%-----------------------------------------------------------------------------%
% Copyright (C) 1998 The University of Melbourne.
% This file may only be copied under the terms of the GNU General
% Public License - see the file COPYING in the Mercury distribution.
%-----------------------------------------------------------------------------%

% Main author: bromage

% This module contains all the option handling code for diff.

%-----------------------------------------------------------------------------%

:- module options.
:- interface.
:- import_module string, std_util, io, getopt.

%-----------------------------------------------------------------------------%

:- pred options__get_option_ops(option_ops(option) :: out(option_ops)) is det.

	% Process the option table, perhaps returning an error message
	% if there was some inconsistentcy or other error.
:- pred postprocess_options(maybe_option_table :: in, maybe(string) :: out,
		io__state::di, io__state::uo) is det.

%-----------------------------------------------------------------------------%

	% Info on the accepted options, displayed in response to --help.
:- pred options_help(io__state::di, io__state::uo) is det.

%-----------------------------------------------------------------------------%

:- type option_table		== option_table(option).
:- type maybe_option_table	== maybe_option_table(option).

	% The master list of options.

:- type option --->
	% Output styles
	 	help
	;	version
	;	context	
	;	context_style_output
	;	unified
	;	unified_style_output
	;	ed
	;	forward_ed
	;	rcs
	;	brief
	;	ifdef
	;	side_by_side
	;	cvs_merge_conflict

	% Output options
	;	show_c_function		% Not handled (and unlikely to be soon)
	;	show_function_line	% Not handled (and unlikely to be soon)
	;	label
	;	width
	;	expand_tabs
	;	initial_tab
	;	paginate		% Not handled (and unlikely to be soon)
	;	left_column
	;	suppress_common_lines
	;	sdiff_merge_assist	% Accepted but ignored

	% Matching options
	;	new_file		% Not handled (and unlikely to be soon)
	;	unidirectional_new_file	% Not handled (and unlikely to be soon)
	;	ignore_case
	;	ignore_all_space
	;	ignore_space_change

	% Diff options
	;	minimal
	;	speed_large_files	% Accepted but ignored
	;	file_split_speed_hack	% Accepted but ignored (GNU diff
					% ignores this too, so let's not
					% feel too bad about it)

	% Change filter options
	;	ignore_matching_lines	% Not handled (and unlikely to be soon)
	;	ignore_blank_lines

	% Directory comparison options
	% None of these are likely to be handled in the near future.
	;	starting_file		% Not handled
	;	recursive		% Not handled
	;	report_identical_files	% Not handled
	;	exclude			% Not handled
	;	exclude_from		% Not handled

	% #ifdef format options
	% None of these are likely to be handled in the very near future.
	;	old_line_format		% Not handled
	;	new_line_format		% Not handled
	;	unchanged_line_format	% Not handled
	;	line_format		% Not handled
	;	old_group_format	% Not handled
	;	new_group_format	% Not handled
	;	unchanged_group_format	% Not handled
	;	changed_group_format	% Not handled
	;	horizon_lines		% Not handled

	% File input options
	% Neither of these are likely to be handled in the near future.
	;	text			% Not handled
	;	binary.			% Not handled

%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%

:- implementation.
:- import_module globals, diff_out.
:- import_module list, int, bool, string, map, require.

:- pred long_option(string::in, option::out) is semidet.
long_option("ignore-blank-lines",	ignore_blank_lines).
long_option("context",			context).
long_option("ifdef",			ifdef).
long_option("show-function-line",	show_function_line).
long_option("speed-large-files",	speed_large_files).
long_option("ignore-matching-lines",	ignore_matching_lines).
long_option("file-label",		label).
long_option("label",			label).
long_option("new-file",			new_file).
long_option("entire-new-file",		new_file).
long_option("unidirectional-new-file",	unidirectional_new_file).
long_option("starting-file",		starting_file).
long_option("initial-tab",		initial_tab).
long_option("unified",			unified).
long_option("width",			width).
long_option("exclude-from",		exclude_from).
long_option("text",			text).
long_option("ascii",			text).
long_option("ignore-space-change",	ignore_space_change).
long_option("minimal",			minimal).
long_option("ed",			ed).
long_option("forward-ed",		forward_ed).
long_option("ignore-case",		ignore_case).
long_option("paginate",			paginate).
long_option("print",			paginate).
long_option("rcs",			rcs).
long_option("show-c-function",		show_c_function).
long_option("brief",			brief).
long_option("recursive",		recursive).
long_option("report-identical-files",	report_identical_files).
long_option("expand-tabs",		expand_tabs).
long_option("version",			version).
long_option("ignore-all-space",		ignore_all_space).
long_option("exclude",			exclude).
long_option("side-by-side",		side_by_side).
long_option("cvs-merge-conflict",	cvs_merge_conflict).
long_option("left-column",		left_column).
long_option("suppress-common-lines",	suppress_common_lines).
long_option("sdiff-merge-assist",	sdiff_merge_assist).
long_option("old-line-format",		old_line_format).
long_option("new-line-format",		new_line_format).
long_option("unchanged-line-format",	unchanged_line_format).
long_option("line-format",		line_format).
long_option("old-group-format",		old_group_format).
long_option("new-group-format",		new_group_format).
long_option("unchanged-group-format",	unchanged_group_format).
long_option("changed-group-format",	changed_group_format).
long_option("horizon-lines",		horizon_lines).
long_option("help",			help).
long_option("binary",			binary).

