke
import app.tauri.plugin.JSArray
import app.tauri.plugin.JSObject
import app.tauri.plugin.Plugin
import java.io.ByteArrayInputStream
import java.io.File
import java.security.KeyStore
import java.security.cert.CertificateException
import java.security.cert.CertificateFactory
import java.security.cert.X509Certificate
import java.util.concurrent.atomic.AtomicBoolean
import javax.net.ssl.SSLContext
import javax.net.ssl.TrustManagerFactory
import javax.net.ssl.X509TrustManager
import okhttp3.OkHttpClient
import org.videolan.libvlc.util.VLCVideoLayout

/** Android/TV integration with a direct SurfaceView playback plane. */
@TauriPlugin
class VideoPlugin(private val activity: Activity) : Plugin(activity) {
    private val audioManager = activity.getSystemService(Context.AUDIO_SERVICE) as AudioManager
    private var focusRequest: AudioFocusRequest? = null
    private var nativeRoot: FrameLayout? = null
    private var nativeView: PlayerView? = null
    private var vlcView: VLCVideoLayout? = null
    private var hostWebView: WebView? = null
    private var nativeDocumentX = 0.0
    private var nativeDocumentY = 0.0
    private var nativeLayoutActive = false
    private var nativeScrollSynchronizerRegistered = false
    private val nativeScrollSynchronizer = ViewTreeObserver.OnPreDrawListener {
        syncNativeScrollPosition()
        true
    }
    private var nativePlayer: ExoPlayer? = null
    private var vlcPlayer: VlcPlayer? = null
    private var openGeneration = 0
    private var activeSessionKey: String? = null
    private var videoSize = VideoSize.UNKNOWN
    private val trackTargets = HashMap<Int, Pair<Tracks.Group, Int>>()
    private var cachedNativeTracks = JSArray()
    private var cachedVlcTrackSource: List<VlcTrack>? = null
    private var cachedVlcTracks = JSArray()
    private val customCaClients = object : LinkedHashMap<String, OkHttpClient>(4, 0.75f, true) {
        override fun removeEldestEntry(
            eldest: MutableMap.MutableEntry<String, OkHttpClient>?,
        ): Boolean = size > 4
    }
    private var allocator: DefaultAllocator? = null
    private var videoDecoderName = "uninitialized"
    private var lastRenderedFrames = 0L
    private var lastFrameSampleNs = 0L
    private var measuredFps = 0.0
    private val bundledCaFile: File?
    private var nativeContainer = "unknown"

    init {
        bundledCaFile = runCatching {
            val trustDirectory = File(activity.filesDir, "tauri-video-ca").apply { mkdirs() }
            File(trustDirectory, "ca-certificates.crt").also { destination ->
                activity.assets.open("tauri-video-ca-certificates.crt").use { input ->
                    destination.outputStream().use(input::copyTo)
                }
            }
        }.getOrNull()
    }

    override fun load(webView: WebView) {
        webView.settings.mediaPlaybackRequiresUserGesture = false
        webView.settings.mixedContentMode = WebSettings.MIXED_CONTENT_NEVER_ALLOW
        var transparentAncestor: View? = webView
        while (transparentAncestor != null && transparentAncestor !== activity.window.decorView) {
            transparentAncestor.setBackgroundColor(Color.TRANSPARENT)
            transparentAncestor = transparentAncestor.parent as? View
        }
        activity.runOnUiThread {
            unregisterNativeScrollSynchronizer()
            hostWebView = webView
            registerNativeScrollSynchronizerIfNeeded()
            val nativeContainer = FrameLayout(activity).apply {
                setBackgroundColor(Color.BLACK)
                visibility = View.GONE
            }
            val playerView = PlayerView(activity).apply {
                useController = false
                resizeMode = AspectRatioFrameLayout.RESIZE_MODE_FIT
                setShutterBackgroundColor(Color.BLACK)
                val uiType = resources.configuration.uiMode and Configuration.UI_MODE_TYPE_MASK
                subtitleView?.setBottomPaddingFraction(
                    if (uiType == Configuration.UI_MODE_TYPE_TELEVISION) 0.24f else 0.16f
                )
            }
            val vlcLayout = VLCVideoLayout(activity).apply { visibility = View.GONE }
            val match = FrameLayout.LayoutParams(
                FrameLayout.LayoutParams.MATCH_PARENT,
                FrameLayout.LayoutParams.MATCH_PARENT,
            )
            nativeContainer.addView(playerView, match)
            nativeContainer.addView(vlcLayout, match)
            val root = activity.findViewById<ViewGroup>(android.R.id.content)
            root.addView(nativeContainer, 0, FrameLayout.LayoutParams(1, 1))
            nativeRoot = nativeContainer
            nativeView = playerView
            vlcView = vlcLayout
        }
    }

