Merge pull request #867 from lihenggui/fix/cannot_find_rules

Use assets when there is no files in the internal storage

core/data/src/main/kotlin/com/merxury/blocker/core/data/respository/generalrule/LocalGeneralRuleDataSource.kt

@@ -16,7 +16,9 @@
 
 package com.merxury.blocker.core.data.respository.generalrule
 
-import android.os.Build
+import android.content.res.AssetManager
+import android.os.Build.VERSION
+import android.os.Build.VERSION_CODES
 import com.merxury.blocker.core.data.di.RuleBaseFolder
 import com.merxury.blocker.core.data.respository.userdata.UserDataRepository
 import com.merxury.blocker.core.di.FilesDir
@@ -34,6 +36,8 @@ import kotlinx.serialization.json.Json
 import kotlinx.serialization.json.decodeFromStream
 import timber.log.Timber
 import java.io.File
+import java.io.IOException
+import java.io.InputStream
 import javax.inject.Inject
 
 private const val RULES_FOLDER = "rules"
@@ -42,37 +46,64 @@ private const val RULE_NAME = "general.json"
 internal class LocalGeneralRuleDataSource @Inject constructor(
  private val json: Json,
  private val userDataRepository: UserDataRepository,
+ private val assetManager: AssetManager,
  @FilesDir private val filesDir: File,
  @RuleBaseFolder private val ruleBaseFolder: String,
  @Dispatcher(IO) private val ioDispatcher: CoroutineDispatcher,
 ) : GeneralRuleDataSource {
- @OptIn(ExperimentalSerializationApi::class)
+
  override fun getGeneralRules(): Flow<List<GeneralRule>> = flow {
  val language = userDataRepository.getLibDisplayLanguage()
  val ruleFile = getRuleFile(language)
- ruleFile.inputStream().use { inputStream ->
- val serializedRule = if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
- // https://github.com/Kotlin/kotlinx.serialization/issues/2457
- // Use decodeFromString instead of decodeFromStream to avoid the issue
- val text = inputStream.bufferedReader().use { it.readText() }
- json.decodeFromString<List<NetworkGeneralRule>>(text)
- .map { it.asExternalModel() }
- } else {
- json.decodeFromStream<List<NetworkGeneralRule>>(inputStream)
- .map { it.asExternalModel() }
- }
+ ruleFile?.use { inputStream ->
+ val serializedRule = readContentFromStream(inputStream)
+ emit(serializedRule)
+ return@flow
+ }
+
+ // Fallback to assets
+ val assetRuleFile = getRuleFileFromAssets(language)
+ assetRuleFile?.use { inputStream ->
+ val serializedRule = readContentFromStream(inputStream)
  emit(serializedRule)
+ return@flow
  }
+ Timber.e("No general rule file found")
+ emit(emptyList())
  }
  .flowOn(ioDispatcher)
 
- private suspend fun getRuleFile(language: String): File = withContext(ioDispatcher) {
+ @OptIn(ExperimentalSerializationApi::class)
+ private fun readContentFromStream(inputStream: InputStream) =
+ if (VERSION.SDK_INT <= VERSION_CODES.M) {
+ // https://github.com/Kotlin/kotlinx.serialization/issues/2457
+ // Use decodeFromString instead of decodeFromStream to avoid the issue
+ val text = inputStream.bufferedReader().use { it.readText() }
+ json.decodeFromString<List<NetworkGeneralRule>>(text)
+ .map { it.asExternalModel() }
+ } else {
+ json.decodeFromStream<List<NetworkGeneralRule>>(inputStream)
+ .map { it.asExternalModel() }
+ }
+
+ private suspend fun getRuleFileFromAssets(language: String): InputStream? =
+ withContext(ioDispatcher) {
+ Timber.d("Get rule file from assets, language: $language")
+ try {
+ return@withContext assetManager.open("$ruleBaseFolder/$RULES_FOLDER/$language/$RULE_NAME")
+ } catch (e: IOException) {
+ Timber.e(e, "Failed to get rule file from assets")
+ return@withContext null
+ }
+ }
+
+ private suspend fun getRuleFile(language: String): InputStream? = withContext(ioDispatcher) {
  val ruleFile = filesDir.resolve(ruleBaseFolder)
  .resolve(RULES_FOLDER)
  .resolve(language)
  .resolve(RULE_NAME)
  if (ruleFile.exists()) {
- return@withContext ruleFile
+ return@withContext ruleFile.inputStream()
  }
  // TODO should be removed in future
  val lowercaseFolder = filesDir.resolve(ruleBaseFolder)
@@ -81,15 +112,16 @@ internal class LocalGeneralRuleDataSource @Inject constructor(
  .resolve(RULE_NAME)
  if (lowercaseFolder.exists()) {
  Timber.i("Fallback to lowercase-language folder")
- return@withContext lowercaseFolder
+ return@withContext lowercaseFolder.inputStream()
  }
  val oldRuleFile = filesDir.resolve(ruleBaseFolder)
  .resolve("zh-cn")
  .resolve(RULE_NAME)
  if (oldRuleFile.exists()) {
  Timber.i("Fallback to old version of rules without RULES_FOLDER")
- return@withContext oldRuleFile
+ return@withContext oldRuleFile.inputStream()
  }
- throw IllegalStateException("Cannot find general rule in files folder. language: $language")
+ Timber.e("General rule file not found, language: $language")
+ return@withContext null
  }
 }