(WIP) refactor: type-safe app preferences

app/src/main/java/me/ash/reader/infrastructure/preference/DarkThemePreference.kt

@@ -6,27 +6,21 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.ReadOnlyComposable
 import androidx.compose.runtime.compositionLocalOf
 import androidx.datastore.preferences.core.Preferences
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.launch
 import me.ash.reader.R
-import me.ash.reader.ui.ext.DataStoreKey
-import me.ash.reader.ui.ext.DataStoreKey.Companion.darkTheme
-import me.ash.reader.ui.ext.dataStore
-import me.ash.reader.ui.ext.put
+import me.ash.reader.ui.ext.PreferenceKey
+import me.ash.reader.ui.ext.get
 
-val LocalDarkTheme =
-    compositionLocalOf<DarkThemePreference> { DarkThemePreference.default }
+val LocalDarkTheme = compositionLocalOf<DarkThemePreference> { DarkThemePreference.default }
+
+sealed class DarkThemePreference(override val value: Int) :
+    AppPreference.IntPreference {
+    override val key: PreferenceKey.IntKey = Companion.key
 
-sealed class DarkThemePreference(val value: Int) : Preference() {
     object UseDeviceTheme : DarkThemePreference(0)
+
     object ON : DarkThemePreference(1)
-    object OFF : DarkThemePreference(2)
 
-    override fun put(context: Context, scope: CoroutineScope) {
-        scope.launch {
-            context.dataStore.put(darkTheme, value)
-        }
-    }
+    object OFF : DarkThemePreference(2)
 
     fun toDesc(context: Context): String =
         when (this) {
@@ -37,19 +31,21 @@ sealed class DarkThemePreference(val value: Int) : Preference() {
 
     @Composable
     @ReadOnlyComposable
-    fun isDarkTheme(): Boolean = when (this) {
-        UseDeviceTheme -> isSystemInDarkTheme()
-        ON -> true
-        OFF -> false
-    }
+    fun isDarkTheme(): Boolean =
+        when (this) {
+            UseDeviceTheme -> isSystemInDarkTheme()
+            ON -> true
+            OFF -> false
+        }
 
-    companion object {
+    companion object : AppPreference.PreferenceCompanion {
+        override val key: PreferenceKey.IntKey = PreferenceKey.DarkTheme
 
-        val default = UseDeviceTheme
-        val values = listOf(UseDeviceTheme, ON, OFF)
+        override val default = UseDeviceTheme
+        override val values = listOf(UseDeviceTheme, ON, OFF)
 
-        fun fromPreferences(preferences: Preferences) =
-            when (preferences[DataStoreKey.keys[darkTheme]?.key as Preferences.Key<Int>]) {
+        override fun fromPreferences(preferences: Preferences) =
+            when (preferences[key]) {
                 0 -> UseDeviceTheme
                 1 -> ON
                 2 -> OFF
@@ -61,11 +57,12 @@ sealed class DarkThemePreference(val value: Int) : Preference() {
 @Composable
 operator fun DarkThemePreference.not(): DarkThemePreference =
     when (this) {
-        DarkThemePreference.UseDeviceTheme -> if (isSystemInDarkTheme()) {
-            DarkThemePreference.OFF
-        } else {
-            DarkThemePreference.ON
-        }
+        DarkThemePreference.UseDeviceTheme ->
+            if (isSystemInDarkTheme()) {
+                DarkThemePreference.OFF
+            } else {
+                DarkThemePreference.ON
+            }
 
         DarkThemePreference.ON -> DarkThemePreference.OFF
         DarkThemePreference.OFF -> DarkThemePreference.ON

app/src/main/java/me/ash/reader/infrastructure/preference/Preference.kt

@@ -2,7 +2,74 @@ package me.ash.reader.infrastructure.preference
 
 import android.content.Context
 import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.edit
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+import me.ash.reader.ui.ext.PreferenceKey
+import me.ash.reader.ui.ext.dataStore
+import me.ash.reader.ui.ext.set
+import org.json.JSONObject
+
+sealed interface AppPreference {
+    val value: Any
+    val key: PreferenceKey
+
+    interface IntPreference : AppPreference, Editable {
+        override val value: Int
+        override val key: PreferenceKey.IntKey
+
+        override suspend fun put(context: Context) {
+            context.dataStore.edit { it[key] = value }
+        }
+    }
+
+    interface LongPreference : AppPreference {
+        override val value: Long
+        override val key: PreferenceKey.LongKey
+    }
+
+    interface StringPreference : AppPreference {
+        override val value: String
+        override val key: PreferenceKey.StringKey
+    }
+
+    interface BooleanPreference : AppPreference {
+        override val value: Boolean
+        override val key: PreferenceKey.BooleanKey
+    }
+
+    interface FloatPreference : AppPreference {
+        override val value: Float
+        override val key: PreferenceKey.FloatKey
+    }
+
+    interface PreferenceCompanion {
+        val key: PreferenceKey
+        val default: AppPreference
+
+        fun fromPreferences(preferences: Preferences): AppPreference
+
+        val values: List<AppPreference>
+    }
+
+    sealed interface Editable {
+        suspend fun put(context: Context)
+
+        @Deprecated("Use the suspend function instead")
+        fun put(context: Context, coroutineScope: CoroutineScope) =
+            coroutineScope.launch { put(context) }
+    }
+}
+
+fun JSONObject.put(preference: AppPreference) {
+    when (preference) {
+        is AppPreference.BooleanPreference -> put(preference.key.name, preference.value)
+        is AppPreference.FloatPreference -> put(preference.key.name, preference.value)
+        is AppPreference.IntPreference -> put(preference.key.name, preference.value)
+        is AppPreference.LongPreference -> put(preference.key.name, preference.value)
+        is AppPreference.StringPreference -> put(preference.key.name, preference.value)
+    }
+}
 
 sealed class Preference {
 
@@ -44,11 +111,11 @@ fun Preferences.toSettings(): Settings {
         flowArticleListImage = FlowArticleListImagePreference.fromPreferences(this),
         flowArticleListDesc = FlowArticleListDescPreference.fromPreferences(this),
         flowArticleListTime = FlowArticleListTimePreference.fromPreferences(this),
-        flowArticleListDateStickyHeader = FlowArticleListDateStickyHeaderPreference.fromPreferences(
-            this
-        ),
+        flowArticleListDateStickyHeader =
+            FlowArticleListDateStickyHeaderPreference.fromPreferences(this),
         flowArticleListReadIndicator = FlowArticleReadIndicatorPreference.fromPreferences(this),
-        flowArticleListTonalElevation = FlowArticleListTonalElevationPreference.fromPreferences(this),
+        flowArticleListTonalElevation =
+            FlowArticleListTonalElevationPreference.fromPreferences(this),
         flowSortUnreadArticles = SortUnreadArticlesPreference.fromPreferences(this),
 
         // Reading page
@@ -70,7 +137,8 @@ fun Preferences.toSettings(): Settings {
         readingSubheadBold = ReadingSubheadBoldPreference.fromPreferences(this),
         readingTitleUpperCase = ReadingTitleUpperCasePreference.fromPreferences(this),
         readingSubheadUpperCase = ReadingSubheadUpperCasePreference.fromPreferences(this),
-        readingImageHorizontalPadding = ReadingImageHorizontalPaddingPreference.fromPreferences(this),
+        readingImageHorizontalPadding =
+            ReadingImageHorizontalPaddingPreference.fromPreferences(this),
         readingImageRoundedCorners = ReadingImageRoundedCornersPreference.fromPreferences(this),
         readingImageMaximize = ReadingImageMaximizePreference.fromPreferences(this),