/**
 * collate.c - NTFS collation handling.  Originated from the Linux-NTFS project.
 *
 * Copyright (c) 2004 Anton Altaparmakov
 * Copyright (c) 2005 Yura Pakhuchiy
 *
 * This program/include file 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/include file 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.
 */

#include "antfs.h"
#include "attrib.h"
#include "index.h"
#include "collate.h"
#include "debug.h"
#include "unistr.h"

/**
 * ntfs_collate_binary - Which of two binary objects should be listed first
 *
 * @param vol        unused
 * @param data1      first object to compare
 * @param data1_len  object 1 length
 * @param data2      second object to compare
 * @param data2_len  object 2 length
 *
 * Compare two binary objects
 *
 * @retval 0 Objects are equal
 * @retval -1 Object 2 > object 1
 * @retval 1 Object 2 < object 1
 */
static int ntfs_collate_binary(struct ntfs_volume *vol __attribute__ ((unused)),
			       const void *data1, const int data1_len,
			       const void *data2, const int data2_len)
{
	int rc;

	antfs_log_enter();
	rc = memcmp(data1, data2, min(data1_len, data2_len));
	if (!rc && (data1_len != data2_len)) {
		if (data1_len < data2_len)
			rc = -1;
		else
			rc = 1;
	}
	antfs_log_leave("Done, returning %i.", rc);
	return rc;
}

/**
 * ntfs_collate_ntofs_ulong - Which of two long ints should be listed first
 *
 * @param vol        unused
 * @param data1      first object to compare
 * @param data1_len  object 1 length
 * @param data2      second object to compare
 * @param data2_len  object 2 length
 *
 * Compare two binary objects
 *
 * @retval 0 Objects are equal
 * @retval -1 Object 2 > object 1
 * @retval 1 Object 2 < object 1
 */
static int ntfs_collate_ntofs_ulong(struct ntfs_volume *vol
				    __attribute__ ((unused)), const void *data1,
				    const int data1_len, const void *data2,
				    const int data2_len)
{
	int rc;
	u32 d1, d2;

	antfs_log_enter();
	if (data1_len != data2_len || data1_len != 4) {
		antfs_log_error("data1_len or/and data2_len not equal to 4.");
		return NTFS_COLLATION_ERROR;
	}
	d1 = le32_to_cpup(data1);
	d2 = le32_to_cpup(data2);
	if (d1 < d2)
		rc = -1;
	else {
		if (d1 == d2)
			rc = 0;
		else
			rc = 1;
	}
	antfs_log_leave("Done, returning %i.", rc);
	return rc;
}

/**
 * ntfs_collate_ntofs_ulongs - Which of two le32 arrays should be listed first
 *
 * @param vol        unused
 * @param data1      first object to compare
 * @param data1_len  object 1 length
 * @param data2      second object to compare
 * @param data2_len  object 2 length
 *
 * Compare two binary objects
 *
 * @retval 0 Objects are equal
 * @retval -1 Object 2 > object 1
 * @retval 1 Object 2 < object 1
 */
static int ntfs_collate_ntofs_ulongs(struct ntfs_volume *vol
				     __attribute__ ((unused)),
				     const void *data1, const int data1_len,
				     const void *data2, const int data2_len)
{
	int rc;
	int len;
	const le32 *p1, *p2;
	u32 d1, d2;

	antfs_log_enter();
	if ((data1_len != data2_len) || (data1_len <= 0) || (data1_len & 3)) {
		antfs_log_error("data1_len or data2_len not valid");
		return NTFS_COLLATION_ERROR;
	}
	p1 = (const le32 *)data1;
	p2 = (const le32 *)data2;
	len = data1_len;
	do {
		d1 = le32_to_cpup(p1);
		p1++;
		d2 = le32_to_cpup(p2);
		p2++;
	} while ((d1 == d2) && ((len -= 4) > 0));
	if (d1 < d2)
		rc = -1;
	else {
		if (d1 == d2)
			rc = 0;
		else
			rc = 1;
	}
	antfs_log_leave("Done, returning %i.", rc);
	return rc;
}

