/*  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)  1985-2002, 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(emacs_shell_mode,
          []).
:- use_module(library(pce)).
:- require([ between/3
           , default/3
           , forall/2
           , ignore/1
           ]).


:- pce_begin_class(emacs_process_buffer, emacs_buffer).

variable(process,          process*,    get,    "Associated process").
variable(process_fragment, fragment,    get,    "Process' insertion point").
variable(prompt_regex,     regex*,      both,   "Regex for prompt").
variable(history,          chain,       get,    "Chain of commands send").

delegate_to(process).

class_variable(prompt_regex, regex*, @nil, "Default prompt").

initialise(B, Process:[process]*, Name:[name]) :->
    "Create from process and name"::
    (   Name == @default
    ->  new(BufName, string('*%s*', Process?name))
    ;   BufName = Name
    ),

    send(B, send_super, initialise, @nil, BufName),
    send(B, slot, process_fragment, fragment(B, 0, 0)),
    send(B, slot, history, new(chain)),
    send(B, mode, shell),
    (   Process \== @default
    ->  send(B, process, Process)
    ;   true
    ),
    send(B, obtain_class_variables).


unlink(B) :->
    "Kill the process"::
    get(B, process, P),
    (   P \== @nil
    ->  send(P, free)
    ;   true
    ),
    send(B, send_super, unlink).


lookup(_Ctx, Process:[process]*, Name:name, Buffer:emacs_buffer) :<-
    "Reuse named buffer"::
    get(@emacs_buffers, member, Name, DictItem),
    get(DictItem, object, Buffer),
    send(Buffer, instance_of, emacs_process_buffer),
    (   Process \== @default
    ->  send(Buffer, clear),
        send(Buffer, process, Process)
    ;   true
    ).



                 /*******************************
                 *             LABEL            *
                 *******************************/

modified(_B, _Val:bool) :->
    "Just succeed"::
    true.


update_label(B) :->
    "Update label in the buffer-menu"::
    get(B, name, Name),
    get(B, process, Process),
    (   Name \== @nil,
        Process \== @nil
    ->  get(Process, status, Status),
        map_status(Status, Indicator),
        get(@emacs_buffers, member, Name, DictItem),
        send(DictItem, label, string('%s\t%s', Name, Indicator)),
        new(FrameLabel, string('%s [%s]', Name, Status)),
        send(B?editors, for_all,
             message(@arg1, label, FrameLabel))
    ;   true
    ).

map_status(running, 'R').
map_status(stopped, 'Z').
map_status(killed,  'K').
map_status(exited,  'Done').
map_status(_,       '??').


                 /*******************************
                 *          THE PROCESS         *
                 *******************************/

process(B, Process:process*) :->
    "Associate process with buffer"::
    (   get(B, process, OldProcess),
        OldProcess \== @nil
    ->  send(OldProcess, free)
    ;   true
    ),
    send(B, slot, process, Process),
    send(Process, attribute, report_to, B),
    get(B, process_fragment, Fragment),
    send(Fragment, start, B?size),
    send(Fragment, length, 0),
    (   Process \== @nil
    ->  send(Process, record_separator, @nil),
        send(Process, input_message,
             message(B, insert_process_input, @arg1)),
        send(Process, terminate_message,
             message(B, terminated, @arg1)),
        send(Process, environment, 'TERM', emacs),
        ignore(send(Process?environment, delete, 'TERMCAP')),
        send(Process, environment, 'INFERIOR', yes),
        send(B, update_label)
    ;   true
    ).


insert_process_input(B, Input:string) :->
    send(Input, translate, 13, @nil),     % delete \r's (fixed in process)
    get(B, process_fragment, Fragment),
    send(Fragment, insert, @default, Input).


terminated(B, Code:'name|int') :->
    "Indicate proces terminated"::
    (   atom(Code)
    ->  send(B, report, warning, 'Terminated on signal %s at %s',
             Code, @pce?date)
    ;   Code == 0
    ->  send(B, report, status, 'Finished at %s', @pce?date)
    ;   send(B, report, warning, 'Exited status %s at %s',
             Code, @pce?date)
    ),
    send(B, update_label).



