#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <termios.h>
#include <unistd.h>

#define MAX_SIZE 1000

int fd_adc;
int fd_led;
int fd_bz;
char *adc = "/dev/adc";
char *leds = "/dev/leds";
char *buzzer = "/dev/buzzer_ctl";
char buffer[512];

int set_opt(int fd_uart, int nSpeed, int nBits, char nEvent, int nStop);

void getresist() {
    memset(buffer, 0, sizeof(buffer));

    if ((fd_adc = open(adc, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing ADC !\n");
        return;
    }

    int len;
    int i;
    for (i = 0; i < 20; i++) {
        len = read(fd_adc, buffer, 10);
        printf("\033c"); // Clear screen
        printf("content: %s\n", buffer);
        sleep(1);
    }
}

void ctrl_led(int times) {
    if ((fd_led = open(leds, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing LEDs !\n");
        return;
    }

    int i;
    for (i = 0; i < times; i++) {
        ioctl(fd_led, 0, 0);
        ioctl(fd_led, 0, 1);
        sleep(1);
        ioctl(fd_led, 1, 0);
        ioctl(fd_led, 1, 1);
        sleep(1);
    }
}

void ctrl_buzzer(int times) {
    if ((fd_bz = open(buzzer, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing buzzer !\n");
        return;
    }

    int i;
    for (i = 0; i < times; i++) {
        ioctl(fd_bz, 1);
        sleep(1);
        ioctl(fd_bz, 0);
        sleep(1);
    }
}

void resist_ctrl_led() {
    memset(buffer, 0, sizeof(buffer));

    if ((fd_adc = open(adc, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing ADC !\n");
        return;
    }

    if ((fd_led = open(leds, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing LEDs !\n");
        return;
    }

    if ((fd_bz = open(buzzer, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing buzzer !\n");
        return;
    }

    int i;
    int len;
    int resist;
    double period;
    int beep = 0;
    while (1) {
        len = read(fd_adc, buffer, 10);
        ioctl(fd_bz, 0);
        // printf("\033c"); // Clear screen
        resist = atoi(buffer);
        resist *= 2.442; // 10000/4095

        while (resist < 1000 || resist > 9000) {

            if (!beep) {
                ioctl(fd_bz, 1);
                sleep(1);
                ioctl(fd_bz, 0);
                sleep(1);
                beep = 1;
            }

            memset(buffer, 0, sizeof(buffer));
            len = read(fd_adc, buffer, 10);
            // printf("\033c"); // Clear screen
            resist = atoi(buffer);
            resist *= 2.442;
            printf("Resist: %d\n", resist);
        }

        beep = 0;
        // period = (10000 - resist) * 200;
        period = (13.3 - log(resist) / log(2)) * 200000;
        printf("Resist: %d\n", resist);
        printf("Period: %lf\n", period);

        ioctl(fd_led, 0, 0);
        ioctl(fd_led, 0, 1);
        usleep(period);
        ioctl(fd_led, 1, 0);
        ioctl(fd_led, 1, 1);
        usleep(period);
    }
}

int main(void) {
    // getresist(buffer);
    // ctrl_led(10);
    // ctrl_buzzer(10);
    if ((fd_adc = open(adc, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
        printf("Error initializing ADC !\n");
        return -1;
    }

    int len;
    int resist;

    int fd_uart, fd_file, nByte;

    char *uart3 = "/dev/ttySAC3";
    char *IOtest = "/home/temp/data.txt";

    char uart_out[50];
    char resist_str[4];

    char buffer_read[MAX_SIZE];

    int byte = 0;

    char *str_1 = "Resistance: ";
    char *str_2 = " Ohm Alert: ";
    char *str_alert;

    // (2) 打开串口3，路径名指向指向终端设备
    if ((fd_file = open(IOtest, O_RDWR, 0777)) < 0) {
        printf("open %s failed!\n", IOtest);
        return;
    } else {
        if ((fd_uart = open(uart3, O_RDWR | O_TRUNC, 0777)) < 0)
            printf("open %s is failed", uart3);
        else {
            // (3) 预热实验中, 初始化串口3, 波特率9600, 8位数据位, 无校验,
            // 1位停止位
            // (4) 串口监视器实验中,