/*  Title:      Pure/System/build.scala

    Author:     Makarius

Build and manage Isabelle sessions.

*/

package isabelle

import java.io.File

object Build

{

  /* command line entry point */

  private object Bool

  {

    def unapply(s: String): Option[Boolean] =

      s match {

        case "true" => Some(true)

        case "false" => Some(false)

        case _ => None

      }

  }

  def main(args: Array[String])

  {

    def bad_args(): Nothing = error("Bad arguments: " + args.toString)

    val rc =

      try {

        args.toList match {

          case Bool(all_sessions) :: Bool(build_images) :: Bool(list_only) :: rest =>

            rest.indexWhere(_ == "\n") match {

              case -1 => bad_args()

              case i =>

                val (options, rest1) = rest.splitAt(i)

                val sessions = rest1.tail

                build(all_sessions, build_images, list_only, options, sessions)

            }

          case _ => bad_args()

        }

      }

      catch {

        case exn: Throwable => java.lang.System.err.println(Exn.message(exn)); 2

      }

    sys.exit(rc)

  }

  /* build */

  def build(all_sessions: Boolean, build_images: Boolean, list_only: Boolean,

    options: List[String], sessions: List[String]): Int =

  {

    println("options = " + options.toString)

    println("sessions = " + sessions.toString)

    find_sessions() foreach println

    0

  }

  /* session information */

  val ROOT_NAME = "ROOT"

  type Options = List[(String, Option[String])]

  case class Session_Info(

    dir: Path,

    name: String,

    path: String,

    parent: String,

    alt_name: Option[String],

    description: String,

    options: Options,

    theories: List[(Options, String)],

    files: List[String])

  private object Parser extends Parse.Parser

  {

    val SESSION = "session"

    val IN = "in"

    val NAME = "name"

    val DESCRIPTION = "description"

    val OPTIONS = "options"

    val THEORIES = "theories"

    val FILES = "files"

    val syntax =

      Outer_Syntax.empty + "(" + ")" + "+" + "," + "=" + "[" + "]" +

        SESSION + IN + NAME + DESCRIPTION + OPTIONS + THEORIES + FILES

    def session_info(dir: Path): Parser[Session_Info] =

    {

      val session_name = atom("session name", _.is_name)

      val theory_name = atom("theory name", _.is_name)

      val file_name = atom("file name", _.is_name)

      val option =

        name ~ opt(keyword("=") ~! name ^^ { case _ ~ x => x }) ^^ { case x ~ y => (x, y) }

      val options: Parser[Options] =

        keyword("[") ~> repsep(option, keyword(",")) <~ keyword("]")

      val theories =

        keyword(THEORIES) ~! ((options | success(Nil)) ~ rep1(theory_name)) ^^

          { case _ ~ (x ~ y) => (x, y) }

      ((keyword(SESSION) ~! session_name) ^^ { case _ ~ x => x }) ~

        (opt(keyword(IN) ~! string ^^ { case _ ~ x => x })) ~

        (keyword("=") ~> session_name <~ keyword("+")) ~

        (opt(keyword(NAME) ~! session_name ^^ { case _ ~ x => x })) ~

        (keyword(DESCRIPTION) ~! text ^^ { case _ ~ x => x } | success("")) ~

        (keyword(OPTIONS) ~! options ^^ { case _ ~ x => x } | success(Nil)) ~

        rep(theories) ~

        (keyword(FILES) ~! rep1(file_name) ^^ { case _ ~ x => x } | success(Nil)) ^^

          { case a ~ b ~ c ~ d ~ e ~ f ~ g ~ h =>

            Session_Info(dir, a, b getOrElse a, c, d, e, f,

              g.map({ case (x, ys) => ys.map(y => (x, y)) }).flatten, h) }

    }

    def parse_entries(dir: Path, root: File): List[Session_Info] =

    {

      val toks = syntax.scan(Standard_System.read_file(root))

      parse_all(rep(session_info(dir)), Token.reader(toks, root.toString)) match {

        case Success(result, _) => result

        case bad => error(bad.toString)

      }

    }

  }

  def find_sessions(): List[Session_Info] =

  {

    for {

      dir <- Isabelle_System.components()

      root = Isabelle_System.platform_file(dir + Path.basic(ROOT_NAME))

      if root.isFile

      entry <- Parser.parse_entries(dir, root)

    } yield entry

  }

}