/*  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

 {

   /** session information **/

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

   object Session

   {

     object Key

     {

       object Ordering extends scala.math.Ordering[Key]

       {

         def compare(key1: Key, key2: Key): Int =

           key1.order compare key2.order match {

             case 0 => key1.name compare key2.name

             case ord => ord

           }

       }

     }

     sealed case class Key(name: String, order: Int)

     {

       override def toString: String = name

     }

     sealed case class Info(

       dir: Path,

       description: String,

       options: Options,

       theories: List[(Options, String)],

       files: List[String])

     object Queue

     {

       val empty: Queue = new Queue()

     }

     final class Queue private(

       keys: Map[String, Key] = Map.empty,

       graph: Graph[Key, Info] = Graph.empty(Key.Ordering))

     {

       def defined(name: String): Boolean = keys.isDefinedAt(name)

       def + (key: Key, info: Info, parent: Option[String]): Queue =

       {

         val keys1 =

           if (defined(key.name)) error("Duplicate session: " + quote(key.name))

           else keys + (key.name -> key)

         val graph1 =

           try {

             graph.new_node(key, info).add_deps_acyclic(key, parent.toList.map(keys(_)))

           }

           catch {

             case exn: Graph.Cycles[_] =>

               error(cat_lines(exn.cycles.map(cycle =>

                 "Cyclic session dependency of " +

                   cycle.map(key => quote(key.toString)).mkString(" via "))))

           }

         new Queue(keys1, graph1)

       }

       def required(names: List[String]): Queue =

       {

         val req = graph.all_preds(names.map(keys(_))).map(_.name).toSet

         val keys1 = keys -- keys.keySet.filter(name => !req(name))

         val graph1 = graph.restrict(key => keys1.isDefinedAt(key.name))

         new Queue(keys1, graph1)

       }

       def topological_order: List[(Key, Info)] =

         graph.topological_order.map(key => (key, graph.get_node(key)))

     }

   }

   /* parsing */

   private case class Session_Entry(

     name: String,

     reset: Boolean,

     order: Int,

     path: Option[String],

     parent: Option[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)) ~

         (keyword("(") ~! (nat <~ keyword(")")) ^^ { case _ ~ x => x } | success(Integer.MAX_VALUE)) ~

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

         (keyword("=") ~> opt(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 ~ i => Session_Entry(a, b, c, d, e, f, g, h, i) }

     }

     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 sessions */

   private val ROOT = Path.explode("ROOT")

   private val SESSIONS = Path.explode("etc/sessions")

   private def is_pure(name: String): Boolean = name == "RAW" || name == "Pure"

   private def sessions_root(dir: Path, root: File, queue: Session.Queue): Session.Queue =

   {

     (queue /: Parser.parse_entries(root))((queue1, entry) =>

       try {

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

         val full_name =

           if (is_pure(entry.name)) {

             if (entry.parent.isDefined) error("Illegal parent session")

             else entry.name

           }

           else

             entry.parent match {

               case Some(parent_name) if queue1.defined(parent_name) =>

                 if (entry.reset) entry.name

                 else parent_name + "-" + entry.name

               case _ => error("Bad parent session")

             }

         val path =

           entry.path match {

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

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

           }

         val key = Session.Key(full_name, entry.order)

         val info = Session.Info(dir + path, entry.description, entry.options,

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

         queue1 + (key, info, entry.parent)

       }

       catch {

         case ERROR(msg) =>

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

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

       })

   }

   private def sessions_dir(strict: Boolean, dir: Path, queue: Session.Queue): Session.Queue =

   {

     val root = Isabelle_System.platform_file(dir + ROOT)

     if (root.isFile) sessions_root(dir, root, queue)

     else if (strict) error("Bad session root file: " + quote(root.toString))

     else queue

   }

   private def sessions_catalog(dir: Path, catalog: File, queue: Session.Queue): Session.Queue =

   {

     val dirs =

       split_lines(Standard_System.read_file(catalog)).

         filterNot(line => line == "" || line.startsWith("#"))

     (queue /: dirs)((queue1, dir1) =>

       try {

         val dir2 = dir + Path.explode(dir1)

         if (Isabelle_System.platform_file(dir2).isDirectory) sessions_dir(true, dir2, queue1)

         else error("Bad session directory: " + dir2.toString)

       }

       catch {

         case ERROR(msg) =>

           error(msg + "\nThe error(s) above occurred in session catalog " + quote(catalog.toString))

       })

   }

   def find_sessions(more_dirs: List[Path]): Session.Queue =

   {

     var queue = Session.Queue.empty

     for (dir <- Isabelle_System.components()) {

       queue = sessions_dir(false, dir, queue)

       val catalog = Isabelle_System.platform_file(dir + SESSIONS)

       if (catalog.isFile)

         queue = sessions_catalog(dir, catalog, queue)

     }

     for (dir <- more_dirs) queue = sessions_dir(true, dir, queue)

     queue

   }

   /** build **/

   private def build_job(build_images: Boolean,  // FIXME

     key: Session.Key, info: Session.Info): Isabelle_System.Bash_Job =

   {

     val cwd = Isabelle_System.platform_file(info.dir)

     val script =

       if (is_pure(key.name)) "./build " + key.name

       else """echo "Bad session" >&2; exit 2"""

     new Isabelle_System.Bash_Job(cwd, null, script)

   }

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

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

   {

     val full_queue = find_sessions(more_dirs)

     sessions.filter(name => !full_queue.defined(name)) match {

       case Nil =>

       case bad => error("Undefined session(s): " + commas_quote(bad))

     }

     val required_queue =

       if (all_sessions) full_queue

       else full_queue.required(sessions)

     for ((key, info) <- required_queue.topological_order) {

       if (list_only) println(key.name + " in " + info.dir)

       else {

         val (out, err, rc) = build_job(build_images, key, info).join

         java.lang.System.err.print(err)

       }

     }

     0

   }

   /* command line entry point */

   def main(args: Array[String])

   {

     Command_Line.tool {

       args.toList match {

         case

           Properties.Value.Boolean(all_sessions) ::

           Properties.Value.Boolean(build_images) ::

           Properties.Value.Boolean(list_only) ::

           Command_Line.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))

       }

     }

   }

 }