From 95e0d2c26a71eaea7c731a053f6cadf2378310ed Mon Sep 17 00:00:00 2001
From: Filipe Bezerra <filipebzerra@gmail.com>
Date: Mon, 7 Dec 2020 13:44:24 -0300
Subject: [PATCH 1/6] refactor: Update libraries and build file to latest
 versions

---
 app/build.gradle | 29 +++++++++++++++++++----------
 build.gradle     | 20 ++++++++++----------
 2 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/app/build.gradle b/app/build.gradle
index f3b69919..940328fb 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -15,17 +15,18 @@
  *
  */
 
-apply plugin: 'com.android.application'
-apply plugin: 'kotlin-android'
-apply plugin: 'kotlin-kapt'
-apply plugin: "androidx.navigation.safeargs"
-apply plugin: 'kotlin-android-extensions'
+plugins {
+    id 'com.android.application'
+    id 'kotlin-android'
+    id 'kotlin-kapt'
+    id 'androidx.navigation.safeargs.kotlin'
+}
 
 android {
     compileSdkVersion 30
     defaultConfig {
         applicationId "com.example.android.devbyteviewer"
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 30
         versionCode 1
         versionName "1.0"
@@ -38,11 +39,20 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
-
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
+    kotlinOptions {
+        jvmTarget = '1.8'
+    }
     buildFeatures {
         dataBinding true
     }
-
+    packagingOptions {
+        exclude 'DebugProbesKt.bin'
+        exclude 'META-INF/atomicfu.kotlin_module'
+    }
 }
 
 dependencies {
@@ -51,7 +61,7 @@ dependencies {
 
     // Support libraries
     implementation "androidx.appcompat:appcompat:$version_appcompat"
-    implementation "androidx.fragment:fragment:$version_fragment"
+    implementation "androidx.fragment:fragment-ktx:$version_fragment"
     implementation "androidx.constraintlayout:constraintlayout:$version_constraint_layout"
 
     // Android KTX
@@ -68,7 +78,6 @@ dependencies {
     // Retrofit for networking
     implementation "com.squareup.retrofit2:retrofit:$version_retrofit"
     implementation "com.squareup.retrofit2:converter-moshi:$version_retrofit"
-    implementation "com.jakewharton.retrofit:retrofit2-kotlin-coroutines-adapter:$version_retrofit_coroutines_adapter"
 
     // Moshi for parsing the JSON format
     implementation "com.squareup.moshi:moshi:$version_moshi"
diff --git a/build.gradle b/build.gradle
index 96b9bbb6..e369b020 100644
--- a/build.gradle
+++ b/build.gradle
@@ -19,23 +19,23 @@
 
 buildscript {
     ext {
-        version_core = "1.3.1"
+        version_core = "1.3.2"
         version_coroutine = "1.3.7"
         version_retrofit_coroutines_adapter = "0.9.2"
         version_navigation = '1.0.0'
-        version_constraint_layout = "2.0.0"
-        version_gradle = '4.0.1'
-        version_kotlin = "1.3.72"
+        version_constraint_layout = "2.0.4"
+        version_gradle = '4.1.1'
+        version_kotlin = "1.4.20"
         version_lifecycle_extensions = "2.2.0"
         lifecycle_version = "2.2.0"
         version_room = "2.2.5"
         version_appcompat = "1.2.0"
-        version_fragment = "1.0.0"
-        version_retrofit = "2.5.0"
-        version_kotlin_coroutines = "1.1.0"
-        version_moshi = "1.8.0"
-        version_glide = "4.8.0"
-        version_joda = "2.10"
+        version_fragment = "1.2.5"
+        version_retrofit = "2.9.0"
+        version_kotlin_coroutines = "1.4.1"
+        version_moshi = "1.11.0"
+        version_glide = "4.11.0"
+        version_joda = "2.10.7"
         version_work = "1.0.1"
         version_timber = "4.7.1"
     }

From a5854c2483d6319f3b18f260737f27e3adf95cf2 Mon Sep 17 00:00:00 2001
From: Filipe Bezerra <filipebzerra@gmail.com>
Date: Mon, 7 Dec 2020 13:45:35 -0300
Subject: [PATCH 2/6] feat: Implement DatabaseVideo entity class

