Create in-app logging framework

app/build.gradle

@@ -27,6 +27,9 @@ android {
 }
 
 dependencies {
+    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+    def room_version = "2.2.5"
+
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.7"
@@ -41,6 +44,9 @@ dependencies {
     implementation 'com.google.dagger:dagger-android-support:2.15'
     implementation 'com.github.adrielcafe:AndroidAudioConverter:0.0.8'
     implementation 'org.luaj:luaj-jse:3.0.1'
+    implementation "org.threeten:threetenbp:1.4.4"
+    implementation "androidx.room:room-runtime:$room_version"
+    kapt "androidx.room:room-compiler:$room_version"
     kapt 'com.google.dagger:dagger-android-processor:2.15'
     kapt 'com.google.dagger:dagger-compiler:2.15'
     testImplementation 'junit:junit:4.12'

app/src/main/AndroidManifest.xml

@@ -17,7 +17,7 @@
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 
     <application
-        android:name="com.bartlomiejpluta.ttsserver.TTSApplication"
+        android:name=".TTSApplication"
         android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
@@ -27,25 +27,29 @@
         android:usesCleartextTraffic="true"
         tools:targetApi="m">
         <activity
-            android:name="com.bartlomiejpluta.ttsserver.ui.help.HelpActivity"
+            android:name=".ui.log.LogActivity"
-            android:parentActivityName="com.bartlomiejpluta.ttsserver.ui.main.MainActivity" />
+            android:parentActivityName=".ui.main.MainActivity" />
-
+        
         <activity
-            android:name="com.bartlomiejpluta.ttsserver.ui.preference.component.PreferencesActivity"
+            android:name=".ui.help.HelpActivity"
+            android:parentActivityName=".ui.main.MainActivity" />
+        <activity
+            android:name=".ui.preference.component.PreferencesActivity"
             android:label="@string/title_activity_preferences"
-            android:parentActivityName="com.bartlomiejpluta.ttsserver.ui.main.MainActivity" />
+            android:parentActivityName=".ui.main.MainActivity" />
 
         <service
-            android:name="com.bartlomiejpluta.ttsserver.service.foreground.ForegroundService"
+            android:name=".service.foreground.ForegroundService"
             android:enabled="true"
             android:exported="true"
             android:permission="com.bartlomiejpluta.permission.TTS_HTTP_SERVICE" />
 
         <activity
-            android:name="com.bartlomiejpluta.ttsserver.ui.main.MainActivity"
+            android:name=".ui.main.MainActivity"
             android:launchMode="singleTop">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
+
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>

app/src/main/java/com/bartlomiejpluta/ttsserver/common/db/converter/InstantConverter.kt

@@ -0,0 +1,15 @@
+package com.bartlomiejpluta.ttsserver.common.db.converter
+
+import androidx.room.TypeConverter
+import org.threeten.bp.Instant
+
+object InstantConverter {
+
+   @TypeConverter
+   @JvmStatic
+   fun toInstant(epoch: Long?) = epoch?.let { Instant.ofEpochMilli(it) }
+
+   @TypeConverter
+   @JvmStatic
+   fun fromInstant(instant: Instant?) = instant?.toEpochMilli()
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/log/converter/LogLevelConverter.kt

@@ -0,0 +1,15 @@
+package com.bartlomiejpluta.ttsserver.core.log.converter
+
+import androidx.room.TypeConverter
+import com.bartlomiejpluta.ttsserver.core.log.model.enumeration.LogLevel
+
+object LogLevelConverter {
+
+   @TypeConverter
+   @JvmStatic
+   fun toLogLevel(string: String?) = string?.let { LogLevel.valueOf(it) }
+
+   @TypeConverter
+   @JvmStatic
+   fun fromLogLevel(logLevel: LogLevel?) = logLevel?.name
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/log/dao/LogDao.kt

@@ -0,0 +1,20 @@
+package com.bartlomiejpluta.ttsserver.core.log.dao
+
+import androidx.room.Dao
+import androidx.room.Delete
+import androidx.room.Insert
+import androidx.room.Query
+import com.bartlomiejpluta.ttsserver.core.log.model.entity.LogEntry
+
+@Dao
+interface LogDao {
+
+   @Insert
+   fun insert(entry: LogEntry)
+
+   @Query("SELECT * FROM logentry ORDER BY date DESC LIMIT 5000")
+   fun getAll(): List<LogEntry>
+
+   @Query("DELETE FROM logentry")
+   fun clear()
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/log/database/LogDatabase.kt

