Rebuild Kotlin Android app for mobile UX and add CI workflow

.github/workflows/android-kotlin-ci.yml

@@ -0,0 +1,47 @@
+name: Android Kotlin CI
+
+on:
+  push:
+    paths:
+      - 'mobile/kotlin-app/**'
+      - '.github/workflows/android-kotlin-ci.yml'
+  pull_request:
+    paths:
+      - 'mobile/kotlin-app/**'
+      - '.github/workflows/android-kotlin-ci.yml'
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: mobile/kotlin-app
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: '17'
+          cache: gradle
+
+      - name: Validate Gradle wrapper
+        uses: gradle/actions/wrapper-validation@v4
+
+      - name: Build debug APK
+        run: ./gradlew clean assembleDebug
+
+      - name: Build release APK
+        run: ./gradlew assembleRelease
+
+      - name: Upload APK artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: kotlin-apk
+          path: |
+            mobile/kotlin-app/app/build/outputs/apk/debug/*.apk
+            mobile/kotlin-app/app/build/outputs/apk/release/*.apk

mobile/kotlin-app/README.md

@@ -1,16 +1,18 @@
-# Kotlin Android wrapper app
+# Kotlin Android app (mobile-optimized web wrapper)
 
-This is a native Kotlin Android app that replicates the existing Sunset web project on phone by loading the deployed web app in a full-screen `WebView`.
+This Android app preserves the same Sunset product idea by loading the existing web experience, but adds mobile-first navigation and interaction patterns:
 
-## Steps
+- Bottom tab navigation to key sections (Home, Courses, About, AI Lab)
+- Pull-to-refresh support
+- Top loading progress indicator
+- Tuned WebView settings and custom Android user-agent suffix
 
-1. Set your production URL in `app/build.gradle.kts`:
-   - `WEB_APP_URL = "https://YOUR_DEPLOYED_WEB_APP_URL"`
+## Setup
+
+1. Set `WEB_APP_URL` in `app/build.gradle.kts` to your deployed site URL.
 2. Open `mobile/kotlin-app` in Android Studio.
 3. Build and run.
 
-## Why this approach
+## CI
 
-- Reuses your existing Next.js codebase.
-- Fastest way to get parity between web and Android.
-- Keeps one product surface while still shipping through Play Store.
+A GitHub Actions workflow is included at `.github/workflows/android-kotlin-ci.yml` to build debug and release APKs automatically on pushes/PRs that touch the Kotlin Android app.

mobile/kotlin-app/app/build.gradle.kts

@@ -46,4 +46,5 @@ dependencies {
     implementation("androidx.core:core-ktx:1.13.1")
     implementation("androidx.appcompat:appcompat:1.7.0")
     implementation("com.google.android.material:material:1.12.0")
+    implementation("androidx.swiperefreshlayout:swiperefreshlayout:1.1.0")
 }

mobile/kotlin-app/app/src/main/java/com/sunset/replica/MainActivity.kt

@@ -1,40 +1,103 @@
 package com.sunset.replica
 
 import android.annotation.SuppressLint
+import android.graphics.Bitmap
 import android.os.Bundle
 import android.webkit.WebChromeClient
 import android.webkit.WebResourceRequest
+import android.webkit.WebSettings
 import android.webkit.WebView
 import android.webkit.WebViewClient
+import android.widget.ProgressBar
 import androidx.appcompat.app.AppCompatActivity
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import com.google.android.material.bottomnavigation.BottomNavigationView
 
 class MainActivity : AppCompatActivity() {
 
     private lateinit var webView: WebView
+    private lateinit var pullToRefresh: SwipeRefreshLayout
+    private lateinit var loadingIndicator: ProgressBar
+
+    private val pages = mapOf(
+        R.id.nav_home to "",
+        R.id.nav_courses to "/courses",
+        R.id.nav_about to "/about",
+        R.id.nav_ai to "/new-design"
+    )
 
     @SuppressLint("SetJavaScriptEnabled")
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
         webView = findViewById(R.id.webView)
-        webView.webChromeClient = WebChromeClient()
-        webView.webViewClient = object : WebViewClient() {
-            override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean {
-                return false
-            }
+        pullToRefresh = findViewById(R.id.pullToRefresh)
+        loadingIndicator = findViewById(R.id.loadingIndicator)
+
+        configureWebView()
+        configureBottomNavigation()
+
+        pullToRefresh.setOnRefreshListener {
+            webView.reload()
+        }
+
+        if (savedInstanceState == null) {
+            navigateTo(R.id.nav_home)
+        } else {
+            webView.restoreState(savedInstanceState)
+        }
+    }
+
+    private fun configureBottomNavigation() {
+        val bottomNavigation: BottomNavigationView = findViewById(R.id.bottomNavigation)
+        bottomNavigation.setOnItemSelectedListener { item ->
+            navigateTo(item.itemId)
+            true
+        }
+    }
+
+    private fun navigateTo(navItemId: Int) {
+        val path = pages[navItemId] ?: ""
+        val destination = "${BuildConfig.WEB_APP_URL.trimEnd('/')}$path"
+        if (webView.url != destination) {
+            webView.loadUrl(destination)
         }
+    }
 
