Add room library. Create Entity+Dao+Database

app/build.gradle

@@ -1,6 +1,7 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-kapt'
 apply plugin: 'shot'
 
 android {
@@ -40,6 +41,9 @@ dependencies {
     implementation "androidx.constraintlayout:constraintlayout:2.0.0-alpha3"
     implementation "androidx.recyclerview:recyclerview:1.0.0"
     implementation "androidx.lifecycle:lifecycle-runtime:2.0.0"
+    implementation "androidx.room:room-runtime:2.1.0-alpha04"
+    kapt "androidx.room:room-compiler:2.1.0-alpha04"
+    implementation "androidx.room:room-coroutines:2.1.0-alpha04"
 
     /* Coroutines */
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.1.0"
@@ -71,6 +75,7 @@ dependencies {
     }
 
     androidTestImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:1.1.0"
+    testImplementation "androidx.room:room-testing:2.1.0-alpha04"
 }
 
 shot {

app/src/main/java/com/karumi/jetpack/superheroes/SuperHeroesApplication.kt

@@ -2,9 +2,12 @@ package com.karumi.jetpack.superheroes
 
 import android.app.Application
 import android.content.Context
+import androidx.room.Room
+import com.karumi.jetpack.superheroes.common.SuperHeroesDatabase
 import com.karumi.jetpack.superheroes.data.repository.LocalSuperHeroDataSource
 import com.karumi.jetpack.superheroes.data.repository.RemoteSuperHeroDataSource
 import com.karumi.jetpack.superheroes.data.repository.SuperHeroRepository
+import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroDao
 import org.kodein.di.Kodein
 import org.kodein.di.KodeinAware
 import org.kodein.di.android.androidModule
@@ -29,11 +32,22 @@ class SuperHeroesApplication : Application(), KodeinAware {
 
     private fun appDependencies(): Kodein.Module {
         return Kodein.Module("Application dependencies", allowSilentOverride = true) {
+            bind<SuperHeroesDatabase>() with singleton {
+                Room.databaseBuilder(
+                    this@SuperHeroesApplication,
+                    SuperHeroesDatabase::class.java,
+                    "superheroes-db"
+                ).build()
+            }
+            bind<SuperHeroDao>() with provider {
+                val database: SuperHeroesDatabase = instance()
+                database.superHeroesDao()
+            }
             bind<SuperHeroRepository>() with provider {
                 SuperHeroRepository(instance(), instance())
             }
             bind<LocalSuperHeroDataSource>() with singleton {
-                LocalSuperHeroDataSource()
+                LocalSuperHeroDataSource(instance())
             }
             bind<RemoteSuperHeroDataSource>() with provider {
                 RemoteSuperHeroDataSource()

app/src/main/java/com/karumi/jetpack/superheroes/common/SuperHeroesDatabase.kt

@@ -0,0 +1,11 @@
+package com.karumi.jetpack.superheroes.common
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroDao
+import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroEntity
+
+@Database(entities = [SuperHeroEntity::class], version = 1)
+abstract class SuperHeroesDatabase : RoomDatabase() {
+    abstract fun superHeroesDao(): SuperHeroDao
+}

app/src/main/java/com/karumi/jetpack/superheroes/data/repository/LocalSuperHeroDataSource.kt

@@ -1,38 +1,32 @@
 package com.karumi.jetpack.superheroes.data.repository
 
+import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroDao
+import com.karumi.jetpack.superheroes.data.repository.room.SuperHeroEntity
 import com.karumi.jetpack.superheroes.domain.model.SuperHero
-import kotlinx.coroutines.delay
 
-class LocalSuperHeroDataSource {
-    companion object {
-        private const val BIT_TIME = 250L
-    }
-
-    private val superHeroes: MutableMap<String, SuperHero> = mutableMapOf()
+class LocalSuperHeroDataSource(
+    private val dao: SuperHeroDao
+) {
+    suspend fun getAllSuperHeroes(): List<SuperHero> =
+        dao.getAll()
+            .map { it.toSuperHero() }
 
-    suspend fun getAllSuperHeroes(): List<SuperHero> {
-        waitABit()
-        return superHeroes.values.toList()
-    }
-
-    suspend fun get(id: String): SuperHero? {
-        waitABit()
-        return superHeroes[id]
-    }
+    suspend fun get(id: String): SuperHero? =
+        dao.getById(id)?.toSuperHero()
 
     suspend fun saveAll(all: List<SuperHero>) {
-        waitABit()
-        superHeroes.clear()
-        superHeroes.putAll(all.associateBy { it.id })
+        dao.deleteAll()
+        dao.insertAll(all.map { it.toEntity() })
     }
 
     suspend fun save(superHero: SuperHero): SuperHero {
-        waitABit()
-        superHeroes[superHero.id] = superHero
+        dao.insertAll(listOf(superHero.toEntity()))
         return superHero
     }
 
-    private suspend fun waitABit() {
-        delay(BIT_TIME)
-    }
+    private fun SuperHeroEntity.toSuperHero(): SuperHero =
+        SuperHero(id, name, photo, isAvenger, description)
+
+    private fun SuperHero.toEntity(): SuperHeroEntity =
+        SuperHeroEntity(id, name, photo, isAvenger, description)
 }

app/src/main/java/com/karumi/jetpack/superheroes/data/repository/room/SuperHeroDao.kt

@@ -0,0 +1,21 @@
+package com.karumi.jetpack.superheroes.data.repository.room
+
+import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
+import androidx.room.Query
+
+@Dao
+interface SuperHeroDao {
+    @Query("SELECT * FROM superheroes")
+    suspend fun getAll(): List<SuperHeroEntity>
+
+    @Query("SELECT * FROM superheroes WHERE id = :id")
+    suspend fun getById(id: String): SuperHeroEntity?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun insertAll(superHeroes: List<SuperHeroEntity>)
+
+    @Query("DELETE FROM superheroes")
+    suspend fun deleteAll()
+}

app/src/main/java/com/karumi/jetpack/superheroes/data/repository/room/SuperHeroEntity.kt

@@ -0,0 +1,13 @@
+package com.karumi.jetpack.superheroes.data.repository.room
+
+import androidx.room.Entity
+import androidx.room.PrimaryKey
+
+@Entity(tableName = "superheroes")
+data class SuperHeroEntity(
+    @PrimaryKey val id: String,
+    val name: String,
+    val photo: String?,
+    val isAvenger: Boolean,
+    val description: String
+)