/*
 *	PROGRAM:	JRD International support
 *	MODULE:		unicode_util.h
 *	DESCRIPTION:	Unicode functions
 *
 *  The contents of this file are subject to the Initial
 *  Developer's Public License Version 1.0 (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.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
 *
 *  Software distributed under the License is distributed AS IS,
 *  WITHOUT WARRANTY OF ANY KIND, either express or implied.
 *  See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Original Code was created by Adriano dos Santos Fernandes
 *  for the Firebird Open Source RDBMS project.
 *
 *  Copyright (c) 2004 Adriano dos Santos Fernandes <adrianosf@uol.com.br>
 *  and all contributors signed below.
 *
 *  All Rights Reserved.
 *  Contributor(s): ______________________________________.
 */

#include "firebird.h"
#include "../jrd/unicode_util.h"
#include "../jrd/gdsassert.h"
#include "unicode/ustring.h"
#include "unicode/ucnv.h"
#include "unicode/ucol.h"


namespace Jrd {


// BOCU-1
USHORT UnicodeUtil::utf16KeyLength(USHORT len)
{
	return (len / 2) * 4;
}


// BOCU-1
USHORT UnicodeUtil::utf16ToKey(USHORT srcLen, const USHORT* src, USHORT dstLen, UCHAR* dst,
							   USHORT key_type)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL && dst != NULL);

	if (dstLen < srcLen / sizeof(*src) * 4)
		return INTL_BAD_KEY_LENGTH;

	UErrorCode status = U_ZERO_ERROR;
	UConverter* conv = ucnv_open("BOCU-1", &status);
	fb_assert(U_SUCCESS(status));

	int32_t len = ucnv_fromUChars(conv, reinterpret_cast<char*>(dst), dstLen, 
								  reinterpret_cast<const UChar*>(src), srcLen / sizeof(*src), &status);
	fb_assert(U_SUCCESS(status));

	ucnv_close(conv);

	return len;
}


ULONG UnicodeUtil::utf16LowerCase(ULONG srcLen, const USHORT* src, ULONG dstLen, USHORT* dst)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL && dst != NULL);

	UErrorCode errorCode = U_ZERO_ERROR;

	int32_t length = u_strToLower(reinterpret_cast<UChar*>(dst), dstLen / sizeof(USHORT),
								  reinterpret_cast<const UChar*>(src), srcLen / sizeof(USHORT),
								  NULL, &errorCode);

	if (errorCode > 0 || length > dstLen)
		return INTL_BAD_STR_LENGTH;
	else
		return static_cast<ULONG>(length * sizeof(USHORT));
}


ULONG UnicodeUtil::utf16UpperCase(ULONG srcLen, const USHORT* src, ULONG dstLen, USHORT* dst)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL && dst != NULL);

	UErrorCode errorCode = U_ZERO_ERROR;

	int32_t length = u_strToUpper(reinterpret_cast<UChar*>(dst), dstLen / sizeof(USHORT),
								  reinterpret_cast<const UChar*>(src), srcLen / sizeof(USHORT),
								  NULL, &errorCode);

	if (errorCode > 0 || length > dstLen)
		return INTL_BAD_STR_LENGTH;
	else
		return static_cast<ULONG>(length * sizeof(USHORT));
}


ULONG UnicodeUtil::utf16ToUtf8(ULONG srcLen, const USHORT* src, ULONG dstLen, UCHAR* dst,
							   USHORT* err_code, ULONG* err_position)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL || dst == NULL);
	fb_assert(err_code != NULL);
	fb_assert(err_position != NULL);

	*err_code = 0;

	if (dst == NULL)
		return srcLen / sizeof(*src) * 4;

	srcLen /= sizeof(*src);

	const USHORT* const srcEnd = src + srcLen;
	const UCHAR* const dstStart = dst;
	const UCHAR* const dstEnd = dst + dstLen;

	for (ULONG i = 0; i < srcLen; )
	{
		if (dstEnd - dst == 0)
		{
			*err_code = CS_TRUNCATION_ERROR;
			*err_position = i * sizeof(*src);
			break;
		}