+    @SuppressLint("SetJavaScriptEnabled")
+    private fun configureWebView() {
         with(webView.settings) {
             javaScriptEnabled = true
             domStorageEnabled = true
             mediaPlaybackRequiresUserGesture = false
+            cacheMode = WebSettings.LOAD_DEFAULT
             useWideViewPort = true
             loadWithOverviewMode = true
+            builtInZoomControls = false
+            displayZoomControls = false
+            userAgentString = "$userAgentString SunsetAndroid/1.1"
         }
 
-        if (savedInstanceState == null) {
-            webView.loadUrl(BuildConfig.WEB_APP_URL)
+        webView.webChromeClient = object : WebChromeClient() {
+            override fun onProgressChanged(view: WebView?, newProgress: Int) {
+                loadingIndicator.progress = newProgress
+                loadingIndicator.visibility = if (newProgress < 100) ProgressBar.VISIBLE else ProgressBar.GONE
+            }
+        }
+
+        webView.webViewClient = object : WebViewClient() {
+            override fun shouldOverrideUrlLoading(view: WebView?, request: WebResourceRequest?): Boolean = false
+
+            override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
+                super.onPageStarted(view, url, favicon)
+                pullToRefresh.isRefreshing = true
+            }
+
+            override fun onPageFinished(view: WebView?, url: String?) {
+                super.onPageFinished(view, url)
+                pullToRefresh.isRefreshing = false
+            }
         }
     }
 
@@ -43,16 +106,8 @@ class MainActivity : AppCompatActivity() {
         super.onSaveInstanceState(outState)
     }
 
-    override fun onRestoreInstanceState(savedInstanceState: Bundle) {
-        super.onRestoreInstanceState(savedInstanceState)
-        webView.restoreState(savedInstanceState)
-    }
-
+    @Deprecated("Deprecated in Java")
     override fun onBackPressed() {
-        if (webView.canGoBack()) {
-            webView.goBack()
-        } else {
-            super.onBackPressed()
-        }
+        if (webView.canGoBack()) webView.goBack() else super.onBackPressed()
     }
 }

mobile/kotlin-app/app/src/main/res/layout/activity_main.xml

@@ -1,11 +1,34 @@
 <?xml version="1.0" encoding="utf-8"?>
-<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    android:orientation="vertical">
 
-    <WebView
-        android:id="@+id/webView"
+    <ProgressBar
+        android:id="@+id/loadingIndicator"
+        style="?android:attr/progressBarStyleHorizontal"
         android:layout_width="match_parent"
-        android:layout_height="match_parent" />
+        android:layout_height="4dp"
+        android:max="100" />
 
-</FrameLayout>
+    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+        android:id="@+id/pullToRefresh"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        android:layout_weight="1">
+
+        <WebView
+            android:id="@+id/webView"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
+    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
+
+    <com.google.android.material.bottomnavigation.BottomNavigationView
+        android:id="@+id/bottomNavigation"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        app:labelVisibilityMode="labeled"
+        app:menu="@menu/bottom_navigation_menu" />
+
+</LinearLayout>

mobile/kotlin-app/app/src/main/res/menu/bottom_navigation_menu.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item
+        android:id="@+id/nav_home"
+        android:icon="@android:drawable/ic_menu_view"
+        android:title="@string/nav_home" />
+    <item
+        android:id="@+id/nav_courses"
+        android:icon="@android:drawable/ic_menu_agenda"
+        android:title="@string/nav_courses" />
+    <item
+        android:id="@+id/nav_about"
+        android:icon="@android:drawable/ic_menu_info_details"
+        android:title="@string/nav_about" />
+    <item
+        android:id="@+id/nav_ai"
+        android:icon="@android:drawable/ic_menu_manage"
+        android:title="@string/nav_ai_lab" />
+</menu>

mobile/kotlin-app/app/src/main/res/values/strings.xml

@@ -1,3 +1,7 @@
 <resources>
-    <string name="app_name">Sunset Replica</string>
+    <string name="app_name">Sunset Mobile</string>
+    <string name="nav_home">Home</string>
+    <string name="nav_courses">Courses</string>
+    <string name="nav_about">About</string>
+    <string name="nav_ai_lab">AI Lab</string>
 </resources>