@@ -0,0 +1,11 @@
+package com.bartlomiejpluta.ttsserver.core.log.database
+
+import androidx.room.Database
+import androidx.room.RoomDatabase
+import com.bartlomiejpluta.ttsserver.core.log.dao.LogDao
+import com.bartlomiejpluta.ttsserver.core.log.model.entity.LogEntry
+
+@Database(entities = [LogEntry::class], version = 1)
+abstract class LogDatabase : RoomDatabase() {
+   abstract fun dao(): LogDao
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/log/model/entity/LogEntry.kt

@@ -0,0 +1,26 @@
+package com.bartlomiejpluta.ttsserver.core.log.model.entity
+
+import androidx.room.*
+import com.bartlomiejpluta.ttsserver.common.db.converter.InstantConverter
+import com.bartlomiejpluta.ttsserver.core.log.converter.LogLevelConverter
+import com.bartlomiejpluta.ttsserver.core.log.model.enumeration.LogLevel
+import org.threeten.bp.Instant
+
+@Entity
+@TypeConverters(InstantConverter::class, LogLevelConverter::class)
+data class LogEntry (
+   @PrimaryKey
+   val id: Int?,
+
+   @ColumnInfo(name = "date")
+   val date: Instant,
+
+   @ColumnInfo(name = "level")
+   val level: LogLevel,
+
+   @ColumnInfo(name = "source")
+   val source: String,
+
+   @ColumnInfo(name = "message")
+   val message: String
+)

app/src/main/java/com/bartlomiejpluta/ttsserver/core/log/model/enumeration/LogLevel.kt

@@ -0,0 +1,9 @@
+package com.bartlomiejpluta.ttsserver.core.log.model.enumeration
+
+enum class LogLevel {
+   DEBUG,
+   INFO,
+   WARN,
+   ERROR,
+   FATAL
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/log/service/LogService.kt

@@ -0,0 +1,53 @@
+package com.bartlomiejpluta.ttsserver.core.log.service
+
+import android.content.Context
+import android.content.Intent
+import androidx.localbroadcastmanager.content.LocalBroadcastManager
+import com.bartlomiejpluta.ttsserver.core.log.database.LogDatabase
+import com.bartlomiejpluta.ttsserver.core.log.model.entity.LogEntry
+import com.bartlomiejpluta.ttsserver.core.log.model.enumeration.LogLevel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withContext
+import org.threeten.bp.Instant
+
+class LogService(private val context: Context, logDatabase: LogDatabase) {
+   private val dao = logDatabase.dao()
+   private val broadcastManager = LocalBroadcastManager.getInstance(context)
+
+   fun debug(source: String, message: String) = log(LogLevel.DEBUG, source, message)
+
+   fun info(source: String, message: String) = log(LogLevel.INFO, source, message)
+
+   fun warn(source: String, message: String) = log(LogLevel.WARN, source, message)
+
+   fun error(source: String, message: String) = log(LogLevel.ERROR, source, message)
+
+   fun fatal(source: String, message: String) = log(LogLevel.FATAL, source, message)
+
+   fun log(level: LogLevel, source: String, message: String) =
+      log(LogEntry(null, Instant.now(), level, source, message))
+
+   fun log(logEntry: LogEntry) {
+      persistLogEntry(logEntry)
+      broadcastLogEntry()
+   }
+
+   private fun persistLogEntry(logEntry: LogEntry) = runBlocking {
+      withContext(Dispatchers.IO + Job()) {
+         dao.insert(logEntry)
+      }
+   }
+
+   private fun broadcastLogEntry() = broadcastManager.sendBroadcast(Intent(UPDATE_LOGS))
+
+   val allLogs: List<LogEntry>
+      get() = dao.getAll()
+
+   fun clearLogs() = dao.clear()
+
+   companion object {
+      const val UPDATE_LOGS = "UPDATE_LOGS"
+   }
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/lua/lib/LogLibrary.kt

@@ -0,0 +1,33 @@
+package com.bartlomiejpluta.ttsserver.core.lua.lib
+
+import com.bartlomiejpluta.ttsserver.core.log.model.enumeration.LogLevel
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
+import org.luaj.vm2.LuaValue
+import org.luaj.vm2.lib.OneArgFunction
+import org.luaj.vm2.lib.TwoArgFunction
+
+class LogLibrary(private val logService: LogService) : TwoArgFunction() {
+   override fun call(modname: LuaValue, env: LuaValue): LuaValue {
+      val scriptName = env.get("_G").get("script").checkjstring()
+      val log = LuaValue.tableOf()
+      log.set("debug", LogFunction(logService, LogLevel.DEBUG, scriptName))
+      log.set("info", LogFunction(logService, LogLevel.INFO, scriptName))
+      log.set("warn", LogFunction(logService, LogLevel.WARN, scriptName))
+      log.set("error", LogFunction(logService, LogLevel.ERROR, scriptName))
+      log.set("fatal", LogFunction(logService, LogLevel.FATAL, scriptName))
+      env.set("log", log)
+
+      return env
+   }
+
+   class LogFunction(
+      private val log: LogService,
+      private val level: LogLevel,
+      private val scriptName: String
+   ) : OneArgFunction() {
+      override fun call(message: LuaValue): LuaValue {
+         log.log(level, scriptName, message.checkjstring())
+         return LuaValue.NIL
+      }
+   }
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/core/lua/loader/ConfigLoader.kt

