src/Pure/Tools/scala_build.scala

clarified signature;

/*  Title:      Pure/Tools/scala_build.scala
    Author:     Makarius

Manage and build Isabelle/Scala/Java modules.
*/

package isabelle


import java.io.{ByteArrayOutputStream, PrintStream}
import java.nio.file.Files
import java.nio.file.{Path => JPath}

import scala.jdk.CollectionConverters._


object Scala_Build {
  class Context private[Scala_Build](java_context: isabelle.setup.Build.Context) {
    override def toString: String = java_context.toString

    def is_module(path: Path): Boolean = {
      val module_name = java_context.module_name()
      module_name.nonEmpty && File.eq(java_context.path(module_name).toFile, path.file)
    }

    def module_result: Option[Path] = {
      java_context.module_result() match {
        case "" => None
        case module => Some(File.path(java_context.path(module).toFile))
      }
    }

    def sources: List[Path] =
      java_context.sources().asScala.toList.map(s => File.path(java_context.path(s).toFile))

    def requirements: List[Path] =
      (for {
        s <- java_context.requirements().asScala.iterator
        p <- java_context.requirement_paths(s).asScala.iterator
      } yield (File.path(p.toFile))).toList

    def build(
      classpath: List[Path] = Path.split(Isabelle_System.getenv("ISABELLE_CLASSPATH")),
      fresh: Boolean = false
    ): String = {
      val java_classpath = new java.util.LinkedList[JPath]
      classpath.foreach(path => java_classpath.add(path.java_path))

      val output0 = new ByteArrayOutputStream
      val output = new PrintStream(output0)
      def get_output(): String = {
        output.flush()
        Library.trim_line(output0.toString(UTF8.charset))
      }

      try {
        isabelle.setup.Build.build(java_classpath, output, java_context, fresh)
        get_output()
      }
      catch { case ERROR(msg) => cat_error(get_output(), msg) }
    }
  }

  def context(dir: Path,
    component: Boolean = false,
    no_title: Boolean = false,
    do_build: Boolean = false,
    module: Option[Path] = None
  ): Context = {
    val props_name =
      if (component) isabelle.setup.Build.COMPONENT_BUILD_PROPS
      else isabelle.setup.Build.BUILD_PROPS
    val props_path = dir + Path.explode(props_name)

    val props = File.read_props(props_path)
    if (no_title) props.remove(isabelle.setup.Build.TITLE)
    if (do_build) props.remove(isabelle.setup.Build.NO_BUILD)
    if (module.isDefined) props.put(isabelle.setup.Build.MODULE, File.standard_path(module.get))

    new Context(new isabelle.setup.Build.Context(dir.java_path, props, props_path.implode))
  }

  sealed case class Result(output: String, jar_bytes: Bytes, jar_path: Option[Path]) {
    def write(): Unit = {
      if (jar_path.isDefined) {
        Isabelle_System.make_directory(jar_path.get.dir)
        Bytes.write(jar_path.get, jar_bytes)
      }
    }
  }

  def build_result(dir: Path, component: Boolean = false): Result = {
    Isabelle_System.with_tmp_file("result", "jar") { tmp_file =>
      val output =
        context(dir, component = component, no_title = true, do_build = true,
          module = Some(tmp_file)).build(classpath = Classpath().jars.map(File.path))
      val jar_bytes = Bytes.read(tmp_file)
      val jar_path = context(dir, component = component).module_result
      Result(output, jar_bytes, jar_path)
    }
  }

  object Scala_Fun extends Scala.Fun("scala_build") with Scala.Bytes_Fun {
    val here = Scala_Project.here
    def invoke(session: Session, args: List[Bytes]): List[Bytes] =
      args match {
        case List(dir) =>
          val result = build_result(Path.explode(dir.text))
          val jar_name =
            result.jar_path match {
              case Some(path) => path.file_name
              case None => "scala_build.jar"
            }
          List(Bytes("classpath/" + jar_name), result.jar_bytes, Bytes(result.output))
        case _ => error("Bad arguments")
      }
  }

  def component_contexts(): List[Context] =
    isabelle.setup.Build.component_contexts().asScala.toList.map(new Context(_))
}