android: add auto-updater to the launcher

android/app/src/main/java/su/xash/engine/MainActivity.kt

@@ -1,15 +1,26 @@
 package su.xash.engine
 
+import android.content.ActivityNotFoundException
+import android.content.Context
+import android.content.Intent
 import android.os.Bundle
+import android.provider.Settings
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.net.toUri
+import androidx.lifecycle.lifecycleScope
 import androidx.navigation.NavController
 import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.navigateUp
 import androidx.navigation.ui.setupActionBarWithNavController
+import com.google.android.material.dialog.MaterialAlertDialogBuilder
+import kotlinx.coroutines.launch
 import su.xash.engine.databinding.ActivityMainBinding
+import su.xash.engine.model.AppUpdater
 import su.xash.engine.util.CrashReports
+import su.xash.engine.util.monospaceTextView
+import su.xash.engine.util.showDownloadProgressDialog
 import java.io.File
 import java.text.SimpleDateFormat
 import java.util.Date
@@ -36,6 +47,94 @@ class MainActivity : AppCompatActivity() {
 
 		CrashReports.prune(this)
 		showPendingCrashReport()
+
+		checkForEngineUpdate()
+	}
+
+	private fun checkForEngineUpdate() {
+		val prefs = getSharedPreferences(UPDATE_PREFS, Context.MODE_PRIVATE)
+		val now = System.currentTimeMillis()
+		if (now - prefs.getLong(KEY_LAST_CHECK, 0L) < CHECK_INTERVAL_MS)
+			return
+
+		val updater = AppUpdater(this)
+		lifecycleScope.launch {
+			val info = updater.checkForUpdate()
+			prefs.edit().putLong(KEY_LAST_CHECK, now).apply()
+			if (info == null)
+				return@launch
+			if (prefs.getInt(KEY_DISMISSED_BUILDNUM, -1) >= info.buildNum)
+				return@launch
+			val changelog = updater.fetchChangelog(BuildConfig.GIT_HASH, info.tagName)
+			showEngineUpdateDialog(updater, info.buildNum, changelog, prefs)
+		}
+	}
+
+	private fun showEngineUpdateDialog(
+		updater: AppUpdater,
+		remoteBuildNum: Int,
+		changelog: List<AppUpdater.CommitInfo>?,
+		prefs: android.content.SharedPreferences,
+	) {
+		val builder = MaterialAlertDialogBuilder(this)
+			.setTitle(R.string.engine_update_available)
+			.setMessage(getString(R.string.engine_update_message, remoteBuildNum))
+			.setPositiveButton(R.string.engine_update_download) { _, _ ->
+				showEngineDownloadDialog(updater)
+			}
+			.setNegativeButton(R.string.engine_update_later) { _, _ ->
+				prefs.edit().putInt(KEY_DISMISSED_BUILDNUM, remoteBuildNum).apply()
+			}
+
+		if (!changelog.isNullOrEmpty()) {
+			val text = buildString {
+				append(getString(R.string.engine_update_changelog_header))
+				val shown = changelog.take(CHANGELOG_MAX_LINES)
+				for (c in shown)
+					append("\n• ").append(c.subject)
+				val extra = changelog.size - shown.size
+				if (extra > 0)
+					append("\n").append(getString(R.string.engine_update_changelog_more, extra))
+			}
+			builder.setView(monospaceTextView(this, text))
+		}
+
+		builder.show()
+	}
+
+	private fun showEngineDownloadDialog(updater: AppUpdater) {
+		if (!updater.canInstall()) {
+			promptForInstallPermission()
+			return
+		}
+		showDownloadProgressDialog(
+			ctx = this,
+			titleRes = R.string.engine_update_downloading,
+			cancelable = true,
+			scope = lifecycleScope,
+			download = { onProgress -> updater.downloadAndInstall(onProgress) },
+		)
+	}
+
+	private fun promptForInstallPermission() {
+		MaterialAlertDialogBuilder(this)
+			.setTitle(R.string.engine_update_permission_needed)
+			.setMessage(R.string.engine_update_permission_message)
+			.setPositiveButton(R.string.engine_update_open_settings) { _, _ ->
+				val packageIntent = Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES,
+					"package:$packageName".toUri())
+				try {
+					startActivity(packageIntent)
+				} catch (_: ActivityNotFoundException) {
+					try {
+						startActivity(Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES))
+					} catch (_: ActivityNotFoundException) {
+						// no settings screen — nothing more we can do
+					}
+				}
+			}
+			.setNegativeButton(android.R.string.cancel, null)
+			.show()
 	}
 
 	override fun onSupportNavigateUp(): Boolean {
@@ -58,7 +157,7 @@ class MainActivity : AppCompatActivity() {
 		val entry = CrashReports.Entry(entryDir)
 		AlertDialog.Builder(this)
 			.setTitle(R.string.crash_dialog_title)
-			.setView(CrashReports.buildContentView(this, entry.summary()))
+			.setView(monospaceTextView(this, entry.summary()))
 			.setPositiveButton(R.string.crash_send_to_developers) { _, _ -> CrashReports.sendByEmail(this, entry) }
 			.setNeutralButton(R.string.crash_share) { _, _ -> CrashReports.share(this, entry) }
 			.setNegativeButton(R.string.crash_dismiss, null)
@@ -75,4 +174,12 @@ class MainActivity : AppCompatActivity() {
 		dst.writeText(src.readText())
 		src.delete()
 	}
+
+	companion object {
+		private const val CHANGELOG_MAX_LINES = 15
+		private const val UPDATE_PREFS = "app_updater"
+		private const val KEY_LAST_CHECK = "last_check_ms"
+		private const val KEY_DISMISSED_BUILDNUM = "dismissed_buildnum"
+		private const val CHECK_INTERVAL_MS = 24 * 60 * 60 * 1000L
+	}
 }