@@ -8,12 +8,18 @@ import org.luaj.vm2.lib.TwoArgFunction
 import java.io.File
 
 class ConfigLoader(context: Context) {
-   private val configDirectory = context.getExternalFilesDir("config")
+   private val configFile = File(context.getExternalFilesDir("config"), "config.lua")
+   private var cachedConfig: LuaTable? = null
+
+   fun refreshConfig(env: Globals) {
+      cachedConfig = env.loadfile(configFile.absolutePath).call().checktable()
+   }
 
    fun loadConfig(env: Globals) {
-      val configFile = File(configDirectory, "config.lua")
+      cachedConfig
-      val table = env.loadfile(configFile.absolutePath).call().checktable()
+         ?.let { ConfigLibrary(it) }
-      env.load(ConfigLibrary(table))
+         ?.let { env.load(it) }
+         ?: error("Config has not been refreshed before loading start")
    }
 
    class ConfigLibrary(private val table: LuaTable) : TwoArgFunction() {

app/src/main/java/com/bartlomiejpluta/ttsserver/core/lua/loader/EndpointLoader.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.content.Intent
 import androidx.localbroadcastmanager.content.LocalBroadcastManager
 import com.bartlomiejpluta.ttsserver.R
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.lua.sandbox.SandboxFactory
 import com.bartlomiejpluta.ttsserver.core.web.endpoint.DefaultEndpoint
 import com.bartlomiejpluta.ttsserver.core.web.endpoint.Endpoint
@@ -19,28 +20,37 @@ import java.io.File
 class EndpointLoader(
    private val context: Context,
    private val sandboxFactory: SandboxFactory,
-   private val tasksQueueFactory: TasksQueueFactory
+   private val tasksQueueFactory: TasksQueueFactory,
+   private val log: LogService
 ) {
 
    fun loadEndpoints(): List<Endpoint> {
+      sandboxFactory.refreshConfig()
+      log.info(TAG, "Loading endpoint scripts...")
       val scripts = context.getExternalFilesDir("endpoints")?.listFiles() ?: emptyArray()
 
-      return scripts.mapNotNull { loadEndpoint(it) }
+      return scripts
+         .mapNotNull { loadEndpoint(it) }
+         .also { log.info(TAG, "Loading endpoints is complete") }
    }
 
    private fun loadEndpoint(script: File): Endpoint? {
       try {
+         log.info(TAG, "Loading ${script.name} script...")
          return sandboxFactory
-            .createSandbox()
+            .createSandbox(script.name)
             .loadfile(script.absolutePath)
             .call()
             .checktable()
             .takeIf { parseEnabled(it) }
             ?.let { createEndpoint(it) }
+            ?.also { log.info(TAG, "Script ${script.name} has been loaded successfully") }
       } catch (e: LuaError) {
          handleError(e)
+         log.error(TAG, "Loading script ${script.name} failed: ${e.message}")
          return null
       } catch (e: Exception) {
+         log.error(TAG, "Loading script ${script.name} failed: ${e.message}")
          throw e
       }
    }
@@ -91,6 +101,7 @@ class EndpointLoader(
       ?: throw LuaError("Invalid HTTP method. Allowed methods are: $ALLOWED_METHODS")
 
    companion object {
+      private val TAG = "@endpoints"
       private val ALLOWED_METHODS = Method.values().joinToString(", ")
    }
 }

app/src/main/java/com/bartlomiejpluta/ttsserver/core/lua/sandbox/SandboxFactory.kt

