/*  Title:      Pure/System/build.scala

     Author:     Makarius

 Build and manage Isabelle sessions.

 */

 package isabelle

 import java.io.{File => JFile}

 import scala.collection.mutable

 import scala.annotation.tailrec

 object Build

 {

   /** session information **/

   object Session

   {

     /* Key */

     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

     }

     /* Info */

     sealed case class Info(

       dir: Path,

       parent: Option[String],

       description: String,

       options: Options,

       theories: List[(Options, List[Path])],

       files: List[Path],

       digest: SHA1.Digest)

     /* Queue */

     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 is_empty: Boolean = graph.is_empty

       def apply(name: String): Info = graph.get_node(keys(name))

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

       def is_inner(name: String): Boolean = !graph.is_maximal(keys(name))

       def + (key: Key, info: Info): 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, info.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 - (name: String): Queue = new Queue(keys - name, graph.del_node(keys(name)))

       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 dequeue(skip: String => Boolean): Option[(String, Info)] =

       {

         val it = graph.entries.dropWhile(

           { case (key, (_, (deps, _))) => !deps.isEmpty || skip(key.name) })

         if (it.hasNext) { val (key, (info, _)) = it.next; Some((key.name, info)) }

         else None

       }

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

         graph.topological_order.map(key => (key.name, 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: List[Options.Spec],

     theories: List[(List[Options.Spec], 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: JFile): List[Session_Entry] =

     {

       val toks = syntax.scan(File.read(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(options: Options, dir: Path, root: JFile, 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 theories =

           entry.theories.map({ case (opts, thys) => (options ++ opts, thys.map(Path.explode(_))) })

         val files = entry.files.map(Path.explode(_))

         val digest = SHA1.digest((full_name, entry.parent, entry.options, entry.theories).toString)

         val info =

           Session.Info(dir + path, entry.parent,

             entry.description, options ++ entry.options, theories, files, digest)

         queue1 + (key, info)

       }

       catch {

         case ERROR(msg) =>

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

             quote(entry.name) + Position.str_of(Position.file(root)))

       })

   }

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

     : Session.Queue =

   {

     val root = (dir + ROOT).file

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

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

     else queue

   }

   private def sessions_catalog(options: Options, dir: Path, catalog: JFile, queue: Session.Queue)

     : Session.Queue =

   {

     val dirs =

       split_lines(File.read(catalog)).filterNot(line => line == "" || line.startsWith("#"))

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

       try {

         val dir2 = dir + Path.explode(dir1)

         if (dir2.file.isDirectory) sessions_dir(options, 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(options: Options, all_sessions: Boolean, sessions: List[String],

     more_dirs: List[Path]): Session.Queue =

   {

     var queue = Session.Queue.empty

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

       queue = sessions_dir(options, false, dir, queue)

       val catalog = (dir + SESSIONS).file

       if (catalog.isFile)

         queue = sessions_catalog(options, dir, catalog, queue)

     }

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

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

       case Nil =>

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

     }

     if (all_sessions) queue else queue.required(sessions)

   }

   /** build **/

   /* dependencies */

   sealed case class Node(

     loaded_theories: Set[String],

     sources: List[(Path, SHA1.Digest)])

   sealed case class Deps(deps: Map[String, Node])

   {

     def sources(name: String): List[(Path, SHA1.Digest)] = deps(name).sources

   }

   def dependencies(queue: Session.Queue): Deps =

     Deps((Map.empty[String, Node] /: queue.topological_order)(

       { case (deps, (name, info)) =>

           val preloaded =

             info.parent match {

               case None => Set.empty[String]

               case Some(parent) => deps(parent).loaded_theories

             }

           val thy_info = new Thy_Info(new Thy_Load(preloaded))

           val thy_deps =

             thy_info.dependencies(

               info.theories.map(_._2).flatten.

                 map(thy => Document.Node.Name(info.dir + Thy_Load.thy_path(thy))))

           val loaded_theories = preloaded ++ thy_deps.map(_._1.theory)

           val all_files =

             thy_deps.map({ case (n, h) =>

               val thy = Path.explode(n.node).expand

               val uses =

                 h match {

                   case Exn.Res(d) =>

                     d.uses.map(p => (Path.explode(n.dir) + Path.explode(p._1)).expand)

                   case _ => Nil

                 }

               thy :: uses

             }).flatten ::: info.files.map(file => info.dir + file)

           val sources = all_files.par.map(p => (p, SHA1.digest(p))).toList

           deps + (name -> Node(loaded_theories, sources))

       }))

   /* jobs */

   private class Job(cwd: JFile, env: Map[String, String], script: String, args: String)

   {

     private val args_file = File.tmp_file("args")

     private val env1 = env + ("ARGS_FILE" -> Isabelle_System.posix_path(args_file.getPath))

     File.write(args_file, args)

     private val (thread, result) =

       Simple_Thread.future("build") { Isabelle_System.bash_env(cwd, env1, script) }

     def terminate: Unit = thread.interrupt

     def is_finished: Boolean = result.is_finished

     def join: (String, String, Int) = { val res = result.join; args_file.delete; res }

