Redo DI gradle setup code

plugins/src/main/kotlin/extension/DependencyInjectionExtensions.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2024 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package extension
+
+import org.gradle.accessors.dm.LibrariesForLibs
+import org.gradle.api.Project
+import org.gradle.api.provider.Provider
+import org.gradle.kotlin.dsl.the
+import org.gradle.plugin.use.PluginDependency
+
+/**
+ * Setup the Metro plugin with the shared configuration.
+ * @param generateNodeFactories Whether to set up the KSP plugin and dependencies to generate Appyx Node factories.
+ */
+fun Project.setupDependencyInjection(
+    generateNodeFactories: Boolean = shouldApplyAppyxCodegen(),
+) {
+    val libs = the<LibrariesForLibs>()
+
+    // Apply Metro plugin and configure it
+    applyPluginIfNeeded(libs.plugins.metro)
+
+    if (generateNodeFactories) {
+        applyPluginIfNeeded(libs.plugins.ksp)
+
+        // Annotations to generate DI code for Appyx nodes
+        dependencies.implementation(project.project(":anvilannotations"))
+        // Code generator for the annotations above
+        dependencies.add("ksp", project.project(":anvilcodegen"))
+    }
+}
+
+// These dependencies should only be needed for compose library or application modules
+private fun Project.shouldApplyAppyxCodegen(): Boolean {
+    return project.pluginManager.hasPlugin("io.element.android-compose-library")
+        || project.pluginManager.hasPlugin("io.element.android-compose-application")
+}
+
+private fun Project.applyPluginIfNeeded(plugin: Provider<PluginDependency>) {
+    val pluginId = plugin.get().pluginId
+    if (!pluginManager.hasPlugin(pluginId)) {
+        pluginManager.apply(pluginId)
+    }
+}