		UChar32 c = src[i++];

		if (c <= 0x7F)
			*dst++ = c;
		else
		{
			*err_position = (i - 1) * sizeof(*src);

			if (UTF_IS_SURROGATE(c))
			{
				UChar32 c2;

				if (UTF_IS_SURROGATE_FIRST(c) && src < srcEnd && UTF_IS_TRAIL(c2 = *src))
				{
					++src;
					c = UTF16_GET_PAIR_VALUE(c, c2);
				}
				else
				{
					*err_code = CS_BAD_INPUT;
					break;
				}
			}

			if (U8_LENGTH(c) <= dstEnd - dst)
			{
				int j = 0;
				U8_APPEND_UNSAFE(dst, j, c);
				dst += j;
			}
			else
			{
				*err_code = CS_TRUNCATION_ERROR;
				break;
			}
		}
	}

	return (dst - dstStart) * sizeof(*dst);
}


ULONG UnicodeUtil::utf8ToUtf16(ULONG srcLen, const UCHAR* src, ULONG dstLen, USHORT* dst,
							   USHORT* err_code, ULONG* err_position)
{
	fb_assert(src != NULL || dst == NULL);
	fb_assert(err_code != NULL);
	fb_assert(err_position != NULL);

	*err_code = 0;

	if (dst == NULL)
		return srcLen * sizeof(*dst);

	const UCHAR* const srcEnd = src + srcLen;
	const USHORT* const dstStart = dst;
	const USHORT* const dstEnd = dst + dstLen / sizeof(*dst);

	for (ULONG i = 0; i < srcLen; )
	{
		if (dstEnd - dst == 0)
		{
			*err_code = CS_TRUNCATION_ERROR;
			*err_position = i;
			break;
		}

		UChar32 c = src[i++];

		if (c <= 0x7F)
			*dst++ = c;
		else
		{
			*err_position = i - 1;

			c = utf8_nextCharSafeBody(src, reinterpret_cast<int32_t*>(&i),
					srcLen, c, -1);

			if (c < 0)
			{
				*err_code = CS_BAD_INPUT;
				break;
			}
			else if (c <= 0xFFFF)
				*dst++ = c;
			else
			{
				if (dstEnd - dst > 1)
				{
					*dst++ = UTF16_LEAD(c);
					*dst++ = UTF16_TRAIL(c);
				}
				else
				{
					*err_code = CS_TRUNCATION_ERROR;
					break;
				}
			}
		}
	}

	return (dst - dstStart) * sizeof(*dst);
}


ULONG UnicodeUtil::utf16ToUtf32(ULONG srcLen, const USHORT* src, ULONG dstLen, ULONG* dst,
								USHORT* err_code, ULONG* err_position)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL || dst == NULL);
	fb_assert(err_code != NULL);
	fb_assert(err_position != NULL);

	*err_code = 0;

	if (dst == NULL)
		return srcLen / sizeof(*src) * sizeof(*dst);

	// based on u_strToUTF32 from ICU
	const USHORT* const srcStart = src;
	const ULONG* const dstStart = dst;
	const USHORT* const srcEnd = src + srcLen / sizeof(*src);
	const ULONG* const dstEnd = dst + dstLen / sizeof(*dst);

	while (src < srcEnd && dst < dstEnd)
	{
		ULONG ch = *src++;
		ULONG ch2;

		if (UTF_IS_LEAD(ch))
		{
			if (src < srcEnd && UTF_IS_TRAIL(ch2 = *src))
			{
				ch = UTF16_GET_PAIR_VALUE(ch, ch2);
				++src;
			}
			else
			{
				*err_code = CS_BAD_INPUT;
				--src;
				break;
			}
		}