                 /*******************************
                 *        SENDING INPUT         *
                 *******************************/

:- pce_global(@newline, new(string('\n'))).

send_input(B, Caret:int) :->
    "Send data from the process input"::
    get(B, process_fragment, Fragment),
    get(Fragment, end, End),
    (   Caret >= End
    ->  get(B, contents, End, Caret-End, Data),
        send(B, insert, Caret, @newline)
    ;   get(B, scan, Caret, line, 0, start, SOL),
        get(B, scan, Caret, line, 0, end, EOL),
        get(B, contents, SOL, EOL-SOL, Data),
        (   get(B, prompt_regex, Prompt), Prompt \== @nil,
            get(Prompt, match, Data, Size)
        ->  send(Data, delete, 0, Size)
        ;   true
        ),
        send(B, append, Data),
        send(B, append, @newline),
        send(B?editors, for_all, message(@arg1, caret))
    ),
    get(B, size, Size),
    send(Fragment, start, Size),
    send(Fragment, length, 0),
    (   get(Data, size, 0)
    ->  send(Data, newline)
    ;   send(Data, ensure_nl)
    ),
    new(H, string('%s', Data)),
    send(H, strip),
    (   \+ send(H, equal, '')
    ->  send(B?history, prepend, H)
    ;   true
    ),
    (   pce_catch_error(not_open,
                        send(B?process, append, Data))
    ->  true
    ;   send(B, report, warning, 'No process')
    ).


format_data(B, Fmt:char_array, Args:any...) :->
    "Send formatted data to process"::
    StringTerm =.. [string,Fmt|Args],
    new(S, StringTerm),
    send(B, append, S),
    get(B, size, Size),
    send(B?editors, for_some, message(@arg1, caret, Size)),
    get(B, process_fragment, Fragment),
    send(Fragment, start, Size),
    send(Fragment, length, 0),
    send(B?process, append, S).


                 /*******************************
                 *        EDIT OPERATIONS       *
                 *******************************/

clear(B) :->
    "->clear, but reinsert ->process_fragment"::
    send(B, send_super, clear),
    send(B?history, clear),
    send(B, slot, process_fragment, fragment(B, 0, 0)).


kill(B) :->
    "Kill buffer and process"::
    get(B, process, Process),
    (   get(Process, pid, Pid), Pid \== @nil
    ->  new(D, dialog('Kill running process buffer?')),
        send(D, append, new(L, label(reporter))),
        send(L, format, 'Process is running'),
        send(D, append,
             button(kill, message(D, return, kill))),
        send(D, append,
             button(cancel, message(D, return, cancel))),
        get(D, confirm_centered, Rval),
        send(D, destroy),
        (   Rval == kill
        ->  send(B, free)
        ;   fail
        )
    ;   send(B, free)
    ).


properties(B) :->
    get(B, properties, V),
    get(B, process, Process),
    send(V, appendf, 'Command:\t%s\n', Process?name),
    send(V, appendf, 'Arguments:\t'),
    get(Process, arguments, Argv),
    get(Argv, size, Size),
    (   Size == 0
    ->  send(V, appendf, '<none>')
    ;   get(Argv, element, 1, A1),
        send(V, appendf, '%s', A1),
        forall(between(2, Size, AN),
               send(V, appendf, ' %s', ?(Argv, element, AN)))
    ),
    send(V, appendf, '\n'),
    send(V, appendf, 'Status:\t%s\n', Process?status).


                 /*******************************
                 *      WINDOW INTERFACE        *
                 *******************************/

start_process(B) :->
    "Start process if not running"::
    (   get(B, process, Process), Process \== @nil
    ->  send(Process, open),
        send(B, update_label)
    ;   send(B, report, warning, 'No process')
    ).


open(B, Where:[{here,tab,window}]) :->
    "Create window for buffer"::
    get(B, open, Where, Frame),
    send(Frame?editor, caret, @default),
    send(B, update_label).

