/*
    Modbus.h - Header for Modbus Core Library
    Copyright (C) 2014 Andr� Sarmento Barbosa
                  2017-2020 Alexander Emelianov (a.m.emelianov@gmail.com)
*/
#pragma once

#include "mbed.h"
#include <algorithm>
#include <vector>

#ifdef ARDUINO_ARCH_ESP32
#include <byteswap.h>
#endif

#ifndef __bswap_16
#define __bswap_16(num) (((uint16_t)num >> 8) | ((uint16_t)num << 8))
#endif

//#define MB_GLOBAL_REGS
//#define MB_MAX_REGS     32
#define MODBUS_MAX_FRAME 256
#define COIL(n) \
    (TAddress) { TAddress::COIL, n }
#define ISTS(n) \
    (TAddress) { TAddress::ISTS, n }
#define IREG(n) \
    (TAddress) { TAddress::IREG, n }
#define HREG(n) \
    (TAddress) { TAddress::HREG, n }
#define BIT_VAL(v) (v ? 0xFF00 : 0x0000)
#define BIT_BOOL(v) (v == 0xFF00)
#define COIL_VAL(v) (v ? 0xFF00 : 0x0000)
#define COIL_BOOL(v) (v == 0xFF00U)
#define ISTS_VAL(v) (v ? 0xFF00 : 0x0000)
#define ISTS_BOOL(v) (v == 0xFF00)

// For depricated (v1.xx) onSet/onGet format compatibility
#define cbDefault nullptr

struct TRegister;

typedef uint16_t (*cbModbus)(TRegister *reg, uint16_t val); // Callback function Type

struct TAddress {
    enum RegType {
        COIL,
        ISTS,
        IREG,
        HREG
    };
    RegType type;
    uint16_t address;

    bool operator==(const TAddress &obj) const { // TAddress == TAddress
        return type == obj.type && address == obj.address;
    }

    bool operator!=(const TAddress &obj) const { // TAddress != TAddress
        return type != obj.type || address != obj.address;
    }

    TAddress &operator++() { // ++TAddress
        address++;
        return *this;
    }

    const TAddress operator++(int) { // TAddress++
        TAddress result(*this);
        ++(*this);
        return result;
    }

    TAddress &operator+=(const int &inc) { // TAddress += integer
        address += inc;
        return *this;
    }

    TAddress operator+(const int &inc) const { // TAddress + integer
        TAddress result(*this);
        result.address += inc;
        return result;
    }

    bool isCoil() const {
        return type == COIL;
    }

    bool isIsts() const {
        return type == ISTS;
    }

    bool isIreg() const {
        return type == IREG;
    }

    bool isHreg() const {
        return type == HREG;
    }
};

struct TCallback {
    enum CallbackType {
        ON_SET,
        ON_GET
    };
    CallbackType type;
    TAddress address;
    cbModbus cb;
};

struct TRegister {
    TAddress address;
    uint16_t value;

    bool operator==(const TRegister &obj) const {
        return address == obj.address;
    }
};

class Modbus {
public:
    //Function Codes
    enum FunctionCode {
        FC_READ_COILS = 0x01, // Read Coils (Output) Status
        FC_READ_INPUT_STAT = 0x02, // Read Input Status (Discrete Inputs)
        FC_READ_REGS = 0x03, // Read Holding Registers
        FC_READ_INPUT_REGS = 0x04, // Read Input Registers
        FC_WRITE_COIL = 0x05, // Write Single Coil (Output)
        FC_WRITE_REG = 0x06, // Preset Single Register
        FC_DIAGNOSTICS = 0x08, // Not implemented. Diagnostics (Serial Line only)
        FC_WRITE_COILS = 0x0F, // Write Multiple Coils (Outputs)
        FC_WRITE_REGS = 0x10, // Write block of contiguous registers
        FC_READ_FILE_REC = 0x14, // Not implemented. Read File Record
        FC_WRITE_FILE_REC = 0x15, // Not implemented. Write File Record
        FC_MASKWRITE_REG = 0x16, // Not implemented. Mask Write Register
        FC_READWRITE_REGS = 0x17 // Not implemented. Read/Write Multiple registers
    };
    //Exception Codes
    //Custom result codes used internally and for callbacks but never used for Modbus responce
    enum ResultCode {
        EX_SUCCESS = 0x00, // Custom. No error
        EX_ILLEGAL_FUNCTION = 0x01, // Function Code not Supported
        EX_ILLEGAL_ADDRESS = 0x02, // Output Address not exists
        EX_ILLEGAL_VALUE = 0x03, // Output Value not in Range
        EX_SLAVE_FAILURE = 0x04, // Slave or Master Device Fails to process request
        EX_ACKNOWLEDGE = 0x05, // Not used
        EX_SLAVE_DEVICE_BUSY = 0x06, // Not used
        EX_MEMORY_PARITY_ERROR = 0x08, // Not used
        EX_PATH_UNAVAILABLE = 0x0A, // Not used
        EX_DEVICE_FAILED_TO_RESPOND = 0x0B, // Not used
        EX_GENERAL_FAILURE = 0xE1, // Custom. Unexpected master error
        EX_DATA_MISMACH = 0xE2, // Custom. Inpud data size mismach
        EX_UNEXPECTED_RESPONSE = 0xE3, // Custom. Returned result doesn't mach transaction
        EX_TIMEOUT = 0xE4, // Custom. Operation not finished within reasonable time
        EX_CONNECTION_LOST = 0xE5, // Custom. Connection with device lost
        EX_CANCEL = 0xE6 // Custom. Transaction/request canceled
    };

