/*
 *	aegis - project change supervisor
 *	Copyright (C) 1999, 2002, 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 run_diffs
 */

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


void
change_run_diff_command(change_ty *cp, user_ty *up, string_ty *original,
    string_ty *input, string_ty *output)
{
    sub_context_ty  *scp;
    pconf_ty        *pconf_data;
    string_ty       *dd;
    string_ty       *the_command;

    /*
     * Run the diff_command.
     * All of the substitutions described in aesub(5) are available.
     * In addition
     *
     * ${Original}
     *	absolute path of original file copied from the baseline
     *	usually, but not always
     *
     * ${Input}
     *	absolute path of current file in the development directory
     *	usually, but not always
     *
     * ${Output}
     *	absolute path of file in which to write the difference listing
     *	usually in the development diretcory
     */
    trace
    ((
	"change_run_diff_command(cp = %8.8lX, up = %8.8lX, original = \"%s\", "
	    "input = \"%s\", output = \"%s\")\n{\n",
	(long)cp,
	(long)up,
	original->str_text,
	input->str_text,
	output->str_text
    ));
    assert(cp->reference_count >= 1);
    pconf_data = change_pconf_get(cp, 1);
    switch (change_cstate_get(cp)->state)
    {
    case cstate_state_being_developed:
    case cstate_state_awaiting_review:
    case cstate_state_being_reviewed:
    case cstate_state_awaiting_integration:
	dd = change_development_directory_get(cp, 0);
	break;

    case cstate_state_being_integrated:
	dd = change_integration_directory_get(cp, 0);
	break;

    default:
	dd = os_tmpdir();
	break;
    }
    assert(dd);
    scp = sub_context_new();
    sub_var_set_string(scp, "ORiginal", original);
    sub_var_set_string(scp, "Input", input);
    sub_var_set_string(scp, "Output", output);
    sub_var_set_charstar(scp, "1", "${original}");
    sub_var_set_charstar(scp, "2", "${input}");
    sub_var_set_charstar(scp, "3", "${output}");
    the_command = pconf_data->diff_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", "diff_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);
    trace_string(the_command->str_text);
    change_env_set(cp, 0);
    user_become(up);
    if (os_exists(output))
	os_unlink(output);
    os_execute(the_command, OS_EXEC_FLAG_NO_INPUT, dd);
    user_become_undo();
    str_free(the_command);
    trace(("}\n"));
}
