Extract constants

app/src/main/java/io/bartek/MainActivity.kt

@@ -27,7 +27,9 @@ class MainActivity : AppCompatActivity() {
         override fun onReceive(context: Context?, intent: Intent?) {
             intent?.let {
                 updateViewAccordingToServiceState(
-                    ServiceState.valueOf(it.getStringExtra("STATE") ?: "STOPPED")
+                    ServiceState.valueOf(
+                        it.getStringExtra(ForegroundService.STATE) ?: ServiceState.STOPPED.name
+                    )
                 )
             }
         }
@@ -39,7 +41,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
-        when(item.itemId) {
+        when (item.itemId) {
             R.id.open_preferences -> startActivity(Intent(this, PreferencesActivity::class.java))
             R.id.open_help -> startActivity(Intent(this, HelpActivity::class.java))
         }
@@ -72,7 +74,7 @@ class MainActivity : AppCompatActivity() {
         super.onResume()
         LocalBroadcastManager
             .getInstance(this)
-            .registerReceiver(receiver, IntentFilter("io.bartek.web.server.CHANGE_STATE"))
+            .registerReceiver(receiver, IntentFilter(ForegroundService.CHANGE_STATE))
         updateViewAccordingToServiceState(ForegroundService.state)
     }
 

app/src/main/java/io/bartek/preference/Preference.kt

@@ -0,0 +1,9 @@
+package io.bartek.preference
+
+
+object PreferenceKey {
+    const val PORT = "preference_port"
+    const val ENABLE_SAY_ENDPOINT = "preference_enable_say_endpoint"
+    const val ENABLE_WAVE_ENDPOINT = "preference_enable_wave_endpoint"
+    const val TTS = "preference_tts"
+}

app/src/main/java/io/bartek/preference/PreferencesFragment.kt

@@ -24,7 +24,9 @@ class PreferencesFragment : PreferenceFragmentCompat() {
         override fun onReceive(context: Context?, intent: Intent?) {
             intent?.let {
                 updateViewAccordingToServiceState(
-                    ServiceState.valueOf(it.getStringExtra("STATE") ?: "STOPPED")
+                    ServiceState.valueOf(
+                        it.getStringExtra(ForegroundService.STATE) ?: ServiceState.STOPPED.name
+                    )
                 )
             }
         }
@@ -38,7 +40,7 @@ class PreferencesFragment : PreferenceFragmentCompat() {
         super.onResume()
         LocalBroadcastManager
             .getInstance(context!!)
-            .registerReceiver(receiver, IntentFilter("io.bartek.web.server.CHANGE_STATE"))
+            .registerReceiver(receiver, IntentFilter(ForegroundService.CHANGE_STATE))
         updateViewAccordingToServiceState(ForegroundService.state)
     }
 
@@ -51,15 +53,19 @@ class PreferencesFragment : PreferenceFragmentCompat() {
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         setPreferencesFromResource(R.xml.preferences, rootKey)
-        portPreference = findPreference("preference_port")!!
+        portPreference = findPreference(PreferenceKey.PORT)!!
         portPreference.setOnBindEditTextListener { it.inputType = InputType.TYPE_CLASS_NUMBER }
-        sayEndpointPreference = findPreference("preference_enable_say_endpoint")!!
+        sayEndpointPreference = findPreference(PreferenceKey.ENABLE_SAY_ENDPOINT)!!
-        waveEndpointPreference = findPreference("preference_enable_wave_endpoint")!!
+        waveEndpointPreference = findPreference(PreferenceKey.ENABLE_WAVE_ENDPOINT)!!
-        ttsEnginePreference = findPreference("preference_tts")!!
+        ttsEnginePreference = findPreference(PreferenceKey.TTS)!!
         ttsEnginePreference.setOnPreferenceClickListener {
-            startActivity(Intent("com.android.settings.TTS_SETTINGS"))
+            startActivity(Intent(ANDROID_TTS_SETTINGS))
             true
         }
         updateViewAccordingToServiceState(ForegroundService.state)
     }
+
+    companion object {
+        private const val ANDROID_TTS_SETTINGS = "com.android.settings.TTS_SETTINGS"
+    }
 }

app/src/main/java/io/bartek/service/ForegroundService.kt

@@ -5,15 +5,13 @@ import android.content.Context
 import android.content.Intent
 import android.content.SharedPreferences
 import android.graphics.Color
-import android.os.Binder
 import android.os.Build
-import android.os.IBinder
 import android.os.PowerManager
 import androidx.preference.PreferenceManager
 import io.bartek.MainActivity
 import io.bartek.R
+import io.bartek.preference.PreferenceKey
 import io.bartek.web.TTSServer
-import java.lang.Integer.parseInt
 
 
 class ForegroundService : Service() {
@@ -22,7 +20,7 @@ class ForegroundService : Service() {
     private var isServiceStarted = false
     private var ttsServer: TTSServer? = null
     private val port: Int
-        get() = preferences.getInt("preference_port", 8080)
+        get() = preferences.getInt(PreferenceKey.PORT, 8080)
 
