/*  Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    Copyright (c)  1996-2011, University of Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

:- module(man_search, []).
:- use_module(library(pce)).
:- require([ absolute_file_name/3
           , append/3
           , default/3
           , ignore/1
           , atomic_list_concat/2
           ]).


                 /*******************************
                 *  PAUSE INDICATING TEXT-ITEM  *
                 *******************************/

:- pce_begin_class(man_pause_item, text_item,
                   "Item that sends message after pause").

variable(pause_message, code*, both, "Message if pause has elapsed").
variable(timer,         timer, get, "Timer for pause").
variable(last_typed,    int,   get, "Time of last type action").

initialise(I, Name:[name], Def:[any|function], Msg:[code]*, PMsg:[code]*) :->
    default(PMsg, @nil, PauseMsg),
    send(I, send_super, initialise, Name, Def, Msg),
    send(I, slot, pause_message, PauseMsg),
    send(I, slot, last_typed, 0),
    send(I, slot, timer, timer(0.5, message(I, timeout))).


unlink(I) :->
    "Stop associated <-timer"::
    get(I, timer, Timer),
    send(Timer, stop).


event(I, Ev:event) :->
    (   send(Ev, is_a, focus)
    ->  get(I, timer, Timer),
        (   send(Ev, is_a, deactivate_keyboard_focus)
        ->  send(Timer, stop)
        ;   send(Ev, is_a, activate_keyboard_focus)
        ->  send(Timer, start)
        ;   true
        )
    ;   true
    ),
    send(I, send_super, event, Ev).


timeout(I) :->
    get(I, pause_message, Msg),
    Msg \== @nil,
    get(@pce, mclock, Now),
    get(I, last_typed, Last),
    Now - Last > 1500,
    get(I, modified, @on),
    get(I, selection, Selection),
    \+ get(Selection, size, 0),
    send(I, modified, @off),
    send(I?display, busy_cursor),
    ignore(send(Msg, forward, Selection)),
    send(I?display, busy_cursor, @nil).


typed(I, Id:event_id) :->
    send(I, slot, last_typed, @pce?mclock),
    send(I, send_super, typed, Id),
    send(I?frame, typed_in_search_item, Id, I?value_text?string).

:- pce_end_class.

                 /*******************************
                 *        INDEX DATABASE        *
                 *******************************/

make_index(_, Ref) :-
    object(Ref),
    !.
make_index(IV, @Ref) :-
    absolute_file_name(pce('/man/reference/index'),
                       [ extensions([obj]),
                         access(read),
                         file_errors(fail)
                       ],
                       IndexFile),
    !,
    send(IV, report, progress, 'Loading index ...'),
    get(file(IndexFile), object, Obj),
    send(IV, report, done),
    send(Obj, name_reference, Ref).
make_index(IV, @Ref) :-
    absolute_file_name(pce('/man/reference'),
                       [ file_type(directory),
                         access(write),
                         file_errors(fail)
                       ],
                       IndexDir),
    !,
    atomic_list_concat([IndexDir, /, 'index.obj'], IndexFile),
    send(@display, confirm,
         '%s\n%s %s',
         'Cannot find PCE manual index file.',
         'Create', IndexFile),
    send(IV, busy_cursor),
    get(new(man_index_manager), make_index, IndexFile, TmpTable),
    send(IV, busy_cursor, @nil),
    send(TmpTable, name_reference, Ref),
    send(@display, inform,
         '%s\n%s\n%s\n%s',
         'Creating the manual index has loaded the entire manual',
         'and introduced considerable fragmentation in XPCE''s',
         'memory management.  If you are tight on memory, please',
         'quit and restart XPCE').
make_index(_, Ref) :-
    send(@display, inform,
         'Sorry, no manual index and no permission to write one.'),
    new(Ref, chain_table).


                 /*******************************
                 *            THE FRAME         *
                 *******************************/

:- pce_begin_class(man_search_tool, man_frame,
                   "Search tool for the manual index").

