//
// Created by Matthew on 2023/12/27.
//

#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>


#include "GPIOControl.h"

#define GPIO_DIRECTION_IN              0
#define GPIO_DIRECTION_OUT             1
#define GPIO_VALUE_LOW             0
#define GPIO_VALUE_HIGH            1

#define BUFFER_MAX    3
#define DIRECTION_MAX 48

int GpioControl::exp(int gpio)
{
    char buffer[BUFFER_MAX];
    int len;
    int fd;

    fd = open("/sys/class/gpio/export", O_WRONLY);
    if (fd < 0)
    {
        // LOGE("Failed to open export for writing!\n");
        return(0);
    }

    len = snprintf(buffer, BUFFER_MAX, "%d", gpio);
    if (write(fd, buffer, len) < 0)
    {
        // LOGE("Fail to export gpio!\n");
        return 0;
    }

    close(fd);
    return 1;
}

int GpioControl::setDirection(int gpio, int direction)
{
    static const char dir_str[]  = "in\0out";
    char path[DIRECTION_MAX];
    int fd;

    snprintf(path, DIRECTION_MAX, "/sys/class/gpio/gpio%d/direction", gpio);
    fd = open(path, O_WRONLY);
    if (fd < 0)
    {
        // LOGE("failed to open gpio direction for writing!\n");
        return 0;
    }

    if (write(fd, &dir_str[direction == GPIO_DIRECTION_IN ? 0 : 3], direction == GPIO_DIRECTION_IN ? 2 : 3) < 0)
    {
        // LOGE("failed to set direction!\n");
        return 0;
    }

    close(fd);
    return 1;
}
int GpioControl::readStatus(int gpio)
{
    char path[DIRECTION_MAX];
    char value_str[3];
    int fd;

    snprintf(path, DIRECTION_MAX, "/sys/class/gpio/gpio%d/value", gpio);
    fd = open(path, O_RDONLY);
    if (fd < 0)
    {
        // LOGE("failed to open gpio value for reading!\n");
        return -1;
    }

    if (read(fd, value_str, 3) < 0)
    {
        // LOGE("failed to read value!\n");
        return -1;
    }

    close(fd);
    return (atoi(value_str));
}

int GpioControl::writeStatus(int gpio, int value)
{
    static const char values_str[] = "01";
    char path[DIRECTION_MAX];
    int fd;

    snprintf(path, DIRECTION_MAX, "/sys/class/gpio/gpio%d/value", gpio);
    fd = open(path, O_WRONLY);
    if (fd < 0)
    {
        // LOGE("failed to open gpio value for writing!\n");
        return 0;
    }

    if (write(fd, &values_str[value == GPIO_VALUE_LOW ? 0 : 1], 1) < 0)
    {
        // LOGE("failed to write value!\n");
        return 0;
    }

    close(fd);
    return 1;
}

int GpioControl::unexp(int gpio)
{
    char buffer[BUFFER_MAX];
    int len;
    int fd;

    fd = open("/sys/class/gpio/unexport", O_WRONLY);
    if (fd < 0)
    {
        // LOGE("Failed to open unexport for writing!\n");
        return 0;
    }

    len = snprintf(buffer, BUFFER_MAX, "%d", gpio);
    if (write(fd, buffer, len) < 0)
    {
        // LOGE("Fail to unexport gpio!");
        return 0;
    }

    close(fd);
    return 1;
}

bool GpioControl::EnableGpio(int gpio, bool en)
{
    GpioControl gpioControl;
    gpioControl.exp(gpio);
    gpioControl.setDirection(gpio, GPIO_DIRECTION_OUT);

    gpioControl.writeStatus(gpio, en ? GPIO_VALUE_HIGH : GPIO_VALUE_LOW);

    gpioControl.unexp(gpio);

    return true;
}