chore: Temporarily disable the license report generation to speed up build (#704)

* fix: using project/index generator

* fix: broken link

* chore: reformat code

* simplify generator and build fixes

* additional documentation clarify

* code format chore

* chore: reducing cr cost

* chore: remove unnecessary

* reset link configuration

* keep index doc

* disable license report by default

* reduce license because disable by default

* Change the description of build paradox

* chore: code fmt

project/Paradox.scala

@@ -95,10 +95,10 @@ object Paradox {
   lazy val sourceGeneratorSettings = Seq(
     Compile / paradoxMarkdownToHtml / sourceGenerators += Def.taskDyn {
       val targetFile = (Compile / paradox / sourceManaged).value / "project" / "license-report.md"
-
-      (LocalRootProject / dumpLicenseReportAggregate).map { dir =>
-        IO.copy(List(dir / "pekko-root-licenses.md" -> targetFile)).toList
-      }
+      ProjectIndexGenerator.CliOptions.generateLicenseReportEnabled.ifTrue(
+        (LocalRootProject / dumpLicenseReportAggregate).map { dir =>
+          IO.copy(List(dir / "pekko-root-licenses.md" -> targetFile)).toList
+        }).orElse(Some(Def.task(List.empty[File]))).get
     }.taskValue)
 
   lazy val settings =

project/PekkoBuild.scala

@@ -308,8 +308,9 @@ object PekkoBuild {
         UsefulTask("sortImports", "Sort the imports"),
         UsefulTask("mimaReportBinaryIssues ", "Check binary issues"),
         UsefulTask("validatePullRequest ", "Validate pull request"),
-        UsefulTask("docs/paradox", "Build documentation (takes ~10+ minutes)"),
-        UsefulTask("docs/paradoxBrowse", "Browse the generated documentation (takes ~10+ minutes)"),
+        UsefulTask("docs/paradox", "Build documentation (license report will be generate on CI or Publish)"),
+        UsefulTask("docs/paradoxBrowse",
+          "Browse the generated documentation (license report will be generate on CI or Publish)"),
         UsefulTask("tips:", "prefix commands with `+` to run against cross Scala versions."),
         UsefulTask("Contributing guide:", "https://github.com/apache/incubator-pekko/blob/main/CONTRIBUTING.md")).map(
         _.noAlias))

project/ProjectIndexGenerator.scala

@@ -0,0 +1,75 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import sbt._
+import Keys._
+
+object ProjectIndexGenerator extends AutoPlugin {
+
+  object CliOptions {
+    val generateLicenseReportEnabled = CliOption("pekko.genlicensereport.enabled", false)
+  }
+
+  override val projectSettings: Seq[Setting[_]] = inConfig(Compile)(
+    Seq(
+      resourceGenerators +=
+        generateIndex(sourceDirectory, _ / "paradox" / "project" / "project-index.md")))
+
+  def generateIndex(dir: SettingKey[File], locate: File => File) = Def.task[Seq[File]] {
+    val file = locate(dir.value)
+
+    val markdownFilesBeforeLicense = Seq(
+      "../common/binary-compatibility-rules.md",
+      "scala3.md",
+      "downstream-upgrade-strategy.md",
+      "../common/may-change.md",
+      "../additional/ide.md",
+      "immutable.md",
+      "../additional/osgi.md",
+      "migration-guides.md",
+      "rolling-update.md",
+      "issue-tracking.md",
+      "licenses.md")
+    val markdownFilesAfterLicense = Seq(
+      "../additional/faq.md",
+      "../additional/books.md",
+      "examples.md",
+      "links.md")
+
+    val markdownFiles = if (CliOptions.generateLicenseReportEnabled.get) {
+      markdownFilesBeforeLicense ++ Seq("license-report.md") ++ markdownFilesAfterLicense
+    } else {
+      markdownFilesBeforeLicense ++ markdownFilesAfterLicense
+    }
+
+    val content =
+      s"""<!-- DO NOT EDIT DIRECTLY: This file is generated by `project/ProjectIndexGenerator`. See CONTRIBUTING.md for details. -->
+                     |# Project Information
+                     |
+                     |@@toc { depth=2 }
+                     |
+                     |@@@ index
+                     |
+                     |${markdownFiles.map(f => s"* [${f.replace(".md", "")}]($f)").mkString("\n")}
+                     |
+                     |@@@
+                     |""".stripMargin
+
+    if (!file.exists || IO.read(file) != content) IO.write(file, content)
+    Seq(file)
+  }
+}