Add support for intercepting CDN file requests (#6295)

* Add new CDN contract.

* Add CDN for document files.

* Add CDN support for downloading attachments.

* Deprecate current CDN methods.

* Add progress indicator snackbar.

* Add useDocumentGView config flag.

* Add file sharing cache handling.

* Add file sharing cache handling.

* Remove CDNResponse.kt

* Add tests

* PR remarks

Author: VelikovPetar

stream-chat-android-client/api/stream-chat-android-client.api

@@ -274,6 +274,7 @@ public final class io/getstream/chat/android/client/ChatClient$Builder : io/gets
 	public final fun appVersion (Ljava/lang/String;)Lio/getstream/chat/android/client/ChatClient$Builder;
 	public final fun baseUrl (Ljava/lang/String;)Lio/getstream/chat/android/client/ChatClient$Builder;
 	public fun build ()Lio/getstream/chat/android/client/ChatClient;
+	public final fun cdn (Lio/getstream/chat/android/client/cdn/CDN;)Lio/getstream/chat/android/client/ChatClient$Builder;
 	public final fun cdnUrl (Ljava/lang/String;)Lio/getstream/chat/android/client/ChatClient$Builder;
 	public final fun clientDebugger (Lio/getstream/chat/android/client/debugger/ChatClientDebugger;)Lio/getstream/chat/android/client/ChatClient$Builder;
 	public final fun credentialStorage (Lio/getstream/chat/android/client/user/storage/UserCredentialStorage;)Lio/getstream/chat/android/client/ChatClient$Builder;
@@ -711,6 +712,27 @@ public final class io/getstream/chat/android/client/audio/WaveformExtractorKt {
 	public static final fun isEof (Landroid/media/MediaCodec$BufferInfo;)Z
 }
 
+public abstract interface class io/getstream/chat/android/client/cdn/CDN {
+	public fun fileRequest (Ljava/lang/String;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static synthetic fun fileRequest$suspendImpl (Lio/getstream/chat/android/client/cdn/CDN;Ljava/lang/String;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public fun imageRequest (Ljava/lang/String;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static synthetic fun imageRequest$suspendImpl (Lio/getstream/chat/android/client/cdn/CDN;Ljava/lang/String;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+}
+
+public final class io/getstream/chat/android/client/cdn/CDNRequest {
+	public fun <init> (Ljava/lang/String;Ljava/util/Map;)V
+	public synthetic fun <init> (Ljava/lang/String;Ljava/util/Map;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun component1 ()Ljava/lang/String;
+	public final fun component2 ()Ljava/util/Map;
+	public final fun copy (Ljava/lang/String;Ljava/util/Map;)Lio/getstream/chat/android/client/cdn/CDNRequest;
+	public static synthetic fun copy$default (Lio/getstream/chat/android/client/cdn/CDNRequest;Ljava/lang/String;Ljava/util/Map;ILjava/lang/Object;)Lio/getstream/chat/android/client/cdn/CDNRequest;
+	public fun equals (Ljava/lang/Object;)Z
+	public final fun getHeaders ()Ljava/util/Map;
+	public final fun getUrl ()Ljava/lang/String;
+	public fun hashCode ()I
+	public fun toString ()Ljava/lang/String;
+}
+
 public final class io/getstream/chat/android/client/channel/ChannelClient {
 	public final fun acceptInvite (Ljava/lang/String;)Lio/getstream/result/call/Call;
 	public final fun addMembers (Lio/getstream/chat/android/client/query/AddMembersParams;)Lio/getstream/result/call/Call;

stream-chat-android-client/src/main/java/io/getstream/chat/android/client/ChatClient.kt