---
 .../database/DatabaseEntities.kt              | 24 +++++++++++++++++++
 .../network/DataTransferObjects.kt            | 12 ++++++++++
 .../android/devbyteviewer/network/Service.kt  |  4 +---
 .../viewmodels/DevByteViewModel.kt            |  2 +-
 4 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt b/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt
index 777e11bd..1369ba95 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt
@@ -17,3 +17,27 @@
 
 package com.example.android.devbyteviewer.database
 
+import androidx.room.ColumnInfo
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+import com.example.android.devbyteviewer.domain.Video
+
+@Entity
+data class DatabaseVideo(
+        @PrimaryKey @ColumnInfo(name = "url") val url: String,
+        @ColumnInfo(name = "title") val title: String,
+        @ColumnInfo(name = "description") val description: String,
+        @ColumnInfo(name = "updated") val updated: String,
+        @ColumnInfo(name = "thumbnail") val thumbnail: String,
+)
+
+fun List<DatabaseVideo>.asDomainModel(): List<Video> =
+        map {
+            Video(
+                    url = it.url,
+                    title = it.url,
+                    description = it.description,
+                    updated = it.updated,
+                    thumbnail = it.thumbnail,
+            )
+        }
\ No newline at end of file
diff --git a/app/src/main/java/com/example/android/devbyteviewer/network/DataTransferObjects.kt b/app/src/main/java/com/example/android/devbyteviewer/network/DataTransferObjects.kt
index b9a89a7d..4c4b9df3 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/network/DataTransferObjects.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/network/DataTransferObjects.kt
@@ -17,6 +17,7 @@
 
 package com.example.android.devbyteviewer.network
 
+import com.example.android.devbyteviewer.database.DatabaseVideo
 import com.example.android.devbyteviewer.domain.Video
 import com.squareup.moshi.JsonClass
 
@@ -63,3 +64,14 @@ fun NetworkVideoContainer.asDomainModel(): List<Video> {
                 thumbnail = it.thumbnail)
     }
 }
+
+fun NetworkVideoContainer.asDatabaseModel(): Array<DatabaseVideo> =
+        videos.map {
+            DatabaseVideo(
+                    url = it.url,
+                    title = it.url,
+                    description = it.description,
+                    updated = it.updated,
+                    thumbnail = it.thumbnail,
+            )
+        }.toTypedArray()
\ No newline at end of file
diff --git a/app/src/main/java/com/example/android/devbyteviewer/network/Service.kt b/app/src/main/java/com/example/android/devbyteviewer/network/Service.kt
index 6c28dd4d..cdb4f9e0 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/network/Service.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/network/Service.kt
@@ -17,7 +17,6 @@
 
 package com.example.android.devbyteviewer.network
 
-import com.jakewharton.retrofit2.adapter.kotlin.coroutines.CoroutineCallAdapterFactory
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.kotlin.reflect.KotlinJsonAdapterFactory
 import kotlinx.coroutines.Deferred
@@ -34,7 +33,7 @@ import retrofit2.http.GET
  */
 interface DevbyteService {
     @GET("devbytes.json")
-    fun getPlaylist(): Deferred<NetworkVideoContainer>
+    suspend fun getPlaylist(): NetworkVideoContainer
 }
 
 /**
@@ -53,7 +52,6 @@ object Network {
     private val retrofit = Retrofit.Builder()
             .baseUrl("https://devbytes.udacity.com/")
             .addConverterFactory(MoshiConverterFactory.create(moshi))
-            .addCallAdapterFactory(CoroutineCallAdapterFactory())
             .build()
 
     val devbytes = retrofit.create(DevbyteService::class.java)
diff --git a/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt b/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt
index a5dd550b..a49d3953 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt
@@ -74,7 +74,7 @@ class DevByteViewModel(application: Application) : AndroidViewModel(application)
      */
     private fun refreshDataFromNetwork() = viewModelScope.launch {
         try {
-            val playlist = Network.devbytes.getPlaylist().await()
+            val playlist = Network.devbytes.getPlaylist()
             _playlist.postValue(playlist.asDomainModel())
         } catch (networkError: IOException) {
             // Show an infinite loading spinner if the request fails

