/**
  * @file SMBus.h
  * @brief smbus-cpp项目头文件，包含所有类定义
  * @author 梅花
  * @data 2024年10月9日22:32:29
  * @version 0.1
  * @copyright 梅花
  */
#ifndef __SMBus_h__
#define __SMBus_h__

#include <sys/ioctl.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <ios>
#include <string>

extern "C"
{
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
#include <i2c/smbus.h>
}

/*
** These are required to build this module against Linux older than 2.6.23.
*/
#ifndef I2C_SMBUS_I2C_BLOCK_BROKEN
#undef I2C_SMBUS_I2C_BLOCK_DATA
#define I2C_SMBUS_I2C_BLOCK_BROKEN	6
#define I2C_SMBUS_I2C_BLOCK_DATA	8
#endif

#define MAXPATH 16
#define ARRAY_END 2147483647

/**
 * @class SMBus
 * @brief a SMBus class that is (optionally) connected to the specified I2C device interface.
 *
 * @see https://github.com/Gadgetoid/py-smbus/blob/master/library/smbusmodule.c
 */
class SMBus
{
public:
    int fd = -1;   //!< open file descriptor: /dev/i2c-?, or -1 
    int addr = -1; //!< current client SMBus address 


    /**
    * @brief Disconnects the object from the bus.
    */
    void close();

    /**
    * @brief Connects the object to the specified SMBus.
    *
    * @param bus
    */
    void open(int bus);

    /**
    * @brief Construct a new SMBus object
    *
    * @param bus
    */
    SMBus(int bus = -1);

    /**
    * @brief Perform SMBus Quick transaction.
    *
    * @param addr
    */
    void write_quick(int addr);

    /**
    * @brief Perform SMBus Read Byte transaction.
    *
    * @param addr
    *
    * @return long
    */
    long read_byte(int addr);

    /**
    * @brief Perform SMBus Write Byte transaction.
    *
    * @param addr
    */
    void write_byte(int addr, int val);

    /**
    * @brief Perform SMBus Read Byte Data transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @return long
    */
    long read_byte_data(int addr, int cmd);

    /**
    * @brief Perform SMBus Write Byte Data transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param val
    */
    void write_byte_data(int addr, int cmd, int val);

    /**
    * @brief Perform SMBus Read Word Data transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @return long
    */
    long read_word_data(int addr, int cmd);

    /**
    * @brief Perform SMBus Write Word Data transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param val
    */
    void write_word_data(int addr, int cmd, int val);

    /**
    * @brief Perform SMBus Process Call transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param val
    */
    void process_call(int addr, int cmd, int val);

    /**
    * @brief Perform SMBus Read Block Data transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @return long*
    */
    long* read_block_data(int addr, int cmd);

    /**
    * @brief Perform SMBus Write Block Data transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param vals
    *
    * @param len
    */
    void write_block_data(int addr, int cmd, long* vals, int len);

    /**
    * @brief Perform SMBus Block Process Call transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param vals
    *
    * @param len
    *
    * @return long*
    */
    long* block_process_call(int addr, int cmd, long* vals, int len);

    /**
    * @brief Perform I2C Block Read transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param len
    *
    * @return long*
    */
    long* read_i2c_block_data(int addr, int cmd, int len = 32);

    /**
    * @brief Perform I2C Block Write transaction.
    *
    * @param addr
    *
    * @param cmd
    *
    * @param vals
    *
    * @param len
    */
    void i2c_block_data(int addr, int cmd, long* vals, int len);

    /**
    * @brief Whether Packet Error Codes (PEC) are enabled.
    *
    * @return bool
    */
    bool get_pec() { return this->pec; }

    /**
    * @brief Set the status of PEC
    *
    * @param pec
    */
    void set_pec(bool pec);

private:
    bool pec = false;   //!< !0 => Packet Error Codes enabled

    void set_addr(int addr);
    long* buf_to_array(__u8 const* buf, int len);
    void array_to_data(long* list, int list_len, union i2c_smbus_data* data);
};
#endif