//
// TextBufferIterator.cpp
//
// Library: Foundation
// Package: Text
// Module:  TextBufferIterator
//
// Copyright (c) 2010, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#include "Poco/TextBufferIterator.h"
#include "Poco/TextEncoding.h"
#include <algorithm>
#include <cstring>


namespace Poco {


TextBufferIterator::TextBufferIterator():
	_pEncoding(nullptr),
	_it(nullptr),
	_end(nullptr)
{
}


TextBufferIterator::TextBufferIterator(const char* begin, const TextEncoding& encoding):
	_pEncoding(&encoding),
	_it(begin),
	_end(begin + std::strlen(begin))
{
}


TextBufferIterator::TextBufferIterator(const char* begin, std::size_t size, const TextEncoding& encoding):
	_pEncoding(&encoding),
	_it(begin),
	_end(begin + size)
{
}


TextBufferIterator::TextBufferIterator(const char* begin, const char* end, const TextEncoding& encoding):
	_pEncoding(&encoding),
	_it(begin),
	_end(end)
{
}


TextBufferIterator::TextBufferIterator(const char* end):
	_pEncoding(nullptr),
	_it(end),
	_end(end)
{
}


TextBufferIterator::~TextBufferIterator()
{
}


TextBufferIterator::TextBufferIterator(const TextBufferIterator& it):
	_pEncoding(it._pEncoding),
	_it(it._it),
	_end(it._end)
{
}


TextBufferIterator& TextBufferIterator::operator = (const TextBufferIterator& it)
{
	if (&it != this)
	{
		_pEncoding = it._pEncoding;
		_it        = it._it;
		_end       = it._end;
	}
	return *this;
}


void TextBufferIterator::swap(TextBufferIterator& it) noexcept
{
	std::swap(_pEncoding, it._pEncoding);
	std::swap(_it, it._it);
	std::swap(_end, it._end);
}


int TextBufferIterator::operator * () const
{
	poco_check_ptr (_pEncoding);
	poco_assert (_it != _end);
	const char* it = _it;

	unsigned char buffer[TextEncoding::MAX_SEQUENCE_LENGTH];
	unsigned char* p = buffer;
	unsigned char* pend = p + TextEncoding::MAX_SEQUENCE_LENGTH;

	if (it != _end)
		*p++ = *it++;
	else
		*p++ = 0;

	int read = 1;
	int n = _pEncoding->queryConvert(buffer, 1);

	while (-1 > n && (_end - it) >= -n - read)
	{
		while (read < -n && it != _end)
		{
			poco_assert(p != pend);
			*p++ = *it++;
			read++;
		}
		n = _pEncoding->queryConvert(buffer, read);
	}

	if (-1 > n)
	{
		return -1;
	}
	else
	{
		return n;
	}
}


TextBufferIterator& TextBufferIterator::operator ++ ()
{
	poco_check_ptr (_pEncoding);
	poco_assert (_it != _end);

	unsigned char buffer[TextEncoding::MAX_SEQUENCE_LENGTH];
	unsigned char* p = buffer;

	if (_it != _end)
		*p++ = *_it++;
	else
		*p++ = 0;

	int read = 1;
	int n = _pEncoding->sequenceLength(buffer, 1);

	while (-1 > n && (_end - _it) >= -n - read)
	{
		while (read < -n && _it != _end)
		{
			*p++ = *_it++;
			read++;
		}
		n = _pEncoding->sequenceLength(buffer, read);
	}
	while (read < n && _it != _end)
	{
		_it++;
		read++;
	}

	return *this;
}


TextBufferIterator TextBufferIterator::operator ++ (int)
{
	TextBufferIterator prev(*this);
	operator ++ ();
	return prev;
}


} // namespace Poco
