/*****************************************************************************************
 *                                                                                       *
 * OpenSpace                                                                             *
 *                                                                                       *
 * Copyright (c) 2014-2016                                                               *
 *                                                                                       *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
 * software and associated documentation files (the "Software"), to deal in the Software *
 * without restriction, including without limitation the rights to use, copy, modify,    *
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
 * permit persons to whom the Software is furnished to do so, subject to the following   *
 * conditions:                                                                           *
 *                                                                                       *
 * The above copyright notice and this permission notice shall be included in all copies *
 * or substantial portions of the Software.                                              *
 *                                                                                       *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
 * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
 ****************************************************************************************/

#ifndef SYNCBUFFER_H
#define SYNCBUFFER_H

#include <ghoul/opengl/ghoul_gl.h>
#include <ghoul/misc/assert.h>

#include <cstring>
#include <memory>
#include <stdint.h>
#include <vector>

namespace sgct {
    template <typename T>
    class SharedVector;
} // namespace sgct

namespace openspace {

class SyncBuffer {
public:

    SyncBuffer(size_t n);

    ~SyncBuffer();

    void encode(const std::string& s) {
        const size_t size = sizeof(char) * s.size() + sizeof(int32_t);
        ghoul_assert(_encodeOffset + size < _n, "");

        int32_t length = static_cast<int32_t>(s.length());
        memcpy(_dataStream.data() + _encodeOffset, reinterpret_cast<const char*>(&length), sizeof(int32_t));
        _encodeOffset += sizeof(int32_t);
        memcpy(_dataStream.data() + _encodeOffset, s.c_str(), length);
        _encodeOffset += length;
    }

    template <typename T>
    void encode(const T& v) {
        const size_t size = sizeof(T);
        ghoul_assert(_encodeOffset + size < _n, "");

        memcpy(_dataStream.data() + _encodeOffset, &v, size);
        _encodeOffset += size;
    }

    std::string decode() {
        int32_t length;
        memcpy(reinterpret_cast<char*>(&length), _dataStream.data() + _decodeOffset, sizeof(int32_t));
        char* tmp = new char[length + 1];
        _decodeOffset += sizeof(int32_t);
        memcpy(tmp, _dataStream.data() + _decodeOffset, length);
        _decodeOffset += length;
        tmp[length] = '\0';
        std::string ret(tmp);
        delete[] tmp;
        return ret;
    }

    template <typename T>
    T decode() {
        const size_t size = sizeof(T);
        ghoul_assert(_decodeOffset + size < _n, "");
        T value;
        memcpy(&value, _dataStream.data() + _decodeOffset, size);
        _decodeOffset += size;
        return value;
    }

    void decode(std::string& s) {
        s = decode();
    }

    template <typename T>
    void decode(T& value) {
        const size_t size = sizeof(T);
        ghoul_assert(_decodeOffset + size < _n, "");
        memcpy(&value, _dataStream.data() + _decodeOffset, size);
        _decodeOffset += size;
    }

    void write();

    void read();

private:
    size_t _n;
    size_t _encodeOffset;
    size_t _decodeOffset;
    std::vector<char> _dataStream;
    std::unique_ptr<sgct::SharedVector<char>> _synchronizationBuffer;
};

} // namespace openspace

#endif // SYNCBUFFER_H
