(*  Title:      Pure/PIDE/document.ML

    Author:     Makarius

Document as collection of named nodes, each consisting of an editable

list of commands, associated with asynchronous execution process.

*)

signature DOCUMENT =

sig

  type id = int

  type version_id = id

  type command_id = id

  type exec_id = id

  val no_id: id

  val new_id: unit -> id

  val parse_id: string -> id

  val print_id: id -> string

  type edit = string * ((command_id option * command_id option) list) option

  type state

  val init_state: state

  val cancel: state -> unit

  val define_command: command_id -> string -> state -> state

  val edit: version_id -> version_id -> edit list -> state -> (command_id * exec_id) list * state

  val execute: version_id -> state -> state

end;

structure Document: DOCUMENT =

struct

(* unique identifiers *)

type id = int;

type version_id = id;

type command_id = id;

type exec_id = id;

val no_id = 0;

val new_id = Synchronized.counter ();

val parse_id = Markup.parse_int;

val print_id = Markup.print_int;

fun err_dup kind id = error ("Duplicate " ^ kind ^ ": " ^ print_id id);

fun err_undef kind id = error ("Undefined " ^ kind ^ ": " ^ print_id id);

(** document structure **)

structure Entries = Linear_Set(type key = command_id val ord = int_ord);

abstype node = Node of exec_id option Entries.T  (*command entries with excecutions*)

  and version = Version of node Graph.T  (*development graph wrt. static imports*)

with

val empty_node = Node Entries.empty;

val empty_version = Version Graph.empty;

fun fold_entries start f (Node entries) = Entries.fold start f entries;

fun first_entry start P (Node entries) = Entries.get_first start P entries;

(* node edits and associated executions *)

type edit =

  string *

  (*NONE: remove node, SOME: insert/remove commands*)

  ((command_id option * command_id option) list) option;

fun the_entry (Node entries) id =

  (case Entries.lookup entries id of

    NONE => err_undef "command entry" id

  | SOME entry => entry);

fun update_entry (id, exec_id) (Node entries) =

  Node (Entries.update (id, SOME exec_id) entries);

fun reset_after id entries =

  (case Entries.get_after entries id of

    NONE => entries

  | SOME next => Entries.update (next, NONE) entries);

fun edit_node (hook, SOME id2) (Node entries) =

      Node (Entries.insert_after hook (id2, NONE) entries)

  | edit_node (hook, NONE) (Node entries) =

      Node (entries |> Entries.delete_after hook |> reset_after hook);

(* version operations *)

fun nodes_of (Version nodes) = nodes;

val node_names_of = Graph.keys o nodes_of;

fun get_node version name = Graph.get_node (nodes_of version) name

  handle Graph.UNDEF _ => empty_node;

fun edit_nodes (name, SOME edits) (Version nodes) =

      Version (nodes

        |> Graph.default_node (name, empty_node)

        |> Graph.map_node name (fold edit_node edits))

  | edit_nodes (name, NONE) (Version nodes) =

      Version (perhaps (try (Graph.del_node name)) nodes);

fun put_node name node (Version nodes) =

  Version (nodes

    |> Graph.default_node (name, empty_node)

    |> Graph.map_node name (K node));

end;

(** global state -- document structure and execution process **)

abstype state = State of

 {versions: version Inttab.table,  (*version_id -> document content*)

  commands: Toplevel.transition future Inttab.table,  (*command_id -> transition (future parsing)*)

  execs: (bool * Toplevel.state) lazy Inttab.table,  (*exec_id -> execution process*)

  execution: unit future list}  (*global execution process*)

with

fun make_state (versions, commands, execs, execution) =

  State {versions = versions, commands = commands, execs = execs, execution = execution};

fun map_state f (State {versions, commands, execs, execution}) =

  make_state (f (versions, commands, execs, execution));

val init_state =

  make_state (Inttab.make [(no_id, empty_version)],

    Inttab.make [(no_id, Future.value Toplevel.empty)],

    Inttab.make [(no_id, Lazy.value (true, Toplevel.toplevel))],

    []);

(* document versions *)

fun define_version (id: version_id) version =

  map_state (fn (versions, commands, execs, execution) =>

    let val versions' = Inttab.update_new (id, version) versions

      handle Inttab.DUP dup => err_dup "document version" dup

    in (versions', commands, execs, execution) end);

fun the_version (State {versions, ...}) (id: version_id) =

  (case Inttab.lookup versions id of

    NONE => err_undef "document version" id

  | SOME version => version);

(* commands *)

fun define_command (id: command_id) text =

  map_state (fn (versions, commands, execs, execution) =>

    let

      val id_string = print_id id;

      val tr = Future.fork_pri 2 (fn () =>

        Position.setmp_thread_data (Position.id_only id_string)

          (fn () => Outer_Syntax.prepare_command (Position.id id_string) text) ());

      val commands' =

        Inttab.update_new (id, tr) commands

          handle Inttab.DUP dup => err_dup "command" dup;

    in (versions, commands', execs, execution) end);

fun the_command (State {commands, ...}) (id: command_id) =

  (case Inttab.lookup commands id of

    NONE => err_undef "command" id

  | SOME tr => tr);

fun join_commands (State {commands, ...}) =

  Inttab.fold (fn (_, tr) => fn () => ignore (Future.join_result tr)) commands ();

(* command executions *)

fun define_exec (id: exec_id) exec =

  map_state (fn (versions, commands, execs, execution) =>

    let val execs' = Inttab.update_new (id, exec) execs

      handle Inttab.DUP dup => err_dup "command execution" dup

    in (versions, commands, execs', execution) end);

fun the_exec (State {execs, ...}) (id: exec_id) =

  (case Inttab.lookup execs id of

    NONE => err_undef "command execution" id

  | SOME exec => exec);

