/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "ultima/nuvie/core/nuvie_defs.h"
#include "ultima/nuvie/files/nuvie_io.h"

namespace Ultima {
namespace Nuvie {

NuvieIO::NuvieIO() : size(0), pos(0) {
}

NuvieIO::~NuvieIO() {
}

unsigned char *NuvieIO::readAll() {
	uint32 bytes_read;
	return readBuf(size, &bytes_read);
}

unsigned char *NuvieIO::readBuf(uint32 read_size, uint32 *bytes_read) {
	unsigned char *buf;

	*bytes_read = 0;

	if (pos + read_size > size)
		return nullptr;

	buf = (unsigned char *)malloc(read_size);
	if (buf == nullptr)
		return nullptr;

	if (readToBuf(buf, read_size) == false) {
		free(buf);
		return nullptr;
	}

	*bytes_read = read_size;

	return buf;
}


// NuvieIOBuffer

NuvieIOBuffer::NuvieIOBuffer() : NuvieIO() {
	data = nullptr;
	copied_data = false;
}

NuvieIOBuffer::~NuvieIOBuffer() {
	close();
}

bool NuvieIOBuffer::open(unsigned char *buf, uint32 buf_size, bool copy_buf) {
	if (data != nullptr)
		return false;

	if (copy_buf == NUVIE_BUF_COPY) {
		copied_data = true;
		data = (unsigned char *)malloc(buf_size);
		if (data == nullptr) {
			DEBUG(0, LEVEL_ERROR, "NuvieIOBuffer::open() allocating %d bytes.\n", buf_size);
			return false;
		}

		memcpy(data, buf, buf_size);
	} else
		data = buf;

	size = buf_size;

	return true;
}

void NuvieIOBuffer::close() {
	size = 0;
	pos = 0;

	if (copied_data && data != nullptr)
		free(data);

	data = nullptr;

}

uint8 NuvieIOBuffer::read1() {
	if (pos >= size)
		return 0;

	return data[pos++];
}

uint16 NuvieIOBuffer::read2() {
	uint16 val;

	if (pos > size - 2)
		return 0;

	val = data[pos] + (data[pos + 1] << 8);
	pos += 2;

	return val;
}

uint32 NuvieIOBuffer::read4() {
	uint32 val;

	if (pos > size - 4)
		return 0;

	val = (data[pos] + (data[pos + 1] << 8) + (data[pos + 2] << 16) + (data[pos + 3] << 24));
	pos += 4;

	return val;
}

bool NuvieIOBuffer::readToBuf(unsigned char *buf, uint32 buf_size) {
	if (pos + buf_size > size || buf == nullptr)
		return false;

	memcpy(buf, &data[pos], buf_size);

	pos += buf_size;

	return true;
}

bool NuvieIOBuffer::write1(uint8 src) {
	if (pos >= size)
		return false;

	data[pos] = src;
	pos++;

	return true;
}


bool NuvieIOBuffer::write2(uint16 src) {
	if (pos > size - 2)
		return false;

	data[pos] = src & 0xff;
	data[pos + 1] = (src >> 8) & 0xff;
	pos += 2;

	return true;
}

bool NuvieIOBuffer::write4(uint32 src) {
	unsigned char *ptr;
	if (pos > size - 4)
		return false;

	ptr = &data[pos];

	*ptr++ = src & 0xff;
	*ptr++ = (src >> 8) & 0xff;
	*ptr++ = (src >> 16) & 0xff;
	*ptr++ = (src >> 24) & 0xff;

	pos += 4;

	return true;
}

uint32 NuvieIOBuffer::writeBuf(const unsigned char *src, uint32 src_size) {
	if (pos + src_size > size || src == nullptr)
		return 0;

	memcpy(&data[pos], src, src_size);

	pos += src_size;

	return src_size;
}

uint32 NuvieIOBuffer::write(NuvieIO *src) {
	return 0;
}


void NuvieIOBuffer::seek(uint32 new_pos) {
	if (data && new_pos < size)
		pos = new_pos;
}

char *strgets(char *str, int n, Common::ReadStream *stream) {
	int count = 0;
	char c;

	while (!stream->eos() && (count < (n - 1)) && (c = stream->readByte()) != '\n') {
		if (c == '\r')
			continue;

		str[count] = c;
		++count;
	}

	str[count] = '\0';
	return count ? str : nullptr;
}

} // End of namespace Nuvie
} // End of namespace Ultima