initialise(IV, Manual:[man_manual]) :->
    default(Manual, @manual, TheManual),
    send(IV, send_super, initialise, TheManual, 'PCE Manual --- Search'),
    send(IV, append, new(D, dialog)),
    send(D, append, button(quit, message(IV, quit))),
    send(D, append, button(help, message(IV, help))),
    send(D, append, new(B, button(search_for))),
    send(D, append, new(S, man_pause_item(search, '')), right),
    send(S, length, 40),
    send(S, show_label, @off),
    send(S, pause_message, message(IV, pause, @arg1)),
    send(D, append, label(reporter), right),
    send(B, message, message(IV, search, S?selection)),
    new(WL, browser),
    send(WL, name, wordlist),
    new(WLMsg, message(S, selection, create(string, '<%s>', @arg1?key))),
    send(WL, select_message,
         and(WLMsg, message(IV, pause, S?selection))),
    send(WL, open_message,
         and(WLMsg, message(IV, search, S?selection))),
    send(new(H, man_summary_browser(man_summary, size(90, 15))),
         right, WL),
    send(WL, above, D),
    send(H, name, hitlist),
    send(D, default_button, B),
    send(IV, input_window, D),
    send(IV, open),
    send(IV, wait),
    make_index(IV, @man_index),
    send(IV, report, progress, 'Extracting word-list ...'),
    word_list(@man_index, List),
    send(WL, members, List),
    send(IV, report, progress, done).


unlink(IV) :->
    ignore(send(IV?manual, search_patterns, @nil)),
    send(IV, send_super, unlink).


typed_in_search_item(IV, Id:event_id, Current:char_array) :->
    "Handle typing in the search string"::
    get(IV, member, wordlist, WL),
    (   get(Current, size, 0)
    ->  send(WL, cancel_search),
        get(IV, member, hitlist, List),
        send(List, clear),
        get(IV, manual, Manual),
        send(Manual, search_patterns, @nil)
    ;   send(Current, suffix, ' ')
    ->  send(WL, cancel_search)
    ;   Id == 13                    % return
    ->  true
    ;   get(WL, key_binding, KB),
        get(KB, function, Id, F),
        F \== alert
    ->  send(WL, typed, Id)
    ;   true
    ).


search(IV, Spec:name) :->
    "Perform the actual search"::
    (   parse_search_spec(Spec, Term)
    ->  execute_search(Term, @man_index, CardsIds),
        search_patterns(Term, Patterns),
        send(IV?manual, search_patterns, Patterns),
        send(IV, show_cards, CardsIds)
    ;   send(IV, report, warning, 'Bad search expression'),
        fail
    ).


pause(IV, Spec:char_array) :->
    "Timeout pause, show number of matches"::
    (   parse_search_spec(Spec, Term)
    ->  execute_search(Term, @man_index, CardsIds),
        send(IV, report, status, '%d matches', CardsIds?size)
    ;   send(IV, report, status, 'Incomplete expression')
    ).


show_cards(IV, Cards:chain) :->
    get(IV, member, hitlist, Browser),
    get(Cards, map, ?(@prolog, object_from_id, @arg1), Objects),
    send(Browser, members, Objects).


object_from_id(Id, Obj) :-
    atom_codes(Id, Chars),
    phrase(id(Obj), Chars),
    !.
object_from_id(Id, _) :-
    format('Cannot parse card id "~w"~n', [Id]),
    fail.

id(Obj) -->                             % methods
    "M.", string(C), ".", sendget(SG), ".", string(N), eos,
    !,
    { atom_codes(ClassName, C),
      atom_codes(MName, N),
      get(@pce, convert, ClassName, class, Class),
      get(Class, SG, MName, Obj)
    }.
id(Obj) -->                             % variable
    "V.", string(C), ".", string(N), eos,
    !,
    { atom_codes(ClassName, C),
      atom_codes(VarName, N),
      get(@pce, convert, ClassName, class, Class),
      get(Class, instance_variable, VarName, Obj)
    }.
id(Obj) -->                             % resource
    "R.", string(C), ".", string(N), eos,
    !,
    { atom_codes(ClassName, C),
      atom_codes(ResName, N),
      get(@pce, convert, ClassName, class, Class),
      get(Class, class_variable, ResName, Obj)
    }.
id(Obj) -->                             % classes
    "C.", string(C), eos,
    !,
    { atom_codes(ClassName, C),
      get(@pce, convert, ClassName, class, Obj)
    }.
id(Obj) -->                             % plain cards
    "$", string(MS), "$", string(I), eos,
    !,
    { atom_codes(Module, MS),
      name(CardId, I),
      get(@manual, space, ManSpace),
      get(ManSpace, module, Module, @on, M),
      get(M, card, CardId, Obj)
    }.

sendget(send_method) --> "S".
sendget(get_method) --> "G".

string(S, In, Rest) :-
    append(S, Rest, In).

eos([], []).