:- pce_end_class.


                 /*******************************
                 *         SHELL MODE           *
                 *******************************/

:- pce_begin_class(emacs_shell_mode, emacs_fundamental_mode).

:- initialization
    new(KB, emacs_key_binding(shell, fundamental)),
    send(KB, function, 'RET', send_input),
    send(KB, function, '\\C-c\\C-c', interrupt_subjob),
    send(KB, function, '\\C-c\\C-d', end_of_file),
    send(KB, function, '\\C-c\\C-h', show_history),
    send(KB, function, '\\ep',      backward_history),
    send(KB, function, '\\en',      forward_history),
    send(KB, function, '\\C-cRET',  mark_errors),
    send(KB, function, '\\C-c\\C-f', visit_file),
    send(KB, function, '\\C-c\\C-e', goto_error),
    send(KB, function, '\\C-c\\C-\\', quit_subjob),
    send(KB, function, '\\C-c\\C-k', kill_subjob).

:- initialization
    new(T, syntax_table(shell)),
    send(T, syntax, '.', symbol),
    send(T, syntax, '-', symbol),
    send(T, syntax, '"', string_quote, '\\'),
    send(T, syntax, '''', string_quote, '\\').

:- initialization
    new(MM, emacs_mode_menu(shell, fundamental)),
    send(MM, append, shell, start_process),
    send(MM, append, shell, goto_error),
    send(MM, append, shell, mark_errors),
    send(MM, append, shell, visit_file),

    send(MM, append, shell, end_of_file),
    send(MM, append, shell, interrupt),
    send(MM, append, shell, kill_subjob).


variable(current_history, number*, both, "Current history number").

:- pce_global(@event_mode, new(@event?receiver?window?editor?mode)).

process(E, P:process) :<-
    "Process object associated with editor"::
    get(E, text_buffer, TB),
    send(TB, instance_of, emacs_process_buffer),
    get(TB, process, P),
    (   get(P, pid, Pid), Pid \== @nil
    ->  true
    ;   send(E, report, error, 'No process'),
        fail
    ).


                 /*******************************
                 *        SENDING INPUT         *
                 *******************************/

send_input(E) :->
    "Send data to process"::
    send(E, end_of_line),
    send(E?text_buffer, send_input, E?caret).


                 /*******************************
                 *             EDIT             *
                 *******************************/

beginning_of_line(E, Lines:[int]) :->
    "Move to start of input"::
    (   Lines == @default,
        get(E, caret, Caret),
        get(E, text_buffer, B),
        get(B, scan, Caret, line, 0, start, SOL),
        get(B, process_fragment, Fragment),
        get(Fragment, end, End),
        Caret >= End,
        SOL =< Caret
    ->  send(E, caret, End)
    ;   send(E?editor, beginning_of_line, Lines)
    ).


clear(E) :->
    "Clear process buffer"::
    get(E, text_buffer, TB),
    send(TB, clear).

                 /*******************************
                 *           HISTORY            *
                 *******************************/

show_history(E, N:[int]) :->
    "Show last N commands"::
    default(N, 10, Cmds),
    get(E, text_buffer, TB),
    get(E, caret, Caret),
    get(TB, scan, Caret, line, 0, start, SOL),
    get(TB, contents, SOL, Caret-SOL, Prompt),
    get(TB, history, Chain),
    insert_history(Cmds, Chain, E),
    send(E, format, '\n%s', Prompt),
    get(TB, process_fragment, Frag),
    send(Frag, end, E?caret).

insert_history(0, _, _) :- !.
insert_history(N, Chain, E) :-
    (   get(Chain, nth1, N, Data)
    ->  send(E, format, '\n\t%s', Data)
    ;   true
    ),
    NN is N - 1,
    insert_history(NN, Chain, E).


backward_history(E, Id:event_id) :->
    "Insert last command"::
    send(E, current_history, 0),
    send(E, focus_function, '_history'),
    send(E, '_history', Id).