    ~Modbus();

    bool addHreg(uint16_t offset, uint16_t value = 0, uint16_t numregs = 1);

    bool Hreg(uint16_t offset, uint16_t value);

    uint16_t Hreg(uint16_t offset);

    uint16_t removeHreg(uint16_t offset, uint16_t numregs = 1);

    bool addCoil(uint16_t offset, bool value = false, uint16_t numregs = 1);

    bool addIsts(uint16_t offset, bool value = false, uint16_t numregs = 1);

    bool addIreg(uint16_t offset, uint16_t value = 0, uint16_t numregs = 1);

    bool Coil(uint16_t offset, bool value);

    bool Ists(uint16_t offset, bool value);

    bool Ireg(uint16_t offset, uint16_t value);

    bool Coil(uint16_t offset);

    bool Ists(uint16_t offset);

    uint16_t Ireg(uint16_t offset);

    bool removeCoil(uint16_t offset, uint16_t numregs = 1);

    bool removeIsts(uint16_t offset, uint16_t numregs = 1);

    bool removeIreg(uint16_t offset, uint16_t numregs = 1);

    /*
        bool Hreg(uint16_t offset, uint16_t* value);
        bool Coil(uint16_t offset, bool* value);
        bool Ists(uint16_t offset, bool* value);
        bool Ireg(uint16_t offset, uint16_t* value);
        */
    void cbEnable(bool state = true);

    void cbDisable();

    bool onGetCoil(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onSetCoil(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onGetHreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onSetHreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onGetIsts(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onSetIsts(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onGetIreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onSetIreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnGetCoil(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnSetCoil(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnGetHreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnSetHreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnGetIsts(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnSetIsts(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnGetIreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnSetIreg(uint16_t offset, cbModbus cb = nullptr, uint16_t numregs = 1);

private:
    void readBits(TAddress startreg, uint16_t numregs, FunctionCode fn);

    void readWords(TAddress startreg, uint16_t numregs, FunctionCode fn);

    void setMultipleBits(const uint8_t *frame, TAddress startreg, uint16_t numoutputs);

    void setMultipleWords(const uint16_t *frame, TAddress startreg, uint16_t numoutputs);

    void getMultipleBits(uint8_t *frame, TAddress startreg, uint16_t numregs);

    void getMultipleWords(uint16_t *frame, TAddress startreg, uint16_t numregs);

    static void bitsToBool(bool *dst, const uint8_t *src, uint16_t numregs);

    static void boolToBits(uint8_t *dst, const bool *src, uint16_t numregs);

protected:
    //Reply Types
    enum ReplyCode {
        REPLY_OFF = 0x01,
        REPLY_ECHO = 0x02,
        REPLY_NORMAL = 0x03,
        REPLY_ERROR = 0x04,
        REPLY_UNEXPECTED = 0x05
    };
#ifndef MB_GLOBAL_REGS
    std::vector<TRegister> _regs;
    std::vector<TCallback> _callbacks;
#endif
    uint8_t *_frame = nullptr;
    uint16_t _len = 0;
    uint8_t _reply = 0;
    bool cbEnabled = true;

    uint16_t mbCallback(TRegister *reg, uint16_t val, TCallback::CallbackType t);

    TRegister *searchRegister(TAddress addr);

    void exceptionResponse(FunctionCode fn, ResultCode excode); // Fills _frame with response
    void successResponce(TAddress startreg, uint16_t numoutputs, FunctionCode fn); // Fills frame with response
    void slavePDU(uint8_t *frame); //For Slave
    void
    masterPDU(uint8_t *frame, const uint8_t *sourceFrame, TAddress startreg, uint16_t *output = nullptr); //For Master
    // frame - data received form slave
    // sourceFrame - data have sent fo slave
    // startreg - local register to start put data to
    // output - if not null put data to the buffer insted local registers. output assumed to by array of uint16_t or boolean

    bool readSlave(uint16_t address, uint16_t numregs, FunctionCode fn);

    bool writeSlaveBits(TAddress startreg, uint16_t to, uint16_t numregs, FunctionCode fn, bool *data = nullptr);

    bool
    writeSlaveWords(TAddress startreg, uint16_t to, uint16_t numregs, FunctionCode fn, const uint16_t *data = nullptr);
    // startreg - local register to get data from
    // to - slave register to write data to
    // numregs - number of registers
    // fn - Modbus function
    // data - if null use local registers. Otherwise use data from array to erite to slave

    bool addReg(TAddress address, uint16_t value = 0, uint16_t numregs = 1);

    bool Reg(TAddress address, uint16_t value);

    uint16_t Reg(TAddress address);

    bool removeReg(TAddress address, uint16_t numregs = 1);

    bool onGet(TAddress address, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool onSet(TAddress address, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnSet(TAddress address, cbModbus cb = nullptr, uint16_t numregs = 1);

    bool removeOnGet(TAddress address, cbModbus cb = nullptr, uint16_t numregs = 1);

    virtual uint32_t eventSource() { return 0; }
};

typedef bool (*cbTransaction)(Modbus::ResultCode event, uint16_t transactionId,
                              void *data); // Callback skeleton for requests