     override fun onCreate() {
         super.onCreate()
@@ -91,7 +89,7 @@ class ForegroundService : Service() {
         isServiceStarted = true
         wakeLock =
             (getSystemService(Context.POWER_SERVICE) as PowerManager).run {
-                newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "WebService::lock").apply {
+                newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKELOCK_TAG).apply {
                     acquire()
                 }
             }
@@ -119,7 +117,9 @@ class ForegroundService : Service() {
         // than to place it as a static field
         var state = ServiceState.STOPPED
         private const val NOTIFICATION_CHANNEL_ID = "TTSService.NOTIFICATION_CHANNEL"
-        const val PORT = "TTSService.PORT"
+        private const val WAKELOCK_TAG = "ForegroundService::lock"
+        const val CHANGE_STATE = "io.bartek.service.CHANGE_STATE"
+        const val STATE = "STATE"
         const val START = "START"
         const val STOP = "STOP"
     }

app/src/main/java/io/bartek/web/WebServer.kt

@@ -7,6 +7,8 @@ import androidx.localbroadcastmanager.content.LocalBroadcastManager
 import androidx.preference.PreferenceManager
 import fi.iki.elonen.NanoHTTPD
 import fi.iki.elonen.NanoHTTPD.Response.Status.*
+import io.bartek.preference.PreferenceKey
+import io.bartek.service.ForegroundService
 import io.bartek.service.ServiceState
 import io.bartek.tts.TTS
 import org.json.JSONObject
@@ -23,7 +25,7 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
     override fun serve(session: IHTTPSession?): Response {
         try {
             session?.let {
-                return when(it.uri) {
+                return when (it.uri) {
                     "/wave" -> wave(it)
                     "/say" -> say(it)
                     else -> throw ResponseException(NOT_FOUND, "")
@@ -39,7 +41,7 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
     }
 
     private fun wave(session: IHTTPSession): Response {
-        if(!preferences.getBoolean("preference_enable_wave_endpoint", true)) {
+        if (!preferences.getBoolean(PreferenceKey.ENABLE_WAVE_ENDPOINT, true)) {
             throw ResponseException(NOT_FOUND, "")
         }
 
@@ -47,17 +49,17 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
             throw ResponseException(METHOD_NOT_ALLOWED, "")
         }
 
-        if (session.headers["content-type"]?.let { it != "application/json" } != false) {
+        if (session.headers[CONTENT_TYPE]?.let { it != MIME_JSON } != false) {
             throw ResponseException(BAD_REQUEST, "")
         }
 
         val (text, language) = getRequestData(session)
         val (stream, size) = tts.fetchTTSStream(text, language)
-        return newFixedLengthResponse(OK, "audio/x-wav", stream, size)
+        return newFixedLengthResponse(OK, MIME_WAVE, stream, size)
     }
 
     private fun say(session: IHTTPSession): Response {
-        if(!preferences.getBoolean("preference_enable_say_endpoint", true)) {
+        if (!preferences.getBoolean(PreferenceKey.ENABLE_SAY_ENDPOINT, true)) {
             throw ResponseException(NOT_FOUND, "")
         }
 
@@ -65,7 +67,7 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
             throw ResponseException(METHOD_NOT_ALLOWED, "")
         }
 
-        if (session.headers["content-type"]?.let { it != "application/json" } != false) {
+        if (session.headers[CONTENT_TYPE]?.let { it != MIME_JSON } != false) {
             throw ResponseException(BAD_REQUEST, "")
         }
 
@@ -78,7 +80,10 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
         val map = mutableMapOf<String, String>()
         session.parseBody(map)
         val json = JSONObject(map["postData"] ?: "{}")
-        val language = Locale(json.optString("language", "en_US"))
+        val language = json.optString("language")
+            .takeIf { it.isNotBlank() }
+            ?.let { Locale(it) }
+            ?: Locale.US
         val text = json.optString("text") ?: throw ResponseException(BAD_REQUEST, "")
         return TTSRequestData(text, language)
     }
@@ -89,8 +94,8 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
         super.start()
         LocalBroadcastManager
             .getInstance(context)
-            .sendBroadcast(Intent("io.bartek.web.server.CHANGE_STATE").also {
+            .sendBroadcast(Intent(ForegroundService.CHANGE_STATE).also {
-                it.putExtra("STATE", ServiceState.RUNNING.name)
+                it.putExtra(ForegroundService.STATE, ServiceState.RUNNING.name)
             })
     }
 
@@ -98,8 +103,14 @@ class TTSServer(port: Int, private val context: Context) : NanoHTTPD(port),
         super.stop()
         LocalBroadcastManager
             .getInstance(context)
-            .sendBroadcast(Intent("io.bartek.web.server.CHANGE_STATE").also {
+            .sendBroadcast(Intent(ForegroundService.CHANGE_STATE).also {
-                it.putExtra("STATE", ServiceState.STOPPED.name)
+                it.putExtra(ForegroundService.STATE, ServiceState.STOPPED.name)
             })
     }
+
+    companion object {
+        private const val MIME_JSON = "application/json"
+        private const val MIME_WAVE = "audio/x-wav"
+        private const val CONTENT_TYPE = "content-type"
+    }
 }