    @Command
    fun openNative(invoke: Invoke) {
        val args = invoke.parseArgs(NativeOpenArgs::class.java)
        activity.runOnUiThread {
            closeNativePlayer()
            activeSessionKey = args.sessionKey
            val generation = openGeneration
            val view = nativeView
            val root = nativeRoot
            if (view == null || root == null) {
                invoke.reject("native video surface is unavailable")
                return@runOnUiThread
            }
            applyNativeLayout(
                args.x,
                args.y,
                args.width,
                args.height,
                args.scrollX,
                args.scrollY,
            )
            root.visibility = View.VISIBLE
            view.visibility = View.VISIBLE
            vlcView?.visibility = View.GONE
            view.videoSurfaceView?.apply {
                scaleX = 1f
                scaleY = 1f
            }
            nativeContainer = containerFromUri(args.uri)
            val requestedBackend = args.backend?.lowercase() ?: "media3"
            if (requestedBackend !in setOf("media3", "libvlc")) {
                root.visibility = View.GONE
                deactivateNativeLayout()
                invoke.reject("backend '$requestedBackend' is not available on Android")
                return@runOnUiThread
            }
            if (requestedBackend == "libvlc") {
                startVlc(
                    args,
                    invoke,
                    AtomicBoolean(false),
                    generation,
                )
                return@runOnUiThread
            }
            val playerAllocator = DefaultAllocator(true, 64 * 1024)
            allocator = playerAllocator
            val loadControlBuilder = DefaultLoadControl.Builder().setAllocator(playerAllocator)
            resolveRequestedBufferDurations(args)?.let { durations ->
                loadControlBuilder.setBufferDurationsMs(
                    durations.minMs,
                    durations.maxMs,
                    durations.playbackMs,
                    durations.rebufferMs,
                )
            }
            resolveRequestedTargetBufferBytes(args.targetBufferBytes)?.let {
                loadControlBuilder.setTargetBufferBytes(it)
            }
            val loadControl = loadControlBuilder.build()
            // Several Amlogic TV firmwares advertise Dolby Vision profile 7
            // decoders that open successfully but render black. Profile 7 has
            // a standards-compliant HEVC base layer, so select the HEVC codec
            // directly and keep the zero-copy SurfaceView path.
            val codecSelector = MediaCodecSelector { mimeType, secure, tunneling ->
                val decoderMime = if (
                    mimeType == MimeTypes.VIDEO_DOLBY_VISION
                    && args.dolbyVisionMode != "platform"
                ) {
                    MimeTypes.VIDEO_H265
                } else mimeType
                MediaCodecSelector.DEFAULT.getDecoderInfos(decoderMime, secure, tunneling)
            }
            val renderersFactory = DefaultRenderersFactory(activity)
                .setMediaCodecSelector(codecSelector)
                .setEnableDecoderFallback(args.decoderFallback ?: true)
            val requestHeaders = HashMap(args.headers)
            args.cookies?.takeIf(String::isNotBlank)?.let { requestHeaders["Cookie"] = it }
            args.referrer?.takeIf(String::isNotBlank)?.let { requestHeaders["Referer"] = it }
            val httpFactory = try {
                createHttpDataSourceFactory(args, requestHeaders)
            } catch (error: Exception) {
                root.visibility = View.GONE
                deactivateNativeLayout()
                invoke.reject(error.message ?: "Could not configure the HTTPS media source")
                return@runOnUiThread
            }
            val dataSourceFactory = DefaultDataSource.Factory(activity, httpFactory)
            val mediaSourceFactory = DefaultMediaSourceFactory(dataSourceFactory)
            val trackSelector = DefaultTrackSelector(activity).apply {
                parameters = buildUponParameters()
                    .setTunnelingEnabled(args.tunneling ?: false)
                    .build()
            }
            val player = ExoPlayer.Builder(activity)
                .setRenderersFactory(renderersFactory)
                .setMediaSourceFactory(mediaSourceFactory)
                .setTrackSelector(trackSelector)
                .setLoadControl(loadControl)
                .build()
            nativePlayer = player
            view.player = player
            player.volume = if (args.muted) 0f else args.volume.toFloat().coerceIn(0f, 1f)
            player.addAnalyticsListener(object : AnalyticsListener {
                override fun onVideoDecoderInitialized(
                    eventTime: AnalyticsListener.EventTime,
                    decoderName: String,
                    initializedTimestampMs: Long,
                    initializationDurationMs: Long,
                ) {
                    videoDecoderName = decoderName
                }
            })
            val resolved = AtomicBoolean(false)
            var playerReady = false
            var firstFrameRendered = false
            fun resolveWhenRenderable() {
                if (playerReady
                    && (firstFrameRendered || !args.autoplay)
                    && resolved.compareAndSet(false, true)
                ) {
                    invoke.resolve(nativeSnapshot(player))
                }
            }
            fun rejectMedia3(message: String) {
                if (resolved.compareAndSet(false, true)) {
                    invoke.reject(message)
                    closeNativePlayer()
                }
            }
            player.addListener(object : Player.Listener {
                override fun onPlaybackStateChanged(state: Int) {
                    if (state == Player.STATE_READY) {
                        // onTracksChanged normally arrives before READY, but initialize from
                        // the authoritative player state so the first resolved snapshot can
                        // never expose an empty cache because of callback ordering.
                        refreshNativeTracks(player.currentTracks)
                        playerReady = true
                        resolveWhenRenderable()
                    } else if (state == Player.STATE_ENDED) {
                        // ExoPlayer keeps playWhenReady armed at EOF. Clear it
                        // so a later seek behaves like an ended HTML video:
                        // update the frame, but stay paused until play() is
                        // explicitly requested.
                        player.playWhenReady = false
                        setPlaybackActive(false)
                    }
                }