%-----------------------------------------------------------------------------%

:- pred short_option(character::in, option::out) is semidet.
short_option('B', ignore_blank_lines).
short_option('C', context).
short_option('D', ifdef).
short_option('F', show_function_line).
short_option('H', speed_large_files).
short_option('I', ignore_matching_lines).
short_option('L', label).
short_option('N', new_file).
short_option('P', unidirectional_new_file).
short_option('S', starting_file).
short_option('T', initial_tab).
short_option('U', unified).
short_option('W', width).
short_option('X', exclude_from).
short_option('a', text).
short_option('b', ignore_space_change).
short_option('c', context_style_output).
short_option('d', minimal).
short_option('e', ed).
short_option('f', forward_ed).
short_option('h', file_split_speed_hack).
short_option('i', ignore_case).
short_option('l', paginate).
short_option('n', rcs).
short_option('p', show_c_function).
short_option('q', brief).
short_option('r', recursive).
short_option('s', report_identical_files).
short_option('t', expand_tabs).
short_option('u', unified_style_output).
short_option('v', version).
short_option('w', ignore_all_space).
short_option('x', exclude).
short_option('y', side_by_side).

%-----------------------------------------------------------------------------%

:- pred option_defaults(option :: out, option_data :: out) is nondet.

	% Output styles
option_defaults(help,				bool(no)).
option_defaults(version, 			bool(no)).
option_defaults(context,			maybe_int(no)).
option_defaults(context_style_output,		bool_special).
option_defaults(unified,			maybe_int(no)).
option_defaults(unified_style_output, 		bool_special).
option_defaults(ed,				bool(no)).
option_defaults(forward_ed,			bool(no)).
option_defaults(rcs,				bool(no)).
option_defaults(brief,				bool(no)).
option_defaults(ifdef,				maybe_string(no)).
option_defaults(side_by_side,			bool(no)).
option_defaults(cvs_merge_conflict,		bool(no)).

	% Output options
option_defaults(show_c_function,		bool_special).
option_defaults(show_function_line,		string_special).
option_defaults(label,				accumulating([])).
option_defaults(width,				int(130)).
option_defaults(expand_tabs,			bool(no)).
option_defaults(initial_tab,			bool(no)).
option_defaults(paginate,			bool_special).
option_defaults(left_column,			bool(no)).
option_defaults(suppress_common_lines,		bool(no)).
option_defaults(sdiff_merge_assist,		bool(no)).

	% Matching options
option_defaults(new_file,			bool_special).
option_defaults(unidirectional_new_file,	bool_special).
option_defaults(ignore_case,			bool(no)).
option_defaults(ignore_all_space,		bool(no)).
option_defaults(ignore_space_change,		bool(no)).

	% Diff options
option_defaults(minimal,			bool(no)).
option_defaults(speed_large_files,		bool(no)).
option_defaults(file_split_speed_hack,		bool(no)).

	% Change filter options
option_defaults(ignore_matching_lines,		string_special).
option_defaults(ignore_blank_lines,		bool(no)).

	% Directory comparison options (none of these are handled)
option_defaults(starting_file,			string_special).
option_defaults(recursive,			bool_special).
option_defaults(report_identical_files,		bool_special).
option_defaults(exclude,			string_special).
option_defaults(exclude_from,			string_special).

	% Format options (none of these are handled)
option_defaults(old_line_format,		string_special).
option_defaults(new_line_format,		string_special).
option_defaults(unchanged_line_format,		string_special).
option_defaults(line_format,			string_special).
option_defaults(old_group_format,		string_special).
option_defaults(new_group_format,		string_special).
option_defaults(unchanged_group_format,		string_special).
option_defaults(changed_group_format,		string_special).
option_defaults(horizon_lines,			int_special).