From 2e0c045ee4a495c105498f15f35f4342de6bdd57 Mon Sep 17 00:00:00 2001
From: Filipe Bezerra <filipebzerra@gmail.com>
Date: Mon, 7 Dec 2020 14:59:33 -0300
Subject: [PATCH 3/6] refactor: Update WorkManager to latest version

---
 app/build.gradle | 15 ++++++++++++---
 build.gradle     |  6 +++---
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/app/build.gradle b/app/build.gradle
index 940328fb..b210edd2 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -32,6 +32,15 @@ android {
         versionName "1.0"
         multiDexEnabled true
         vectorDrawables.useSupportLibrary = true
+
+        javaCompileOptions {
+            annotationProcessorOptions {
+                arguments += [
+                        "room.schemaLocation":"$projectDir/schemas".toString(),
+                        "room.incremental":"true"
+                ]
+            }
+        }
     }
     buildTypes {
         release {
@@ -68,8 +77,8 @@ dependencies {
     implementation "androidx.core:core-ktx:$version_core"
 
     // Navigation
-    implementation "android.arch.navigation:navigation-fragment-ktx:$version_navigation"
-    implementation "android.arch.navigation:navigation-ui-ktx:$version_navigation"
+    implementation "androidx.navigation:navigation-fragment-ktx:$version_navigation"
+    implementation "androidx.navigation:navigation-ui-ktx:$version_navigation"
 
     // Coroutines for getting off the UI thread
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$version_kotlin_coroutines"
@@ -104,5 +113,5 @@ dependencies {
     implementation "androidx.room:room-ktx:$version_room"
 
     // WorkManager
-    implementation "android.arch.work:work-runtime-ktx:$version_work"
+    implementation "androidx.work:work-runtime-ktx:$work_version"
 }
diff --git a/build.gradle b/build.gradle
index e369b020..b8e37b05 100644
--- a/build.gradle
+++ b/build.gradle
@@ -22,7 +22,7 @@ buildscript {
         version_core = "1.3.2"
         version_coroutine = "1.3.7"
         version_retrofit_coroutines_adapter = "0.9.2"
-        version_navigation = '1.0.0'
+        version_navigation = '2.3.2'
         version_constraint_layout = "2.0.4"
         version_gradle = '4.1.1'
         version_kotlin = "1.4.20"
@@ -36,7 +36,7 @@ buildscript {
         version_moshi = "1.11.0"
         version_glide = "4.11.0"
         version_joda = "2.10.7"
-        version_work = "1.0.1"
+        work_version = "2.4.0"
         version_timber = "4.7.1"
     }
 
@@ -48,7 +48,7 @@ buildscript {
     dependencies {
         classpath "com.android.tools.build:gradle:$version_gradle"
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$version_kotlin"
-        classpath "android.arch.navigation:navigation-safe-args-gradle-plugin:$version_navigation"
+        classpath "androidx.navigation:navigation-safe-args-gradle-plugin:$version_navigation"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

From c74f9bcca3e1d0a0e35e0abd59445c2543338cab Mon Sep 17 00:00:00 2001
From: Filipe Bezerra <filipebzerra@gmail.com>
Date: Mon, 7 Dec 2020 15:00:22 -0300
Subject: [PATCH 4/6] feat: Implement DAL components

---
 .../1.json                                    | 58 +++++++++++++++++++
 .../database/DatabaseEntities.kt              |  4 +-
 .../android/devbyteviewer/database/Room.kt    | 40 +++++++++++++
 3 files changed, 101 insertions(+), 1 deletion(-)
 create mode 100644 app/schemas/com.example.android.devbyteviewer.database.DevBytesDatabase/1.json