                override fun onRenderedFirstFrame() {
                    firstFrameRendered = true
                    resolveWhenRenderable()
                }

                override fun onPlayerError(error: PlaybackException) {
                    rejectMedia3(error.message ?: "Media3 playback failed")
                }

                override fun onVideoSizeChanged(size: VideoSize) {
                    videoSize = size
                }

                override fun onTracksChanged(tracks: Tracks) {
                    refreshNativeTracks(tracks)
                }
            })
            val mediaItem = MediaItem.fromUri(args.uri)
            val startPositionMs = args.startPositionSeconds
                ?.takeIf { it.isFinite() && it >= 0.0 }
                ?.times(1_000.0)
                ?.toLong()
            if (startPositionMs == null) player.setMediaItem(mediaItem)
            else player.setMediaItem(mediaItem, startPositionMs)
            if (args.autoplay && setPlaybackActive(true)) {
                // Arm autoplay while the player is still buffering. Media3 will
                // begin immediately on READY instead of waiting for a second
                // manual play transition.
                player.playWhenReady = true
            }
            player.prepare()
        }
    }

    @Command
    fun controlNative(invoke: Invoke) {
        val args = invoke.parseArgs(NativeControlArgs::class.java)
        activity.runOnUiThread {
            if (args.sessionKey != activeSessionKey) {
                invoke.reject("native player session is stale")
                return@runOnUiThread
            }
            val player = nativePlayer
            val vlc = vlcPlayer
            if (player == null && vlc == null) {
                invoke.reject("native player is not open")
                return@runOnUiThread
            }
            try {
                when (args.action) {
                    "play" -> {
                        check(setPlaybackActive(true)) { "audio focus was denied" }
                        if (player != null) {
                            if (player.playbackState == Player.STATE_ENDED) {
                                player.seekToDefaultPosition()
                            }
                            player.play()
                        } else vlc?.play()
                    }
                    "pause" -> {
                        player?.pause() ?: vlc?.pause()
                        setPlaybackActive(false)
                    }
                    "seek" -> if (player != null) player.seekTo((args.value * 1000.0).toLong())
                        else vlc?.seekTo((args.value * 1000.0).toLong())
                    "volume" -> if (player != null) {
                        player.volume = args.value.toFloat().coerceIn(0f, 1f)
                    } else vlc?.setVolume(args.value.toFloat())
                    "track" -> if (player != null) selectNativeTrack(player, args.index)
                        else vlc?.selectTrack(args.index)
                    "deselectTrack" -> if (player != null) deselectNativeTrack(player, args.index)
                        else vlc?.deselectTrack(args.index)
                    "fit", "crop", "stretch" -> if (player != null) {
                        nativeView?.resizeMode = when (args.action) {
                            "crop" -> AspectRatioFrameLayout.RESIZE_MODE_ZOOM
                            "stretch" -> AspectRatioFrameLayout.RESIZE_MODE_FILL
                            else -> AspectRatioFrameLayout.RESIZE_MODE_FIT
                        }
                    } else vlc?.setFit(args.action)
                    "zoom" -> if (player != null) {
                        nativeView?.videoSurfaceView?.apply {
                            val zoom = args.value.toFloat().coerceIn(1f, 2f)
                            scaleX = zoom
                            scaleY = zoom
                        }
                    } else {
                        vlc?.setZoom(args.value.toFloat())
                    }
                    else -> throw IllegalArgumentException("unknown native action ${args.action}")
                }
                invoke.resolve(activeNativeSnapshot())
            } catch (error: Exception) {
                invoke.reject(error.message ?: "native playback command failed")
            }
        }
    }