@@ -71,6 +71,8 @@ import io.getstream.chat.android.client.attachment.AttachmentsSender
 import io.getstream.chat.android.client.audio.AudioPlayer
 import io.getstream.chat.android.client.audio.NativeMediaPlayerImpl
 import io.getstream.chat.android.client.audio.StreamAudioPlayer
+import io.getstream.chat.android.client.cdn.CDN
+import io.getstream.chat.android.client.cdn.internal.StreamMediaDataSource
 import io.getstream.chat.android.client.channel.ChannelClient
 import io.getstream.chat.android.client.channel.state.ChannelStateLogicProvider
 import io.getstream.chat.android.client.clientstate.DisconnectCause
@@ -293,6 +295,8 @@ internal constructor(
     private val repository: ChatClientRepository,
     private val messageReceiptReporter: MessageReceiptReporter,
     internal val messageReceiptManager: MessageReceiptManager,
+    @InternalStreamChatApi
+    public val cdn: CDN? = null,
 ) {
     private val logger by taggedLogger(TAG)
     private val fileManager = StreamFileManager()
@@ -4731,6 +4735,7 @@ internal constructor(
         private var uploadAttachmentsNetworkType = UploadAttachmentsNetworkType.CONNECTED
         private var fileTransformer: FileTransformer = NoOpFileTransformer
         private var apiModelTransformers: ApiModelTransformers = ApiModelTransformers()
+        private var cdn: CDN? = null
         private var appName: String? = null
         private var appVersion: String? = null
 
@@ -4859,7 +4864,11 @@ internal constructor(
          *
          * @param shareFileDownloadRequestInterceptor Your [Interceptor] implementation for the share file download
          * call.
+         * @deprecated Use [io.getstream.chat.android.client.cdn.CDN] instead. Configure a custom CDN via
+         * [io.getstream.chat.android.client.ChatClient.Builder.cdn] to provide headers and transform URLs
+         * for all image, file, and download requests.
          */
+        @Deprecated("Use CDN instead. Configure via ChatClient.Builder.cdn().")
         public fun shareFileDownloadRequestInterceptor(shareFileDownloadRequestInterceptor: Interceptor): Builder {
             this.shareFileDownloadRequestInterceptor = shareFileDownloadRequestInterceptor
             return this
@@ -4930,6 +4939,15 @@ internal constructor(
             forceWsUrl = value
         }
 
+        /**
+         * Sets a custom [CDN] implementation to be used by the client.
+         *
+         * @param cdn The custom CDN implementation.
+         */
+        public fun cdn(cdn: CDN): Builder = apply {
+            this.cdn = cdn
+        }
+
         /**
          * Sets the CDN URL to be used by the client.
          */
@@ -5078,6 +5096,7 @@ internal constructor(
                     fileUploader = fileUploader,
                     sendMessageInterceptor = sendMessageInterceptor,
                     shareFileDownloadRequestInterceptor = shareFileDownloadRequestInterceptor,
+                    cdn = cdn,
                     tokenManager = tokenManager,
                     customOkHttpClient = customOkHttpClient,
                     clientDebugger = clientDebugger,
@@ -5090,8 +5109,9 @@ internal constructor(
             val api = module.api()
             val appSettingsManager = AppSettingManager(api)
 
+            val mediaDataSourceFactory = StreamMediaDataSource.factory(appContext, cdn)
             val audioPlayer: AudioPlayer = StreamAudioPlayer(
-                mediaPlayer = NativeMediaPlayerImpl(appContext) {
+                mediaPlayer = NativeMediaPlayerImpl(mediaDataSourceFactory) {
                     ExoPlayer.Builder(appContext)
                         .setAudioAttributes(
                             AudioAttributes.Builder()
@@ -5143,6 +5163,7 @@ internal constructor(
                     messageReceiptRepository = repository,
                     api = api,
                 ),
+                cdn = cdn,
             ).apply {
                 attachmentsSender = AttachmentsSender(
                     context = appContext,

stream-chat-android-client/src/main/java/io/getstream/chat/android/client/audio/NativeMediaPlayer.kt

@@ -16,14 +16,13 @@
 
 package io.getstream.chat.android.client.audio
 
-import android.content.Context
 import androidx.annotation.OptIn
 import androidx.media3.common.MediaItem
 import androidx.media3.common.PlaybackException
 import androidx.media3.common.PlaybackParameters
 import androidx.media3.common.Player
 import androidx.media3.common.util.UnstableApi
-import androidx.media3.datasource.DefaultDataSource
+import androidx.media3.datasource.DataSource
 import androidx.media3.exoplayer.ExoPlayer
 import androidx.media3.exoplayer.source.MediaSource
 import androidx.media3.exoplayer.source.ProgressiveMediaSource
@@ -358,12 +357,12 @@ public enum class NativeMediaPlayerState {
 /**
  * Default implementation of [NativeMediaPlayer] based on ExoPlayer.
  *
- * @param context The context.
+ * @param dataSourceFactory The data source factory used for creating media sources.
  * @param builder A builder function to create an [ExoPlayer] instance.
  */
 @OptIn(UnstableApi::class)
 internal class NativeMediaPlayerImpl(
-    context: Context,
+    dataSourceFactory: DataSource.Factory,
     private val builder: () -> ExoPlayer,
 ) : NativeMediaPlayer {
 
