feat(horizon): add horizon support with flavor

CLAUDE.md

@@ -17,8 +17,14 @@ openiap/
 
 ## Required Pre-Work
 
-- Before writing or editing anything, load and review the relevant `CONVENTION.md` file in the specific package directory
-- For cross-package changes, review conventions for all affected packages
+**CRITICAL**: Before writing or editing anything in a package, **ALWAYS** load and review the relevant `CONVENTION.md` file:
+
+- **GraphQL Types** (`packages/gql`): See [`packages/gql/CONVENTION.md`](packages/gql/CONVENTION.md)
+- **Android Library** (`packages/google`): See [`packages/google/CONVENTION.md`](packages/google/CONVENTION.md)
+- **Apple Library** (`packages/apple`): See [`packages/apple/CONVENTION.md`](packages/apple/CONVENTION.md)
+- **Documentation** (`packages/docs`): Follow conventions in this file (below)
+
+For cross-package changes, review conventions for all affected packages.
 
 ---
 
@@ -289,20 +295,20 @@ Before committing any changes:
 
 ### Android Function Naming Conventions
 
-- **Android-specific functions MUST have `Android` suffix**
-- **Cross-platform functions have NO suffix**
+**IMPORTANT**: See [`packages/google/CONVENTION.md`](packages/google/CONVENTION.md) for detailed Android naming conventions.
 
-#### Android Examples
+**Key Rule**: Since `packages/google` is Android-only, **DO NOT add `Android` suffix** to function names, even for Android-specific APIs.
 
 **✅ Correct**:
 
 ```kotlin
-// Android-specific
-fun acknowledgePurchaseAndroid()
-fun consumePurchaseAndroid()
-fun getPackageNameAndroid()
+// Android-specific functions (no suffix needed)
+fun acknowledgePurchase()
+fun consumePurchase()
+fun getPackageName()
+fun buildModule(context: Context)
 
-// Cross-platform
+// Cross-platform API functions
 fun initConnection()
 fun fetchProducts()
 fun requestPurchase()
@@ -311,10 +317,13 @@ fun requestPurchase()
 **❌ Incorrect**:
 
 ```kotlin
-// Missing Android suffix
-fun acknowledgePurchase()  // Should be acknowledgePurchaseAndroid()
+// Don't add Android suffix in Android-only package
+fun acknowledgePurchaseAndroid()  // Wrong!
+fun buildModuleAndroid()          // Wrong!
 ```
 
+**Exception**: Only use `Android` suffix for types that are part of a cross-platform API (e.g., `ProductAndroid`, `PurchaseAndroid` that contrast with iOS types).
+
 ---
 
 ## iOS Library (`packages/apple`)

packages/google/.github/workflows/ci-horizon.yml

@@ -0,0 +1,54 @@
+name: CI Horizon
+
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ci-horizon-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  wrapper-validation:
+    name: Validate Gradle Wrapper
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Validate Wrapper
+        uses: gradle/wrapper-validation-action@v2
+
+  horizon-build:
+    name: Build Horizon flavors
+    runs-on: ubuntu-latest
+    needs: wrapper-validation
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Java 17
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: '17'
+
+      - name: Set up Gradle
+        uses: gradle/gradle-build-action@v2
+
+      - name: Set up Android SDK
+        uses: android-actions/setup-android@v3
+
+      - name: Install required SDK packages
+        run: |
+          yes | sdkmanager --licenses
+          sdkmanager --install \
+            "platform-tools" \
+            "platforms;android-34" \
+            "build-tools;34.0.0"
+
+      - name: Build Horizon variants
+        working-directory: packages/google
+        run: ./gradlew --stacktrace --no-daemon :openiap:assembleHorizonDebug :Example:assembleHorizonDebug

packages/google/CONTRIBUTING.md

@@ -33,6 +33,58 @@ cd openiap-google
 adb shell am start -n dev.hyo.martie/.MainActivity
 ```
 
