/*  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,

     reset_name: Boolean,

     parent: 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 DESCRIPTION = "description"

     val OPTIONS = "options"

     val THEORIES = "theories"

     val FILES = "files"

     val syntax =

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

         SESSION + IN + 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 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 }) ~

         (keyword("!") ^^^ true | success(false)) ~

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

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

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

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

         rep(theories) ~

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

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

               val dir1 = dir + c.getOrElse(Path.basic(a))

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

               Session_Info(dir1, a, b, d, e, f, thys, 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

   }

 }