		*(dst++) = ch;
	}

	*err_position = (src - srcStart) * sizeof(*src);

	if (*err_code == 0 && src < srcEnd)
		*err_code = CS_TRUNCATION_ERROR;

	return (dst - dstStart) * sizeof(*dst);
}


ULONG UnicodeUtil::utf32ToUtf16(ULONG srcLen, const ULONG* src, ULONG dstLen, USHORT* dst,
								USHORT* err_code, ULONG* err_position)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL || dst == NULL);
	fb_assert(err_code != NULL);
	fb_assert(err_position != NULL);

	*err_code = 0;

	if (dst == NULL)
		return srcLen;

	// based on u_strFromUTF32 from ICU
	const ULONG* const srcStart = src;
	const USHORT* const dstStart = dst;
	const ULONG* const srcEnd = src + srcLen / sizeof(*src);
	const USHORT* const dstEnd = dst + dstLen / sizeof(*dst);

	while (src < srcEnd && dst < dstEnd)
	{
		ULONG ch = *src++;

		if (ch <= 0xFFFF)
			*(dst++) = ch;
		else if (ch <= 0x10FFFF)
		{
			*(dst++) = UTF16_LEAD(ch);

			if (dst < dstEnd)
				*(dst++) = UTF16_TRAIL(ch);
			else
			{
				*err_code = CS_TRUNCATION_ERROR;
				--dst;
				break;
			}
		}
		else
		{
			*err_code = CS_BAD_INPUT;
			--src;
			break;
		}
	}

	*err_position = (src - srcStart) * sizeof(*src);

	if (*err_code == 0 && src < srcEnd)
		*err_code = CS_TRUNCATION_ERROR;

	return (dst - dstStart) * sizeof(*dst);
}


SSHORT UnicodeUtil::utf16Compare(ULONG len1, const USHORT* str1, ULONG len2, const USHORT* str2,
								 INTL_BOOL* error_flag)
{
	fb_assert(len1 % sizeof(*str1) == 0);
	fb_assert(len2 % sizeof(*str2) == 0);
	fb_assert(str1 != NULL);
	fb_assert(str2 != NULL);
	fb_assert(error_flag != NULL);

	*error_flag = false;

	int32_t cmp = u_strCompare(reinterpret_cast<const UChar*>(str1), len1 / sizeof(*str1), 
							   reinterpret_cast<const UChar*>(str2), len2 / sizeof(*str2), true);
	
	return (cmp < 0 ? -1 : (cmp > 0 ? 1 : 0));
}


ULONG UnicodeUtil::utf16Length(ULONG len, const USHORT* str)
{
	fb_assert(len % sizeof(*str) == 0);
	return u_countChar32(reinterpret_cast<const UChar*>(str), len / sizeof(*str));
}


ULONG UnicodeUtil::utf16Substring(ULONG srcLen, const USHORT* src, ULONG dstLen, USHORT* dst, 
								  ULONG startPos, ULONG length)
{
	fb_assert(srcLen % sizeof(*src) == 0);
	fb_assert(src != NULL && dst != NULL);

	if (length == 0)
		return 0;

	const USHORT* const srcStart = src;
	const USHORT* const dstStart = dst;
	const USHORT* const srcEnd = src + srcLen / sizeof(*src);
	const USHORT* const dstEnd = dst + dstLen / sizeof(*dst);
	ULONG pos = 0;

	while (src < srcEnd && dst < dstEnd && pos < startPos)
	{
		ULONG ch = *src++;

		if (UTF_IS_LEAD(ch))
		{
			if (src < srcEnd && UTF_IS_TRAIL(*src))
				++src;
		}

		++pos;
	}

	while (src < srcEnd && dst < dstEnd && pos < startPos + length)
	{
		ULONG ch = *src++;
		ULONG ch2;

		*(dst++) = ch;

		if (UTF_IS_LEAD(ch))
		{
			if (src < srcEnd && UTF_IS_TRAIL(ch2 = *src))
			{
				*(dst++) = ch2;
				++src;
			}
		}