    @Command
    fun layoutNative(invoke: Invoke) {
        val args = invoke.parseArgs(NativeLayoutArgs::class.java)
        activity.runOnUiThread {
            if (args.sessionKey != activeSessionKey) {
                invoke.reject("native player session is stale")
                return@runOnUiThread
            }
            applyNativeLayout(
                args.x,
                args.y,
                args.width,
                args.height,
                args.scrollX,
                args.scrollY,
            )
            invoke.resolve()
        }
    }

    @Command
    fun statsNative(invoke: Invoke) {
        val args = invoke.parseArgs(NativeSessionArgs::class.java)
        activity.runOnUiThread {
            if (args.sessionKey != activeSessionKey) {
                invoke.reject("native player session is stale")
                return@runOnUiThread
            }
            val player = nativePlayer
            val vlc = vlcPlayer
            if (player == null && vlc == null) invoke.reject("native player is not open")
            else player?.playerError?.let { invoke.reject(it.message ?: "Media3 playback failed") }
                ?: invoke.resolve(activeNativeSnapshot())
        }
    }

    @Command
    fun closeNative(invoke: Invoke) {
        val args = invoke.parseArgs(NativeSessionArgs::class.java)
        activity.runOnUiThread {
            if (args.sessionKey == activeSessionKey) closeNativePlayer()
            invoke.resolve()
        }
    }

    private fun setPlaybackActive(playing: Boolean): Boolean {
        if (!playing) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                focusRequest?.let(audioManager::abandonAudioFocusRequest)
                focusRequest = null
            } else {
                @Suppress("DEPRECATION")
                audioManager.abandonAudioFocus(null)
            }
            activity.window.clearFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
            return true
        }
        val result = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val request = AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN)
                .setAudioAttributes(
                    AudioAttributes.Builder()
                        .setUsage(AudioAttributes.USAGE_MEDIA)
                        .setContentType(AudioAttributes.CONTENT_TYPE_MOVIE)
                        .build()
                )
                .setOnAudioFocusChangeListener { change ->
                    if (change == AudioManager.AUDIOFOCUS_LOSS
                        || change == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT
                    ) {
                        activity.runOnUiThread {
                            nativePlayer?.pause()
                            vlcPlayer?.pause()
                        }
                    }
                }
                .build()
            focusRequest = request
            audioManager.requestAudioFocus(request)
        } else {
            @Suppress("DEPRECATION")
            audioManager.requestAudioFocus(null, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN)
        }
        return if (result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
            activity.window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
            true
        } else false
    }

    private fun selectNativeTrack(player: ExoPlayer, target: Int) {
        val (group, track) = trackTargets[target] ?: return
        player.trackSelectionParameters = player.trackSelectionParameters
            .buildUpon()
            .setTrackTypeDisabled(group.type, false)
            .clearOverridesOfType(group.type)
            .addOverride(TrackSelectionOverride(group.mediaTrackGroup, track))
            .build()
        refreshNativeTracks(player.currentTracks)
    }

    private fun deselectNativeTrack(player: ExoPlayer, target: Int) {
        val (group, _) = trackTargets[target] ?: return
        player.trackSelectionParameters = player.trackSelectionParameters
            .buildUpon()
            .setTrackTypeDisabled(group.type, true)
            .build()
        refreshNativeTracks(player.currentTracks)
    }

