Refactor: Persistence clean-up

app/src/main/java/com/monstarlab/core/persistence/DataSource.kt

@@ -1,8 +1,7 @@
 package com.monstarlab.core.persistence
 
 interface DataSource<T> {
-    suspend fun getAll(): List<T>
-    suspend fun add(item: T)
-    suspend fun addAll(items: List<T>)
+    suspend fun load(): T?
+    suspend fun save(item: T)
     suspend fun clear()
 }

app/src/main/java/com/monstarlab/core/persistence/ListDataSource.kt

@@ -0,0 +1,6 @@
+package com.monstarlab.core.persistence
+
+interface ListDataSource<T> : DataSource<List<T>> {
+    override suspend fun save(items: List<T>)
+    suspend fun add(item: T)
+}

app/src/main/java/com/monstarlab/core/persistence/SharedPreferenceDataStore.kt → app/src/main/java/com/monstarlab/core/persistence/ListPreferenceDataStore.kt

@@ -11,38 +11,48 @@ import kotlinx.serialization.SerializationException
 import kotlinx.serialization.builtins.ListSerializer
 import kotlinx.serialization.json.Json
 
-abstract class SharedPreferenceDataStore<T> constructor(
+abstract class ListPreferenceDataStore<T> constructor(
     private val dataStore: DataStore<Preferences>,
     private val serializer: KSerializer<T>,
-) : DataSource<T> {
+) : ListDataSource<T> {
 
     private val key = stringPreferencesKey(this.javaClass.simpleName)
 
-    override suspend fun getAll(): List<T> {
+    /**
+     * @return the stored collection of objects or an empty list, if no object was stored
+     */
+    override suspend fun load(): List<T> {
         return try {
             val json = dataStore.data.map { it[key] ?: "" }.first()
             Json.decodeFromString(ListSerializer(serializer), json)
         } catch (e: SerializationException) {
-            emptyList<T>()
+            emptyList()
         }
     }
 
+    /**
+     * Add a single [item] to the collection of stored elements
+     */
     override suspend fun add(item: T) {
-        val list = getAll().toMutableList()
-        list.add(item)
-        addAll(list)
+        save(load().plus(item))
     }
 
-    override suspend fun addAll(items: List<T>) {
+    /**
+     * Write [items] to storage, replacing any current ones
+     */
+    override suspend fun save(items: List<T>) {
         val json = Json.encodeToString(ListSerializer(serializer), items)
         dataStore.edit {
             it[key] = json
         }
     }
 
+    /**
+     * Remove the storage
+     */
     override suspend fun clear() {
         dataStore.edit {
-            it[key] = ""
+            it.remove(key)
         }
     }
 }

app/src/main/java/com/monstarlab/core/persistence/SingleSharedPreferenceDataStore.kt → app/src/main/java/com/monstarlab/core/persistence/SinglePreferenceDataStore.kt

@@ -11,24 +11,29 @@ import kotlinx.serialization.SerializationException
 import kotlinx.serialization.json.Json
 import timber.log.Timber
 
-abstract class SingleSharedPreferenceDataStore<T> constructor(
+abstract class SinglePreferenceDataStore<T> constructor(
     private val dataStore: DataStore<Preferences>,
     private val serializer: KSerializer<T>,
-) : SingleDataSource<T> {
+) : DataSource<T> {
 
     private val key = stringPreferencesKey(this.javaClass.simpleName)
 
-    override suspend fun get(): T? {
+    /**
+     * @return the stored object or null, if no object was stored
+     */
+    override suspend fun load(): T? {
         return try {
             val json = dataStore.data.map { it[key] ?: "" }.first()
-            val entries = Json.decodeFromString(serializer, json)
-            entries
+            Json.decodeFromString(serializer, json)
         } catch (e: SerializationException) {
             null
         }
     }
 