@@ -1,6 +1,7 @@
 package com.bartlomiejpluta.ttsserver.core.lua.sandbox
 
 import android.content.Context
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.lua.lib.*
 import com.bartlomiejpluta.ttsserver.core.lua.loader.ConfigLoader
 import kotlinx.coroutines.Dispatchers
@@ -18,21 +19,31 @@ import org.luaj.vm2.lib.jse.JseOsLib
 
 class SandboxFactory(
    private val context: Context,
+   private val log: LogService,
    private val configLoader: ConfigLoader,
    private val threadLibrary: ThreadLibrary,
    private val serverLibrary: ServerLibrary,
+   private val logLibrary: LogLibrary,
    private val httpLibrary: HTTPLibrary,
    private val ttsLibrary: TTSLibrary,
    private val sonosLibrary: SonosLibrary
 ) {
-   fun createSandbox() = runBlocking {
+   fun createSandbox(scriptName: String) = createLuaGlobals(scriptName).also {
+      loadConfiguration(it)
+   }
+
+   fun refreshConfig() = runBlocking {
       withContext(Dispatchers.Default) {
-         createLuaGlobals()
+         log.info(TAG, "Loading configuration file")
+         val configEnvironment = createLuaGlobals(":config")
+         configLoader.refreshConfig(configEnvironment)
       }
    }
 
-   private fun createLuaGlobals() = Globals().also { sandbox ->
+   private fun createLuaGlobals(scriptName: String) = Globals().also { sandbox ->
+      log.info(TAG, "Installing sandbox for $scriptName...")
       loadStandardLibraries(sandbox)
+      sandbox.get("_G").checktable().set("script", scriptName)
       loadApplicationLibraries(sandbox)
       install(sandbox)
       loadLuaLibraries(sandbox)
@@ -49,6 +60,7 @@ class SandboxFactory(
 
    private fun loadApplicationLibraries(sandbox: Globals) {
       sandbox.load(serverLibrary)
+      sandbox.load(logLibrary)
       sandbox.load(threadLibrary)
       sandbox.load(httpLibrary)
       sandbox.load(ttsLibrary)
@@ -58,6 +70,9 @@ class SandboxFactory(
    private fun install(sandbox: Globals) {
       LoadState.install(sandbox)
       LuaC.install(sandbox)
+   }
+
+   private fun loadConfiguration(sandbox: Globals) {
       configLoader.loadConfig(sandbox)
    }
 
@@ -68,4 +83,8 @@ class SandboxFactory(
          ?.map { (name, reader) -> name.substringBeforeLast(".") to sandbox.load(reader, name) }
          ?.forEach { (name, value) -> sandbox.set(name, value.call()) }
    }
+
+   companion object {
+      private const val TAG = "@sandbox"
+   }
 }

app/src/main/java/com/bartlomiejpluta/ttsserver/core/web/server/WebServer.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.content.Intent
 import android.content.SharedPreferences
 import androidx.localbroadcastmanager.content.LocalBroadcastManager
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.tts.engine.TTSEngine
 import com.bartlomiejpluta.ttsserver.core.tts.status.TTSStatus
 import com.bartlomiejpluta.ttsserver.core.web.endpoint.Endpoint
@@ -22,7 +23,8 @@ class WebServer(
    private val context: Context,
    private val preferences: SharedPreferences,
    private val tts: TTSEngine,
-   private val endpoints: List<Endpoint>
+   private val endpoints: List<Endpoint>,
+   private val log: LogService
 ) : NanoHTTPD(port) {
    private val queuedEndpoints = endpoints.mapNotNull { it as? QueuedEndpoint }
 
@@ -36,10 +38,13 @@ class WebServer(
 
          throw WebException(BAD_REQUEST, "Unknown error")
       } catch (e: WebException) {
+         log.error(TAG, "Web exception occurred: ${e.message}")
          return handleWebException(e)
       } catch (e: LuaError) {
+         log.error(TAG, "Lua error occurred: ${e.message}")
          return handleLuaError(e)
       } catch (e: Exception) {
+         log.fatal(TAG, "Unknown error occurred: ${e.message}")
          return handleUnknownException(e)
       }
    }
@@ -75,6 +80,7 @@ class WebServer(
 
    override fun start() {
       super.start()
+      log.info(TAG, "Web server is up")
 
       LocalBroadcastManager
          .getInstance(context)
@@ -84,6 +90,7 @@ class WebServer(
    }
 
    override fun stop() {
+      log.info(TAG, "Stopping web server...")
       super.stop()
       queuedEndpoints.forEach { it.shutdownQueue() }
 
@@ -95,6 +102,7 @@ class WebServer(
    }
 
    companion object {
+      private const val TAG = "@webserver"
       private const val MIME_JSON = "application/json"
       const val DEFAULT_PORT = 8080
    }

app/src/main/java/com/bartlomiejpluta/ttsserver/core/web/server/WebServerFactory.kt