    private fun startVlc(
        args: NativeOpenArgs,
        invoke: Invoke,
        resolved: AtomicBoolean,
        generation: Int,
    ) {
        if (generation != openGeneration || vlcPlayer != null) return
        val root = nativeRoot
        val vlcLayout = vlcView
        if (root == null || vlcLayout == null) {
            root?.visibility = View.GONE
            deactivateNativeLayout()
            if (resolved.compareAndSet(false, true)) invoke.reject("LibVLC video surface is unavailable")
            return
        }
        clearVlcTrackCache()
        nativeView?.visibility = View.GONE
        vlcLayout.visibility = View.VISIBLE
        root.visibility = View.VISIBLE
        val vlc = try {
            VlcPlayer(
                activity,
                vlcLayout,
                VlcPlayerConfig(
                    uri = args.uri,
                    autoplay = args.autoplay,
                    initialVolume = if (args.muted) 0f else args.volume.toFloat().coerceIn(0f, 1f),
                    startPositionMs = args.startPositionSeconds?.times(1_000.0)?.toLong(),
                    networkCachingMs = args.minBufferMs?.coerceIn(1_000, 120_000),
                    userAgent = args.userAgent,
                    referrer = args.referrer,
                    cookies = args.cookies,
                    caFile = resolveCaFile(args),
                ),
            )
        } catch (error: Throwable) {
            Log.e("TauriVideo", "LibVLC backend failed to initialize", error)
            vlcLayout.visibility = View.GONE
            root.visibility = View.GONE
            deactivateNativeLayout()
            if (resolved.compareAndSet(false, true)) {
                invoke.reject(
                    "LibVLC startup failed: ${error.javaClass.simpleName}: " +
                        (error.message ?: "no diagnostic message")
                )
            }
            return
        }
        vlcPlayer = vlc
        vlcLayout.post {
            if (generation != openGeneration || vlcPlayer !== vlc) return@post
            vlc.open(
                onRenderable = {
                    activity.runOnUiThread {
                        if (generation != openGeneration || vlcPlayer !== vlc) return@runOnUiThread
                        if (args.autoplay) setPlaybackActive(true)
                        if (resolved.compareAndSet(false, true)) {
                            invoke.resolve(activeNativeSnapshot())
                        }
                    }
                },
                onError = { vlcFailure ->
                    activity.runOnUiThread {
                        if (generation != openGeneration || vlcPlayer !== vlc) return@runOnUiThread
                        vlc.release()
                        vlcPlayer = null
                        vlcLayout.visibility = View.GONE
                        root.visibility = View.GONE
                        deactivateNativeLayout()
                        if (resolved.compareAndSet(false, true)) {
                            invoke.reject(vlcFailure)
                        }
                    }
                },
            )
        }
    }

    private fun activeNativeSnapshot(): JSObject {
        nativePlayer?.let { return nativeSnapshot(it) }
        val vlc = vlcPlayer ?: error("native player is not open")
        return vlcSnapshot(vlc.snapshot(nativeContainer))
    }

    private fun vlcSnapshot(snapshot: VlcSnapshot): JSObject {
        val tracks = vlcTrackArray(snapshot.tracks)
        return JSObject().apply {
            put("durationSeconds", snapshot.durationSeconds)
            put("currentTimeSeconds", snapshot.currentTimeSeconds)
            put("bufferedSeconds", snapshot.bufferedSeconds)
            put("playing", snapshot.playing)
            put("videoWidth", snapshot.videoWidth)
            put("videoHeight", snapshot.videoHeight)
            put("presentedFrames", snapshot.presentedFrames)
            put("droppedFrames", snapshot.droppedFrames)
            put("measuredFps", snapshot.measuredFps)
            put("hardwareBackend", snapshot.hardwareBackend)
            put("encodedBytesBuffered", snapshot.encodedBytesBuffered)
            put("averageFrameProcessingUs", snapshot.averageFrameProcessingUs)
            put("container", snapshot.container)
            put("tracks", tracks)
        }
    }

    private fun vlcTrackArray(tracks: List<VlcTrack>): JSArray {
        if (cachedVlcTrackSource === tracks) return cachedVlcTracks
        cachedVlcTrackSource = tracks
        cachedVlcTracks = JSArray(tracks.map { track ->
            JSObject().apply {
                put("id", track.id.toString())
                put("index", track.id)
                put("kind", track.kind)
                put("language", track.language)
                put("label", track.label)
                put("codec", track.codec)
                put("selected", track.selected)
            }
        })
        return cachedVlcTracks
    }

    private fun clearVlcTrackCache() {
        cachedVlcTrackSource = null
        cachedVlcTracks = JSArray()
    }

    private fun resolveCaFile(args: NativeOpenArgs): File? = when (val requested = args.tlsCaFile?.trim()) {
        null, "" -> null
        "bundled" -> bundledCaFile
            ?: throw IllegalArgumentException("Bundled TLS CA file is unavailable to the Android app")
        else -> File(requested).takeIf { it.isFile }
            ?: throw IllegalArgumentException("TLS CA file is unavailable to the Android app")
    }

