Ability to check proxy connection

app/src/main/kotlin/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -704,6 +704,7 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		const val KEY_LOGS_SHARE = "logs_share"
 		const val KEY_APP_UPDATE = "app_update"
 		const val KEY_APP_TRANSLATION = "about_app_translation"
+		const val PROXY_TEST = "proxy_test"
 
 		// old keys are for migration only
 		private const val KEY_IMAGES_PROXY_OLD = "images_proxy"

app/src/main/kotlin/org/koitharu/kotatsu/settings/ProxySettingsFragment.kt

@@ -7,20 +7,40 @@ import android.view.inputmethod.EditorInfo
 import androidx.preference.EditTextPreference
 import androidx.preference.Preference
 import androidx.preference.PreferenceCategory
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import dagger.hilt.android.AndroidEntryPoint
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import okhttp3.OkHttpClient
+import okhttp3.Request
 import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.core.network.BaseHttpClient
 import org.koitharu.kotatsu.core.prefs.AppSettings
 import org.koitharu.kotatsu.core.ui.BasePreferenceFragment
+import org.koitharu.kotatsu.core.util.ext.getDisplayMessage
+import org.koitharu.kotatsu.core.util.ext.printStackTraceDebug
+import org.koitharu.kotatsu.core.util.ext.viewLifecycleScope
+import org.koitharu.kotatsu.parsers.util.await
 import org.koitharu.kotatsu.settings.utils.EditTextBindListener
 import org.koitharu.kotatsu.settings.utils.PasswordSummaryProvider
 import org.koitharu.kotatsu.settings.utils.validation.DomainValidator
 import org.koitharu.kotatsu.settings.utils.validation.PortNumberValidator
 import java.net.Proxy
+import javax.inject.Inject
+import kotlin.coroutines.cancellation.CancellationException
 
 @AndroidEntryPoint
 class ProxySettingsFragment : BasePreferenceFragment(R.string.proxy),
 	SharedPreferences.OnSharedPreferenceChangeListener {
 
+	private var testJob: Job? = null
+
+	@Inject
+	@BaseHttpClient
+	lateinit var okHttpClient: OkHttpClient
+
 	override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
 		addPreferencesFromResource(R.xml.pref_proxy)
 		findPreference<EditTextPreference>(AppSettings.KEY_PROXY_ADDRESS)?.setOnBindEditTextListener(
@@ -60,6 +80,15 @@ class ProxySettingsFragment : BasePreferenceFragment(R.string.proxy),
 		super.onDestroyView()
 	}
 
+	override fun onPreferenceTreeClick(preference: Preference): Boolean = when (preference.key) {
+		AppSettings.PROXY_TEST -> {
+			testConnection()
+			true
+		}
+
+		else -> super.onPreferenceTreeClick(preference)
+	}
+
 	override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
 		when (key) {
 			AppSettings.KEY_PROXY_TYPE -> updateDependencies()
@@ -73,5 +102,47 @@ class ProxySettingsFragment : BasePreferenceFragment(R.string.proxy),
 		findPreference<PreferenceCategory>(AppSettings.KEY_PROXY_AUTH)?.isEnabled = isProxyEnabled
 		findPreference<Preference>(AppSettings.KEY_PROXY_LOGIN)?.isEnabled = isProxyEnabled
 		findPreference<Preference>(AppSettings.KEY_PROXY_PASSWORD)?.isEnabled = isProxyEnabled
+		findPreference<Preference>(AppSettings.PROXY_TEST)?.isEnabled = isProxyEnabled && testJob?.isActive != true
+	}
+
+	private fun testConnection() {
+		testJob?.cancel()
+		testJob = viewLifecycleScope.launch {
+			val pref = findPreference<Preference>(AppSettings.PROXY_TEST)
+			pref?.run {
+				setSummary(R.string.loading_)
+				isEnabled = false
+			}
+			try {
+				withContext(Dispatchers.Default) {
+					val request = Request.Builder()
+						.get()
+						.url("http://neverssl.com")
+						.build()
+					val response = okHttpClient.newCall(request).await()
+					check(response.isSuccessful) { response.message }
+				}
+				showTestResult(null)
+			} catch (e: CancellationException) {
+				throw e
+			} catch (e: Throwable) {
+				e.printStackTraceDebug()
+				showTestResult(e)
+			} finally {
+				pref?.run {
+					isEnabled = true
+					summary = null
+				}
+			}
+		}
+	}
+
+	private fun showTestResult(error: Throwable?) {
+		MaterialAlertDialogBuilder(requireContext())
+			.setTitle(R.string.proxy)
+			.setMessage(error?.getDisplayMessage(resources) ?: getString(R.string.connection_ok))
+			.setPositiveButton(android.R.string.ok, null)
+			.setCancelable(true)
+			.show()
 	}
 }

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

@@ -670,4 +670,5 @@
 	<string name="chapters_left">Chapters left</string>
 	<string name="external_source">External/plugin</string>
 	<string name="plugin_incompatible">Incompatible plugin or internal error. Make sure you are using the latest version of the plugin and Kotatsu</string>
+	<string name="connection_ok">Connection is OK</string>
 </resources>

app/src/main/res/xml/pref_proxy.xml

@@ -36,4 +36,10 @@
 
 	</PreferenceCategory>
 
+	<Preference
+		android:key="proxy_test"
+		android:persistent="false"
+		android:title="Test connection"
+		app:allowDividerAbove="true" />
+
 </PreferenceScreen>