		++pos;
	}

	return (dst - dstStart) * sizeof(*dst);
}


INTL_BOOL UnicodeUtil::utf8WellFormed(ULONG len, const UCHAR* str, ULONG* offending_position)
{
	fb_assert(str != NULL);

	for (ULONG i = 0; i < len; )
	{
		UChar32 c = str[i++];

		if (c > 0x7F)
		{
			ULONG save_i = i - 1;

			c = utf8_nextCharSafeBody(str, reinterpret_cast<int32_t*>(&i), len, c, -1);

			if (c < 0)
			{
				if (offending_position)
					*offending_position = save_i;
				return false;	// malformed
			}
		}
	}

	return true;	// well-formed
}


INTL_BOOL UnicodeUtil::utf16WellFormed(ULONG len, const USHORT* str, ULONG* offending_position)
{
	fb_assert(str != NULL);
	fb_assert(len % sizeof(*str) == 0);

	len = len / sizeof(*str);

	for (ULONG i = 0; i < len; i++)
	{
		ULONG save_i = i;

		uint32_t c;
		U16_NEXT(str, i, len, c);

		if (!U_IS_SUPPLEMENTARY(c) && (U16_IS_LEAD(c) || U16_IS_TRAIL(c)))
		{
			if (offending_position)
				*offending_position = save_i * sizeof(*str);
			return false;	// malformed
		}
	}

	return true;	// well-formed
}


INTL_BOOL UnicodeUtil::utf32WellFormed(ULONG len, const ULONG* str, ULONG* offending_position)
{
	fb_assert(str != NULL);
	fb_assert(len % sizeof(*str) == 0);

	const ULONG* strStart = str;

	while (len)
	{
		if (!U_IS_UNICODE_CHAR(*str))
		{
			if (offending_position)
				*offending_position = (str - strStart) * sizeof(*str);
			return false;	// malformed
		}
		else
		{
			++str;
			len -= sizeof(*str);
		}
	}

	return true;	// well-formed
}


UnicodeUtil::Utf16Collation* UnicodeUtil::Utf16Collation::create(const char* locale)
{
	UErrorCode status = U_ZERO_ERROR;
	UCollator* collator = ucol_open(locale, &status);

	if (!collator)
		return NULL;

	Utf16Collation* obj = new Utf16Collation();
	obj->collator = collator;

	return obj;
}


UnicodeUtil::Utf16Collation::~Utf16Collation()
{
	ucol_close((UCollator*)collator);
}


USHORT UnicodeUtil::Utf16Collation::keyLength(USHORT len)
{
	return MAX(256, 4 * len);
}


USHORT UnicodeUtil::Utf16Collation::stringToKey(USHORT srcLen, const USHORT* src,
												USHORT dstLen, UCHAR* dst,
												USHORT key_type)
{
	fb_assert(src != NULL && dst != NULL);
	fb_assert(srcLen % sizeof(*src) == 0);

	if (dstLen < keyLength(srcLen))
	{
		fb_assert(false);
		return INTL_BAD_KEY_LENGTH;
	}

	return ucol_getSortKey((UCollator*)collator, reinterpret_cast<const UChar *>(src), srcLen / sizeof(*src), dst, dstLen);
}


SSHORT UnicodeUtil::Utf16Collation::compare(ULONG len1, const USHORT* str1,
											ULONG len2, const USHORT* str2,
											INTL_BOOL* error_flag)
{
	fb_assert(len1 % sizeof(*str1) == 0 && len2 % sizeof(*str2) == 0);
	fb_assert(str1 != NULL && str2 != NULL);
	fb_assert(error_flag != NULL);

	*error_flag = false;

	return (SSHORT)ucol_strcoll((UCollator*)collator,
								reinterpret_cast<const UChar*>(str1), len1 / sizeof(*str1), 
								reinterpret_cast<const UChar*>(str2), len2 / sizeof(*str2));
}


}	// namespace Jrd