/*
 * Copyright 2015 Lightbend Inc.
 *
 * Licensed 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 com.google.googlejavaformat.java.JavaFormatterOptions
import sbt._
import sbt.Keys._

/** A local fork of https://github.com/sbt/sbt-java-formatter. The original plugin uses a very outdated version
  * of `google-java-format` dependency which does not support syntax > JDK8. It's unlikely we will see the
  * dependency upgraded any time soon, if ever, hence the almost one-to-one copy of the plugin.
  */
object JavaFormatterPlugin extends AutoPlugin {
  object autoImport {
    val javafmt: TaskKey[Unit] = taskKey("Format Java sources")
    val javafmtCheck: TaskKey[Boolean] = taskKey(
      "Fail, if a Java source needs reformatting."
    )
    val javafmtAll: TaskKey[Unit] = taskKey(
      "Execute the javafmt task for all configurations in which it is enabled. " +
      "(By default this means the Compile and Test configurations.)"
    )
    val javafmtCheckAll: TaskKey[Unit] = taskKey(
      "Execute the javafmtCheck task for all configurations in which it is enabled. " +
      "(By default this means the Compile and Test configurations.)"
    )
    val javafmtOnCompile = settingKey[Boolean](
      "Format Java source files on compile, off by default."
    )
    val javafmtStyle =
      settingKey[JavaFormatterOptions.Style](
        "Define formatting style, Google Java Style (default) or AOSP"
      )
    val javafmtOptions = settingKey[JavaFormatterOptions](
      "Define all formatting options such as style or enabling Javadoc formatting. See _JavaFormatterOptions_ for more"
    )
  }

  import autoImport._

  override def trigger = allRequirements

  override def `requires` = plugins.JvmPlugin

  override def projectSettings: Seq[Def.Setting[_]] = {
    val anyConfigsInThisProject =
      ScopeFilter(configurations = inAnyConfiguration)

    notToBeScopedSettings ++
    Seq(Compile, Test).flatMap(inConfig(_)(toBeScopedSettings)) ++
    Seq(
      javafmtAll := javafmt.?.all(anyConfigsInThisProject).value,
      javafmtCheckAll := javafmtCheck.?.all(anyConfigsInThisProject).value
    )
  }

  override def globalSettings: Seq[Def.Setting[_]] =
    Seq(
      javafmtOnCompile := false,
      javafmtStyle := JavaFormatterOptions.Style.GOOGLE
    )

  def toBeScopedSettings: Seq[Setting[_]] =
    List(
      (javafmt / sourceDirectories) := List(javaSource.value),
      javafmtOptions := JavaFormatterOptions
        .builder()
        .style(javafmtStyle.value)
        .build(),
      javafmt := {
        val streamz = streams.value
        val sD      = (javafmt / sourceDirectories).value.toList
        val iF      = (javafmt / includeFilter).value
        val eF      = (javafmt / excludeFilter).value
        val cache   = streamz.cacheStoreFactory
        val options = javafmtOptions.value
        JavaFormatter(sD, iF, eF, streamz, cache, options)
      },
      javafmtCheck := {
        val streamz = streams.value
        val baseDir = (ThisBuild / baseDirectory).value
        val sD      = (javafmt / sourceDirectories).value.toList
        val iF      = (javafmt / includeFilter).value
        val eF      = (javafmt / excludeFilter).value
        val cache   = (javafmt / streams).value.cacheStoreFactory
        val options = javafmtOptions.value
        JavaFormatter.check(baseDir, sD, iF, eF, streamz, cache, options)
      },
      javafmtDoFormatOnCompile := Def.settingDyn {
        if (javafmtOnCompile.value) {
          javafmt in resolvedScoped.value.scope
        } else {
          Def.task(())
        }
      }.value,
      compile / compileInputs := (compile / compileInputs)
        .dependsOn(javafmtDoFormatOnCompile)
        .value
    )

  def notToBeScopedSettings: Seq[Setting[_]] =
    List(javafmt / includeFilter := "*.java")

  private[this] val javafmtDoFormatOnCompile =
    taskKey[Unit]("Format Java source files if javafmtOnCompile is on.")

}