@@ -2,6 +2,7 @@ package com.bartlomiejpluta.ttsserver.core.web.server
 
 import android.content.Context
 import android.content.SharedPreferences
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.lua.loader.EndpointLoader
 import com.bartlomiejpluta.ttsserver.core.tts.engine.TTSEngine
 import com.bartlomiejpluta.ttsserver.ui.preference.key.PreferenceKey
@@ -10,13 +11,15 @@ class WebServerFactory(
    private val preferences: SharedPreferences,
    private val context: Context,
    private val tts: TTSEngine,
-   private val endpointLoader: EndpointLoader
+   private val endpointLoader: EndpointLoader,
+   private val logService: LogService
 ) {
    fun createWebServer() = WebServer(
       preferences.getInt(PreferenceKey.PORT, WebServer.DEFAULT_PORT),
       context,
       preferences,
       tts,
-      endpointLoader.loadEndpoints()
+      endpointLoader.loadEndpoints(),
+      logService
    )
 }

app/src/main/java/com/bartlomiejpluta/ttsserver/di/module/AndroidModule.kt

@@ -2,6 +2,7 @@ package com.bartlomiejpluta.ttsserver.di.module
 
 import com.bartlomiejpluta.ttsserver.service.foreground.ForegroundService
 import com.bartlomiejpluta.ttsserver.ui.help.HelpActivity
+import com.bartlomiejpluta.ttsserver.ui.log.LogActivity
 import com.bartlomiejpluta.ttsserver.ui.main.MainActivity
 import com.bartlomiejpluta.ttsserver.ui.preference.component.PreferencesActivity
 import dagger.Module
@@ -19,6 +20,9 @@ abstract class AndroidModule {
    @ContributesAndroidInjector
    abstract fun preferencesActivity(): PreferencesActivity
 
+   @ContributesAndroidInjector
+   abstract fun logActivity(): LogActivity
+
    @ContributesAndroidInjector
    abstract fun foregroundService(): ForegroundService
 }

app/src/main/java/com/bartlomiejpluta/ttsserver/di/module/LuaModule.kt

@@ -2,6 +2,7 @@ package com.bartlomiejpluta.ttsserver.di.module
 
 import android.content.Context
 import android.content.SharedPreferences
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.lua.lib.*
 import com.bartlomiejpluta.ttsserver.core.lua.loader.ConfigLoader
 import com.bartlomiejpluta.ttsserver.core.lua.loader.EndpointLoader
@@ -22,9 +23,10 @@ class LuaModule {
    fun endpointLoader(
       context: Context,
       sandboxFactory: SandboxFactory,
-      tasksQueueFactory: TasksQueueFactory
+      tasksQueueFactory: TasksQueueFactory,
+      logService: LogService
    ) =
-      EndpointLoader(context, sandboxFactory, tasksQueueFactory)
+      EndpointLoader(context, sandboxFactory, tasksQueueFactory, logService)
 
    @Provides
    @Singleton
@@ -34,17 +36,21 @@ class LuaModule {
    @Singleton
    fun sandboxFactory(
       context: Context,
+      logService: LogService,
       configLoader: ConfigLoader,
       threadLibrary: ThreadLibrary,
       serverLibrary: ServerLibrary,
+      logLibrary: LogLibrary,
       httpLibrary: HTTPLibrary,
       ttsLibrary: TTSLibrary,
       sonosLibrary: SonosLibrary
    ) = SandboxFactory(
       context,
+      logService,
       configLoader,
       threadLibrary,
       serverLibrary,
+      logLibrary,
       httpLibrary,
       ttsLibrary,
       sonosLibrary
@@ -63,6 +69,10 @@ class LuaModule {
    fun serverLibrary(context: Context, networkUtil: NetworkUtil) =
       ServerLibrary(context, networkUtil)
 
+   @Provides
+   @Singleton
+   fun logLibrary(logService: LogService) = LogLibrary(logService)
+
    @Provides
    @Singleton
    fun httpLibrary() = HTTPLibrary()

app/src/main/java/com/bartlomiejpluta/ttsserver/di/module/TTSModule.kt

@@ -4,6 +4,9 @@ import android.content.Context
 import android.content.SharedPreferences
 import android.speech.tts.TextToSpeech
 import androidx.preference.PreferenceManager
+import androidx.room.Room
+import com.bartlomiejpluta.ttsserver.core.log.database.LogDatabase
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.lua.loader.EndpointLoader
 import com.bartlomiejpluta.ttsserver.core.tts.engine.TTSEngine
 import com.bartlomiejpluta.ttsserver.core.tts.status.TTSStatusHolder
@@ -43,12 +46,14 @@ class TTSModule {
       preferences: SharedPreferences,
       context: Context,
       tts: TTSEngine,
-      endpointLoader: EndpointLoader
+      endpointLoader: EndpointLoader,
+      logService: LogService
    ) = WebServerFactory(
       preferences,
       context,
       tts,
-      endpointLoader
+      endpointLoader,
+      logService
    )
 