	% File input options (none of these are handled)
option_defaults(text,				bool_special).
option_defaults(binary,				bool_special).

%-----------------------------------------------------------------------------%

:- pred special_handler(option :: in, special_data :: in, option_table :: in,
		maybe_option_table :: out) is semidet.

special_handler(context_style_output, bool(yes), Options0, ok(Options)) :-
	map__lookup(Options0, context, maybe_int(Context0)),
	( Context0 = no,
		Context = yes(3)
	; Context0 = yes(C),
		Context = yes(C)
	),
	map__set(Options0, context, maybe_int(Context), Options).
special_handler(unified_style_output, bool(yes), Options0, ok(Options)) :-
	map__lookup(Options0, unified, maybe_int(Unified0)),
	( Unified0 = no,
		Unified = yes(3)
	; Unified0 = yes(C),
		Unified = yes(C)
	),
	map__set(Options0, unified, maybe_int(Unified), Options).

	% Special handlers for unhandled options
special_handler(show_c_function, _, _, error(Msg)) :-
	Msg = "Option not handled: --show-c-function".
special_handler(show_function_line, _, _, error(Msg)) :-
	Msg = "Option not handled: --show-function-line".
special_handler(paginate, _, _, error(Msg)) :-
	Msg = "Option not handled: --paginate".
special_handler(sdiff_merge_assist, _, _, error(Msg)) :-
	Msg = "Option not handled: --sdiff-merge-assist".
special_handler(new_file, _, _, error(Msg)) :-
	Msg = "Option not handled: --new-file".
special_handler(unidirectional_new_file, _, _, error(Msg)) :-
	Msg = "Option not handled: --unidirectional-new-file".
special_handler(speed_large_files, _, _, error(Msg)) :-
	Msg = "Option not handled: --speed-large-files".
special_handler(ignore_matching_lines, _, _, error(Msg)) :-
	Msg = "Option not handled: --ignore-matching-lines".
special_handler(ignore_blank_lines, _, _, error(Msg)) :-
	Msg = "Option not handled: --ignore-blank-lines".
special_handler(starting_file, _, _, error(Msg)) :-
	Msg = "Option not handled: --starting-file".
special_handler(recursive, _, _, error(Msg)) :-
	Msg = "Option not handled: --recursive".
special_handler(report_identical_files, _, _, error(Msg)) :-
	Msg = "Option not handled: --report-identical-files".
special_handler(exclude, _, _, error(Msg)) :-
	Msg = "Option not handled: --exclude".
special_handler(exclude_from, _, _, error(Msg)) :-
	Msg = "Option not handled: --exclude-from".
special_handler(old_line_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --old-line-format".
special_handler(new_line_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --new-line-format".
special_handler(unchanged_line_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --unchangedline-format".
special_handler(line_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --line-format".
special_handler(old_group_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --old-group-format".
special_handler(new_group_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --new-group-format".
special_handler(unchanged_group_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --unchanged-group-format".
special_handler(changed_group_format, _, _, error(Msg)) :-
	Msg = "Option not handled: --changed-group-format".
special_handler(horizon_lines, _, _, error(Msg)) :-
	Msg = "Option not handled: --horizon-lines".
special_handler(text, _, _, error(Msg)) :-
	Msg = "Option not handled: --text".
special_handler(binary, _, _, error(Msg)) :-
	Msg = "Option not handled: --binary".

%-----------------------------------------------------------------------------%

options__get_option_ops(OptionOps) :-
	OptionOps = option_ops(
		short_option,
		long_option,
		option_defaults,
		special_handler
	).

%-----------------------------------------------------------------------------%

	% Postprocess the options
postprocess_options(ok(OptionTable0), Result) -->
	( { postprocess_output_style(OptionTable0, OutputStyle) } ->
		globals__io_init(OptionTable0),
		globals__io_set_output_style(OutputStyle),
		{ Result = no }
	;
		{ Result = yes("Can't set more than one output style.") }
	).
postprocess_options(error(Msg), yes(Msg)) --> [].

