/*
  message.h

  Copyright (c) 2021 Kevin Matz (kevin.matz@gmail.com)

  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.
*/
#pragma once

#include <cstdint>
#include <vector>
#include "rdm.h"
#include "uid.h"

namespace RDM {

struct Message
{
  UID source;
  UID destination;
  uint8_t transaction;
  union {
    uint8_t portID;
    uint8_t responseType;
  };
  uint8_t messageCount;
  uint16_t subDevice;
  uint8_t commandClass;
  PID propertyID;

  Message();
  Message(const Message &obj);
  ~Message();

  const std::vector<uint8_t>* data() const { return &data_; }
  uint8_t length() const { return data_.size(); }
  uint16_t checksum();

  template<typename T>
  void appendData(const T & val)
  {
    Message::writeType<T>(data_, val);
  }

  template<typename T>
  static T readType(const std::vector<uint8_t>& vect, size_t start)
  {
    if (vect.size() < sizeof(T))
      return 0;
    T ret = 0;
    auto data = reinterpret_cast<uint8_t*>(&ret);
    for (int i = sizeof(T);  --i >= 0; )
        data[i] = vect[start + i];
    return ret;
  }

  template<typename T>
  static void writeType(std::vector<uint8_t>& data, T val)
  {
    auto raw = reinterpret_cast<uint8_t*>(val);
    for (int i = sizeof(T);  --i >= 0; )
      data.push_back(raw[i]);
  }

private:
  std::vector<uint8_t> data_;

  template<typename T>
  uint16_t addSum_(uint16_t sum, T val) const
  {
    uint16_t carry;
    auto raw = reinterpret_cast<uint8_t*>(val);
    for (int i = sizeof(T);  --i >= 0; )
      {
        uint8_t num = raw[i];
        while (num != 0)
          {
            carry = sum & num;
            sum = sum ^ num;
            num = carry << 1;
          }
      }
    return sum;
  }
};

} // namespace RDM