/*
 *	aegis - project change supervisor
 *	Copyright (C) 1997, 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 walk parallel directory trees
 */

#include <ac/errno.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <cmdline.h>
#include <descend.h>
#include <glue.h>
#include <str_list.h>
#include <sub.h>
#include <trace.h>
#include <tree.h>


static string_ty *path_cat _((string_ty *, string_ty *));

static string_ty *
path_cat(s1, s2)
	string_ty	*s1;
	string_ty	*s2;
{
	static string_ty *dot;

	if (!dot)
		dot = str_from_c(".");
	if (str_equal(s1, dot))
		return str_copy(s2);
	if (str_equal(s2, dot))
		return str_copy(s1);
	return str_format("%S/%S", s1, s2);
}


string_ty *
stat_stack(path, st)
	string_ty	*path;
	struct stat	*st;
{
	size_t		j;
	string_ty	*dir;
	string_ty	*resolved_path;
	sub_context_ty	*scp;

	for (j = 0; ; ++j)
	{
		dir = stack_nth(j);
		if (!dir)
			break;
		resolved_path = path_cat(dir, path);

#ifdef S_IFLNK
		if (!glue_lstat(resolved_path->str_text, st))
			return resolved_path;

		if (errno != ENOENT)
		{
			scp = sub_context_new();
			sub_errno_set(scp);
			sub_var_set_string(scp, "File_Name", resolved_path);
			fatal_intl(scp, i18n("lstat $filename: $errno"));
			/* NOTREACHED */
		}
#else
		if (!glue_stat(resolved_path->str_text, st))
			return resolved_path;

		if (errno != ENOENT)
		{
			scp = sub_context_new();
			sub_errno_set(scp);
			sub_var_set_string(scp, "File_Name", resolved_path);
			fatal_intl(scp, i18n("stat $filename: $errno"));
			/* NOTREACHED */
		}
#endif
		str_free(resolved_path);
	}
	scp = sub_context_new();
	sub_errno_setx(scp, ENOENT);
	sub_var_set_string(scp, "File_Name", path);
	fatal_intl(scp, i18n("stat $filename: $errno"));
	/* NOTREACHED */
	return 0;
}


static void readdir_stack _((string_ty *, string_list_ty *));

static void
readdir_stack(path, result)
	string_ty	*path;
	string_list_ty	*result;
{
	size_t		j;
	string_ty	*s;
	string_ty	*dir;
	char		*data;
	long		data_len;
	char		*cp;

	string_list_constructor(result);
	for (j = 0; ; ++j)
	{
		dir = stack_nth(j);
		if (!dir)
			break;
		s = path_cat(dir, path);
		if (glue_read_whole_dir(s->str_text, &data, &data_len))
		{
			sub_context_ty	*scp;

			if (errno == ENOENT)
			{
				str_free(s);
				continue;
			}

			scp = sub_context_new();
			sub_errno_set(scp);
			sub_var_set_string(scp, "File_Name", path);
			fatal_intl(scp, i18n("read $filename: $errno"));
			/* NOTREACHED */
		}
		str_free(s);

		cp = data;
		while (cp < data + data_len)
		{
			s = str_from_c(cp);
			cp += s->str_length + 1;
			string_list_append_unique(result, s);
			str_free(s);
		}
	}
}


void
descend(path, resolve, callback, arg)
	string_ty	*path;
	int		resolve;
	descend_callback_ty callback;
	void		*arg;
{
	string_list_ty	wl;
	struct stat	st;
	size_t		j;
	string_ty	*s;
	string_ty	*resolved_path;

	trace(("descend(path = %08lX, callback = %08lX, \
arg = %08lX)\n{\n"/*}*/, path, callback, arg));
	trace_string(path->str_text);
	resolved_path = stat_stack(path, &st);
	if ((st.st_mode & S_IFMT) == S_IFDIR)
	{
		callback
		(
			arg,
			descend_message_dir_before,
			(resolve ? resolved_path : path),
			&st
		);
		readdir_stack(path, &wl);
		for (j = 0; j < wl.nstrings; ++j)
		{
			s = path_cat(path, wl.string[j]);
			descend(s, resolve, callback, arg);
			str_free(s);
		}
		string_list_destructor(&wl);
		callback
		(
			arg,
			descend_message_dir_after,
			(resolve ? resolved_path : path),
			&st
		);
	}
	else
	{
		callback
		(
			arg,
			descend_message_file,
			(resolve ? resolved_path : path),
			&st
		);
	}
	str_free(resolved_path);
	trace((/*{*/"}\n"));
}