//
//	aegis - project change supervisor
//	Copyright (C) 1991-1997, 1999, 2002-2008 Peter Miller
//
//	This program is free software; you can redistribute it and/or modify
//	it under the terms of the GNU General Public License as published by
//	the Free Software Foundation; either version 3 of the License, or
//	(at your option) any later version.
//
//	This program is distributed in the hope that it will be useful,
//	but WITHOUT ANY WARRANTY; without even the implied warranty of
//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//	GNU General Public License for more details.
//
//	You should have received a copy of the GNU General Public License
//	along with this program. If not, see
//	<http://www.gnu.org/licenses/>.
//

#include <common/ac/stdlib.h>
#include <common/ac/unistd.h>

#include <common/env.h>
#include <common/libdir.h>
#include <common/progname.h>
#include <common/quit.h>
#include <common/str_list.h>
#include <common/trace.h>
#include <libaegis/arglex2.h>
#include <libaegis/gonzo.h>
#include <libaegis/help.h>
#include <libaegis/option.h>
#include <libaegis/os.h>
#include <libaegis/output/pager.h>
#include <libaegis/sub.h>


static void
help_env(void)
{
    char            *cp;
    string_list_ty  manpath;
    string_ty       *s;
    string_list_ty  lib;
    size_t          j, k;

    //
    // Honour any existing MANPATH setting by appending only.
    // Read the MANPATH to set the initial path.
    //
    cp = getenv("MANPATH");
    if (cp)
    {
	s = str_from_c(cp);
	manpath.split(s, ":");
	str_free(s);
    }
    else
    {
	s = str_from_c("/usr/man:/usr/share/man");
	manpath.push_back(s);
	str_free(s);
    }

    s = str_from_c(configured_mandir());
    manpath.push_back_unique(s);
    str_free(s);

    //
    // Read the AEGIS_PATH environment variable for the list of
    // places to look for Aegis libraries.
    //
    gonzo_report_path(&lib);

    //
    // Use the AEGIS_LIB and LANGUAGE (or LANG) environment
    // variables to know which languages to add.
    // Default to "en" if not set.
    //
    string_list_ty lang;
    cp = getenv("LANGUAGE");
    if (cp)
    {
	string_list_ty wl;
	s = str_from_c(cp);
	wl.split(s, ":");
	str_free(s);
	lang.push_back_unique(wl);
    }
    cp = getenv("LANG");
    if (cp)
    {
	string_list_ty wl;
	s = str_from_c(cp);
	wl.split(s, ":");
	str_free(s);
	lang.push_back_unique(wl);
    }
    if (lang.empty())
    {
	s = str_from_c("en");
	lang.push_back(s);
	str_free(s);
    }

    //
    // convolve the lib and lang lists and append them to the manpath
    //
    for (j = 0; j < lib.nstrings; ++j)
    {
	manpath.push_back_unique(lib.string[j]);
	for (k = 0; k < lang.nstrings; ++k)
	{
	    s = os_path_join(lib.string[j], lang.string[k]);
	    manpath.push_back_unique(s);
	    str_free(s);
	}
    }

    //
    // set the MANPATH environment variable
    //
    s = manpath.unsplit(":");
    env_set("MANPATH", s->str_text);
    str_free(s);
}


void
help(const char *progname, void (*usage)(void))
{
    int             flags;
    string_ty       *s;

    //
    // collect the rest of the command line,
    // if necessary
    //
    if (usage)
	{
            arglex();
            while (arglex_token != arglex_token_eoln)
                generic_argument(usage);
	}
    if (!progname)
        progname = progname_get();

    //
    // set the MANPATH environment variable
    // to point into the libraries
    //
    help_env();

    //
    // become the user who invoked this program
    //
    os_become_orig();

    //
    // Invoke the appropriate "man" command.  This will find the
    // right language on the search path, and it already knows how
    // to translate the *roff into text.
    //
    s = str_format("man %s", progname);
    flags = OS_EXEC_FLAG_INPUT | OS_EXEC_FLAG_ERROK;
    os_execute(s, flags, (string_ty *)0);
    str_free(s);
}


void
generic_argument(void (*usage)(void))
{
    trace(("generic_argument()\n{\n"));
    switch (arglex_token)
    {
    default:
	bad_argument(usage);
	// NOTREACHED

    case arglex_token_library:
	if (arglex() != arglex_token_string)
	    option_needs_dir(arglex_token_library, usage);
	gonzo_library_append(arglex_value.alv_string);
	arglex();
	break;

    case arglex_token_pager:
	option_pager_set(1, usage);
	arglex();
	break;

    case arglex_token_pager_not:
	option_pager_set(0, usage);
	arglex();
	break;

