/*
 * Copyright (C) 2008-2019 TrinityCore <https://www.trinitycore.org/>
 * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
 *
 * 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 2 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/>.
 */

#ifndef _BYTEBUFFER_H
#define _BYTEBUFFER_H

#include "Define.h"
#include "ByteConverter.h"
#include <string>
#include <vector>
#include <cstring>

class MessageBuffer;

// Root of ByteBuffer exception hierarchy
class TC_SHARED_API ByteBufferException : public std::exception
{
public:
    ~ByteBufferException() throw() { }

    char const* what() const throw() override { return msg_.c_str(); }

protected:
    std::string & message() throw() { return msg_; }

private:
    std::string msg_;
};

class TC_SHARED_API ByteBufferPositionException : public ByteBufferException
{
public:
    ByteBufferPositionException(bool add, size_t pos, size_t size, size_t valueSize);

    ~ByteBufferPositionException() throw() { }
};

class TC_SHARED_API ByteBufferSourceException : public ByteBufferException
{
public:
    ByteBufferSourceException(size_t pos, size_t size, size_t valueSize);

    ~ByteBufferSourceException() throw() { }
};

class TC_SHARED_API ByteBuffer
{
    public:
        const static size_t DEFAULT_SIZE = 0x1000;

        // constructor
        ByteBuffer() : _rpos(0), _wpos(0)
        {
            _storage.reserve(DEFAULT_SIZE);
        }

        ByteBuffer(size_t reserve) : _rpos(0), _wpos(0)
        {
            _storage.reserve(reserve);
        }

        ByteBuffer(ByteBuffer&& buf) : _rpos(buf._rpos), _wpos(buf._wpos), _storage(std::move(buf._storage))
        {
            buf._rpos = 0;
            buf._wpos = 0;
        }

        ByteBuffer(ByteBuffer const& right) : _rpos(right._rpos), _wpos(right._wpos), _storage(right._storage) { }

        ByteBuffer(MessageBuffer&& buffer);

        ByteBuffer& operator=(ByteBuffer const& right)
        {
            if (this != &right)
            {
                _rpos = right._rpos;
                _wpos = right._wpos;
                _storage = right._storage;
            }

            return *this;
        }

        ByteBuffer& operator=(ByteBuffer&& right)
        {
            if (this != &right)
            {
                _rpos = right._rpos;
                right._rpos = 0;
                _wpos = right._wpos;
                right._wpos = 0;
                _storage = std::move(right._storage);
            }

            return *this;
        }

        virtual ~ByteBuffer() { }

        void clear()
        {
            _storage.clear();
            _rpos = _wpos = 0;
        }

        template <typename T> void append(T value)
        {
            static_assert(std::is_fundamental<T>::value, "append(compound)");
            EndianConvert(value);
            append((uint8 *)&value, sizeof(value));
        }

        template <typename T>
        void put(std::size_t pos, T value)
        {
            static_assert(std::is_fundamental<T>::value, "append(compound)");
            EndianConvert(value);
            put(pos, (uint8 *)&value, sizeof(value));
        }

        ByteBuffer &operator<<(uint8 value)
        {
            append<uint8>(value);
            return *this;
        }

        ByteBuffer &operator<<(uint16 value)
        {
            append<uint16>(value);
            return *this;
        }

        ByteBuffer &operator<<(uint32 value)
        {
            append<uint32>(value);
            return *this;
        }

        ByteBuffer &operator<<(uint64 value)
        {
            append<uint64>(value);
            return *this;
        }

        // signed as in 2e complement
        ByteBuffer &operator<<(int8 value)
        {
            append<int8>(value);
            return *this;
        }

        ByteBuffer &operator<<(int16 value)
        {
            append<int16>(value);
            return *this;
        }

        ByteBuffer &operator<<(int32 value)
        {
            append<int32>(value);
            return *this;
        }

        ByteBuffer &operator<<(int64 value)
        {
            append<int64>(value);
            return *this;
        }

        // floating points
        ByteBuffer &operator<<(float value)
        {
            append<float>(value);
            return *this;
        }

        ByteBuffer &operator<<(double value)
        {
            append<double>(value);
            return *this;
        }

        ByteBuffer &operator<<(const std::string &value)
        {
            if (size_t len = value.length())
                append((uint8 const*)value.c_str(), len);
            append((uint8)0);
            return *this;
        }

        ByteBuffer &operator<<(const char *str)
        {
            if (size_t len = (str ? strlen(str) : 0))
                append((uint8 const*)str, len);
            append((uint8)0);
            return *this;
        }

        ByteBuffer &operator>>(bool &value)
        {
            value = read<char>() > 0 ? true : false;
            return *this;
        }

        ByteBuffer &operator>>(uint8 &value)
        {
            value = read<uint8>();
            return *this;
        }

        ByteBuffer &operator>>(uint16 &value)
        {
            value = read<uint16>();
            return *this;
        }

        ByteBuffer &operator>>(uint32 &value)
        {
            value = read<uint32>();
            return *this;
        }

        ByteBuffer &operator>>(uint64 &value)
        {
            value = read<uint64>();
            return *this;
        }

        //signed as in 2e complement
        ByteBuffer &operator>>(int8 &value)
        {
            value = read<int8>();
            return *this;
        }

        ByteBuffer &operator>>(int16 &value)
        {
            value = read<int16>();
            return *this;
        }

        ByteBuffer &operator>>(int32 &value)
        {
            value = read<int32>();
            return *this;
        }

        ByteBuffer &operator>>(int64 &value)
        {
            value = read<int64>();
            return *this;
        }