    /** Build an HTTPS source with an explicit CA bundle without disabling hostname validation. */
    private fun createHttpDataSourceFactory(
        args: NativeOpenArgs,
        requestHeaders: Map<String, String>,
    ): HttpDataSource.Factory {
        val caFile = resolveCaFile(args)
        if (caFile == null) {
            val factory = DefaultHttpDataSource.Factory()
                .setAllowCrossProtocolRedirects(true)
                .setDefaultRequestProperties(requestHeaders)
            args.userAgent?.takeIf(String::isNotBlank)?.let(factory::setUserAgent)
            return factory
        }

        val cacheKey = "${caFile.canonicalPath}:${caFile.length()}:${caFile.lastModified()}"
        val client = customCaClients.getOrPut(cacheKey) { buildCustomCaClient(caFile) }
        val factory = OkHttpDataSource.Factory(client)
            .setDefaultRequestProperties(requestHeaders)
        args.userAgent?.takeIf(String::isNotBlank)?.let(factory::setUserAgent)
        return factory
    }

    private fun buildCustomCaClient(caFile: File): OkHttpClient {
        val certificateFactory = CertificateFactory.getInstance("X.509")
        val certificates = PEM_CERTIFICATE.findAll(caFile.readText()).map { match ->
            ByteArrayInputStream(match.value.toByteArray(Charsets.US_ASCII)).use {
                certificateFactory.generateCertificate(it)
            }
        }.toList()
        require(certificates.isNotEmpty()) { "TLS CA bundle contains no certificates" }
        val keyStore = KeyStore.getInstance(KeyStore.getDefaultType()).apply {
            load(null)
            certificates.forEachIndexed { index, certificate ->
                setCertificateEntry("tauri-video-ca-$index", certificate)
            }
        }
        val trustManagerFactory = TrustManagerFactory
            .getInstance(TrustManagerFactory.getDefaultAlgorithm())
            .apply { init(keyStore) }
        val customTrustManager = trustManagerFactory.trustManagers
            .filterIsInstance<X509TrustManager>()
            .singleOrNull()
            ?: error("TLS CA bundle did not create an X.509 trust manager")
        val systemTrustManager = TrustManagerFactory
            .getInstance(TrustManagerFactory.getDefaultAlgorithm())
            .apply { init(null as KeyStore?) }
            .trustManagers
            .filterIsInstance<X509TrustManager>()
            .singleOrNull()
            ?: error("Android did not provide a system X.509 trust manager")
        val trustManager = CompositeTrustManager(systemTrustManager, customTrustManager)
        val sslContext = SSLContext.getInstance("TLS").apply {
            init(null, arrayOf(trustManager), null)
        }
        return OkHttpClient.Builder()
            .sslSocketFactory(sslContext.socketFactory, trustManager)
            .followRedirects(true)
            .followSslRedirects(true)
            .retryOnConnectionFailure(true)
            .build()
    }

    private fun applyNativeLayout(
        x: Double,
        y: Double,
        width: Double,
        height: Double,
        scrollX: Double,
        scrollY: Double,
    ) {
        val view = nativeRoot ?: return
        val params = (view.layoutParams as? FrameLayout.LayoutParams) ?: FrameLayout.LayoutParams(1, 1)
        val nextWidth = width.toInt().coerceAtLeast(1)
        val nextHeight = height.toInt().coerceAtLeast(1)
        if (params.width != nextWidth || params.height != nextHeight
            || params.leftMargin != 0 || params.topMargin != 0
        ) {
            params.width = nextWidth
            params.height = nextHeight
            params.leftMargin = 0
            params.topMargin = 0
            view.layoutParams = params
        }
        nativeDocumentX = x + scrollX
        nativeDocumentY = y + scrollY
        nativeLayoutActive = true
        registerNativeScrollSynchronizerIfNeeded()
        syncNativeScrollPosition()
    }

    private fun registerNativeScrollSynchronizerIfNeeded() {
        if (!nativeLayoutActive || nativeScrollSynchronizerRegistered) return
        val observer = hostWebView?.viewTreeObserver?.takeIf { it.isAlive } ?: return
        observer.addOnPreDrawListener(nativeScrollSynchronizer)
        nativeScrollSynchronizerRegistered = true
    }

    private fun unregisterNativeScrollSynchronizer() {
        if (!nativeScrollSynchronizerRegistered) return
        hostWebView?.viewTreeObserver?.takeIf { it.isAlive }
            ?.removeOnPreDrawListener(nativeScrollSynchronizer)
        nativeScrollSynchronizerRegistered = false
    }

    private fun deactivateNativeLayout() {
        nativeLayoutActive = false
        unregisterNativeScrollSynchronizer()
    }

