Check the git for a newer release and install it from the Car screen.

README.md

@@ -16,6 +16,8 @@ Each car has its own 8-digit token, shown on the **Car** screen. **Share token**
 
 **Remove from this phone** takes the car off that phone only. The other phone and the server keep it.
 
+**Check for updates** on the Car screen looks at the latest release on this git. When a newer one is posted, the app downloads it and Android asks you to install it.
+
 The book icon opens the setup guide. **Car setup** on the home screen is the original setup for the selected car, plus a log of later changes. A race night keeps its own chassis sheet.
 
 ## Sync server

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "com.racingapp.pitlog"
         minSdk = 26
         targetSdk = 36
-        versionCode = 1
-        versionName = "1.0"
+        versionCode = 2
+        versionName = "1.1"
     }
 
     buildTypes {

app/src/main/AndroidManifest.xml

@@ -2,6 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
     <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
 
@@ -10,6 +11,10 @@
             <action android:name="android.intent.action.SEND" />
             <data android:mimeType="text/csv" />
         </intent>
+        <intent>
+            <action android:name="android.intent.action.VIEW" />
+            <data android:mimeType="application/vnd.android.package-archive" />
+        </intent>
     </queries>
 
     <application

app/src/main/java/com/racingapp/pitlog/data/AppUpdate.kt

@@ -0,0 +1,142 @@
+package com.racingapp.pitlog.data
+
+import android.content.ClipData
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import android.provider.Settings
+import androidx.core.content.FileProvider
+import java.io.File
+import java.net.HttpURLConnection
+import java.net.URL
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import org.json.JSONObject
+
+private const val LATEST_RELEASE =
+    "https://git.ny.daprogs.com/api/v1/repos/RallyBlock/Pit-Log-App/releases/latest"
+
+private const val MAX_APK_BYTES = 80_000_000
+
+private data class PostedRelease(val versionCode: Long, val apkUrl: String)
+
+fun installedVersionCode(context: Context): Long {
+    val info = context.packageManager.getPackageInfo(context.packageName, 0)
+    return if (Build.VERSION.SDK_INT >= 28) {
+        info.longVersionCode
+    } else {
+        @Suppress("DEPRECATION")
+        info.versionCode.toLong()
+    }
+}
+
+suspend fun checkForAppUpdate(context: Context, onStatus: (String) -> Unit): String {
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O && !context.packageManager.canRequestPackageInstalls()) {
+        val settings = Intent(
+            Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES,
+            Uri.parse("package:${context.packageName}"),
+        ).addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+        context.startActivity(settings)
+        return "Allow Pit Log to install updates, then check again."
+    }
+    val release = withContext(Dispatchers.IO) { fetchLatest() } ?: return "Couldn't check for an update."
+    if (release.versionCode == 0L) return "No update has been posted."
+    if (release.versionCode <= installedVersionCode(context)) return "This is the latest version."
+    onStatus("Downloading…")
+    val file = withContext(Dispatchers.IO) { downloadApk(context, release.apkUrl) }
+        ?: return "Couldn't download the update."
+    promptInstall(context, file)
+    return "Confirm the install when Android asks."
+}
+
+private fun fetchLatest(): PostedRelease? {
+    val connection = open(LATEST_RELEASE) ?: return null
+    return try {
+        val code = connection.responseCode
+        if (code == 404) return PostedRelease(0, "")
+        if (code !in 200..299) return null
+        val body = connection.inputStream.bufferedReader().use { it.readText() }
+        parseRelease(body)
+    } catch (_: Exception) {
+        null
+    } finally {
+        connection.disconnect()
+    }
+}
+
+private fun parseRelease(body: String): PostedRelease? {
+    val json = JSONObject(body)
+    val versionCode = json.optString("tag_name").removePrefix("v").toLongOrNull() ?: return null
+    val assets = json.optJSONArray("assets") ?: return null
+    for (index in 0 until assets.length()) {
+        val asset = assets.optJSONObject(index) ?: continue
+        val name = asset.optString("name")
+        val url = asset.optString("browser_download_url")
+        if (name.endsWith(".apk") && url.startsWith("https://")) {
+            return PostedRelease(versionCode, url)
+        }
+    }
+    return null
+}
+
+private fun downloadApk(context: Context, apkUrl: String): File? {
+    val connection = open(apkUrl) ?: return null
+    return try {
+        if (connection.responseCode !in 200..299) return null
+        val length = connection.contentLengthLong
+        if (length > MAX_APK_BYTES) return null
+        val dir = File(context.cacheDir, "updates").apply { mkdirs() }
+        val file = File(dir, "pit-log.apk")
+        connection.inputStream.use { input ->
+            file.outputStream().use { output ->
+                val buffer = ByteArray(8192)
+                var total = 0L
+                while (true) {
+                    val read = input.read(buffer)
+                    if (read < 0) break
+                    total += read
+                    if (total > MAX_APK_BYTES) {
+                        file.delete()
+                        return null
+                    }
+                    output.write(buffer, 0, read)
+                }
+            }
+        }
+        val zip = file.inputStream().use { stream -> stream.read() == 0x50 && stream.read() == 0x4B }
+        if (!zip) {
+            file.delete()
+            return null
+        }
+        file
+    } catch (_: Exception) {
+        null
+    } finally {
+        connection.disconnect()
+    }
+}
+
+private fun promptInstall(context: Context, file: File) {
+    val uri = FileProvider.getUriForFile(context, "${context.packageName}.fileprovider", file)
+    val install = Intent(Intent.ACTION_VIEW).apply {
+        setDataAndType(uri, "application/vnd.android.package-archive")
+        addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_ACTIVITY_NEW_TASK)
+        clipData = ClipData.newRawUri("Pit Log", uri)
+    }
+    context.startActivity(install)
+}
+
+private fun open(address: String): HttpURLConnection? {
+    return try {
+        (URL(address).openConnection() as HttpURLConnection).apply {
+            instanceFollowRedirects = true
+            connectTimeout = 20_000
+            readTimeout = 120_000
+            setRequestProperty("User-Agent", "PitLog")
+            setRequestProperty("Accept", "application/json, application/vnd.android.package-archive")
+        }
+    } catch (_: Exception) {
+        null
+    }
+}