+## Horizon OS Development (Meta Quest)
+
+This library supports both Google Play Store and Meta Horizon OS (Quest devices) using product flavors.
+
+### Setting Up Horizon App ID
+
+1. **Create `local.properties`** in the project root (if it doesn't exist):
+
+```properties
+# local.properties (DO NOT commit this file)
+sdk.dir=/path/to/Android/sdk
+
+# Horizon OS App ID (Meta Quest)
+EXAMPLE_HORIZON_APP_ID=your_horizon_app_id_here
+```
+
+1. **Alternative: Pass via command line**:
+
+```bash
+# Build with App ID
+./gradlew :Example:assembleHorizonDebug -PEXAMPLE_HORIZON_APP_ID=your_app_id
+
+# Install with App ID
+./gradlew :Example:installHorizonDebug -PEXAMPLE_HORIZON_APP_ID=your_app_id
+```
+
+1. **Using Android Studio**:
+   - Open **View > Tool Windows > Build Variants**
+   - Set **Example** module to **horizonDebug**
+   - Set **openiap** module to **horizonDebug**
+   - Run the app (App ID will be read from `local.properties`)
+
+### Build Variants
+
+- **playDebug** / **playRelease** - Google Play Store billing
+- **horizonDebug** / **horizonRelease** - Meta Horizon OS billing
+
+### Testing on Quest Devices
+
+```bash
+# Connect Quest via ADB
+adb devices
+
+# Install Horizon variant
+./gradlew :Example:installHorizonDebug
+
+# View logs
+adb logcat | grep -E "OpenIap|Horizon"
+```
+
+**Note**: The Horizon App ID is required for Horizon Billing to work. Without it, the billing client will fail to connect.
+
 ## Generated Types
 
 - All GraphQL models in `openiap/src/main/java/dev/hyo/openiap/Types.kt` are generated from the [`openiap` monorepo](https://github.com/hyodotdev/openiap/tree/main/packages/gql). When you update API behavior, adjust the upstream type generator first so the Kotlin output stays in sync across platforms.

packages/google/CONVENTION.md

@@ -2,6 +2,28 @@
 
 ## Naming Conventions
 
+### Android-Specific Functions
+
+**IMPORTANT**: Since this is an Android-only package, **DO NOT add `Android` suffix** to function names, even for Android-specific APIs.
+
+**✅ Correct**:
+```kotlin
+fun acknowledgePurchase()
+fun consumePurchase()
+fun getPackageName()
+fun buildModule(context: Context)
+fun isHorizonEnvironment(context: Context)
+```
+
+**❌ Incorrect**:
+```kotlin
+fun acknowledgePurchaseAndroid()  // Don't add Android suffix
+fun consumePurchaseAndroid()      // Don't add Android suffix
+fun buildModuleAndroid()          // Don't add Android suffix
+```
+
+**Exception**: Only add `Android` suffix when the function is part of a cross-platform API that has platform-specific variants (e.g., `ProductAndroid`, `PurchaseAndroid` types that contrast with iOS types).
+
 ### Enum Values
 - Enum values in this codebase must use **kebab-case** (e.g., `non-consumable`, `in-app`, `user-cancelled`)
 - This matches the convention used in the auto-generated Types.kt from GraphQL schemas

packages/google/Example/build.gradle.kts

@@ -1,9 +1,18 @@
+import java.util.Properties
+
 plugins {
     id("com.android.application")
     id("org.jetbrains.kotlin.android")
     id("org.jetbrains.kotlin.plugin.compose")
 }
 
+// Load local.properties
+val localProperties = Properties()
+val localPropertiesFile = rootProject.file("local.properties")
+if (localPropertiesFile.exists()) {
+    localPropertiesFile.inputStream().use { localProperties.load(it) }
+}
+
 android {
     namespace = "dev.hyo.martie"
     compileSdk = 34
@@ -17,6 +26,50 @@ android {
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables.useSupportLibrary = true
+
+        val appId = localProperties.getProperty("EXAMPLE_HORIZON_APP_ID")
+            ?: localProperties.getProperty("EXAMPLE_OPENIAP_APP_ID")
+            ?: (project.findProperty("EXAMPLE_HORIZON_APP_ID") as String?)
+            ?: (project.findProperty("EXAMPLE_OPENIAP_APP_ID") as String?)
+            ?: ""
+        buildConfigField("String", "HORIZON_APP_ID", "\"${appId}\"")
+        // Ensure placeholder exists for all variants (play included)
+        manifestPlaceholders["OCULUS_APP_ID"] = appId
+    }
+
+    flavorDimensions += "platform"
+
+    productFlavors {
+        // Auto flavor (default) - includes both libraries, detects platform at runtime
+        create("auto") {
+            dimension = "platform"
+            buildConfigField("String", "OPENIAP_STORE", "\"auto\"")
+            isDefault = true
+
+            // Dynamically inject OCULUS_APP_ID into AndroidManifest (needed for Horizon)
+            val appId = localProperties.getProperty("EXAMPLE_HORIZON_APP_ID")
+                ?: (project.findProperty("EXAMPLE_HORIZON_APP_ID") as String?)
+                ?: ""
+            manifestPlaceholders["OCULUS_APP_ID"] = appId
+        }
+
+        // Play flavor - Google Play Billing only
+        create("play") {
+            dimension = "platform"
+            buildConfigField("String", "OPENIAP_STORE", "\"play\"")
+        }
+
+        // Horizon flavor - Meta Horizon Billing only
+        create("horizon") {
+            dimension = "platform"
+            buildConfigField("String", "OPENIAP_STORE", "\"horizon\"")
+
+            // Dynamically inject OCULUS_APP_ID into AndroidManifest
+            val appId = localProperties.getProperty("EXAMPLE_HORIZON_APP_ID")
+                ?: (project.findProperty("EXAMPLE_HORIZON_APP_ID") as String?)
+                ?: ""
+            manifestPlaceholders["OCULUS_APP_ID"] = appId
+        }
     }
 
