PreviewUrl: create the task and the service

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/Session.kt

@@ -35,6 +35,7 @@ import org.matrix.android.sdk.api.session.group.GroupService
 import org.matrix.android.sdk.api.session.homeserver.HomeServerCapabilitiesService
 import org.matrix.android.sdk.api.session.identity.IdentityService
 import org.matrix.android.sdk.api.session.integrationmanager.IntegrationManagerService
+import org.matrix.android.sdk.api.session.media.MediaService
 import org.matrix.android.sdk.api.session.permalinks.PermalinkService
 import org.matrix.android.sdk.api.session.profile.ProfileService
 import org.matrix.android.sdk.api.session.pushers.PushersService
@@ -181,6 +182,11 @@ interface Session :
      */
     fun widgetService(): WidgetService
 
+    /**
+     * Returns the media service associated with the session
+     */
+    fun mediaService(): MediaService
+
     /**
      * Returns the integration manager service associated with the session
      */

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/session/media/MediaService.kt

@@ -29,14 +29,19 @@ interface MediaService {
 
     /**
      * Get Raw Url Preview data from the homeserver. There is no cache management for this request
+     * @param url The url to get the preview data from
+     * @param timestamp The optional timestamp
      */
-    suspend fun getRawPreviewUrl(url: String): JsonDict
+    suspend fun getRawPreviewUrl(url: String, timestamp: Long?): JsonDict
 
     /**
      * Get Url Preview data from the homeserver, or from cache, depending on the cache strategy
-     * @param url
+     * @param url The url to get the preview data from
+     * @param timestamp The optional timestamp. Note that this parameter is not taken into account
+     * if the data is already in cache and the cache strategy allow to use it
+     * @param cacheStrategy the cache strategy, see the type for more details
      */
-    suspend fun getPreviewUrl(url: String, cacheStrategy: CacheStrategy): PreviewUrlData
+    suspend fun getPreviewUrl(url: String, timestamp: Long?, cacheStrategy: CacheStrategy): PreviewUrlData
 
     /**
      * Clear the cache of all retrieved UrlPreview data

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/DefaultSession.kt

@@ -43,6 +43,7 @@ import org.matrix.android.sdk.api.session.file.FileService
 import org.matrix.android.sdk.api.session.group.GroupService
 import org.matrix.android.sdk.api.session.homeserver.HomeServerCapabilitiesService
 import org.matrix.android.sdk.api.session.integrationmanager.IntegrationManagerService
+import org.matrix.android.sdk.api.session.media.MediaService
 import org.matrix.android.sdk.api.session.permalinks.PermalinkService
 import org.matrix.android.sdk.api.session.profile.ProfileService
 import org.matrix.android.sdk.api.session.pushers.PushersService
@@ -102,6 +103,7 @@ internal class DefaultSession @Inject constructor(
         private val permalinkService: Lazy<PermalinkService>,
         private val secureStorageService: Lazy<SecureStorageService>,
         private val profileService: Lazy<ProfileService>,
+        private val mediaService: Lazy<MediaService>,
         private val widgetService: Lazy<WidgetService>,
         private val syncThreadProvider: Provider<SyncThread>,
         private val contentUrlResolver: ContentUrlResolver,
@@ -263,6 +265,8 @@ internal class DefaultSession @Inject constructor(
 
     override fun widgetService(): WidgetService = widgetService.get()
 
+    override fun mediaService(): MediaService = mediaService.get()
+
     override fun integrationManagerService() = integrationManagerService
 
     override fun callSignalingService(): CallSignalingService = callSignalingService.get()

