From ff119a61e410800fb9055aaa25924774d9dd3815 Mon Sep 17 00:00:00 2001
From: rosariopf <rosariopf@google.com>
Date: Wed, 23 Aug 2023 01:26:53 +0100
Subject: [PATCH 1/2] chore: rename MainActivity in AndroidManifest.xml

---
 build-android/app/src/main/AndroidManifest.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/build-android/app/src/main/AndroidManifest.xml b/build-android/app/src/main/AndroidManifest.xml
index 1ccae8c6..34e1a860 100644
--- a/build-android/app/src/main/AndroidManifest.xml
+++ b/build-android/app/src/main/AndroidManifest.xml
@@ -9,7 +9,7 @@
         android:supportsRtl="true"
         android:theme="@style/AppTheme"
         android:networkSecurityConfig="@xml/network_security_config">
-        <activity android:name="com.google.firebase.codelab.friendlychat.MainActivity"
+        <activity android:name=".MainActivity"
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

From c954ec4613e2589b1ad9519150f7db0111b9dfdb Mon Sep 17 00:00:00 2001
From: rosariopf <rosariopf@google.com>
Date: Wed, 23 Aug 2023 01:28:08 +0100
Subject: [PATCH 2/2] chore: create Gradle script to change applicationId

---
 build-android/build.gradle.kts | 52 ++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/build-android/build.gradle.kts b/build-android/build.gradle.kts
index 7948041a..8d334562 100644
--- a/build-android/build.gradle.kts
+++ b/build-android/build.gradle.kts
@@ -1,3 +1,8 @@
+import java.nio.file.Files
+import java.nio.file.Paths
+import kotlin.io.path.readText
+import kotlin.io.path.writeText
+
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 plugins {
     id("com.android.application") version "8.1.0" apply false
@@ -18,4 +23,51 @@ tasks {
     register("clean", Delete::class) {
         delete(rootProject.buildDir)
     }
+
+    register("rename") {
+        val applicationId = project.properties["applicationId"] as String?
+        val DEFAULT_APP_ID = "com.google.firebase.codelab.friendlychat"
+        val DEFAULT_DIRECTORY = appIdToPath(DEFAULT_APP_ID)
+
+        doFirst {
+            // Assert that an applicationId argument was passed
+            if (applicationId == null) {
+                throw IllegalArgumentException(
+                    "Please specify an applicationId when running this command:\n" +
+                            "./gradlew rename -PapplicationId=com.example.id"
+                )
+            }
+        }
+
+        doLast {
+            // Iterate through all files under DEFAULT_DIRECTORY
+            val defaultDirectoryFile = file(DEFAULT_DIRECTORY)
+            val absolutePath = Paths.get(defaultDirectoryFile.absolutePath)
+            Files.walk(absolutePath).forEach { path ->
+                val file = path.toFile()
+                if (file.isFile) {
+                    // Replace the default applicationId with the new one
+                    // For the package declaration and any relevant imports
+                    path.writeText(path.readText()
+                        .replace("(package|import)\\s+${DEFAULT_APP_ID}".toRegex(), "$1 $applicationId"))
+                }
+
+                // Copy file to new directory
+                val newDirectory = file(appIdToPath(applicationId!!))
+                val newFile = file("${newDirectory.absolutePath}/${file.relativeTo(defaultDirectoryFile)}")
+                file.copyTo(target = newFile)
+                // Delete original file
+                file.delete()
+            }
+
+            // Update applicationId and namespace in build.gradle.kts
+            with (file("app/build.gradle.kts").toPath()) {
+                writeText(
+                    readText().replace("(namespace|applicationId)\\s*=\\s*\"${DEFAULT_APP_ID}\"".toRegex(),
+                        "$1 = \"$applicationId\""))
+            }
+        }
+    }
 }
+
+fun appIdToPath(appId: String) = "app/src/main/java/${appId.replace(".", "/")}"
\ No newline at end of file