'_history'(E, Id:event_id) :->
    get(E?bindings, function, Id, Func),
    get(E, text_buffer, B),
    get(B, history, Chain),

    get(E, current_history, Current),
    (   Func == backward_history
    ->  send(Current, plus, 1)
    ;   Func == forward_history
    ->  send(Current, minus, 1)
    ),

    get(B, process_fragment, Frag),
    get(Frag, end, End),
    send(E, caret, End),
    get(B, size, Size),
    send(B, delete, End, Size),

    (   get(Chain, nth1, Current, Data)
    ->  send(B, insert, End, Data)
    ;   send(E, report, status, 'No (more) history')
    ).

                 /*******************************
                 *           SIGNALS            *
                 *******************************/

kill_subjob(E, Signal:'[int|name]') :->
    "Send signal to shell"::
    send(E?process, kill, Signal).

interrupt_subjob(E) :->
    "Send control-C to process"::
    send(E, char_code, 3).          % ^C

quit_subjob(E) :->
    "Send control-\\ to process"::
    send(E, char_code, 28).         % ^\

suspend_subjob(E) :->
    "Send control-Z to process"::
    send(E, char_code, 26).         % ^Z

end_of_file(E) :->
    "Send control-D to process"::
    send(E, char_code, 4).          % ^D

char_code(E, Code:int) :->
    "Send a specific character code"::
    char_code(Char, Code),
    send(E?process, append, Char).


                 /*******************************
                 *        FINDING ERRORS        *
                 *******************************/

:- pce_global(@emacs_error_regexs,
              new(chain(regex('(\\S+):\\s*(\\d+):'),        % gcc, grep
                        regex('"(\\S+)", line (\\d+):')))). % SUN cc
:- pce_global(@emacs_cd_regexs,
              new(chain(regex('\\ycd\\s+((\\w|[_/+-.: ])+)'),
                        regex('Entering directory `([^\']+)\'')))).
:- pce_global(@emacs_canonicalise_dir_regex,
              new(regex('[^/]+/\\.\\./'))).

canonicalise_path(Path) :-
    send(regex('[^/]+/\\.\\./'), for_all, Path,
         message(@arg1, replace, Path, '')),
    send(regex('/\\./|//'), for_all, Path,
         message(@arg1, replace, Path, '/')).

directory_name(M, Pos:[int]*, DirName:string) :<-
    "New string with Directory at position"::
    get(M, text_buffer, TB),
    (   Pos == @nil
    ->  get(TB, directory, Dir),
        new(DirName, string('%s', Dir?path))
    ;   (   Pos == @default
        ->  get(M, caret, P0)
        ;   P0 = Pos
        ),
        (   match_cd_regex(TB, P0, Dir0, Here)
        ->  (   send(file(Dir0), is_absolute)
            ->  DirName = Dir0
            ;   get(M, directory_name, Here, DirName),
                send(DirName, ensure_suffix, /),
                send(DirName, append, Dir0)
            )
        ;   get(M?text_buffer, directory, Dir),
            new(DirName, string('%s', Dir?path))
        )
    ),
    send(DirName, ensure_suffix, /),
    canonicalise_path(DirName).


match_cd_regex(TB, P0, Dir, Here) :-
    get(@emacs_cd_regexs, find_all,
        message(@arg1, search, TB, P0, 0), Hits),
    send(Hits, sort,
         ?(@arg2?register_start, compare, @arg1?register_start)),
    get(Hits, head, Regex),
    get(Regex, register_start, Here),
    get(Regex, register_value, TB, 1, Dir),
    send(Hits, done).


directory(M, Pos:[int]*, Dir:directory) :<-
    "Current working directory"::
    get(M, directory_name, Pos, DirName),
    new(Dir, directory(DirName)).