   }

   private def start_job(save: Boolean, name: String, info: Session.Info): Job =

   {

     val parent = info.parent.getOrElse("")

     val cwd = info.dir.file

     val env = Map("INPUT" -> parent, "TARGET" -> name)

     val script =

       if (is_pure(name)) "./build " + (if (save) "-b " else "") + name

       else {

         """

         . "$ISABELLE_HOME/lib/scripts/timestart.bash"

         """ +

           (if (save)

             """ "$ISABELLE_PROCESS" -e "Build.build \"$ARGS_FILE\";" -q -w "$INPUT" "$TARGET" """

           else

             """ "$ISABELLE_PROCESS" -e "Build.build \"$ARGS_FILE\";" -r -q "$INPUT" """) +

         """

         RC="$?"

         . "$ISABELLE_HOME/lib/scripts/timestop.bash"

         if [ "$RC" -eq 0 ]; then

           echo "Finished $TARGET ($TIMES_REPORT)" >&2

         fi

         exit "$RC"

         """

       }

     val args_xml =

     {

       import XML.Encode._

       pair(bool, pair(string, pair(string, list(string))))(

         save, (parent, (name, info.theories.map(_._2).flatten.map(_.implode))))

     }

     new Job(cwd, env, script, YXML.string_of_body(args_xml))

   }

   /* build */

   private def echo(msg: String) { java.lang.System.out.println(msg) }

   private def sleep(): Unit = Thread.sleep(500)

   def build(all_sessions: Boolean, build_images: Boolean, max_jobs: Int,

     list_only: Boolean, verbose: Boolean,

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

   {

     val options = (Options.init() /: more_options)(_.define_simple(_))

     val queue = find_sessions(options, all_sessions, sessions, more_dirs)

     val deps = dependencies(queue)

     // prepare browser info dir

     if (options.bool("browser_info") &&

       !Path.explode("$ISABELLE_BROWSER_INFO/index.html").file.isFile)

     {

       Path.explode("$ISABELLE_BROWSER_INFO").file.mkdirs()

       File.copy(Path.explode("$ISABELLE_HOME/lib/logo/isabelle.gif"),

         Path.explode("$ISABELLE_BROWSER_INFO/isabelle.gif"))

       File.write(Path.explode("$ISABELLE_BROWSER_INFO/index.html"),

         File.read(Path.explode("$ISABELLE_HOME/lib/html/library_index_header.template")) +

         File.read(Path.explode("$ISABELLE_HOME/lib/html/library_index_content.template")) +

         File.read(Path.explode("$ISABELLE_HOME/lib/html/library_index_footer.template")))

     }

     // prepare log dir

     val log_dir = Path.explode("$ISABELLE_OUTPUT/log")

     log_dir.file.mkdirs()

     // scheduler loop

     @tailrec def loop(

       pending: Session.Queue,

       running: Map[String, Job],

       results: Map[String, Int]): Map[String, Int] =

     {

       if (pending.is_empty) results

       else if (running.exists({ case (_, job) => job.is_finished })) {

         val (name, job) = running.find({ case (_, job) => job.is_finished }).get

         val (out, err, rc) = job.join

         echo(Library.trim_line(err))

         val log = log_dir + Path.basic(name)

         if (rc == 0) {

           val sources =

             (queue(name).digest :: deps.sources(name).map(_._2)).map(_.toString).sorted

               .mkString("sources: ", " ", "\n")

           File.write_zip(log.ext("gz"), sources + out)

         }

         else {

           File.write(log, out)

           echo(name + " FAILED")

           echo("(see also " + log.file + ")")

           val lines = split_lines(out)

           val tail = lines.drop(lines.length - 20 max 0)

           echo("\n" + cat_lines(tail))

         }

         loop(pending - name, running - name, results + (name -> rc))

       }

       else if (running.size < (max_jobs max 1)) {

         pending.dequeue(running.isDefinedAt(_)) match {

           case Some((name, info)) =>

             if (list_only) {

               echo(name + " in " + info.dir)

               loop(pending - name, running, results + (name -> 0))

             }

             else if (info.parent.map(results(_)).forall(_ == 0)) {

               val save = build_images || queue.is_inner(name)

               echo((if (save) "Building " else "Running ") + name + " ...")

               val job = start_job(save, name, info)

               loop(pending, running + (name -> job), results)

             }

             else {

               echo(name + " CANCELLED")

               loop(pending - name, running, results + (name -> 1))

             }

           case None => sleep(); loop(pending, running, results)

         }

       }

       else { sleep(); loop(pending, running, results) }

     }

     (0 /: loop(queue, Map.empty, Map.empty))({ case (rc1, (_, rc2)) => rc1 max rc2 })

   }

   /* 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.Int(max_jobs) ::

           Properties.Value.Boolean(list_only) ::

           Properties.Value.Boolean(verbose) ::

           Command_Line.Chunks(more_dirs, options, sessions) =>

             build(all_sessions, build_images, max_jobs, list_only, verbose,

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

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

       }

     }

   }

 }