    @Provides
@@ -70,4 +75,14 @@ class TTSModule {
       context: Context,
       networkUtil: NetworkUtil
    ) = ForegroundNotificationFactory(context, networkUtil)
+
+   @Provides
+   @Singleton
+   fun logDatabase(context: Context) = Room
+      .databaseBuilder(context, LogDatabase::class.java, "log.db")
+      .build()
+
+   @Provides
+   @Singleton
+   fun logService(context: Context, logDatabase: LogDatabase) = LogService(context, logDatabase)
 }

app/src/main/java/com/bartlomiejpluta/ttsserver/service/foreground/ForegroundService.kt

@@ -4,6 +4,7 @@ import android.annotation.SuppressLint
 import android.content.Context
 import android.content.Intent
 import android.os.PowerManager
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
 import com.bartlomiejpluta.ttsserver.core.web.server.WebServer
 import com.bartlomiejpluta.ttsserver.core.web.server.WebServerFactory
 import com.bartlomiejpluta.ttsserver.service.notification.ForegroundNotificationFactory
@@ -23,6 +24,9 @@ class ForegroundService : DaggerService() {
    @Inject
    lateinit var notificationFactory: ForegroundNotificationFactory
 
+   @Inject
+   lateinit var log: LogService
+
    override fun onCreate() {
       super.onCreate()
       startForeground(1, notificationFactory.createForegroundNotification())
@@ -50,6 +54,7 @@ class ForegroundService : DaggerService() {
    private fun startService() {
       if (isServiceStarted) return
       isServiceStarted = true
+      log.info(TAG, "Starting service...")
       wakeLock =
          (getSystemService(Context.POWER_SERVICE) as PowerManager).run {
             newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
@@ -62,10 +67,12 @@ class ForegroundService : DaggerService() {
       webServer?.let {
          state = ServiceState.RUNNING
          it.start()
+         log.info(TAG, "Service started successfully")
       }
    }
 
    private fun stopService() {
+      log.info(TAG, "Stopping service...")
       webServer?.stop()
       webServer = null
       wakeLock?.let {
@@ -77,6 +84,7 @@ class ForegroundService : DaggerService() {
          stopSelf()
       }
       state = ServiceState.STOPPED
+      log.info(TAG, "Service stopped successfully")
    }
 
    companion object {
@@ -85,6 +93,7 @@ class ForegroundService : DaggerService() {
       // than to place it as a static field
       var state = ServiceState.STOPPED
 
+      private const val TAG = "@service"
       private const val WAKELOCK_TAG = "ForegroundService::lock"
       const val START = "START"
       const val STOP = "STOP"

