/*  Title:      Pure/System/build.scala

     Author:     Makarius

 Build and manage Isabelle sessions.

 */

 package isabelle

 import java.io.File

 import scala.collection.mutable

 import scala.annotation.tailrec

 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

       }

   }

   private object Chunks

   {

     private def chunks(list: List[String]): List[List[String]] =

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

         case -1 => List(list)

         case i =>

           val (chunk, rest) = list.splitAt(i)

           chunk :: chunks(rest.tail)

       }

     def unapplySeq(list: List[String]): Option[List[List[String]]] = Some(chunks(list))

   }

   def main(args: Array[String])

   {

     val rc =

       try {

         args.toList match {

           case Bool(all_sessions) :: Bool(build_images) :: Bool(list_only) ::

             Chunks(more_dirs, options, sessions) =>

               build(all_sessions, build_images, list_only,

                 more_dirs.map(Path.explode), options, sessions)

           case _ => error("Bad arguments:\n" + cat_lines(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,

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

   {

     println("more_dirs = " + more_dirs.toString)

     println("options = " + options.toString)

     println("sessions = " + sessions.toString)

     find_sessions(more_dirs) foreach println

     0

   }

   /** session information **/

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

   case class Session_Info(

     dir: Path,

     name: String,

     parent: String,

     description: String,

     options: Options,

     theories: List[(Options, String)],

     files: List[String])

   private val pure_info =

     Session_Info(Path.current, "Pure", "", "", Nil, List((Nil, "Pure")), Nil)

   /* parsing */

   val ROOT_NAME = "ROOT"

   private case class Session_Entry(

     name: String,

     reset: Boolean,

     path: Option[String],

     parent: String,

     description: String,

     options: Options,

     theories: List[(Options, List[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

     val session_entry: Parser[Session_Entry] =

     {

       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 = 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 => x })) ~

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

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

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

         rep1(theories) ~

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

           { case a ~ b ~ c ~ d ~ e ~ f ~ g ~ h => Session_Entry(a, b, c, d, e, f, g, h) }

     }

     def parse_entries(root: File): List[Session_Entry] =

     {

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

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

         case Success(result, _) => result

         case bad => error(bad.toString)

       }

     }

   }

   /* find session */

   def find_sessions(more_dirs: List[Path]): List[Session_Info] =

   {

     val infos = new mutable.ListBuffer[Session_Info]

     infos += pure_info

     for {

       (dir, strict) <- Isabelle_System.components().map((_, false)) ++ more_dirs.map((_, true))

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

       _ = (strict && !root.isFile && error("Bad session root file: " + quote(root.toString)))

       if root.isFile

       entry <- Parser.parse_entries(root)

     }

     {

       try {

         val parent =

           infos.find(_.name == entry.parent) getOrElse

            error("Unknown parent session: " + quote(entry.parent))

         val full_name =

           if (entry.reset) entry.name

           else parent.name + "-" + entry.name

         if (entry.name == "") error("Bad session name")

         if (infos.exists(_.name == full_name))

           error("Duplicate session name: " + quote(full_name))

         val path =

           entry.path match {

             case Some(p) => Path.explode(p)

             case None => Path.basic(entry.name)

           }

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

         val info =

           Session_Info(dir + path, full_name, entry.parent, entry.description,

             entry.options, thys, entry.files)

         infos += info

       }

       catch {

         case ERROR(msg) =>

           error(msg + "\nThe error(s) above occurred in session entry " +

             quote(entry.name) + " (file " + quote(root.toString) + ")")

       }

     }

     infos.toList

   }

 }