    private fun syncNativeScrollPosition() {
        if (!nativeLayoutActive) return
        val view = nativeRoot ?: return
        val webView = hostWebView ?: return
        val nextX = (nativeDocumentX - webView.scrollX).toFloat()
        val nextY = (nativeDocumentY - webView.scrollY).toFloat()
        if (view.translationX != nextX) view.translationX = nextX
        if (view.translationY != nextY) view.translationY = nextY
    }

    private fun nativeSnapshot(player: ExoPlayer): JSObject {
        val counters = player.videoDecoderCounters
        counters?.ensureUpdated()
        val presentedFrames = counters?.renderedOutputBufferCount?.toLong()?.coerceAtLeast(0) ?: 0L
        val droppedFrames = counters?.droppedBufferCount?.toLong()?.coerceAtLeast(0) ?: 0L
        val nowNs = SystemClock.elapsedRealtimeNanos()
        if (lastFrameSampleNs == 0L) {
            lastFrameSampleNs = nowNs
            lastRenderedFrames = presentedFrames
        } else if (nowNs - lastFrameSampleNs >= 500_000_000L) {
            val elapsedSeconds = (nowNs - lastFrameSampleNs) / 1_000_000_000.0
            measuredFps = (presentedFrames - lastRenderedFrames).coerceAtLeast(0) / elapsedSeconds
            lastFrameSampleNs = nowNs
            lastRenderedFrames = presentedFrames
        }
        val processingCount = counters?.videoFrameProcessingOffsetCount ?: 0
        val averageProcessingUs = if (processingCount > 0) {
            (counters?.totalVideoFrameProcessingOffsetUs ?: 0L).toDouble() / processingCount
        } else 0.0
        val durationMs = player.duration.takeIf { it != C.TIME_UNSET }?.coerceAtLeast(0) ?: 0
        return JSObject().apply {
            put("durationSeconds", durationMs / 1000.0)
            put("currentTimeSeconds", player.currentPosition.coerceAtLeast(0) / 1000.0)
            put("bufferedSeconds", player.bufferedPosition.coerceAtLeast(0) / 1000.0)
            put("playing", player.isPlaying)
            put("videoWidth", videoSize.width)
            put("videoHeight", videoSize.height)
            put("presentedFrames", presentedFrames)
            put("droppedFrames", droppedFrames)
            put("measuredFps", measuredFps)
            put("hardwareBackend", "android-mediacodec:$videoDecoderName:surface-view")
            put("encodedBytesBuffered", allocator?.totalBytesAllocated?.toLong() ?: 0L)
            put("averageFrameProcessingUs", averageProcessingUs)
            put("container", nativeContainer)
            put("tracks", cachedNativeTracks)
        }
    }

    private fun refreshNativeTracks(tracks: Tracks) {
        val cachedTracks = ArrayList<JSObject>()
        trackTargets.clear()
        var target = 0
        tracks.groups.forEach { group ->
            val kind = when (group.type) {
                C.TRACK_TYPE_VIDEO -> "video"
                C.TRACK_TYPE_AUDIO -> "audio"
                C.TRACK_TYPE_TEXT -> "subtitle"
                else -> return@forEach
            }
            for (index in 0 until group.length) {
                val format: Format = group.getTrackFormat(index)
                val language = format.language ?: "und"
                trackTargets[target] = group to index
                cachedTracks.add(JSObject().apply {
                    put("id", target.toString())
                    put("index", target)
                    put("kind", kind)
                    put("language", language)
                    put("label", format.label ?: if (language == "und") kind else language.uppercase())
                    put("codec", format.codecs ?: format.sampleMimeType?.substringAfter('/') ?: "")
                    put("selected", group.isTrackSelected(index))
                })
                target += 1
            }
        }
        cachedNativeTracks = JSArray(cachedTracks)
    }

    private fun clearNativeTrackCache() {
        trackTargets.clear()
        cachedNativeTracks = JSArray()
    }

    private fun closeNativePlayer() {
        openGeneration += 1
        activeSessionKey = null
        setPlaybackActive(false)
        nativeView?.player = null
        nativePlayer?.release()
        nativePlayer = null
        vlcPlayer?.release()
        vlcPlayer = null
        nativeView?.visibility = View.VISIBLE
        vlcView?.visibility = View.GONE
        nativeRoot?.visibility = View.GONE
        deactivateNativeLayout()
        allocator = null
        videoDecoderName = "uninitialized"
        lastRenderedFrames = 0L
        lastFrameSampleNs = 0L
        measuredFps = 0.0
        nativeContainer = "unknown"
        clearNativeTrackCache()
        clearVlcTrackCache()
        videoSize = VideoSize.UNKNOWN
    }
}