app/src/main/java/com/bartlomiejpluta/ttsserver/ui/log/LogActivity.kt

@@ -0,0 +1,145 @@
+package com.bartlomiejpluta.ttsserver.ui.log
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.os.Bundle
+import android.view.Menu
+import android.view.MenuItem
+import android.webkit.WebView
+import android.webkit.WebViewClient
+import androidx.appcompat.app.AlertDialog
+import androidx.localbroadcastmanager.content.LocalBroadcastManager
+import com.bartlomiejpluta.ttsserver.R
+import com.bartlomiejpluta.ttsserver.core.log.model.entity.LogEntry
+import com.bartlomiejpluta.ttsserver.core.log.model.enumeration.LogLevel
+import com.bartlomiejpluta.ttsserver.core.log.service.LogService
+import dagger.android.support.DaggerAppCompatActivity
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withContext
+import org.threeten.bp.ZoneId
+import org.threeten.bp.format.DateTimeFormatter
+import org.threeten.bp.format.FormatStyle
+import java.util.*
+import javax.inject.Inject
+
+
+class LogActivity : DaggerAppCompatActivity() {
+   private val formatter = DateTimeFormatter
+      .ofLocalizedDateTime(FormatStyle.MEDIUM)
+      .withLocale(Locale.getDefault())
+      .withZone(ZoneId.systemDefault())
+
+   private lateinit var logView: WebView
+
+   @Inject
+   lateinit var logService: LogService
+
+   private val receiver = object : BroadcastReceiver() {
+      override fun onReceive(context: Context?, intent: Intent?) {
+         when (intent?.action) {
+            LogService.UPDATE_LOGS -> updateLogs()
+            else -> throw UnsupportedOperationException("This action is not supported")
+         }
+      }
+   }
+
+   override fun onCreate(savedInstanceState: Bundle?) {
+      super.onCreate(savedInstanceState)
+      setContentView(R.layout.activity_log)
+      logView = findViewById(R.id.logview)
+      logView.webViewClient = object : WebViewClient() {
+         override fun onPageCommitVisible(view: WebView?, url: String?) {
+            view?.scrollY = view?.contentHeight ?: 0
+            //view?.pageDown(true)
+         }
+      }
+   }
+
+   override fun onResume() {
+      super.onResume()
+
+      super.onResume()
+      val filter = IntentFilter().apply {
+         addAction(LogService.UPDATE_LOGS)
+      }
+
+      LocalBroadcastManager
+         .getInstance(this)
+         .registerReceiver(receiver, filter)
+
+      updateLogs()
+   }
+
+   private fun updateLogs() {
+      val logs = fetchLogs()
+      val logsHTML = logsToHTML(logs)
+      val html = LOGS_STYLES + logsHTML
+      logView.loadDataWithBaseURL("", html, "text/html", "UTF-8", "");
+   }
+
+   private fun fetchLogs() = runBlocking {
+      withContext(Dispatchers.IO + Job()) {
+         logService.allLogs.asReversed()
+      }
+   }
+
+   private fun logsToHTML(logs: List<LogEntry>) = logs.joinToString("<br />") {
+      String.format(
+         "%s <span style=\"color: %s\">%s</span> [ %s ] %s",
+         formatter.format(it.date).padEnd(23, ' ').replace(" ", "&nbsp;"),
+         logLevelColor(it.level),
+         it.level.name.padEnd(5, ' ').replace(" ", "&nbsp;"),
+         it.source.padEnd(15, ' ').replace(" ", "&nbsp;"),
+         it.message
+      )
+   }
+
+   private fun logLevelColor(level: LogLevel) = when (level) {
+      LogLevel.DEBUG -> "#0044FF"
+      LogLevel.INFO -> "#00FF00"
+      LogLevel.WARN -> "#FFEB3B"
+      LogLevel.ERROR -> "#FF7777"
+      LogLevel.FATAL -> "#FF0000"
+   }
+
+   override fun onPause() {
+      LocalBroadcastManager
+         .getInstance(this)
+         .unregisterReceiver(receiver)
+      super.onPause()
+   }
+
+   override fun onCreateOptionsMenu(menu: Menu?): Boolean {
+      menuInflater.inflate(R.menu.menu_logs, menu)
+      return true
+   }
+
+   override fun onOptionsItemSelected(item: MenuItem): Boolean {
+      when (item.itemId) {
+         R.id.clear_logs -> clearLogs()
+      }
+
+      return super.onOptionsItemSelected(item)
+   }
+
+   private fun clearLogs() = AlertDialog.Builder(this)
+      .setTitle(getString(R.string.dialog_confirmation))
+      .setMessage(getString(R.string.dialog_clear_logs_confirmation))
+      .setIcon(android.R.drawable.ic_dialog_alert)
+      .setPositiveButton(android.R.string.yes) { _, _ ->
+         runBlocking {
+            withContext(Dispatchers.IO + Job()) {
+               logService.clearLogs()
+            }
+         }.also { updateLogs() }
+      }
+      .setNegativeButton(android.R.string.no, null).show()
+
+   companion object {
+      private const val LOGS_STYLES = "<style> * { font-family: monospace; } </style>"
+   }
+}

app/src/main/java/com/bartlomiejpluta/ttsserver/ui/main/MainActivity.kt

@@ -16,6 +16,7 @@ import com.bartlomiejpluta.ttsserver.initializer.ScriptsInitializer
 import com.bartlomiejpluta.ttsserver.service.foreground.ForegroundService
 import com.bartlomiejpluta.ttsserver.service.state.ServiceState
 import com.bartlomiejpluta.ttsserver.ui.help.HelpActivity
+import com.bartlomiejpluta.ttsserver.ui.log.LogActivity
 import com.bartlomiejpluta.ttsserver.ui.preference.component.PreferencesActivity
 import dagger.android.support.DaggerAppCompatActivity
 import javax.inject.Inject
@@ -68,6 +69,7 @@ class MainActivity : DaggerAppCompatActivity() {
       when (item.itemId) {
          R.id.open_preferences -> startActivity(Intent(this, PreferencesActivity::class.java))
          R.id.open_help -> startActivity(Intent(this, HelpActivity::class.java))
+         R.id.open_logs -> startActivity(Intent(this, LogActivity::class.java))
       }
 
       return super.onOptionsItemSelected(item)