diff --git a/app/schemas/com.example.android.devbyteviewer.database.DevBytesDatabase/1.json b/app/schemas/com.example.android.devbyteviewer.database.DevBytesDatabase/1.json
new file mode 100644
index 00000000..a3a7fcf9
--- /dev/null
+++ b/app/schemas/com.example.android.devbyteviewer.database.DevBytesDatabase/1.json
@@ -0,0 +1,58 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 1,
+    "identityHash": "21c90e8223ebcb03b6bfb045f4a26142",
+    "entities": [
+      {
+        "tableName": "videos",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`url` TEXT NOT NULL, `title` TEXT NOT NULL, `description` TEXT NOT NULL, `updated` TEXT NOT NULL, `thumbnail` TEXT NOT NULL, PRIMARY KEY(`url`))",
+        "fields": [
+          {
+            "fieldPath": "url",
+            "columnName": "url",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "title",
+            "columnName": "title",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "description",
+            "columnName": "description",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "updated",
+            "columnName": "updated",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "thumbnail",
+            "columnName": "thumbnail",
+            "affinity": "TEXT",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "columnNames": [
+            "url"
+          ],
+          "autoGenerate": false
+        },
+        "indices": [],
+        "foreignKeys": []
+      }
+    ],
+    "views": [],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, '21c90e8223ebcb03b6bfb045f4a26142')"
+    ]
+  }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt b/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt
index 1369ba95..adbe9c6e 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/database/DatabaseEntities.kt
@@ -22,7 +22,9 @@ import androidx.room.Entity
 import androidx.room.PrimaryKey
 import com.example.android.devbyteviewer.domain.Video
 
-@Entity
+@Entity(
+        tableName = "videos",
+)
 data class DatabaseVideo(
         @PrimaryKey @ColumnInfo(name = "url") val url: String,
         @ColumnInfo(name = "title") val title: String,
diff --git a/app/src/main/java/com/example/android/devbyteviewer/database/Room.kt b/app/src/main/java/com/example/android/devbyteviewer/database/Room.kt
index f236fdeb..eb78e634 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/database/Room.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/database/Room.kt
@@ -16,3 +16,43 @@
  */
 
 package com.example.android.devbyteviewer.database
+
+import android.content.Context
+import androidx.lifecycle.LiveData
+import androidx.room.*
+
+@Dao
+interface VideoDao {
+
+    @Query("SELECT * FROM videos")
+    fun getVideos(): LiveData<List<DatabaseVideo>>
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertAll(vararg videos: DatabaseVideo): List<Long>
+}
+
+@Database(
+        entities = [DatabaseVideo::class],
+        version = 1,
+        exportSchema = true
+)
+abstract class DevBytesDatabase : RoomDatabase() {
+
+    abstract val videoDao: VideoDao
+}
+
+private var INSTANCE: DevBytesDatabase? = null
+
+fun getDatabase(context: Context): DevBytesDatabase =
+        synchronized(DevBytesDatabase::class.java) {
+            var instance = INSTANCE
+            if (instance == null) {
+                instance = Room.databaseBuilder(
+                        context,
+                        DevBytesDatabase::class.java,
+                        "dev-bytes.db"
+                ).build()
+                INSTANCE = instance
+            }
+            instance
+        }
\ No newline at end of file

From 4327ba3b6703cb8f312454f6beb642ecd3414e6a Mon Sep 17 00:00:00 2001
From: Filipe Bezerra <filipebzerra@gmail.com>
Date: Mon, 7 Dec 2020 15:46:01 -0300
Subject: [PATCH 5/6] feat: Use Repository to fetch and refresh data

---
 .../repository/VideoRepository.kt             | 50 +++++++++++++++++++
 .../repository/VideosRepository.kt            | 18 -------
 .../viewmodels/DevByteViewModel.kt            | 45 ++++-------------
 3 files changed, 59 insertions(+), 54 deletions(-)
 create mode 100644 app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt
 delete mode 100644 app/src/main/java/com/example/android/devbyteviewer/repository/VideosRepository.kt

