1.1.0: release signing, App Links, camera and share, update check

- signed release builds via keystore.properties (gitignored)
- Android App Links (https://chat.n1ko.dev/app-auth) verified through
  /.well-known/assetlinks.json; nikogpt:// stays as fallback
- attach sheet with File/Camera (FileProvider)
- Share to NikoGPT (ACTION_SEND text)
- user agent carries the app version so the web UI can offer updates

.gitignore

@@ -1,6 +1,7 @@
 .gradle/
 build/
 local.properties
+keystore.properties
 *.iml
 .idea/
 .DS_Store

README.md

@@ -41,16 +41,27 @@ Or just open the project in Android Studio.
 
 ### Release signing
 
-Create a keystore and export it as Gradle properties or use
-`apksigner` on the release output:
+The published APKs are signed with the project's release keystore
+(`keystore.properties` + the `.jks` file, both outside git). To build them
+yourself, create a keystore and point `keystore.properties` at it:
 
 ```bash
 keytool -genkeypair -v -keystore nikogpt.jks -alias nikogpt \
   -keyalg RSA -keysize 2048 -validity 10000
-apksigner sign --ks nikogpt.jks --out nikogpt-release.apk \
-  app/build/outputs/apk/release/app-release-unsigned.apk
+cat > keystore.properties <<EOF
+storeFile=../nikogpt.jks
+storePassword=...
+keyAlias=nikogpt
+keyPassword=...
+EOF
+./gradlew assembleRelease
 ```
 
+**Installing over a debug-signed build requires uninstalling it first** (the
+signatures differ). Add the release certificate's SHA-1 to the Android OAuth
+client (Google Cloud) and its SHA-256 to `web.android_cert_sha256` in the bot
+config for App Links.
+
 ## Google sign-in
 
 Native "Continue with Google" is attempted in this order:

app/build.gradle.kts

@@ -1,8 +1,19 @@
+import java.util.Properties
+
 plugins {
     id("com.android.application")
     id("org.jetbrains.kotlin.android")
 }
 
+// Release signing: keystore.properties (gitignored) points at the keystore.
+// Without it, release builds stay unsigned and CI can sign them itself.
+val keystorePropertiesFile = rootProject.file("keystore.properties")
+val keystoreProperties = Properties()
+val hasKeystore = keystorePropertiesFile.exists()
+if (hasKeystore) {
+    keystorePropertiesFile.inputStream().use { keystoreProperties.load(it) }
+}
+
 android {
     namespace = "dev.n1ko.nikogpt"
     compileSdk = 35
@@ -11,8 +22,19 @@ android {
         applicationId = "dev.n1ko.nikogpt"
         minSdk = 29 // Android 10
         targetSdk = 35
-        versionCode = 4
-        versionName = "1.0.4"
+        versionCode = 5
+        versionName = "1.1.0"
+    }
+
+    signingConfigs {
+        if (hasKeystore) {
+            create("release") {
+                storeFile = rootProject.file(keystoreProperties.getProperty("storeFile"))
+                storePassword = keystoreProperties.getProperty("storePassword")
+                keyAlias = keystoreProperties.getProperty("keyAlias")
+                keyPassword = keystoreProperties.getProperty("keyPassword")
+            }
+        }
     }
 
     buildTypes {
@@ -23,6 +45,9 @@ android {
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro",
             )
+            if (hasKeystore) {
+                signingConfig = signingConfigs.getByName("release")
+            }
         }
     }
 

app/src/main/AndroidManifest.xml

@@ -22,15 +22,36 @@
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
-            <!-- Google sign-in handoff: after the browser finishes OAuth the
-                 server redirects to nikogpt://auth?code=… and the app
-                 exchanges the one-time code inside its own WebView. -->
+            <!-- Google sign-in handoff (custom scheme fallback). -->
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
                 <data android:scheme="nikogpt" android:host="auth" />
             </intent-filter>
+            <!-- Android App Link: verified by /.well-known/assetlinks.json. -->
+            <intent-filter android:autoVerify="true">
+                <action android:name="android.intent.action.VIEW" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <category android:name="android.intent.category.BROWSABLE" />
+                <data android:scheme="https" android:host="chat.n1ko.dev" android:pathPrefix="/app-auth" />
+            </intent-filter>
+            <!-- "Share to NikoGPT" from other apps. -->
+            <intent-filter>
+                <action android:name="android.intent.action.SEND" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="text/plain" />
+            </intent-filter>
         </activity>
+
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="dev.n1ko.nikogpt.files"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
     </application>
 </manifest>