internal data class NativeBufferDurations(
    val minMs: Int,
    val maxMs: Int,
    val playbackMs: Int,
    val rebufferMs: Int,
)

internal fun resolveRequestedBufferDurations(args: NativeOpenArgs): NativeBufferDurations? {
    if (
        args.minBufferMs == null && args.maxBufferMs == null &&
        args.playbackBufferMs == null && args.rebufferMs == null
    ) return null

    val requestedMaxMs = args.maxBufferMs?.coerceIn(1_000, 180_000)
    val minMs = (args.minBufferMs
        ?: requestedMaxMs?.coerceAtMost(DefaultLoadControl.DEFAULT_MIN_BUFFER_MS)
        ?: DefaultLoadControl.DEFAULT_MIN_BUFFER_MS)
        .coerceIn(1_000, 120_000)
    val maxMs = (requestedMaxMs ?: DefaultLoadControl.DEFAULT_MAX_BUFFER_MS)
        .coerceIn(minMs, 180_000)
    return NativeBufferDurations(
        minMs = minMs,
        maxMs = maxMs,
        playbackMs = (args.playbackBufferMs ?: DefaultLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_MS)
            .coerceIn(250, minMs),
        rebufferMs = (
            args.rebufferMs
                ?: DefaultLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS
            ).coerceIn(500, minMs),
    )
}

internal fun resolveRequestedTargetBufferBytes(requestedBytes: Long?): Int? = requestedBytes
    ?.coerceIn(8L * 1024 * 1024, 512L * 1024 * 1024)
    ?.toInt()

private fun containerFromUri(value: String): String {
    val name = Uri.parse(value).lastPathSegment?.substringBefore('?')?.lowercase() ?: return "unknown"
    return when {
        name.endsWith(".mkv") || name.endsWith(".mka") -> "matroska"
        name.endsWith(".webm") -> "webm"
        name.endsWith(".mp4") || name.endsWith(".m4v") -> "mp4"
        name.endsWith(".avi") -> "avi"
        name.endsWith(".ts") || name.endsWith(".m2ts") -> "mpeg-ts"
        name.endsWith(".mov") -> "quicktime"
        else -> "unknown"
    }
}

@InvokeArg class NativeOpenArgs {
    var sessionKey: String = ""
    var uri: String = ""; var x: Double = 0.0; var y: Double = 0.0
    var scrollX: Double = 0.0; var scrollY: Double = 0.0
    var backend: String? = null
    var width: Double = 1.0; var height: Double = 1.0; var autoplay: Boolean = false
    var volume: Double = 1.0; var muted: Boolean = false
    var headers: HashMap<String, String> = HashMap()
    var cookies: String? = null; var userAgent: String? = null; var referrer: String? = null
    var tlsCaFile: String? = null; var startPositionSeconds: Double? = null
    var minBufferMs: Int? = null; var maxBufferMs: Int? = null
    var playbackBufferMs: Int? = null; var rebufferMs: Int? = null
    var targetBufferBytes: Long? = null; var decoderFallback: Boolean? = null
    var dolbyVisionMode: String? = null; var tunneling: Boolean? = null
}
@InvokeArg class NativeLayoutArgs {
    var sessionKey: String = ""
    var x: Double = 0.0; var y: Double = 0.0; var width: Double = 1.0; var height: Double = 1.0
    var scrollX: Double = 0.0; var scrollY: Double = 0.0
}
@InvokeArg class NativeControlArgs {
    var sessionKey: String = ""
    var action: String = ""; var value: Double = 0.0; var index: Int = -1
}
@InvokeArg class NativeSessionArgs { var sessionKey: String = "" }

private val PEM_CERTIFICATE = Regex(
    "-----BEGIN CERTIFICATE-----[\\s\\S]+?-----END CERTIFICATE-----"
)

private class CompositeTrustManager(
    private val system: X509TrustManager,
    private val custom: X509TrustManager,
) : X509TrustManager {
    override fun getAcceptedIssuers(): Array<X509Certificate> =
        system.acceptedIssuers + custom.acceptedIssuers

    override fun checkClientTrusted(chain: Array<X509Certificate>, authType: String) {
        system.checkClientTrusted(chain, authType)
    }

    override fun checkServerTrusted(chain: Array<X509Certificate>, authType: String) {
        try {
            system.checkServerTrusted(chain, authType)
        } catch (systemError: CertificateException) {
            try {
                custom.checkServerTrusted(chain, authType)
            } catch (customError: CertificateException) {
                customError.addSuppressed(systemError)
                throw customError
            }
        }
    }
}