/**
 * WinPR: Windows Portable Runtime
 * Unicode Conversion (CRT)
 *
 * Copyright 2022 Armin Novak <anovak@thincast.com>
 * Copyright 2022 Thincast Technologies GmbH
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#import <Foundation/Foundation.h>

#include <winpr/config.h>
#include <winpr/assert.h>

#include <errno.h>
#include <wctype.h>

#include <winpr/crt.h>
#include <winpr/error.h>
#include <winpr/print.h>

#ifndef MIN
#define MIN(a, b) (a) < (b) ? (a) : (b)
#endif

#include "../log.h"
#define TAG WINPR_TAG("unicode")

int int_MultiByteToWideChar(UINT CodePage, DWORD dwFlags, LPCSTR lpMultiByteStr, int cbMultiByte,
                            LPWSTR lpWideCharStr, int cchWideChar)
{
	const BOOL isNullTerminated = cbMultiByte < 0;

	/* If cbMultiByte is 0, the function fails */
	if ((cbMultiByte == 0) || (cbMultiByte < -1))
		return 0;

	/* If cbMultiByte is -1, the string is null-terminated */
	if (isNullTerminated)
	{
		size_t len = strnlen(lpMultiByteStr, INT32_MAX);
		if (len >= INT32_MAX)
			return 0;
		cbMultiByte = (int)len + 1;
	}

	NSString *utf = [[NSString alloc] initWithBytes:lpMultiByteStr
	                                         length:cbMultiByte
	                                       encoding:NSUTF8StringEncoding];
	if (!utf)
	{
		WLog_WARN(TAG, "[NSString alloc] NSUTF8StringEncoding failed [%d] '%s'", cbMultiByte,
		          lpMultiByteStr);
		return -1;
	}

	const WCHAR *utf16 =
	    (const WCHAR *)[utf cStringUsingEncoding:NSUTF16LittleEndianStringEncoding];
	const size_t utf16ByteLen = [utf lengthOfBytesUsingEncoding:NSUTF16LittleEndianStringEncoding];
	const size_t utf16CharLen = utf16ByteLen / sizeof(WCHAR);
	if (!utf16)
	{
		WLog_WARN(TAG, "[utf cStringUsingEncoding:NSUTF16LittleEndianStringEncoding] failed");
		return -1;
	}

	if (cchWideChar == 0)
		return utf16CharLen;
	else if (cchWideChar < utf16CharLen)
	{
		SetLastError(ERROR_INSUFFICIENT_BUFFER);
		return 0;
	}
	else
	{
		const size_t mlen = MIN((size_t)utf16CharLen, cchWideChar);
		const size_t len = _wcsnlen(utf16, mlen);
		memcpy(lpWideCharStr, utf16, len * sizeof(WCHAR));
		if ((len < (size_t)cchWideChar) && (len > 0) && (lpWideCharStr[len - 1] != '\0'))
			lpWideCharStr[len] = '\0';
		return utf16CharLen;
	}
}

int int_WideCharToMultiByte(UINT CodePage, DWORD dwFlags, LPCWSTR lpWideCharStr, int cchWideChar,
                            LPSTR lpMultiByteStr, int cbMultiByte, LPCSTR lpDefaultChar,
                            LPBOOL lpUsedDefaultChar)
{
	const BOOL isNullTerminated = cchWideChar < 0;

	/* If cchWideChar is 0, the function fails */
	if ((cchWideChar == 0) || (cchWideChar < -1))
		return 0;

	/* If cchWideChar is -1, the string is null-terminated */
	if (isNullTerminated)
	{
		size_t len = _wcslen(lpWideCharStr);
		if (len >= INT32_MAX)
			return 0;
		cchWideChar = (int)len + 1;
	}

	NSString *utf = [[NSString alloc] initWithCharacters:lpWideCharStr length:cchWideChar];
	if (!utf)
	{
		WLog_WARN(TAG, "[NSString alloc] initWithCharacters failed [%d] 'XXX'", cchWideChar);
		return -1;
	}

	const char *utf8 = [utf cStringUsingEncoding:NSUTF8StringEncoding];
	const size_t utf8Len = [utf lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
	if (!utf8)
	{
		WLog_WARN(TAG, "[utf cStringUsingEncoding:NSUTF8StringEncoding] failed");
		return -1;
	}

	if (cbMultiByte == 0)
		return utf8Len;
	else if (cbMultiByte < utf8Len)
	{
		SetLastError(ERROR_INSUFFICIENT_BUFFER);
		return 0;
	}
	else
	{
		const size_t mlen = MIN((size_t)cbMultiByte, utf8Len);
		const size_t len = strnlen(utf8, mlen);
		memcpy(lpMultiByteStr, utf8, len * sizeof(char));
		if ((len < (size_t)cbMultiByte) && (len > 0) && (lpMultiByteStr[len - 1] != '\0'))
			lpMultiByteStr[len] = '\0';
		return utf8Len;
	}
}