(* document execution *)

fun cancel (State {execution, ...}) =

  List.app Future.cancel execution;

fun await_cancellation (State {execution, ...}) =

  ignore (Future.join_results execution);

end;

(* toplevel transactions *)

local

fun timing tr t = Toplevel.status tr (Markup.timing t);

fun proof_status tr st =

  (case try Toplevel.proof_of st of

    SOME prf => Toplevel.status tr (Proof.status_markup prf)

  | NONE => ());

fun async_state tr st =

  ignore

    (singleton (Future.bulk {group = SOME (Task_Queue.new_group NONE), deps = [], pri = 0})

      (fn () =>

        Toplevel.setmp_thread_position tr

          (fn () => Toplevel.print_state false st) ()));

fun run int tr st =

  (case Toplevel.transition int tr st of

    SOME (st', NONE) => ([], SOME st')

  | SOME (_, SOME exn_info) =>

      (case ML_Compiler.exn_messages (Runtime.EXCURSION_FAIL exn_info) of

        [] => Exn.interrupt ()

      | errs => (errs, NONE))

  | NONE => ([ML_Compiler.exn_message Runtime.TERMINATE], NONE));

in

fun run_command thy_name raw_tr st =

  (case

      (case Toplevel.init_of raw_tr of

        SOME name => Exn.capture (fn () =>

          let

            val path = Path.explode thy_name;

            val _ = Thy_Header.consistent_name (Path.implode (Path.base path)) name;

          in Toplevel.modify_master (SOME (Path.dir path)) raw_tr end) ()

      | NONE => Exn.Result raw_tr) of

    Exn.Result tr =>

      let

        val is_init = is_some (Toplevel.init_of tr);

        val is_proof = Keyword.is_proof (Toplevel.name_of tr);

        val do_print = not is_init andalso (Toplevel.print_of tr orelse is_proof);

        val start = start_timing ();

        val (errs, result) = run (is_init orelse is_proof) (Toplevel.set_print false tr) st;

        val _ = timing tr (end_timing start);

        val _ = List.app (Toplevel.error_msg tr) errs;

        val res =

          (case result of

            NONE => (Toplevel.status tr Markup.failed; (false, st))

          | SOME st' =>

             (Toplevel.status tr Markup.finished;

              proof_status tr st';

              if do_print then async_state tr st' else ();

              (true, st')));

      in res end

  | Exn.Exn exn =>

      if Exn.is_interrupt exn then reraise exn

      else

       (Toplevel.error_msg raw_tr (ML_Compiler.exn_message exn);

        Toplevel.status raw_tr Markup.failed;

        (false, Toplevel.toplevel)));

end;

(** editing **)

(* edit *)

local

fun is_changed node' ((_, id), exec) =

  (case try (the_entry node') id of

    NONE => true

  | SOME exec' => exec' <> exec);

fun new_exec name (id: command_id) (exec_id, updates, state) =

  let

    val exec = the_exec state exec_id;

    val exec_id' = new_id ();

    val future_tr = the_command state id;

    val exec' =

      Lazy.lazy (fn () =>

        let

          val st = #2 (Lazy.force exec);

          val exec_tr = Toplevel.put_id (print_id exec_id') (Future.join future_tr);

        in run_command name exec_tr st end);

    val state' = define_exec exec_id' exec' state;

  in (exec_id', (id, exec_id') :: updates, state') end;

in

fun edit (old_id: version_id) (new_id: version_id) edits state =

  let

    val old_version = the_version state old_id;

    val _ = Time.now ();  (* FIXME odd workaround *)

    val new_version = fold edit_nodes edits old_version;

    fun update_node name (rev_updates, version, st) =

      let val node = get_node version name in

        (case first_entry NONE (is_changed (get_node old_version name)) node of

          NONE => (rev_updates, version, st)

        | SOME ((prev, id), _) =>

            let

              val prev_exec =

                (case prev of

                  NONE => no_id

                | SOME prev_id => the_default no_id (the_entry node prev_id));

              val (_, rev_upds, st') =

                fold_entries (SOME id) (new_exec name o #2 o #1) node (prev_exec, [], st);

              val node' = fold update_entry rev_upds node;

            in (rev_upds @ rev_updates, put_node name node' version, st') end)

      end;

    (* FIXME proper node deps *)

    val (rev_updates, new_version', state') =

      fold update_node (node_names_of new_version) ([], new_version, state);

    val state'' = define_version new_id new_version' state';

    val _ = join_commands state'';  (* FIXME async!? *)

  in (rev rev_updates, state'') end;

end;

(* execute *)

fun execute version_id state =

  state |> map_state (fn (versions, commands, execs, execution) =>

    let

      val version = the_version state version_id;

      fun force_exec NONE = ()

        | force_exec (SOME exec_id) = ignore (Lazy.force (the_exec state exec_id));

      val _ = cancel state;

      val execution' = (* FIXME proper node deps *)

        Future.bulk {group = NONE, deps = [], pri = 1} [fn () =>

          let

            val _ = await_cancellation state;

            val _ =

              node_names_of version |> List.app (fn name =>

                fold_entries NONE (fn (_, exec) => fn () => force_exec exec)

                    (get_node version name) ());

          in () end];

      val _ = await_cancellation state;  (* FIXME async!? *)

    in (versions, commands, execs, execution') end);

end;