lots of background work for manga extensions

app/src/main/java/eu/kanade/domain/base/ExtensionInstallerPreference.kt

@@ -0,0 +1,70 @@
+package eu.kanade.domain.base
+
+import android.content.Context
+import eu.kanade.tachiyomi.util.system.hasMiuiPackageInstaller
+import eu.kanade.domain.base.BasePreferences.ExtensionInstaller
+import eu.kanade.tachiyomi.util.system.isShizukuInstalled
+import kotlinx.coroutines.CoroutineScope
+import tachiyomi.core.preference.Preference
+import tachiyomi.core.preference.PreferenceStore
+import tachiyomi.core.preference.getEnum
+
+class ExtensionInstallerPreference(
+    private val context: Context,
+    preferenceStore: PreferenceStore
+) : Preference<ExtensionInstaller> {
+
+    private val basePref = preferenceStore.getEnum(key(), defaultValue())
+
+    override fun key() = "extension_installer"
+
+
+
+    val entries get() = BasePreferences.ExtensionInstaller.values().run {
+        if (context.hasMiuiPackageInstaller) {
+            filter { it != BasePreferences.ExtensionInstaller.PACKAGEINSTALLER }
+        } else {
+            toList()
+        }
+    }
+
+    override fun defaultValue() = if (context.hasMiuiPackageInstaller) {
+        ExtensionInstaller.LEGACY
+    } else {
+        ExtensionInstaller.PACKAGEINSTALLER
+    }
+
+    private fun check(value: ExtensionInstaller): ExtensionInstaller {
+        when (value) {
+            ExtensionInstaller.PACKAGEINSTALLER -> {
+                if (context.hasMiuiPackageInstaller) return ExtensionInstaller.LEGACY
+            }
+            ExtensionInstaller.SHIZUKU -> {
+                if (!context.isShizukuInstalled) return defaultValue()
+            }
+            else -> {}
+        }
+        return value
+    }
+
+    override fun get(): ExtensionInstaller {
+        val value = basePref.get()
+        val checkedValue = check(value)
+        if (value != checkedValue) {
+            basePref.set(checkedValue)
+        }
+        return checkedValue
+    }
+
+    override fun set(value: ExtensionInstaller) {
+        basePref.set(check(value))
+    }
+
+    override fun isSet() = basePref.isSet()
+
+    override fun delete() = basePref.delete()
+
+    override fun changes() = basePref.changes()
+
+    override fun stateIn(scope: CoroutineScope) = basePref.stateIn(scope)
+}