app/src/main/java/com/racingapp/pitlog/ui/settings/SettingsScreen.kt

@@ -30,7 +30,9 @@ import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import android.content.Context
 import com.racingapp.pitlog.data.Car
+import com.racingapp.pitlog.data.checkForAppUpdate
 import com.racingapp.pitlog.data.DEFAULT_CAR
 import com.racingapp.pitlog.data.DEFAULT_CLASS
 import com.racingapp.pitlog.data.DEFAULT_DISCIPLINE
@@ -62,6 +64,9 @@ class SettingsViewModel(private val repository: Repository) : ViewModel() {
         private set
     var syncing by mutableStateOf(false)
         private set
+    var updating by mutableStateOf(false)
+        private set
+    var updateStatus by mutableStateOf("")
 
     init {
         serverAddress = repository.syncAddress()
@@ -148,6 +153,20 @@ class SettingsViewModel(private val repository: Repository) : ViewModel() {
         }
     }
 
+    fun checkForUpdate(context: Context) {
+        if (updating) return
+        updating = true
+        updateStatus = "Checking…"
+        viewModelScope.launch {
+            updateStatus = try {
+                checkForAppUpdate(context) { updateStatus = it }
+            } catch (_: Exception) {
+                "Couldn't check for an update."
+            }
+            updating = false
+        }
+    }
+
     fun changeAutomatic(enabled: Boolean) {
         automatic = enabled
         repository.saveAddress(serverAddress)
@@ -325,6 +344,23 @@ fun SettingsScreen(onBack: () -> Unit) {
                         modifier = Modifier.padding(top = 8.dp),
                     )
                 }
+                SectionLabel("App")
+                OutlinedButton(
+                    onClick = { viewModel.checkForUpdate(context) },
+                    enabled = !viewModel.updating,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .padding(top = 8.dp),
+                ) {
+                    Text(if (viewModel.updating) "Checking…" else "Check for updates")
+                }
+                if (viewModel.updateStatus.isNotBlank()) {
+                    Text(
+                        viewModel.updateStatus,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        modifier = Modifier.padding(top = 8.dp),
+                    )
+                }
             }
         }
     }

app/src/main/res/xml/file_paths.xml

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <paths>
     <cache-path name="exports" path="exports/" />
+    <cache-path name="updates" path="updates/" />
 </paths>