[platform] API refactoring: convert enum ProductMode to a regular class (IJPL-182310)

External plugins may start using this class after IJPL-182310 is implemented. It's better not to allow external plugins to use a switch/when statement without an 'else' branch for this type because we may add new variants in the future, and such changes shouldn't break clients.

GitOrigin-RevId: 9a6cc2dd25cc7b63e6248d894de14d267e46b641

platform/bootstrap/src/com/intellij/platform/bootstrap/ModuleBasedProductLoadingStrategy.kt

@@ -31,7 +31,7 @@ import kotlin.io.path.extension
 internal class ModuleBasedProductLoadingStrategy(internal val moduleRepository: RuntimeModuleRepository) : ProductLoadingStrategy() {
   private val currentMode by lazy {
     val currentModeId = System.getProperty(PLATFORM_PRODUCT_MODE_PROPERTY, ProductMode.MONOLITH.id)
-    val currentMode = ProductMode.entries.find { it.id == currentModeId }
+    val currentMode = ProductMode.findById(currentModeId)
     if (currentMode == null) {
       error("Unknown mode '$currentModeId' specified in '$PLATFORM_PRODUCT_MODE_PROPERTY' system property")
     }

platform/runtime/product/api-dump-experimental.txt

@@ -4,14 +4,11 @@
 *:com.intellij.platform.runtime.product.PluginModuleGroup
 - com.intellij.platform.runtime.product.RuntimeModuleGroup
 - a:getMainModule():com.intellij.platform.runtime.repository.RuntimeModuleDescriptor
-*e:com.intellij.platform.runtime.product.ProductMode
-- java.lang.Enum
+*f:com.intellij.platform.runtime.product.ProductMode
 - sf:BACKEND:com.intellij.platform.runtime.product.ProductMode
 - sf:FRONTEND:com.intellij.platform.runtime.product.ProductMode
 - sf:MONOLITH:com.intellij.platform.runtime.product.ProductMode
 - getId():java.lang.String
-- s:valueOf(java.lang.String):com.intellij.platform.runtime.product.ProductMode
-- s:values():com.intellij.platform.runtime.product.ProductMode[]
 *:com.intellij.platform.runtime.product.ProductModules
 - a:getBundledPluginModuleGroups():java.util.List
 - a:getMainModuleGroup():com.intellij.platform.runtime.product.RuntimeModuleGroup

platform/runtime/product/src/ProductMode.java

@@ -1,36 +1,48 @@
 // Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.platform.runtime.product;
 
+import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Describes a mode in which a product may be started.
  * TODO: reuse inside {@link com.intellij.idea.AppMode}?
  */
-public enum ProductMode {
+public final class ProductMode {
   /**
    * Indicates that this process performs all necessary tasks to provide smart features itself. This is the default mode for all IDEs. 
    */
-  MONOLITH("monolith"),
+  public static final ProductMode MONOLITH = new ProductMode("monolith");
   /**
    * Indicates that this process doesn't perform heavy tasks like code analysis, and takes necessary information from another process.
    * Currently, this is used by JetBrains Client process connected to a remote development host or CodeWithMe session.
    */
-  FRONTEND("frontend"),
+  public static final ProductMode FRONTEND = new ProductMode("frontend");
   /**
    * Indicates that this process doesn't perform heavy tasks like code analysis and takes necessary information from another process.
    * Currently, this is used by an IDE running as a remote development host.
    */
-  BACKEND("backend");
+  public static final ProductMode BACKEND = new ProductMode("backend");
 
   private final String myId;
 
-  ProductMode(@NotNull @NonNls String id) {
+  private ProductMode(@NotNull @NonNls String id) {
     myId = id;
   }
 
   public @NotNull @NonNls String getId() {
     return myId;
   }
+
+  @ApiStatus.Internal
+  public static @Nullable ProductMode findById(@NotNull @NonNls String id) {
+    switch (id) {
+      case "monolith": return MONOLITH;
+      case "frontend": return FRONTEND;
+      case "backend": return BACKEND;
+      default: return null;
+    }
+  }
 }

platform/runtime/product/src/impl/ProductModeLoadingRules.java

@@ -6,6 +6,8 @@ import com.intellij.platform.runtime.repository.RuntimeModuleId;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
+import static com.intellij.platform.runtime.product.ProductMode.*;
+
 /**
  * This class is used to determine whether a module should be loaded based on the current {@link ProductMode}.
  * Currently, this is determined by the presence of specific modules in dependencies. We can change this and require to specify modes 
@@ -20,14 +22,18 @@ public final class ProductModeLoadingRules {
    * Returns the module which presence in the dependencies indicates that a module isn't compatible with the given {@code mode}.
    */
   public static @NotNull RuntimeModuleId getIncompatibleRootModule(@NotNull ProductMode mode) {
-    switch (mode) {
-      case FRONTEND: return RuntimeModuleId.module("intellij.platform.backend");
-      
-      case MONOLITH: return RuntimeModuleId.module("intellij.platform.frontend.split");
-
+    if (mode.equals(FRONTEND)) {
+      return RuntimeModuleId.module("intellij.platform.backend");
+    }
+    else if (mode.equals(MONOLITH)) {
       //currently we use the same modules in 'backend' and 'monolith' modes, in the future we may disable some UI-only modules in 'backend' mode
-      case BACKEND: return RuntimeModuleId.module("intellij.platform.frontend.split");
+      return RuntimeModuleId.module("intellij.platform.frontend.split");
+    }
+    else if (mode.equals(BACKEND)) {
+      return RuntimeModuleId.module("intellij.platform.frontend.split");
+    }
+    else {
+      throw new AssertionError("Unexpected value: " + mode);
     }
-    throw new AssertionError(mode);
   }
 }

tools/devLauncher/src/IntellijDevLauncher.kt

@@ -58,7 +58,7 @@ fun main(args: Array<String>) {
 
 private fun loadProductModules(moduleRepository: RuntimeModuleRepository, projectHome: Path): ProductModules {
   val currentModeId = System.getProperty(PLATFORM_PRODUCT_MODE_PROPERTY, ProductMode.MONOLITH.id)
-  val currentMode = ProductMode.entries.find { it.id == currentModeId }
+  val currentMode = ProductMode.findById(currentModeId)
   if (currentMode == null) {
     reportError("Unknown mode '$currentModeId' specified in '$PLATFORM_PRODUCT_MODE_PROPERTY' system property")
   }