/* frameHandler.h
 *
 * Arduino library to read from Victron devices using VE.Direct protocol.
 * Derived from Victron framehandler reference implementation.
 *
 * 2020.05.05 - 0.2 - initial release
 * 2021.02.23 - 0.3 - change frameLen to 22 per VE.Direct Protocol version 3.30
 * 2022.08.20 - 0.4 - changes for OpenDTU
 * 2024.03.08 - 0.4 - adds the ability to send hex commands and disassemble hex messages
 *
 */

#pragma once

#include <Arduino.h>
#include <array>
#include <memory>
#include <utility>
#include <deque>
#include "VeDirectData.h"

template<typename T>
class VeDirectFrameHandler {
public:
    virtual void loop();                         // main loop to read ve.direct data
    uint32_t getLastUpdate() const;              // timestamp of last successful frame read
    bool isDataValid() const;                    // return true if data valid and not outdated
    T const& getData() const { return _tmpFrame; }
    bool sendHexCommand(VeDirectHexCommand cmd, VeDirectHexRegister addr, uint32_t value = 0, uint8_t valsize = 0);

protected:
    VeDirectFrameHandler();
    void init(char const* who, int8_t rx, int8_t tx, Print* msgOut,
        bool verboseLogging, uint8_t hwSerialPort);
    virtual bool hexDataHandler(VeDirectHexData const &data) { return false; } // handles the disassembeled hex response

    bool _verboseLogging;
    Print* _msgOut;
    uint32_t _lastUpdate;

    T _tmpFrame;

    bool _canSend;
    char _logId[32];

private:
    void reset();
    void dumpDebugBuffer();
    void rxData(uint8_t inbyte);              // byte of serial data
    void processTextData(std::string const& name, std::string const& value);
    virtual bool processTextDataDerived(std::string const& name, std::string const& value) = 0;
    virtual void frameValidEvent() { }
    bool disassembleHexData(VeDirectHexData &data);     //return true if disassembling was possible

    std::unique_ptr<HardwareSerial> _vedirectSerial;

    enum class State {
        IDLE = 1,
        RECORD_BEGIN = 2,
        RECORD_NAME = 3,
        RECORD_VALUE = 4,
        CHECKSUM = 5,
        RECORD_HEX = 6
    };
    State _state;
    State _prevState;

    State hexRxEvent(uint8_t inbyte);

    uint8_t _checksum;                         // checksum value
    char * _textPointer;                       // pointer to the private buffer we're writing to, name or value
    int _hexSize;                              // length of hex buffer
    char _hexBuffer[VE_MAX_HEX_LEN];           // buffer for received hex frames
    char _name[VE_MAX_VALUE_LEN];              // buffer for the field name
    char _value[VE_MAX_VALUE_LEN];             // buffer for the field value
    std::array<uint8_t, 512> _debugBuffer;
    unsigned _debugIn;
    uint32_t _lastByteMillis;                  // time of last parsed byte

    /**
     * not every frame contains every value the device is communicating, i.e.,
     * a set of values can be fragmented across multiple frames. frames can be
     * invalid. in order to only process data from valid frames, we add data
     * to this queue and only process it once the frame was found to be valid.
     * this also handles fragmentation nicely, since there is no need to reset
     * our data buffer. we simply update the interpreted data from this event
     * queue, which is fine as we know the source frame was valid.
     */
    std::deque<std::pair<std::string, std::string>> _textData;
};

template class VeDirectFrameHandler<veMpptStruct>;
template class VeDirectFrameHandler<veShuntStruct>;