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/ClearPreviewUrlCacheTask.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 org.matrix.android.sdk.internal.session.media
+
+import com.zhuinden.monarchy.Monarchy
+import io.realm.kotlin.where
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.task.Task
+import org.matrix.android.sdk.internal.util.awaitTransaction
+import javax.inject.Inject
+
+internal interface ClearPreviewUrlCacheTask : Task<Unit, Unit>
+
+internal class DefaultClearPreviewUrlCacheTask @Inject constructor(
+        @SessionDatabase private val monarchy: Monarchy
+) : ClearPreviewUrlCacheTask {
+
+    override suspend fun execute(params: Unit) {
+        monarchy.awaitTransaction { realm ->
+            realm.where<PreviewUrlCacheEntity>()
+                    .findAll()
+                    .deleteAllFromRealm()
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/DefaultMediaService.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 org.matrix.android.sdk.internal.session.media
+
+import org.matrix.android.sdk.api.cache.CacheStrategy
+import org.matrix.android.sdk.api.session.events.model.Event
+import org.matrix.android.sdk.api.session.media.MediaService
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+import org.matrix.android.sdk.api.util.JsonDict
+import javax.inject.Inject
+
+internal class DefaultMediaService @Inject constructor(
+        private val clearPreviewUrlCacheTask: ClearPreviewUrlCacheTask,
+        private val getPreviewUrlTask: GetPreviewUrlTask,
+        private val getRawPreviewUrlTask: GetRawPreviewUrlTask
+) : MediaService {
+    override fun extractUrls(event: Event): List<String> {
+        TODO("Not yet implemented")
+    }
+
+    override suspend fun getRawPreviewUrl(url: String, timestamp: Long?): JsonDict {
+        return getRawPreviewUrlTask.execute(GetRawPreviewUrlTask.Params(url, timestamp))
+    }
+
+    override suspend fun getPreviewUrl(url: String, timestamp: Long?, cacheStrategy: CacheStrategy): PreviewUrlData {
+        return getPreviewUrlTask.execute(GetPreviewUrlTask.Params(url, timestamp, cacheStrategy))
+    }
+
+    override suspend fun clearCache() {
+        clearPreviewUrlCacheTask.execute(Unit)
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/GetPreviewUrlTask.kt

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 org.matrix.android.sdk.internal.session.media
+
+import com.zhuinden.monarchy.Monarchy
+import org.greenrobot.eventbus.EventBus
+import org.matrix.android.sdk.api.cache.CacheStrategy
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+import org.matrix.android.sdk.internal.database.query.get
+import org.matrix.android.sdk.internal.database.query.getOrCreate
+import org.matrix.android.sdk.internal.di.SessionDatabase
+import org.matrix.android.sdk.internal.network.executeRequest
+import org.matrix.android.sdk.internal.task.Task
+import org.matrix.android.sdk.internal.util.awaitTransaction
+import java.util.Date
+import javax.inject.Inject
+
+internal interface GetPreviewUrlTask : Task<GetPreviewUrlTask.Params, PreviewUrlData> {
+    data class Params(
+            val url: String,
+            val timestamp: Long?,
+            val cacheStrategy: CacheStrategy
+    )
+}
+
+internal class DefaultGetPreviewUrlTask @Inject constructor(
+        private val mediaAPI: MediaAPI,
+        private val eventBus: EventBus,
+        @SessionDatabase private val monarchy: Monarchy
+) : GetPreviewUrlTask {
+
+    override suspend fun execute(params: GetPreviewUrlTask.Params): PreviewUrlData {
+        return when (params.cacheStrategy) {
+            CacheStrategy.NoCache -> doRequest(params.url, params.timestamp)
+            is CacheStrategy.TtlCache -> doRequestWithCache(
+                    params.url,
+                    params.timestamp,
+                    params.cacheStrategy.validityDurationInMillis,
+                    params.cacheStrategy.strict
+            )
+            CacheStrategy.InfiniteCache -> doRequestWithCache(
+                    params.url,
+                    params.timestamp,
+                    Long.MAX_VALUE,
+                    true
+            )
+        }
+    }
+
+    private suspend fun doRequest(url: String, timestamp: Long?): PreviewUrlData {
+        return executeRequest<JsonDict>(eventBus) {
+            apiCall = mediaAPI.getPreviewUrlData(url, timestamp)
+        }
+                .toPreviewUrlData(url)
+    }
+
+    private fun JsonDict.toPreviewUrlData(url: String): PreviewUrlData {
+        return PreviewUrlData(
+                url = (get("og:url") as? String) ?: url,
+                siteName = get("og:site_name") as? String,
+                title = get("og:title") as? String,
+                description = get("og:description") as? String,
+                mxcUrl = get("og:image") as? String
+        )
+    }
+
+    private suspend fun doRequestWithCache(url: String, timestamp: Long?, validityDurationInMillis: Long, strict: Boolean): PreviewUrlData {
+        // Get data from cache
+        var dataFromCache: PreviewUrlData? = null
+        var isCacheValid = false
+        monarchy.doWithRealm { realm ->
+            val entity = PreviewUrlCacheEntity.get(realm, url)
+            dataFromCache = entity?.toDomain()
+            isCacheValid = entity != null && Date().time < entity.lastUpdatedTimestamp + validityDurationInMillis
+        }
+
+        val finalDataFromCache = dataFromCache
+        if (finalDataFromCache != null && isCacheValid) {
+            return finalDataFromCache
+        }
+
+        // No cache or outdated cache
+        val data = try {
+            doRequest(url, timestamp)
+        } catch (throwable: Throwable) {
+            // In case of error, we can return value from cache even if outdated
+            return finalDataFromCache
+                    ?.takeIf { !strict }
+                    ?: throw throwable
+        }
+
+        // Store cache
+        monarchy.awaitTransaction { realm ->
+            val previewUrlCacheEntity = PreviewUrlCacheEntity.getOrCreate(realm, url)
+            previewUrlCacheEntity.urlFromServer = data.url
+            previewUrlCacheEntity.siteName = data.siteName
+            previewUrlCacheEntity.title = data.title
+            previewUrlCacheEntity.description = data.description
+            previewUrlCacheEntity.mxcUrl = data.mxcUrl
+
+            previewUrlCacheEntity.lastUpdatedTimestamp = Date().time
+        }
+
+        return data
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/GetRawPreviewUrlTask.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 org.matrix.android.sdk.internal.session.media
+
+import org.greenrobot.eventbus.EventBus
+import org.matrix.android.sdk.api.util.JsonDict
+import org.matrix.android.sdk.internal.network.executeRequest
+import org.matrix.android.sdk.internal.task.Task
+import javax.inject.Inject
+
+internal interface GetRawPreviewUrlTask : Task<GetRawPreviewUrlTask.Params, JsonDict> {
+    data class Params(
+            val url: String,
+            val timestamp: Long?
+    )
+}
+
+internal class DefaultGetRawPreviewUrlTask @Inject constructor(
+        private val mediaAPI: MediaAPI,
+        private val eventBus: EventBus
+) : GetRawPreviewUrlTask {
+
+    override suspend fun execute(params: GetRawPreviewUrlTask.Params): JsonDict {
+        return executeRequest(eventBus) {
+            apiCall = mediaAPI.getPreviewUrlData(params.url, params.timestamp)
+        }
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/MediaAPI.kt