diff --git a/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt b/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt
new file mode 100644
index 00000000..0e106798
--- /dev/null
+++ b/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2018, The Android Open Source Project
+ *
+ * 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 com.example.android.devbyteviewer.repository
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Transformations
+import com.example.android.devbyteviewer.database.VideoDao
+import com.example.android.devbyteviewer.database.asDomainModel
+import com.example.android.devbyteviewer.domain.Video
+import com.example.android.devbyteviewer.network.Network
+import com.example.android.devbyteviewer.network.asDatabaseModel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import timber.log.Timber
+
+/**
+ * Main entry to access [Video] objects wherever it comes from, this is the video repository.
+ */
+class VideoRepository(private val videoDao: VideoDao) {
+
+    val videos: LiveData<List<Video>> = Transformations.map(videoDao.getVideos()) {
+        it.asDomainModel()
+    }
+
+    suspend fun refreshVideos() {
+        withContext(Dispatchers.IO) {
+            try {
+                val playlist = Network.devbytes.getPlaylist()
+                videoDao.insertAll(*playlist.asDatabaseModel())
+            } catch (error: Exception) {
+                Timber.e(error, "Failed to refresh videos")
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/example/android/devbyteviewer/repository/VideosRepository.kt b/app/src/main/java/com/example/android/devbyteviewer/repository/VideosRepository.kt
deleted file mode 100644
index 7db76bd8..00000000
--- a/app/src/main/java/com/example/android/devbyteviewer/repository/VideosRepository.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright 2018, The Android Open Source Project
- *
- * 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 com.example.android.devbyteviewer.repository
diff --git a/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt b/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt
index a49d3953..000f27dd 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/viewmodels/DevByteViewModel.kt
@@ -19,14 +19,11 @@ package com.example.android.devbyteviewer.viewmodels
 
 import android.app.Application
 import androidx.lifecycle.*
+import com.example.android.devbyteviewer.database.DevBytesDatabase
+import com.example.android.devbyteviewer.database.getDatabase
 import com.example.android.devbyteviewer.domain.Video
-import com.example.android.devbyteviewer.network.Network
-import com.example.android.devbyteviewer.network.asDomainModel
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.SupervisorJob
+import com.example.android.devbyteviewer.repository.VideoRepository
 import kotlinx.coroutines.launch
-import java.io.IOException
 
 /**
  * DevByteViewModel designed to store and manage UI-related data in a lifecycle conscious way. This
@@ -35,50 +32,26 @@ import java.io.IOException
  * results after the new Fragment or Activity is available.
  *
  * @param application The application that this viewmodel is attached to, it's safe to hold a
- * reference to applications across rotation since Application is never recreated during actiivty
+ * reference to applications across rotation since Application is never recreated during activity
  * or fragment lifecycle events.
  */
 class DevByteViewModel(application: Application) : AndroidViewModel(application) {
 
-    /**
-     *
-     */
-
-    /**
-     *
-     */
-
-    /**
-     * A playlist of videos that can be shown on the screen. This is private to avoid exposing a
-     * way to set this value to observers.
-     */
-    private val _playlist = MutableLiveData<List<Video>>()
+    private val database: DevBytesDatabase by lazy { getDatabase(application) }
+    private val repository: VideoRepository by lazy { VideoRepository(database.videoDao) }
 
     /**
      * A playlist of videos that can be shown on the screen. Views should use this to get access
      * to the data.
      */
-    val playlist: LiveData<List<Video>>
-        get() = _playlist
+    val playlist = repository.videos
 
     /**
      * init{} is called immediately when this ViewModel is created.
      */
     init {
-        refreshDataFromNetwork()
-    }
-
-    /**
-     * Refresh data from network and pass it via LiveData. Use a coroutine launch to get to
-     * background thread.
-     */
-    private fun refreshDataFromNetwork() = viewModelScope.launch {
-        try {
-            val playlist = Network.devbytes.getPlaylist()
-            _playlist.postValue(playlist.asDomainModel())
-        } catch (networkError: IOException) {
-            // Show an infinite loading spinner if the request fails
-            // challenge exercise: show an error to the user if the network request fails
+        viewModelScope.launch {
+            repository.refreshVideos()
         }
     }
 

From 727d61f8a786cd9602164d790d48e18a1b149866 Mon Sep 17 00:00:00 2001
From: Filipe Bezerra <filipebzerra@gmail.com>
Date: Mon, 7 Dec 2020 16:42:33 -0300
Subject: [PATCH 6/6] feat: Implement recurring work once a day given
 constraints

---
 .../devbyteviewer/DevByteApplication.kt       | 35 ++++++++++++++++++
 .../repository/VideoRepository.kt             |  5 +++
 .../devbyteviewer/work/RefreshDataWork.kt     | 37 +++++++++++++++++++
 3 files changed, 77 insertions(+)

diff --git a/app/src/main/java/com/example/android/devbyteviewer/DevByteApplication.kt b/app/src/main/java/com/example/android/devbyteviewer/DevByteApplication.kt
index 68a15670..11308ce3 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/DevByteApplication.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/DevByteApplication.kt
@@ -18,13 +18,22 @@
 package com.example.android.devbyteviewer
 
 import android.app.Application
+import androidx.work.*
+import androidx.work.impl.Schedulers
+import com.example.android.devbyteviewer.work.RefreshDataWork
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
 import timber.log.Timber
+import java.util.concurrent.TimeUnit
 
