#pragma once


#include <vector>
#include <cstdint>
#include <climits>
#include <chrono>


class ChannelInterface
{
public:
  enum Result
  {
    Success,
    Error, // Connection closed
    DataUnavailable,
    InsufficientCapacity
  };

  // No socket handle exposed, so assumes that n+1 where n is this socket fd, and the appropriate fd_sets
  // have the fd set in them according to the read/write/except flags.
  virtual int Select(bool a_read, bool a_write, bool a_except = false, std::chrono::milliseconds a_timeout = std::chrono::milliseconds(0)) = 0;

  // If a_readSize is -1, reads at most the size of the a_recvBuffer
  // Returns the number of bytes that were read, or 0 for connection closed, or negative values for error
  virtual int Read(std::vector<uint8_t>& a_recvBuffer, int a_readSize = INT_MAX) = 0;

  // If a_writeSize is -1, sends up to the size of a_sendBuffer
  // Returns the number of bytes that were written, or 0 for connection closed, or negative values for error
  virtual int Write(const std::vector<uint8_t>& a_sendBuffer, int a_writeSize = INT_MAX) = 0;

  // If data available (calls select first), reads data after size and up to the capacity of the a_recvBuffer and resizes the buffer accordingly
  virtual Result SelectAndRead(std::vector<uint8_t>& a_recvBuffer, std::chrono::milliseconds a_timeout = std::chrono::milliseconds(0)) = 0;

  // If able to write data (calls select first), writes data after a_offset and up to the size of the a_sendBuffer and updates a_offset accordingly
  virtual Result SelectAndWrite(const std::vector<uint8_t>& a_sendBuffer, int& a_offset, std::chrono::milliseconds a_timeout = std::chrono::milliseconds(0)) = 0;

  // Close the connection
  virtual void Close() = 0;

  // Get connected state
  virtual bool IsConnected() = 0;

  // Aliases for read/write
  int Send(const std::vector<uint8_t>& a_sendBuffer, int a_writeSize = INT_MAX)  { return Write(a_sendBuffer, a_writeSize); }
  int Recv(std::vector<uint8_t>& a_recvBuffer, int a_readSize = INT_MAX)         { return Read(a_recvBuffer, a_readSize); }
};