error(M, Pos:int, Tuple:tuple) :<-
    "FileName and line number from error"::
    get(M, text_buffer, TB),
    get(TB, scan, Pos, line, 0, start, SOL),
    get(TB, scan, Pos, line, 0, end, EOL),
    get(@emacs_error_regexs, find,
        message(@arg1, search, TB, SOL, EOL), Regex),
    get(Regex, register_value, TB, 1, R1),
    get(Regex, register_value, TB, 2, R2),
    (   get(@pce, convert, R1, int, LineNo)
    ->  get(R2, value, File)
    ;   get(@pce, convert, R2, int, LineNo)
    ->  get(R1, value, File)
    ;   send(M, report, warning, 'No line number in error'),
        fail
    ),
    (   send(File, prefix, /)
    ->  new(Tuple, tuple(File, LineNo))
    ;   get(M, directory_name, SOL, DirNameStr),
        send(DirNameStr, append, File),
        canonicalise_path(DirNameStr),
        get(DirNameStr, value, DirName),
        new(Tuple, tuple(DirName, LineNo))
    ).


mark_errors(M, From:[int], To:[int]) :->
    "Mark errors in range using fragments"::
    send(M, report, status, 'Marking errors ...'),
    get(M, text_buffer, TB),
    default(From, 0, F0),
    default(To, TB?size, T),
    get(TB, scan, F0, line, 0, start, F1),
    new(Here, number(F1)),
    new(Errors, number(0)),
    repeat,
         (   get(M, error, Here, tuple(File, Line))
         ->  new(B, emacs_buffer(File)),
             get(B, scan, 0, line, Line-1, start, SOF),
             get(B, scan, SOF, line, 0, end, EOF),
             new(FThere, emacs_link_fragment(B, SOF, EOF-SOF)),
             get(TB, scan, Here, line, 0, end, EOL),
             new(FHere, emacs_link_fragment(TB, Here, EOL-Here)),
             send(FHere, link, FThere),
             send(Errors, plus, 1)
         ;   true
         ),
         get(TB, scan, Here, line, 1, start, NewHere),
         (   send(T, larger, NewHere)
         ->  send(Here, value, NewHere),
             fail
         ;   !,
             (   send(Errors, larger, 0)
             ->  send(M, report, status, 'Marked %d errors', Errors)
             ;   send(M, report, status, 'No errors')
             )
         ).


goto_error(M) :->
    "Goto error from current_line"::
    get(M, caret, Caret),
    (   get(M, find_fragment,
            and(message(@arg1, instance_of, emacs_link_fragment),
                message(@arg1, overlap, Caret)),
            Fragment)
    ->  send(Fragment, follow, tab)
    ;   get(M, error, Caret, tuple(File, Line))
    ->  new(B, emacs_buffer(File)),
        send(B, open, tab),
        send(B?editors?head, line_number, Line)
    ;   send(M, report, warning, 'No error on this line')
    ).

visit_file(M) :->
    "Visit file from the caret"::
    get(M, word, FileName),
    get(M, directory_name, M?caret, Dir),
    send(Dir, append, FileName),
    new(F, file(Dir)),
    (   send(F, exists)
    ->  new(B, emacs_buffer(F)),
        send(B, open)
    ;   send(M, report, error, '%s: no such file', Dir),
        fail
    ).

:- pce_end_class.


                 /*******************************
                 *       LINKED FRAGMENTS       *
                 *******************************/

:- pce_begin_class(emacs_link_fragment, fragment,
                   "Pair of linked fragments").

variable(link,          fragment,       get,    "Fragment I'm linked to").

unlink(F) :->
    "Remove fragment and 'linked-to'"::
    get(F, link, F2),
    (   F2 \== @nil
    ->  send(F, slot, link, @nil),
        free(F2)
    ;   true
    ),
    send(F, send_super, unlink).


link(F, F2:emacs_link_fragment) :->
    send(F, slot, link, F2),
    send(F2, slot, link, F).


follow(F, Where:[{here,tab,window}]) :->
    "Goto other end of link"::
    get(F, link, F2),
    get(F2, text_buffer, B),
    send(B, open, Where),
    send(B?editors?head, caret, F2?start).

:- pce_end_class.