	% Determine which output style to use from the provided
	% options.
:- pred postprocess_output_style(option_table :: in,
		diff_out__output_style :: out) is semidet.

postprocess_output_style(OptionTable, Style) :-
	(
		map__search(OptionTable, help, bool(UseHelp)),
		map__search(OptionTable, version, bool(UseVersion)),
		map__search(OptionTable, context, maybe_int(UseContext)),
		map__search(OptionTable, unified, maybe_int(UseUnified)),
		map__search(OptionTable, ed, bool(UseEd)),
		map__search(OptionTable, forward_ed, bool(UseForwardEd)),
		map__search(OptionTable, rcs, bool(UseRCS)),
		map__search(OptionTable, brief, bool(UseBrief)),
		map__search(OptionTable, ifdef, maybe_string(UseIfdef)),
		map__search(OptionTable, side_by_side, bool(UseSideBySide)),
		map__search(OptionTable, cvs_merge_conflict, bool(CVS))
	->
		postprocess_output_style_2(UseHelp, UseVersion, UseContext,
			UseUnified, UseEd, UseForwardEd, UseRCS, UseBrief,
			UseIfdef, UseSideBySide, CVS,
			Style)
	;
		error("postprocess_output_style")
	).

:- pred postprocess_output_style_2(bool, bool, maybe(int), maybe(int), bool,
		bool, bool, bool, maybe(string), bool, bool,
		diff_out__output_style).
:- mode postprocess_output_style_2(in, in, in, in, in, in, in, in, in, in, in,
		out) is semidet.

postprocess_output_style_2(no, no, no, no, no, no, no, no, no, no, no,
					normal).
postprocess_output_style_2(yes, no, no, no, no, no, no, no, no, no, no,
					help_only).
postprocess_output_style_2(no, yes, no, no, no, no, no, no, no, no, no,
					version_only).
postprocess_output_style_2(no, no, yes(C), no, no, no, no, no, no, no, no,
					context(C)).
postprocess_output_style_2(no, no, no, yes(U), no, no, no, no, no, no, no,
					unified(U)).
postprocess_output_style_2(no, no, no, no, yes, no, no, no, no, no, no,
					ed).
postprocess_output_style_2(no, no, no, no, no, yes, no, no, no, no, no,
					forward_ed).
postprocess_output_style_2(no, no, no, no, no, no, yes, no, no, no, no,
					rcs).
postprocess_output_style_2(no, no, no, no, no, no, no, yes, no, no, no,
					brief).
postprocess_output_style_2(no, no, no, no, no, no, no, no, yes(Sym), no, no,
					ifdef(Sym)).
postprocess_output_style_2(no, no, no, no, no, no, no, no, no, yes, no,
					side_by_side).
postprocess_output_style_2(no, no, no, no, no, no, no, no, no, no, yes,
					cvs_merge_conflict).

%-----------------------------------------------------------------------------%

	% Help text for the options.
options_help -->
	io__write_string("Output styles:\n"),
	io__write_string("\t--help\n"),
	io__write_string("\t\tOutput this help.\n"),
	io__write_string("\t-v, --version\n"),
	io__write_string("\t\tOutput version info.\n"),
	io__write_string("\t-c, -C <num>, --context <num>\n"),
	io__write_string("\t\tOutput <num> (default 2) lines of copied context.\n"),
	io__write_string("\t-u, -U <num>, --unified <num>\n"),
	io__write_string("\t\tOutput <num> (default 2) lines of unified context.\n"),
	io__write_string("\t\t-L <label>, --label <label>  Use <label> instead of file name.\n"),
	io__write_string("\t-e, --ed\n"),
	io__write_string("\t\tOutput an ed script.\n"),
	io__write_string("\t-f, --forward-ed\n"),
	io__write_string("\t\tProduce output similar to --ed, not useful to ed(1),\n"),
	io__write_string("\t\tand in the opposite order.\n"),
	io__write_string("\t-n, --rcs\n"),
	io__write_string("\t\tOutput an RCS format diff.\n"),
	io__write_string("\t-q, --brief\n"),
	io__write_string("\t\tOutput only whether or not files differ.\n"),
	io__write_string("\t-D <name>, --ifdef <name>\n"),
	io__write_string("\t\tProduce output in #ifdef <name> format.\n"), 
	io__write_string("\t-y, --side-by-side\n"),
	io__write_string("\t\tProduce output in side-by-side format.\n"),
	io__write_string("\t\t-w <num>, --width <num>  Output at most <num> (default 130)\n"),
	io__write_string("\t\t\tcharacters per line.\n"),
	io__write_string("\t\t--left-column  Output only the left column of common lines.\n"),
	io__write_string("\t\t--suppress-common-lines  Do not output common lines.\n"),
	io__write_string("\nMatching options:\n"),
	io__write_string("\t-d, --minimal\n"),
	io__write_string("\t\tTry hard to find as small a set of changes as possible.\n"),
	io__write_string("\t-B, --ignore-blank-lines\n"),
	io__write_string("\t\tIgnore changes whose lines are all blank.\n").

%-----------------------------------------------------------------------------%
%-----------------------------------------------------------------------------%