/*
 *	aegis - project change supervisor
 *	Copyright (C) 1999, 2000 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 templates
 */

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


static pconf_file_template find _((change_ty *, string_ty *));

static pconf_file_template
find(cp, file_name)
	change_ty	*cp;
	string_ty	*file_name;
{
	pconf_file_template result;
	size_t		j, k;
	pconf		pconf_data;

	trace(("change_file_template_string(file_name = \"%s\")\n{\n",
		file_name->str_text));
	assert(cp->reference_count >= 1);
	result = 0;
	pconf_data = change_pconf_get(cp, 0);
	if (!pconf_data->file_template)
		goto done;
	for (j = 0; j < pconf_data->file_template->length; ++j)
	{
		pconf_file_template ftp;

		ftp = pconf_data->file_template->list[j];
		if (!ftp->pattern)
			continue;
		for (k = 0; k < ftp->pattern->length; ++k)
		{
			int		m;
			string_ty	*s;

			s = ftp->pattern->list[k];
			m = gmatch(s->str_text, file_name->str_text);
			if (m < 0)
			{
				sub_context_ty	*scp;

				scp = sub_context_new();
				sub_var_set_string(scp, "File_Name", s);
				change_fatal(cp, scp, i18n("bad pattern $filename"));
				/* NOTREACHED */
				sub_context_delete(scp);
			}
			if (m)
			{
				result = ftp;
				goto done;
			}
		}
	}

	/*
	 * here for all exits
	 */
	done:
	trace(("return %08lX;\n", (long)result));
	trace(("}\n"));
	return result;
}


void
change_file_template(cp, filename, up, use_template)
	change_ty	*cp;
	string_ty	*filename;
	user_ty		*up;
	int		use_template;
{
	int		ok;
	string_ty	*dd;
	string_ty	*path;
	pconf_file_template tp;
	sub_context_ty	*scp;

	/*
	 * figure the absolute path of the file
	 */
	trace(("change_file_template(name = \"%s\")\n{\n",
		filename->str_text));
	assert(cp->reference_count >= 1);
	dd = change_development_directory_get(cp, 0);
	path = str_format("%S/%S", dd, filename);

	/*
	 * If the file exists, do not over-write what the user has
	 * already written.
	 */
	user_become(up);
	os_mkdir_between(dd, filename, 02755);
	if (os_symlink_query(path))
		os_unlink(path);
	ok = os_exists(path);
	user_become_undo();
	if (use_template < 0)
		use_template = !ok;
	else if (use_template)
		ok = 0;
	if (!ok)
	{
		/*
		 * Find the template to be used to construct the new file.
		 */
		tp = use_template ? find(cp, filename) : 0;
		if (tp && tp->body_command)
		{
			int		flags;
			string_ty	*the_command;

			/*
			 * Build the command to be executed.
			 */
			scp = sub_context_new();
			sub_var_set_string(scp, "File_Name", filename);
			the_command = substitute(scp, cp, tp->body_command);
			sub_context_delete(scp);

			/*
			 * Execute the command. 
			 */
			flags = OS_EXEC_FLAG_NO_INPUT;
			change_env_set(cp, 1);
			user_become(up);
			os_execute(the_command, flags, dd);
			ok = os_exists(path);
			user_become_undo();
			str_free(the_command);

			/*
			 * It is an error if the command didn't create
			 * the file.
			 */
			if (!ok)
			{
				scp = sub_context_new();
				sub_var_set_string(scp, "File_Name", filename);
				change_fatal
				(
					cp,
					scp,
					i18n("new file $filename not created")
				);
				/* NOTREACHED */
				sub_context_delete(scp);
			}
		}
		else
		{
			string_ty	*body;
			int		mode;

			/*
			 * There is no command, it must be a string template.
			 */
			if (!tp)
				body = str_from_c("");
			else
			{
				scp = sub_context_new();
				sub_var_set_string(scp, "File_Name", filename);
				sub_var_optional(scp, "File_Name");
				body = substitute(scp, cp, tp->body);
				sub_context_delete(scp);
			}

			/*
			 * Now we have the string, write it to the file.
			 */
			mode = 0644 & ~change_umask(cp);
			user_become(up);
			file_from_string(path, body, mode);
			user_become_undo();
			str_free(body);
		}
	}
	str_free(path);
	trace(("}\n"));
}