                 /*******************************
                 *          SEARCH STUFF        *
                 *******************************/

parse_search_spec(Spec, Term) :-
    atom_codes(Spec, Chars),
    phrase(wordlist(List), Chars),
    !,
    phrase(search_specification(Term), List),
    !.

search_patterns(Term, Patterns) :-
    new(Patterns, chain),
    extract_search_patterns(Term, Patterns).

extract_search_patterns(word(W), Ch) :-
    (   atom_codes(W, [0'@|_])
    ->  new(Re, regex(string('%s\\\\b', W)))
    ;   new(Re, regex(string('\\\\b%s\\\\b', W)))
    ),
    send(Ch, append, Re),
    send(Re, ignore_case, @on).
extract_search_patterns(prefix(W), Ch) :-
    (   atom_codes(W, [0'@|_])
    ->  new(Re, regex(string('%s', W)))
    ;   new(Re, regex(string('\\\\b%s', W)))
    ),
    send(Ch, append, Re),
    send(Re, ignore_case, @on).
extract_search_patterns(not(_), _) :- !.
extract_search_patterns(and(S1, S2), Ch) :-
    extract_search_patterns(S1, Ch),
    extract_search_patterns(S2, Ch).
extract_search_patterns(or(S1, S2), Ch) :-
    extract_search_patterns(S1, Ch),
    extract_search_patterns(S2, Ch).


                 /*******************************
                 *        MAKE WORD-LIST        *
                 *******************************/

wordlist([H|T]) -->
    blanks,
    word(H),
    !,
    wordlist(T).
wordlist([]) -->
    blanks.

blanks -->
    blank,
    !,
    blanks.
blanks -->
    [].

blank -->
    [C], { C =< 32 }.

singleton(0'(, '(').
singleton(0'), ')').
singleton(0'<, '<').
singleton(0'>, '>').

word(W) -->
    [C],
    { singleton(C, W) },
    !.
word(W) -->
    wordchar(C0),
    wordchars(CT),
    { atom_codes(W, [C0|CT]) }.

wordchars([H|T]) -->
    wordchar(H),
    !,
    wordchars(T).
wordchars([]) -->
    [].

wordchar(C) -->
    [C],
    { C > 32,
      \+ singleton(C, _)
    }.

                 /*******************************
                 *            COMBINE           *
                 *******************************/

search_specification(Simple) -->
    simple_search(Simple).
search_specification(Compound) -->
    simple_search(Left),
    infix(Connective),
    !,
    search_specification(Right),
    { Compound =.. [Connective, Left, Right] }.
search_specification(and(S1, S2)) -->
    simple_search(S1),
    search_specification(S2).

simple_search(not(S)) -->
    [ not ],
    !,
    simple_search(S),
    !.            % not takes shortest expression
simple_search(S) -->
    ['('],
    !,
    search_specification(S),
    [')'].
simple_search(word(W)) -->
    ['<',W,'>'],
    !.
simple_search(prefix(W)) -->
    [ W ],
    { \+ singleton(_, W) }.

infix(and)  --> [and].
infix(or)   --> [or].


                 /*******************************
                 *           AND DO IT          *
                 *******************************/

execute_search(word(W), DB, Result) :-
    get(DB, member, W, Result).
execute_search(prefix(W), DB, Result) :-
    word_list(DB, List),
    get(List, complete_name, W, Tuple),
    get(Tuple, first, Words),
    new(Result, chain),
    send(Words, for_all,
         message(Result, merge, ?(DB, member, @arg1))),
    send(Result, unique).
execute_search(and(not(S1), S2), DB, Result) :-
    execute_search(S1, DB, R1),
    execute_search(S2, DB, R2),
    get(R2, copy, Result),
    send(Result, subtract, R1),
    send(R1, done),
    send(R2, done).
execute_search(and(S1, not(S2)), DB, Result) :-
    execute_search(and(not(S2), S1), DB, Result).
execute_search(and(S1, S2), DB, Result) :-
    !,
    execute_search(S1, DB, R1),
    execute_search(S2, DB, R2),
    get(R1, intersection, R2, Result),
    send(R1, done),
    send(R2, done).
execute_search(or(S1, S2), DB, Result) :-
    execute_search(S1, DB, R1),
    execute_search(S2, DB, R2),
    get(R1, union, R2, Result),
    send(R1, done),
    send(R2, done).

word_list(HT, Words) :-
    get(HT, attribute, word_list, Words),
    !.
word_list(HT, Words) :-
    send(HT, attribute, word_list, new(Words, chain)),
    send(HT, for_all, message(Words, append, @arg1)),
    send(Words, sort).

:- pce_end_class.