    case arglex_token_page_length:
	if (arglex() != arglex_token_number)
	    option_needs_number(arglex_token_page_length, usage);
	option_page_length_set(arglex_value.alv_number, usage);
	arglex();
	break;

    case arglex_token_page_width:
	if (arglex() != arglex_token_number)
	    option_needs_number(arglex_token_page_width, usage);
	option_page_width_set(arglex_value.alv_number, usage);
	arglex();
	break;

    case arglex_token_page_headers:
	option_page_headers_set(1, usage);
	arglex();
	break;

    case arglex_token_page_headers_not:
	option_page_headers_set(0, usage);
	arglex();
	break;

    case arglex_token_tab_width:
	if (arglex() != arglex_token_number)
	    option_needs_number(arglex_token_tab_width, usage);
	option_tab_width_set(arglex_value.alv_number, usage);
	arglex();
	break;

    case arglex_token_terse:
	option_terse_set(usage);
	arglex();
	break;

    case arglex_token_trace:
	if (arglex() != arglex_token_string)
	    option_needs_files(arglex_token_trace, usage);
	for (;;)
	{
#ifdef DEBUG
	    trace_enable(arglex_value.alv_string);
#endif
	    if (arglex() != arglex_token_string)
		break;
	}
#ifndef DEBUG
	error_intl(0, i18n("-TRace needs DEBUG"));
#endif
	break;

    case arglex_token_unformatted:
	option_unformatted_set(usage);
	arglex();
	break;

    case arglex_token_verbose:
	option_verbose_set(usage);
	arglex();
	break;
    }
    trace(("}\n"));
}


void
bad_argument(void (*usage)(void))
{
    sub_context_ty  *scp;

    trace(("bad_argument()\n{\n"));
    switch (arglex_token)
    {
    case arglex_token_string:
	scp = sub_context_new();
	sub_var_set_charstar(scp, "File_Name", arglex_value.alv_string);
	error_intl(scp, i18n("misplaced file name (\"$filename\")"));
	sub_context_delete(scp);
	break;

    case arglex_token_number:
	scp = sub_context_new();
	sub_var_set_charstar(scp, "Number", arglex_value.alv_string);
	error_intl(scp, i18n("misplaced number ($number)"));
	sub_context_delete(scp);
	break;

    case arglex_token_option:
	scp = sub_context_new();
	sub_var_set_charstar(scp, "Name", arglex_value.alv_string);
	error_intl(scp, i18n("unknown \"$name\" option"));
	sub_context_delete(scp);
	break;

    case arglex_token_eoln:
	error_intl(0, i18n("command line too short"));
	break;

    default:
	scp = sub_context_new();
	sub_var_set_charstar(scp, "Name", arglex_value.alv_string);
	error_intl(scp, i18n("misplaced \"$name\" option"));
	sub_context_delete(scp);
	break;
    }
    usage();
    trace(("}\n"));
    quit(1);
    // NOTREACHED
}


void
mutually_exclusive_options(int a1, int a2, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name1", arglex_token_name(a1));
    sub_var_set_charstar(scp, "Name2", arglex_token_name(a2));
    error_intl(scp, i18n("not $name1 and $name2 together"));
    sub_context_delete(scp);

    usage();
}


void
mutually_exclusive_options3(int a1, int a2, int a3, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name1", arglex_token_name(a1));
    sub_var_set_charstar(scp, "Name2", arglex_token_name(a2));
    sub_var_set_charstar(scp, "Name3", arglex_token_name(a3));
    error_intl(scp, i18n("not $name1 and $name2 and $name3 together"));
    sub_context_delete(scp);

    usage();
}


void
duplicate_option_by_name(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("duplicate $name option"));
    sub_context_delete(scp);

    usage();
}


void
duplicate_option(void (*usage)(void))
{
    duplicate_option_by_name(arglex_token, usage);
}


void
option_needs_number(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$name needs number"));
    sub_context_delete(scp);

    usage();
}


void
option_needs_string(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$name needs string"));
    sub_context_delete(scp);

    usage();
}


void
option_needs_name(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$name needs name"));
    sub_context_delete(scp);

    usage();
}


void
option_needs_file(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$name needs file"));
    sub_context_delete(scp);

    usage();
}


void
option_needs_dir(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$name needs dir"));
    sub_context_delete(scp);

    usage();
}


void
option_needs_files(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$name needs files"));
    sub_context_delete(scp);

    usage();
}


void
option_needs_url(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$Name needs url"));
    sub_context_delete(scp);

    usage ();
}


void
option_needs_uuid(int name, void (*usage)(void))
{
    sub_context_ty *scp = sub_context_new();
    sub_var_set_charstar(scp, "Name", arglex_token_name(name));
    error_intl(scp, i18n("$Name needs an uuid"));
    sub_context_delete(scp);

    usage ();
}