@@ -392,7 +391,7 @@ internal class NativeMediaPlayerImpl(
      * For more info see [ExoPlayer Progressive](https://developer.android.com/media/media3/exoplayer/progressive).
      */
     private val mediaSourceFactory: MediaSource.Factory = ProgressiveMediaSource.Factory(
-        DefaultDataSource.Factory(context),
+        dataSourceFactory,
         DefaultExtractorsFactory().setConstantBitrateSeekingEnabled(true),
     )
 

stream-chat-android-client/src/main/java/io/getstream/chat/android/client/cdn/CDN.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2014-2026 Stream.io Inc. All rights reserved.
+ *
+ * Licensed under the Stream License;
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://github.com/GetStream/stream-chat-android/blob/main/LICENSE
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.getstream.chat.android.client.cdn
+
+/**
+ * Class defining a CDN (Content Delivery Network) interface.
+ * Override to transform requests loading images/files from the custom CDN.
+ */
+public interface CDN {
+
+    /**
+     * Transforms a request for loading an image from the CDN.
+     *
+     * Implementations that perform blocking or network I/O must use `withContext` to switch to the
+     * appropriate dispatcher (e.g. `Dispatchers.IO`).
+     *
+     * @param url Original CDN url for the image.
+     * @return A [CDNRequest] holding the modified request URL and/or custom headers to include with the request.
+     */
+    public suspend fun imageRequest(url: String): CDNRequest = CDNRequest(url)
+
+    /**
+     * Transforms a request for loading a non-image file from the CDN.
+     *
+     * Implementations that perform blocking or network I/O must use `withContext` to switch to the
+     * appropriate dispatcher (e.g. `Dispatchers.IO`).
+     *
+     * @param url Original CDN url for the file.
+     * @return A [CDNRequest] holding the modified request URL and/or custom headers to include with the request.
+     */
+    public suspend fun fileRequest(url: String): CDNRequest = CDNRequest(url)
+}

stream-chat-android-client/src/main/java/io/getstream/chat/android/client/cdn/CDNRequest.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2014-2026 Stream.io Inc. All rights reserved.
+ *
+ * Licensed under the Stream License;
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://github.com/GetStream/stream-chat-android/blob/main/LICENSE
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.getstream.chat.android.client.cdn
+
+/**
+ * Model representing the request for loading a file from a CDN.
+ *
+ * @param url Url of the file to load.
+ * @param headers Map of headers added to the request.
+ */
+public data class CDNRequest(
+    val url: String,
+    val headers: Map<String, String>? = null,
+)

stream-chat-android-client/src/main/java/io/getstream/chat/android/client/cdn/internal/CDNDataSourceFactory.kt

