/*
 *	aegis - project change supervisor
 *	Copyright (C) 1999 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(cp, up, original, input, output)
	change_ty	*cp;
	user_ty		*up;
	string_ty	*original;
	string_ty	*input;
	string_ty	*output;
{
	sub_context_ty	*scp;
	pconf		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
	 *
	 * ${Output}
	 *	absolute path of file in which to write the difference listing
	 *	usually in the development diretcory
	 */
	trace
	((
		"change_run_diff_command(cp = %8.8lX, up = %8.8lX, \
original = \"%s\", input = \"%s\", output = \"%s\")\n{\n"/*}*/,
		(long)cp,
		(long)up,
		original->str_text,
		input->str_text,
		output->str_text
	));
	assert(cp->reference_count >= 1);
	pconf_data = change_pconf_get(cp, 1);
	if (change_cstate_get(cp)->state == cstate_state_being_developed)
		dd = change_development_directory_get(cp, 0);
	else
		dd = change_integration_directory_get(cp, 0);
	assert(dd);
	scp = sub_context_new();
	sub_var_set_string(scp, "ORiginal", original);
	sub_var_set_string(scp, "Input", input);
	sub_var_set_string(scp, "Output", output);
	sub_var_set_charstar(scp, "1", "${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"));
}