/*
 *	aegis - project change supervisor
 *	Copyright (C) 1999, 2001-2003 Peter Miller;
 *	All rights reserved.
 *
 *	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 2 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, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate query_commans
 */

#include <change.h>
#include <change/env_set.h>
#include <error.h> /* for assert */
#include <os.h>
#include <project.h>
#include <sub.h>
#include <trace.h>


string_ty *
change_run_history_query_command(change_ty *cp, string_ty *filename)
{
    sub_context_ty  *scp;
    string_ty	    *hp;
    pconf_ty        *pconf_data;
    string_ty	    *the_command;
    string_ty	    *result;

    /*
     * Ask the history file what its edit number is.  We use this
     * method because the string returned is essentially random,
     * between different history programs.  Only ever executed in
     * the ``being integrated'' state.  Current directory will be
     * set to the base of the history tree.  All of the
     * substitutions described in aesub(5) are available.  In
     * addition
     *
     * ${History}
     *	absolute path of history file
     */
    trace(("change_run_history_query_command(cp = %8.8lX, "
        "filename = \"%s\")\n{\n", (long)cp, filename->str_text));
    assert(cp->reference_count >= 1);
    pconf_data = change_pconf_get(cp, 1);
    hp = project_history_path_get(cp->pp);
    scp = sub_context_new();
    sub_var_set_format(scp, "History", "%S/%S", hp, filename);
    sub_var_set_charstar(scp, "1", "${history}");
    the_command = pconf_data->history_query_command;
    if (!the_command)
    {
	sub_context_ty	*scp2;

	scp2 = sub_context_new();
	sub_var_set_charstar(scp2, "File_Name", THE_CONFIG_FILE);
	sub_var_set_charstar(scp2, "FieLD_Name", "history_query_command");
	change_fatal
	(
	    cp,
	    scp2,
	    i18n("$filename: contains no \"$field_name\" field")
	);
	/* NOTREACHED */
	sub_context_delete(scp2);
    }
    the_command = substitute(scp, cp, the_command);
    sub_context_delete(scp);

    change_env_set(cp, 0);
    project_become(cp->pp);
    result = os_execute_slurp(the_command, OS_EXEC_FLAG_NO_INPUT, hp);
    project_become_undo();
    str_free(the_command);
    if (!result->str_length)
	fatal_intl(0, i18n("history_query_command return empty"));
    trace(("return \"%s\";\n", result->str_text));
    trace(("}\n"));
    return result;
}
