/*
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | Authors: Vadim Savchuk <vsavchuk@productengine.com>                  |
   |          Dmitry Lakhtyuk <dlakhtyuk@productengine.com>               |
   +----------------------------------------------------------------------+
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <php.h>

#include "intl_common.h"
#include "intl_convert.h"

/* {{{ intl_convert_utf8_to_utf16
 * Convert given string from UTF-8 to UTF-16 to *target buffer.
 *
 * It *target is NULL then we allocate a large enough buffer,
 * store the converted string into it, and make target point to it.
 *
 * Otherwise, if *target is non-NULL, we assume that it points to a
 * dynamically allocated buffer of *target_len bytes length.
 * In this case the buffer will be used to store the converted string to,
 * and may be resized (made larger) if needed.
 *
 * Note that ICU uses int32_t as string length and PHP uses size_t. While
 * it is not likely in practical situations to have strings longer than
 * INT32_MAX, these are different types and need to be handled carefully.
 *
 * @param target      Where to place the result.
 * @param target_len  Result length.
 * @param source      String to convert.
 * @param source_len  Length of the source string.
 * @param status      Conversion status.
 *
 * @return void       This function does not return anything.
 */
void intl_convert_utf8_to_utf16(
	UChar**     target, int32_t* target_len,
	const char* src,    size_t  src_len,
	UErrorCode* status )
{
	UChar*      dst_buf = NULL;
	int32_t     dst_len = 0;

	/* If *target is NULL determine required destination buffer size (pre-flighting).
	 * Otherwise, attempt to convert source string; if *target buffer is not large enough
	 * it will be resized appropriately.
	 */
	*status = U_ZERO_ERROR;

	if (UNEXPECTED(src_len > INT32_MAX)) {
		/* we cannot fit this string */
		*status = U_BUFFER_OVERFLOW_ERROR;
		return;
	}

	u_strFromUTF8( *target, *target_len, &dst_len, src, (int32_t)src_len, status );

	if( *status == U_ZERO_ERROR )
	{
		/* String is converted successfully */
		(*target)[dst_len] = 0;
		*target_len = dst_len;
		return;
	}

	/* Bail out if an unexpected error occurred.
	 * (U_BUFFER_OVERFLOW_ERROR means that *target buffer is not large enough).
	 * (U_STRING_NOT_TERMINATED_WARNING usually means that the input string is empty).
	 */
	if( *status != U_BUFFER_OVERFLOW_ERROR && *status != U_STRING_NOT_TERMINATED_WARNING )
		return;

	/* Allocate memory for the destination buffer (it will be zero-terminated). */
	dst_buf = eumalloc( dst_len + 1 );

	/* Convert source string from UTF-8 to UTF-16. */
	*status = U_ZERO_ERROR;
	u_strFromUTF8( dst_buf, dst_len+1, NULL, src, src_len, status );
	if( U_FAILURE( *status ) )
	{
		efree( dst_buf );
		return;
	}

	dst_buf[dst_len] = 0;

	if( *target )
		efree( *target );

	*target     = dst_buf;
	*target_len = dst_len;
}
/* }}} */

/* Convert given string from UTF-8 to UTF-16 to a zend_string*
 *
 * @param src         String to convert.
 * @param src_len     Length of the source string.
 * @param status      Conversion status.
 *
 * @return zend_string* on success and NULL on failure
 */
zend_string *intl_convert_utf8_to_utf16_zstr(
	const char* src,    size_t  src_len,
	UErrorCode* status )
{
	int32_t     dst_len = 0;

	*status = U_ZERO_ERROR;

	if (UNEXPECTED(src_len > INT32_MAX)) {
		/* we cannot fit this string */
		*status = U_BUFFER_OVERFLOW_ERROR;
		return NULL;
	}

	/* Pre-flight */
	u_strFromUTF8( NULL, 0, &dst_len, src, (int32_t)src_len, status );
	if( *status != U_BUFFER_OVERFLOW_ERROR && *status != U_STRING_NOT_TERMINATED_WARNING )
		return NULL;

	/* Note: l=sizeof(UChar)-1 because we need sizeof(UChar) bytes for the NUL terminator instead of 1. */
	zend_string *dst = zend_string_safe_alloc(sizeof(UChar), dst_len, sizeof(UChar) - 1, false);
	UChar *dst_buf = (UChar *) ZSTR_VAL(dst);
	ZEND_ASSERT((ZSTR_LEN(dst) - 1) / 2 == dst_len);
	/* However, the length must not include the NUL terminator that we included previously. */
	ZSTR_LEN(dst)--;

	/* Convert source string from UTF-8 to UTF-16. */
	*status = U_ZERO_ERROR;
	u_strFromUTF8( dst_buf, dst_len + 1, NULL, src, src_len, status );
	if( U_FAILURE( *status ) )
	{
		zend_string_efree( dst );
		return NULL;
	}

	dst_buf[dst_len] = 0;

	return dst;
}

/* {{{ intl_convert_utf16_to_utf8
 * Convert given string from UTF-16 to UTF-8.
 *
 * @param source      String to convert.
 * @param source_len  Length of the source string.
 * @param status      Conversion status.
 *
 * @return zend_string
 */
zend_string* intl_convert_utf16_to_utf8(
	const UChar* src,    int32_t  src_len,
	UErrorCode*  status )
{
	zend_string* dst;
	int32_t      dst_len;

	/* Determine required destination buffer size (pre-flighting). */
	*status = U_ZERO_ERROR;
	u_strToUTF8( NULL, 0, &dst_len, src, src_len, status );

	/* Bail out if an unexpected error occurred.
	 * (U_BUFFER_OVERFLOW_ERROR means that *target buffer is not large enough).
	 * (U_STRING_NOT_TERMINATED_WARNING usually means that the input string is empty).
	 */
	if( *status != U_BUFFER_OVERFLOW_ERROR && *status != U_STRING_NOT_TERMINATED_WARNING )
		return NULL;

	/* Allocate memory for the destination buffer (it will be zero-terminated). */
	dst = zend_string_alloc(dst_len, 0);

	/* Convert source string from UTF-8 to UTF-16. */
	*status = U_ZERO_ERROR;
	u_strToUTF8( ZSTR_VAL(dst), dst_len, NULL, src, src_len, status );
	if( U_FAILURE( *status ) )
	{
		zend_string_efree(dst);
		return NULL;
	}

	/* U_STRING_NOT_TERMINATED_WARNING is OK for us => reset 'status'. */
	*status = U_ZERO_ERROR;

	ZSTR_VAL(dst)[dst_len] = 0;
	return dst;
}
/* }}} */