app/src/main/java/dev/n1ko/nikogpt/MainActivity.kt

@@ -1,6 +1,7 @@
 package dev.n1ko.nikogpt
 
 import android.annotation.SuppressLint
+import android.app.AlertDialog
 import android.app.DownloadManager
 import android.content.ActivityNotFoundException
 import android.content.Context
@@ -31,6 +32,7 @@ import androidx.activity.OnBackPressedCallback
 import androidx.activity.result.ActivityResultLauncher
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.FileProvider
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowCompat
 import androidx.core.view.WindowInsetsCompat
@@ -47,6 +49,7 @@ import com.google.android.gms.common.GoogleApiAvailability
 import com.google.android.gms.common.api.ApiException
 import com.google.android.libraries.identity.googleid.GetGoogleIdOption
 import com.google.android.libraries.identity.googleid.GoogleIdTokenCredential
+import java.io.File
 import kotlinx.coroutines.launch
 
 /**
@@ -61,7 +64,8 @@ class MainActivity : AppCompatActivity() {
     companion object {
         private const val START_URL = "https://chat.n1ko.dev/"
         private const val HOST = "chat.n1ko.dev"
-        private const val UA_SUFFIX = " NikoGPT-Android/1.0"
+        // The web app reads this marker to switch to the app handoff flow.
+        private val UA_SUFFIX = " NikoGPT-Android/" + BuildConfig.VERSION_NAME
     }
 
     private lateinit var webView: WebView
@@ -70,6 +74,11 @@ class MainActivity : AppCompatActivity() {
     private lateinit var errorBox: LinearLayout
     private lateinit var errorText: TextView
 
+    // Shared text ("Share to NikoGPT") waiting for the page to load.
+    private var pendingShare: String? = null
+    // Where the camera writes the picture before it reaches the web app.
+    private var pendingCameraUri: Uri? = null
+
     private var fileCallback: ValueCallback<Array<Uri>>? = null
     private val filePicker: ActivityResultLauncher<Array<String>> =
         registerForActivityResult(ActivityResultContracts.OpenMultipleDocuments()) { uris ->
@@ -94,6 +103,16 @@ class MainActivity : AppCompatActivity() {
             }
         }
 
+    // Camera capture for the attach button.
+    private val takePicture: ActivityResultLauncher<Uri> =
+        registerForActivityResult(ActivityResultContracts.TakePicture()) { ok ->
+            val cb = fileCallback
+            fileCallback = null
+            val uri = pendingCameraUri
+            pendingCameraUri = null
+            if (ok && uri != null) cb?.onReceiveValue(arrayOf(uri)) else cb?.onReceiveValue(null)
+        }
+
     @SuppressLint("SetJavaScriptEnabled")
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -142,7 +161,7 @@ class MainActivity : AppCompatActivity() {
         webView.webViewClient = object : WebViewClient() {
             override fun shouldOverrideUrlLoading(view: WebView, request: WebResourceRequest): Boolean {
                 val url = request.url
-                if (url.scheme == "nikogpt" && url.host == "auth") {
+                if (isAuthUrl(url)) {
                     // Deep link that reached the WebView instead of the browser.
                     handleAuthUri(url)
                     return true
@@ -171,6 +190,7 @@ class MainActivity : AppCompatActivity() {
                 progress.visibility = View.GONE
                 // Persist cookies (the session) right after the page settles.
                 CookieManager.getInstance().flush()
+                maybeDeliverShare()
             }
         }
 