/**
 * ntfs_collate_ntofs_security_hash - Which of two security descriptors
 *                    should be listed first
 * @param vol        unused
 * @param data1      first object to compare
 * @param data1_len  object 1 length
 * @param data2      second object to compare
 * @param data2_len  object 2 length
 *
 * JPA compare two security hash keys made of two unsigned le32
 *
 * @retval 0 Objects are equal
 * @retval -1 Object 2 > object 1
 * @retval 1 Object 2 < object 1
 */
static int ntfs_collate_ntofs_security_hash(struct ntfs_volume *vol
					    __attribute__ ((unused)),
					    const void *data1,
					    const int data1_len,
					    const void *data2,
					    const int data2_len)
{
	int rc;
	u32 d1, d2;
	const le32 *p1, *p2;

	antfs_log_enter();
	if (data1_len != data2_len || data1_len != 8) {
		antfs_log_error("data1_len or/and data2_len not equal to 8.");
		return NTFS_COLLATION_ERROR;
	}
	p1 = (const le32 *)data1;
	p2 = (const le32 *)data2;
	d1 = le32_to_cpup(p1);
	d2 = le32_to_cpup(p2);
	if (d1 < d2)
		rc = -1;
	else {
		if (d1 > d2)
			rc = 1;
		else {
			p1++;
			p2++;
			d1 = le32_to_cpup(p1);
			d2 = le32_to_cpup(p2);
			if (d1 < d2)
				rc = -1;
			else {
				if (d1 > d2)
					rc = 1;
				else
					rc = 0;
			}
		}
	}
	antfs_log_leave("Done, returning %i.", rc);
	return rc;
}

/**
 * ntfs_collate_ntofs_ulongs - Which of two le32 arrays should be listed first
 *
 * @param vol        unused
 * @param data1      first object to compare
 * @param data1_len  object 1 length
 * @param data2      second object to compare
 * @param data2_len  object 2 length
 *
 * Compare two binary objects
 *
 * @retval 0 Objects are equal
 * @retval -1 Object 2 > object 1
 * @retval 1 Object 2 < object 1
 */
static int ntfs_collate_file_name(struct ntfs_volume *vol,
				  const void *data1, const int data1_len
				  __attribute__ ((unused)), const void *data2,
				  const int data2_len __attribute__ ((unused)))
{
	const struct FILE_NAME_ATTR *file_name_attr1;
	const struct FILE_NAME_ATTR *file_name_attr2;
	int rc;

	antfs_log_enter();
	file_name_attr1 = (const struct FILE_NAME_ATTR *)data1;
	file_name_attr2 = (const struct FILE_NAME_ATTR *)data2;
	rc = ntfs_names_full_collate((ntfschar *) &file_name_attr1->file_name,
				     file_name_attr1->file_name_length,
				     (ntfschar *) &file_name_attr2->file_name,
				     file_name_attr2->file_name_length,
				     CASE_SENSITIVE, vol->upcase,
				     vol->upcase_len);
	antfs_log_leave("Done, returning %i.", rc);
	return rc;
}

/*
 *		Get a pointer to appropriate collation function.
 *
 * @retval error ptr if needed function is not implemented
 */
COLLATE ntfs_get_collate_function(enum COLLATION_RULES cr)
{
	COLLATE collate;

	switch (cr) {
	case COLLATION_BINARY:
		collate = ntfs_collate_binary;
		break;
	case COLLATION_FILE_NAME:
		collate = ntfs_collate_file_name;
		break;
	case COLLATION_NTOFS_SECURITY_HASH:
		collate = ntfs_collate_ntofs_security_hash;
		break;
	case COLLATION_NTOFS_ULONG:
		collate = ntfs_collate_ntofs_ulong;
		break;
	case COLLATION_NTOFS_ULONGS:
		collate = ntfs_collate_ntofs_ulongs;
		break;
	default:
		collate = (COLLATE) ERR_PTR(-EOPNOTSUPP);
		break;
	}
	return collate;
}