 /**
  * Override application to setup background work via WorkManager
  */
 class DevByteApplication : Application() {
 
+    private val applicationScope = CoroutineScope(Dispatchers.Default)
+
     /**
      * onCreate is called before the first screen is shown to the user.
      *
@@ -34,5 +43,31 @@ class DevByteApplication : Application() {
     override fun onCreate() {
         super.onCreate()
         Timber.plant(Timber.DebugTree())
+        delayedInit()
+    }
+
+    private fun delayedInit() {
+        applicationScope.launch { setupRecurringWork() }
+    }
+
+    private fun setupRecurringWork() {
+        val constraints = Constraints.Builder()
+                .setRequiredNetworkType(NetworkType.UNMETERED)
+                .setRequiresBatteryNotLow(true)
+                .setRequiresCharging(true)
+                .apply {
+                    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.M) {
+                        setRequiresDeviceIdle(true)
+                    }
+                }
+                .build()
+        val repeatingRequest = PeriodicWorkRequestBuilder<RefreshDataWork>(1, TimeUnit.DAYS)
+                .setConstraints(constraints)
+                .build()
+        WorkManager.getInstance(this).enqueueUniquePeriodicWork(
+                RefreshDataWork.WORK_NAME,
+                ExistingPeriodicWorkPolicy.KEEP,
+                repeatingRequest
+        )
     }
 }
diff --git a/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt b/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt
index 0e106798..f9b0482a 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/repository/VideoRepository.kt
@@ -40,10 +40,15 @@ class VideoRepository(private val videoDao: VideoDao) {
     suspend fun refreshVideos() {
         withContext(Dispatchers.IO) {
             try {
+                Timber.i("Refreshing videos")
                 val playlist = Network.devbytes.getPlaylist()
+                Timber.i("Videos were fetched from internet successfully")
                 videoDao.insertAll(*playlist.asDatabaseModel())
+                Timber.i("Videos were saved to local data store successfully")
             } catch (error: Exception) {
                 Timber.e(error, "Failed to refresh videos")
+                // TODO Log to Crashlytics/Bugsnag
+                // TODO Show visual feedback
             }
         }
     }
diff --git a/app/src/main/java/com/example/android/devbyteviewer/work/RefreshDataWork.kt b/app/src/main/java/com/example/android/devbyteviewer/work/RefreshDataWork.kt
index f7d07f63..312c059a 100644
--- a/app/src/main/java/com/example/android/devbyteviewer/work/RefreshDataWork.kt
+++ b/app/src/main/java/com/example/android/devbyteviewer/work/RefreshDataWork.kt
@@ -16,3 +16,40 @@
  */
 
 package com.example.android.devbyteviewer.work
+
+import android.content.Context
+import androidx.work.CoroutineWorker
+import androidx.work.WorkerParameters
+import com.example.android.devbyteviewer.database.getDatabase
+import com.example.android.devbyteviewer.repository.VideoRepository
+import retrofit2.HttpException
+import timber.log.Timber
+
+/**
+ * Worker which uses [VideoRepository] to refresh data from the internet and cache data to the database.
+ */
+class RefreshDataWork(
+        private val appContext: Context,
+        params: WorkerParameters
+) : CoroutineWorker(appContext, params) {
+
+    override suspend fun doWork(): Result {
+        val database = getDatabase(appContext)
+        val repository = VideoRepository(database.videoDao)
+
+        return try {
+            Timber.i("Starting refresh work")
+            repository.refreshVideos()
+            Timber.i("Refresh work done successfully")
+            Result.success()
+        } catch (error: HttpException) {
+            Timber.e(error, "Failed to complete refresh work. Signalling to retry")
+            Result.retry()
+            // TODO Log to Crashlytics/Bugsnag
+        }
+    }
+
+    companion object {
+        const val WORK_NAME = "RefreshDataWork"
+    }
+}
\ No newline at end of file