@@ -39,5 +39,5 @@ internal interface MediaAPI {
      * if it does not have the requested version available.
      */
     @GET(NetworkConstants.URI_API_MEDIA_PREFIX_PATH_R0 + "preview_url")
-    fun getPreviewUrlData(@Query("url") url: String, @Query("ts") ts: Int?): Call<JsonDict>
+    fun getPreviewUrlData(@Query("url") url: String, @Query("ts") ts: Long?): Call<JsonDict>
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/MediaModule.kt

@@ -16,8 +16,10 @@
 
 package org.matrix.android.sdk.internal.session.media
 
+import dagger.Binds
 import dagger.Module
 import dagger.Provides
+import org.matrix.android.sdk.api.session.media.MediaService
 import org.matrix.android.sdk.internal.session.SessionScope
 import retrofit2.Retrofit
 
@@ -34,6 +36,15 @@ internal abstract class MediaModule {
         }
     }
 
-//    @Binds
+    @Binds
-//    abstract fun bindGetHomeServerCapabilitiesTask(task: DefaultGetHomeServerCapabilitiesTask): GetHomeServerCapabilitiesTask
+    abstract fun bindMediaService(service: DefaultMediaService): MediaService
+
+    @Binds
+    abstract fun bindGetRawPreviewUrlTask(task: DefaultGetRawPreviewUrlTask): GetRawPreviewUrlTask
+
+    @Binds
+    abstract fun bindGetPreviewUrlTask(task: DefaultGetPreviewUrlTask): GetPreviewUrlTask
+
+    @Binds
+    abstract fun bindClearMediaCacheTask(task: DefaultClearPreviewUrlCacheTask): ClearPreviewUrlCacheTask
 }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/media/PreviewUrlMapper.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2020 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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 org.matrix.android.sdk.internal.session.media
+
+import org.matrix.android.sdk.api.session.media.PreviewUrlData
+import org.matrix.android.sdk.internal.database.model.PreviewUrlCacheEntity
+
+/**
+ * PreviewUrlCacheEntity -> PreviewUrlData
+ */
+internal fun PreviewUrlCacheEntity.toDomain() = PreviewUrlData(
+        url = urlFromServer ?: url,
+        siteName = siteName,
+        title = title,
+        description = description,
+        mxcUrl = mxcUrl
+)