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2014-2026 Stream.io Inc. All rights reserved.
+ *
+ * Licensed under the Stream License;
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://github.com/GetStream/stream-chat-android/blob/main/LICENSE
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.getstream.chat.android.client.cdn.internal
+
+import android.net.Uri
+import androidx.core.net.toUri
+import androidx.media3.common.util.UnstableApi
+import androidx.media3.datasource.DataSource
+import androidx.media3.datasource.DataSpec
+import androidx.media3.datasource.DefaultHttpDataSource
+import androidx.media3.datasource.TransferListener
+import io.getstream.chat.android.client.cdn.CDN
+import io.getstream.chat.android.client.cdn.CDNRequest
+import io.getstream.log.taggedLogger
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.runBlocking
+
+/**
+ * A [DataSource.Factory] that creates [CDNDataSource] instances which transform
+ * media requests through the [CDN.fileRequest] method before delegating to an upstream data source.
+ *
+ * @param cdn The CDN used to transform file request URLs and headers.
+ * @param upstreamFactory The factory for creating the upstream data source that performs the actual HTTP requests.
+ */
+@UnstableApi
+internal class CDNDataSourceFactory(
+    private val cdn: CDN,
+    private val upstreamFactory: DataSource.Factory = DefaultHttpDataSource.Factory(),
+) : DataSource.Factory {
+    override fun createDataSource(): DataSource {
+        return CDNDataSource(cdn, upstreamFactory.createDataSource())
+    }
+}
+
+/**
+ * A [DataSource] that transforms media requests through [CDN.fileRequest] before
+ * delegating to an upstream data source. This allows custom CDN implementations
+ * to rewrite URLs and inject headers for video/audio/voice recording playback via ExoPlayer.
+ *
+ * [CDN.fileRequest] is a suspend function and is called via [runBlocking] on [Dispatchers.IO].
+ * This is safe because ExoPlayer always calls [open] from its loader thread, never the main thread.
+ */
+@UnstableApi
+private class CDNDataSource(
+    private val cdn: CDN,
+    private val upstream: DataSource,
+) : DataSource {
+
+    private val logger by taggedLogger("Chat:CDNDataSource")
+
+    override fun open(dataSpec: DataSpec): Long {
+        val scheme = dataSpec.uri.scheme
+        if (scheme != "http" && scheme != "https") {
+            return upstream.open(dataSpec)
+        }
+        val url = dataSpec.uri.toString()
+        val cdnRequest = try {
+            runBlocking {
+                cdn.fileRequest(url)
+            }
+        } catch (@Suppress("TooGenericExceptionCaught") e: Exception) {
+            logger.e(e) { "[open] CDN.fileRequest() failed for url: $url. Falling back to original request." }
+            CDNRequest(url)
+        }
+        val mergedHeaders = buildMap {
+            putAll(dataSpec.httpRequestHeaders)
+            cdnRequest.headers?.let { putAll(it) }
+        }
+        val transformedSpec = dataSpec.buildUpon()
+            .setUri(cdnRequest.url.toUri())
+            .setHttpRequestHeaders(mergedHeaders)
+            .build()
+        return upstream.open(transformedSpec)
+    }
+
+    override fun read(buffer: ByteArray, offset: Int, length: Int): Int =
+        upstream.read(buffer, offset, length)
+
+    override fun close() {
+        upstream.close()
+    }
+
+    override fun getUri(): Uri? = upstream.uri
+
+    override fun getResponseHeaders(): Map<String, List<String>> = upstream.responseHeaders
+
+    override fun addTransferListener(transferListener: TransferListener) {
+        upstream.addTransferListener(transferListener)
+    }
+}

stream-chat-android-client/src/main/java/io/getstream/chat/android/client/cdn/internal/CDNOkHttpInterceptor.kt

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2014-2026 Stream.io Inc. All rights reserved.
+ *
+ * Licensed under the Stream License;
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://github.com/GetStream/stream-chat-android/blob/main/LICENSE
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.getstream.chat.android.client.cdn.internal
+
+import io.getstream.chat.android.client.cdn.CDN
+import io.getstream.chat.android.client.cdn.CDNRequest
+import io.getstream.log.taggedLogger
+import kotlinx.coroutines.runBlocking
+import okhttp3.Interceptor
+import okhttp3.Response
+
+/**
+ * OkHttp interceptor applying transformations to CDN requests.
+ */
+internal class CDNOkHttpInterceptor(private val cdn: CDN) : Interceptor {
+
+    private val logger by taggedLogger("Chat:CDNOkHttpInterceptor")
+
+    override fun intercept(chain: Interceptor.Chain): Response {
+        val originalUrl = chain.request().url.toString()
+        val (url, headers) = try {
+            runBlocking {
+                cdn.fileRequest(originalUrl)
+            }
+        } catch (@Suppress("TooGenericExceptionCaught") e: Exception) {
+            logger.e(e) {
+                "[intercept] CDN.fileRequest() failed for url: $originalUrl. " +
+                    "Falling back to original request."
+            }
+            CDNRequest(originalUrl)
+        }
+        val request = chain.request().newBuilder()
+            .url(url)
+            .apply {
+                headers?.forEach {
+                    header(it.key, it.value)
+                }
+            }
+            .build()
+        return chain.proceed(request)
+    }
+}