        ByteBuffer &operator>>(float &value);
        ByteBuffer &operator>>(double &value);

        ByteBuffer &operator>>(std::string& value)
        {
            value.clear();
            while (rpos() < size())                         // prevent crash at wrong string format in packet
            {
                char c = read<char>();
                if (c == 0)
                    break;
                value += c;
            }
            return *this;
        }

        uint8& operator[](size_t const pos)
        {
            if (pos >= size())
                throw ByteBufferPositionException(false, pos, 1, size());
            return _storage[pos];
        }

        uint8 const& operator[](size_t const pos) const
        {
            if (pos >= size())
                throw ByteBufferPositionException(false, pos, 1, size());
            return _storage[pos];
        }

        size_t rpos() const { return _rpos; }

        size_t rpos(size_t rpos_)
        {
            _rpos = rpos_;
            return _rpos;
        }

        void rfinish()
        {
            _rpos = wpos();
        }

        size_t wpos() const { return _wpos; }

        size_t wpos(size_t wpos_)
        {
            _wpos = wpos_;
            return _wpos;
        }

        template<typename T>
        void read_skip() { read_skip(sizeof(T)); }

        void read_skip(size_t skip)
        {
            if (_rpos + skip > size())
                throw ByteBufferPositionException(false, _rpos, skip, size());
            _rpos += skip;
        }

        template <typename T> T read()
        {
            T r = read<T>(_rpos);
            _rpos += sizeof(T);
            return r;
        }

        template <typename T> T read(size_t pos) const
        {
            if (pos + sizeof(T) > size())
                throw ByteBufferPositionException(false, pos, sizeof(T), size());
            T val = *((T const*)&_storage[pos]);
            EndianConvert(val);
            return val;
        }

        void read(uint8 *dest, size_t len)
        {
            if (_rpos  + len > size())
               throw ByteBufferPositionException(false, _rpos, len, size());
            std::memcpy(dest, &_storage[_rpos], len);
            _rpos += len;
        }

        void readPackGUID(uint64& guid)
        {
            if (rpos() + 1 > size())
                throw ByteBufferPositionException(false, _rpos, 1, size());

            guid = 0;

            uint8 guidmark = 0;
            (*this) >> guidmark;

            for (int i = 0; i < 8; ++i)
            {
                if (guidmark & (uint8(1) << i))
                {
                    if (rpos() + 1 > size())
                        throw ByteBufferPositionException(false, _rpos, 1, size());

                    uint8 bit;
                    (*this) >> bit;
                    guid |= (uint64(bit) << (i * 8));
                }
            }
        }

        uint32 ReadPackedTime();

        ByteBuffer& ReadPackedTime(uint32& time)
        {
            time = ReadPackedTime();
            return *this;
        }

        uint8* contents()
        {
            if (_storage.empty())
                throw ByteBufferException();
            return _storage.data();
        }

        uint8 const* contents() const
        {
            if (_storage.empty())
                throw ByteBufferException();
            return _storage.data();
        }

        size_t size() const { return _storage.size(); }
        bool empty() const { return _storage.empty(); }

        void resize(size_t newsize)
        {
            _storage.resize(newsize, 0);
            _rpos = 0;
            _wpos = size();
        }

        void reserve(size_t ressize)
        {
            if (ressize > size())
                _storage.reserve(ressize);
        }

        void shrink_to_fit()
        {
            _storage.shrink_to_fit();
        }

        void append(const char *src, size_t cnt)
        {
            return append((const uint8 *)src, cnt);
        }

        template<class T> void append(const T *src, size_t cnt)
        {
            return append((const uint8 *)src, cnt * sizeof(T));
        }

        void append(uint8 const* src, size_t cnt);

        void append(ByteBuffer const& buffer)
        {
            if (buffer.wpos())
                append(buffer.contents(), buffer.wpos());
        }

        // can be used in SMSG_MONSTER_MOVE opcode
        void appendPackXYZ(float x, float y, float z)
        {
            uint32 packed = 0;
            packed |= ((int)(x / 0.25f) & 0x7FF);
            packed |= ((int)(y / 0.25f) & 0x7FF) << 11;
            packed |= ((int)(z / 0.25f) & 0x3FF) << 22;
            *this << packed;
        }

        void appendPackGUID(uint64 guid)
        {
            uint8 packGUID[8+1];
            packGUID[0] = 0;
            size_t size = 1;
            for (uint8 i = 0;guid != 0;++i)
            {
                if (guid & 0xFF)
                {
                    packGUID[0] |= uint8(1 << i);
                    packGUID[size] =  uint8(guid & 0xFF);
                    ++size;
                }

                guid >>= 8;
            }
            append(packGUID, size);
        }

        void AppendPackedTime(time_t time);

        void put(size_t pos, const uint8 *src, size_t cnt);

        void print_storage() const;

        void textlike() const;

        void hexlike() const;

    protected:
        size_t _rpos, _wpos;
        std::vector<uint8> _storage;
};

/// @todo Make a ByteBuffer.cpp and move all this inlining to it.
template<> inline std::string ByteBuffer::read<std::string>()
{
    std::string tmp;
    *this >> tmp;
    return tmp;
}

template<>
inline void ByteBuffer::read_skip<char*>()
{
    std::string temp;
    *this >> temp;
}

template<>
inline void ByteBuffer::read_skip<char const*>()
{
    read_skip<char*>();
}

template<>
inline void ByteBuffer::read_skip<std::string>()
{
    read_skip<char*>();
}

#endif