     buildTypes {
@@ -44,6 +97,7 @@ android {
 
     buildFeatures {
         compose = true
+        buildConfig = true
     }
 
     packaging {

packages/google/Example/src/horizon/AndroidManifest.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <application>
+        <!-- Meta Horizon App ID for Horizon Billing -->
+        <!-- Value is injected from local.properties via Gradle -->
+        <meta-data
+            android:name="com.meta.horizon.platform.ovr.OCULUS_APP_ID"
+            android:value="${OCULUS_APP_ID}" />
+    </application>
+
+</manifest>

packages/google/Example/src/main/AndroidManifest.xml

@@ -6,6 +6,11 @@
         android:label="OpenIAP Example"
         android:supportsRtl="true">
 
+        <!-- Horizon OS App ID (set via gradle manifestPlaceholders) -->
+        <meta-data
+            android:name="com.meta.horizon.platform.ovr.OCULUS_APP_ID"
+            android:value="${OCULUS_APP_ID}" />
+
         <activity
             android:name=".MainActivity"
             android:exported="true">

packages/google/Example/src/main/java/dev/hyo/martie/Constants.kt

@@ -1,5 +1,7 @@
 package dev.hyo.martie
 
+import android.os.Build
+
 object IapConstants {
     // App-defined SKU lists
     val INAPP_SKUS = listOf(
@@ -8,13 +10,46 @@ object IapConstants {
         "dev.hyo.martie.certified"  // Non-consumable
     )
 
-    val SUBS_SKUS = listOf(
+    // Google Play: Two separate subscription products
+    private val SUBS_SKUS_PLAY = listOf(
         "dev.hyo.martie.premium",      // Main subscription with multiple offers
         "dev.hyo.martie.premium_year"  // Separate yearly subscription product
     )
 
-    // Base plan IDs for dev.hyo.martie.premium subscription
-    const val PREMIUM_MONTHLY_BASE_PLAN = "premium"       // Monthly base plan
-    const val PREMIUM_YEARLY_BASE_PLAN = "premium-year"   // Yearly base plan
+    // Horizon OS: Two separate SKUs (both at Level 1 to prevent auto-upgrade)
+    // IMPORTANT: In Horizon Developer Console, both must be set to the SAME Level
+    // to prevent automatic tier upgrades. Currently configured as:
+    // - premium (Level 1): Has MONTHLY and ANNUAL offers
+    // - premium_year (Level 1): Has ANNUAL offer only
+    private val SUBS_SKUS_HORIZON = listOf(
+        "dev.hyo.martie.premium",      // Premium with multiple term options
+        "dev.hyo.martie.premium_year"  // Separate yearly-only subscription
+    )
+
+    // Detect if running on Horizon OS at runtime
+    fun isHorizonOS(): Boolean {
+        return Build.MANUFACTURER.equals("Meta", ignoreCase = true) ||
+               Build.BRAND.equals("Meta", ignoreCase = true) ||
+               (Build.MODEL?.contains("Quest", ignoreCase = true) == true)
+    }
+
+    // Get subscription SKUs based on current device
+    fun getSubscriptionSkus(): List<String> {
+        val isHorizon = isHorizonOS()
+        val skus = if (isHorizon) SUBS_SKUS_HORIZON else SUBS_SKUS_PLAY
+        println("IapConstants: getSubscriptionSkus() - isHorizon=$isHorizon, skus=$skus")
+        return skus
+    }
+
+    // Legacy: For screens that don't have platform context yet
+    val SUBS_SKUS = getSubscriptionSkus()
+
+    // Product IDs
+    const val PREMIUM_PRODUCT_ID = "dev.hyo.martie.premium"
+    const val PREMIUM_YEARLY_PRODUCT_ID_PLAY = "dev.hyo.martie.premium_year" // Play only
+
+    // Base plan IDs (used by both Play and Horizon)
+    const val PREMIUM_MONTHLY_BASE_PLAN = "premium"       // 1 month plan
+    const val PREMIUM_YEARLY_BASE_PLAN = "premium-year"   // 12 months plan
 }