app/src/main/res/layout/activity_log.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".ui.log.LogActivity">
+
+    <WebView
+        android:id="@+id/logview"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:layout_margin="10dp" />
+
+</LinearLayout>

app/src/main/res/menu/menu_logs.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item android:id="@+id/clear_logs" app:showAsAction="never" android:title="@string/menu_clear_logs" />
+</menu>

app/src/main/res/menu/menu_main.xml

@@ -3,4 +3,5 @@
     xmlns:app="http://schemas.android.com/apk/res-auto">
     <item android:id="@+id/open_preferences" app:showAsAction="never" android:title="@string/menu_settings" />
     <item android:id="@+id/open_help" app:showAsAction="never" android:title="@string/menu_help" />
+    <item android:id="@+id/open_logs" app:showAsAction="never" android:title="@string/menu_server_logs" />
 </menu>

app/src/main/res/raw/cache.lua

@@ -4,7 +4,10 @@ return {
     consumer = function(request)
         local filename = string.format("%s.%s", request.path.filename, request.path.ext)
         local file = server.getCachedFile(filename)
-        local mime = Mime[request.path.ext:upper()]
+        local format = request.path.ext:upper()
+        local mime = Mime[format]
+
+        log.info("Returning the " .. format .. " file from cache...")
 
         return {
             mime = mime,

app/src/main/res/raw/config.lua

@@ -18,8 +18,11 @@ function discoverSonosDevices()
     local output = {}
     local devices = sonos.discover()
 
+    log.info("Discovering Sonos devices...")
     for _, device in ipairs(devices) do
-        output[device:getZoneGroupState():getName()] = device
+        local name = device:getZoneGroupState():getName()
+        output[name] = device
+        log.info("Discovered '" .. name .. "' as " .. tostring(device))
     end
 
     return output

app/src/main/res/raw/file.lua

@@ -5,8 +5,10 @@ return {
         local format = (request.path.ext or "wav"):upper()
         local audioFormat = AudioFormat[format]
         local mime = Mime[format]
+        local language = request.query.lang or "en"
 
-        local file = tts.sayToCache(request.query.phrase, request.query.lang or "en", audioFormat)
+        log.info("Saying to " .. format .. " file (lang: " .. language .. ")...")
+        local file = tts.sayToCache(request.query.phrase, language, audioFormat)
 
         return {
             mime = mime,

app/src/main/res/raw/say.lua

@@ -5,8 +5,10 @@ return {
     accepts = Mime.JSON,
     consumer = function(request)
         if(config.silenceMode()) then return end
-
         local body = json.decode(request.body)
-        tts.say(body.text, body.language or "en")
+        local language = body.language or "en"
+
+        log.info("Saying (lang: " .. language .. ")...")
+        tts.say(body.text, language)
     end
 }

app/src/main/res/raw/sonos.lua

@@ -1,12 +1,14 @@
 local snapshot
 
 function prepareTTSFile(phrase, language)
+    log.info("Saying to cache file (lang: " .. language .. ")...")
     local file = tts.sayToCache(phrase, language, AudioFormat.MP3)
     return string.format("%s/cache/%s", server.url, file:getName())
 end
 
 function updateSnapshotIfFirst(device)
     if(snapshot == nil) then
+        log.info("Dumping the Sonos state snapshot...")
         snapshot = device:snapshot()
     end
 end
@@ -14,15 +16,18 @@ end
 function announce(device, data, url)
     device:stop()
     device:setVolume(data.volume)
+    log.info("Announcing on '" .. data.zone .. "' zone...")
     device:playUri(url, "")
     while(device:getPlayState():name() ~= "STOPPED") do
         thread.sleep(500)
     end
+    log.info("Announcement is complete")
 end
 
 function restoreSnapshotIfLast(queueLength)
     if(queueLength() == 0) then
         if(snapshot ~= nil) then
+            log.info("Restoring the Sonos state snapshot...")
             snapshot:restore()
             snapshot = nil
         end

app/src/main/res/values/strings.xml

@@ -31,9 +31,14 @@
 
     <string name="menu_settings">Settings</string>
     <string name="menu_help">Help</string>
+    <string name="menu_server_logs">Server logs</string>
+    <string name="menu_clear_logs">Clear logs</string>
 
     <string name="error_invalid_endpoint_script">Skipping %1$s file because of error:\n%2$s</string>
 
+    <string name="dialog_confirmation">Confirmation</string>
+    <string name="dialog_clear_logs_confirmation">Do you want to clear logs?</string>
+
     <string name="error">Error</string>
     <string name="debug">Debug</string>
 </resources>