-    override suspend fun add(item: T) {
+    /**
+     * Write [item] to storage, replacing any existing ones
+     */
+    override suspend fun save(item: T) {
         try {
             val json = Json.encodeToString(serializer, item)
             dataStore.edit {
@@ -39,7 +44,12 @@ abstract class SingleSharedPreferenceDataStore<T> constructor(
         }
     }
 
+    /**
+     * Remove the storage
+     */
     override suspend fun clear() {
-        dataStore.edit { it[key] = "" }
+        dataStore.edit {
+            it.remove(key)
+        }
     }
 }

app/src/main/java/com/monstarlab/features/resources/data/persistence/ResourcePreferenceStore.kt → app/src/main/java/com/monstarlab/features/resources/data/persistence/ResourcesPreferenceStore.kt

@@ -2,10 +2,10 @@ package com.monstarlab.features.resources.data.persistence
 
 import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.Preferences
-import com.monstarlab.core.persistence.SharedPreferenceDataStore
+import com.monstarlab.core.persistence.ListPreferenceDataStore
 import com.monstarlab.features.resources.domain.model.Resource
 import javax.inject.Inject
 
-class ResourcePreferenceStore @Inject constructor(
+class ResourcesPreferenceStore @Inject constructor(
     dataStore: DataStore<Preferences>,
-) : SharedPreferenceDataStore<Resource>(dataStore, Resource.serializer())
+) : ListPreferenceDataStore<Resource>(dataStore, Resource.serializer())

app/src/main/java/com/monstarlab/features/resources/data/repository/ResourceRepositoryImpl.kt

@@ -2,19 +2,19 @@ package com.monstarlab.features.resources.data.repository
 
 import com.monstarlab.features.resources.data.api.ResourcesApi
 import com.monstarlab.features.resources.data.api.dtos.toResource
-import com.monstarlab.features.resources.data.persistence.ResourcePreferenceStore
+import com.monstarlab.features.resources.data.persistence.ResourcesPreferenceStore
 import com.monstarlab.features.resources.domain.model.Resource
 import com.monstarlab.features.resources.domain.repository.ResourceRepository
 import javax.inject.Inject
 
 class ResourceRepositoryImpl @Inject constructor(
     private val api: ResourcesApi,
-    private val resourcePreferenceStore: ResourcePreferenceStore,
+    private val resourcesPreferenceStore: ResourcesPreferenceStore,
 ) : ResourceRepository {
 
     override suspend fun get(): List<Resource> {
         return api.getResources().data.map { it.toResource() }.also {
-            resourcePreferenceStore.addAll(it)
+            resourcesPreferenceStore.save(it)
         }
     }
 }

app/src/main/java/com/monstarlab/features/user/data/persistence/UserPreferenceStore.kt

@@ -2,10 +2,10 @@ package com.monstarlab.features.user.data.persistence
 
 import androidx.datastore.core.DataStore
 import androidx.datastore.preferences.core.Preferences
-import com.monstarlab.core.persistence.SingleSharedPreferenceDataStore
+import com.monstarlab.core.persistence.SinglePreferenceDataStore
 import com.monstarlab.features.user.domain.model.User
 import javax.inject.Inject
 
 class UserPreferenceStore @Inject constructor(
     dataStore: DataStore<Preferences>,
-) : SingleSharedPreferenceDataStore<User>(dataStore, User.serializer())
+) : SinglePreferenceDataStore<User>(dataStore, User.serializer())

app/src/main/java/com/monstarlab/features/user/data/repository/UserRepositoryImpl.kt

@@ -14,7 +14,7 @@ class UserRepositoryImpl @Inject constructor(
 
     override suspend fun get(): User {
         return api.getUser().data.toUser().also {
-            userPreferenceStore.add(it)
+            userPreferenceStore.save(it)
         }
     }
 }

build.gradle.kts

@@ -33,7 +33,7 @@ subprojects {
         kotlin {
             target("**/*.kt")
             targetExclude("**/RateReminderActions.kt")
-            ktlint("0.40.0")
+            ktlint("1.0.0")
         }
     }
 }