@@ -187,13 +207,25 @@ class MainActivity : AppCompatActivity() {
             ): Boolean {
                 fileCallback?.onReceiveValue(null)
                 fileCallback = callback
-                return try {
-                    filePicker.launch(arrayOf("*/*"))
-                    true
-                } catch (e: ActivityNotFoundException) {
-                    fileCallback = null
-                    false
-                }
+                AlertDialog.Builder(this@MainActivity)
+                    .setItems(arrayOf(getString(R.string.attach_file), getString(R.string.attach_camera))) { _, which ->
+                        if (which == 0) {
+                            try {
+                                filePicker.launch(arrayOf("*/*"))
+                            } catch (e: ActivityNotFoundException) {
+                                fileCallback?.onReceiveValue(null)
+                                fileCallback = null
+                            }
+                        } else {
+                            openCamera()
+                        }
+                    }
+                    .setOnCancelListener {
+                        fileCallback?.onReceiveValue(null)
+                        fileCallback = null
+                    }
+                    .show()
+                return true
             }
         }
 
@@ -215,13 +247,53 @@ class MainActivity : AppCompatActivity() {
             webView.restoreState(savedInstanceState)
         }
         handleAuthIntent(intent)
+        handleShareIntent(intent)
     }
 
-    // handleAuthIntent catches the nikogpt://auth?code=… deep link from the
-    // browser and completes the sign-in inside the app's WebView.
+    // isAuthUrl matches both the nikogpt:// scheme and the verified App Link.
+    private fun isAuthUrl(uri: Uri): Boolean {
+        if (uri.scheme == "nikogpt" && uri.host == "auth") return true
+        return uri.scheme == "https" && uri.host == HOST && uri.path == "/app-auth"
+    }
+
+    // openCamera writes the shot into the cache and hands it to the web app.
+    private fun openCamera() {
+        try {
+            val dir = File(cacheDir, "camera").apply { mkdirs() }
+            val file = File(dir, "photo_" + System.currentTimeMillis() + ".jpg")
+            val uri = FileProvider.getUriForFile(this, "dev.n1ko.nikogpt.files", file)
+            pendingCameraUri = uri
+            takePicture.launch(uri)
+        } catch (e: Exception) {
+            fileCallback?.onReceiveValue(null)
+            fileCallback = null
+        }
+    }
+
+    // handleShareIntent catches "Share to NikoGPT" from other apps.
+    private fun handleShareIntent(intent: Intent?) {
+        if (intent == null || intent.action != Intent.ACTION_SEND) return
+        if (intent.type?.startsWith("text/") != true) return
+        val text = intent.getStringExtra(Intent.EXTRA_TEXT)
+        if (!text.isNullOrBlank()) {
+            pendingShare = text
+            maybeDeliverShare()
+        }
+    }
+
+    // maybeDeliverShare fills the composer once the page is ready.
+    private fun maybeDeliverShare() {
+        val text = pendingShare ?: return
+        if (webView.url == null) return
+        pendingShare = null
+        webView.evaluateJavascript("window.nikoShare && window.nikoShare(" + org.json.JSONObject.quote(text) + ")", null)
+    }
+
+    // handleAuthIntent catches the auth deep link (nikogpt:// or App Link) and
+    // completes the sign-in inside the app's WebView.
     private fun handleAuthIntent(intent: Intent?) {
         val data = intent?.data ?: return
-        if (data.scheme == "nikogpt" && data.host == "auth") {
+        if (isAuthUrl(data)) {
             handleAuthUri(data)
         }
     }
@@ -325,6 +397,7 @@ class MainActivity : AppCompatActivity() {
         super.onNewIntent(intent)
         setIntent(intent)
         handleAuthIntent(intent)
+        handleShareIntent(intent)
     }
 
     private fun openExternally(uri: Uri) {

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

@@ -7,4 +7,6 @@
     <string name="download_started">Загрузка началась</string>
     <string name="download_failed">Не удалось начать загрузку</string>
     <string name="google_error">Не удалось войти через Google (%1$s)</string>
+    <string name="attach_file">Файл</string>
+    <string name="attach_camera">Камера</string>
 </resources>

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

@@ -7,4 +7,6 @@
     <string name="download_started">Download started</string>
     <string name="download_failed">Could not start the download</string>
     <string name="google_error">Google sign-in failed (%1$s)</string>
+    <string name="attach_file">File</string>
+    <string name="attach_camera">Camera</string>
 </resources>

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

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <cache-path name="camera" path="camera/" />
+</paths>