#include <stdlib.h>  
#include <stdio.h>   
#include <stdbool.h>   
#include <string.h> 
#include <unistd.h> 
#include <fcntl.h>  
#include <poll.h> 
#include <sys/epoll.h> 
#include <sys/time.h>
#include <errno.h> 
#include <linux/input.h> 

#define MSG(args...) printf(args) 
#define MSG_I(args...) printf(args) 
#define MSG_W(args...) printf(args) 
#define MSG_E(args...) printf(args) 

static int g_epollFd = -1;

//函数声明
static int gpio_export(int pin);
static int gpio_unexport(int pin);
static int gpio_direction(int pin, int dir);
static int gpio_write(int pin, int value);
static int gpio_read(int pin);

static int gpio_export(int pin)  
{  
    char buffer[64];  
    int len;  
    int fd;  

    char gpio_pin[64];
    snprintf( gpio_pin, sizeof(gpio_pin), "/sys/class/gpio/gpio%d", pin );
    if( access( gpio_pin, F_OK ) == 0 ){    // 如果已经申请
        MSG_I("%s it already exists\n", gpio_pin );
        return 0;
    }

    fd = open("/sys/class/gpio/export", O_WRONLY);  
    if (fd < 0) {  
        MSG("Failed to open export for writing!\n");  
        return(-1);  
    }  

    len = snprintf(buffer, sizeof(buffer), "%d", pin);  
    if (write(fd, buffer, len) < 0) {  
        MSG("Failed to export gpio!\n");  
        return -1;  
    }  

    close(fd);  
    return 0;  
}  

static int gpio_unexport(int pin)  
{  
    char buffer[64];  
    int len;  
    int fd;  

    fd = open("/sys/class/gpio/unexport", O_WRONLY);  
    if (fd < 0) {  
        MSG("Failed to open unexport for writing!\n");  
        return -1;  
    }  

    len = snprintf(buffer, sizeof(buffer), "%d", pin);  
    if (write(fd, buffer, len) < 0) {  
        MSG("Failed to unexport gpio!");  
        return -1;  
    }  
    close(fd);  
    return 0;  
} 

//dir: 0-->IN, 1-->OUT
static int gpio_direction(int pin, int dir)  
{  
    static const char dir_str[] = "in\0out";  
    char path[64];  
    int fd;  

    snprintf(path, sizeof(path), "/sys/class/gpio/gpio%d/direction", pin);  

    fd = open(path, O_WRONLY);  
    if (fd < 0) {  
        MSG("Failed to open gpio direction for writing!\n");  
        return -1;  
    }  

    if (write(fd, &dir_str[dir == 0 ? 0 : 3], dir == 0 ? 2 : 3) < 0) {  
        MSG("Failed to set direction!\n");  
        return -1;  
    }  

    close(fd);  
    return 0;  
}  

//value: 0-->LOW, 1-->HIGH
static int gpio_write(int pin, int value)  
{  
    static const char values_str[] = "01";  
    char path[64];  
    int fd;  

    snprintf(path, sizeof(path), "/sys/class/gpio/gpio%d/value", pin);  
    fd = open(path, O_WRONLY);  
    if (fd < 0) {  
        MSG("Failed to open gpio value for writing!\n");  
        return -1;  
    }  

    if (write(fd, &values_str[value == 0 ? 0 : 1], 1) < 0) {  
        MSG("Failed to write value!\n");  
        return -1;  
    }  

    close(fd);  
    return 0;  
}

static int gpio_read(int pin)  
{  
    char path[64];  
    char value_str[3];  
    int fd;  

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

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

    close(fd);  

    return (atoi(value_str));
}  

// none表示引脚为输入，不是中断引脚
// rising表示引脚为中断输入，上升沿触发
// falling表示引脚为中断输入，下降沿触发
// both表示引脚为中断输入，边沿触发
// 0-->none, 1-->rising, 2-->falling, 3-->both
static int gpio_edge(int pin, int edge)
{
    const char dir_str[][9] = {"none\0","rising\0","falling\0","both"}; 
    char path[64];  
    int fd; 

    snprintf(path, sizeof(path), "/sys/class/gpio/gpio%d/edge", pin);  
    fd = open(path, O_WRONLY);  
    if (fd < 0) {  
        MSG("Failed to open gpio edge for writing!\n");  
        return -1;  
    }  

    if (write(fd, &dir_str[edge], strlen(dir_str[edge])) < 0) {  
        MSG("Failed to set edge!\n");  
        return -1;  
    }  

    close(fd);  
    return 0;  
}



static long int getNowTime()
{
    struct timeval p_time;
    gettimeofday( &p_time, NULL );
    return p_time.tv_sec*1000+p_time.tv_usec/1000;
}


int addFdToEpoll( int pollFd, int addFd )
{
    struct epoll_event event;
    event.events = EPOLLET;
    event.data.fd = addFd;
    return epoll_ctl( pollFd, EPOLL_CTL_ADD, addFd, &event );
}

#define CALL_KEY_NUM    ( 32 )
#define VOLDOWN_KEY_NUM ( 30 )
#define VOLUP_KEY_NUM   ( 98 )

typedef struct{
    int fd;
    bool press_key;     // 按下按键
    bool lift_key;
    long int press_time; // 按下按键的时间
}gpio_info;

int main()  
{  

    /* int gpio_fd1, gpio_fd2, gpio_fd3; */
    gpio_info gpioCall, gpioDown,gpioUp;
    int ret;
    struct pollfd fds[1];
    char buff[10];
    unsigned char cnt = 0;

    g_epollFd = epoll_create(4); //创建红黑树,返回给全局 g_efd, linux2.6之后size>0即可
    if(g_epollFd <= 0)
        MSG("create efd in %s err %s\n", __func__, strerror(errno));


    //按键引脚初始化
    gpio_export( VOLDOWN_KEY_NUM );
    gpio_direction( VOLDOWN_KEY_NUM, 0);
    gpio_edge( VOLDOWN_KEY_NUM,3);
    gpioDown.fd = open("/sys/class/gpio/gpio30/value",O_RDONLY);
    if( gpioDown.fd < 0){
        MSG("Failed to open 30 value!\n");  
        return -1;  
    }
    addFdToEpoll( g_epollFd, gpioDown.fd );

    gpio_export(CALL_KEY_NUM);
    gpio_direction(CALL_KEY_NUM, 0);
    gpio_edge(CALL_KEY_NUM,3);
    gpioCall.fd = open("/sys/class/gpio/gpio32/value",O_RDONLY);
    if( gpioCall.fd < 0){
        MSG("Failed to open 32 value!\n");  
        return -1;  
    }
    addFdToEpoll( g_epollFd, gpioCall.fd );

    gpio_export(VOLUP_KEY_NUM);
    gpio_direction(VOLUP_KEY_NUM, 0);
    gpio_edge(VOLUP_KEY_NUM,3);
    gpioUp.fd = open("/sys/class/gpio/gpio98/value",O_RDONLY);
    if(gpioUp.fd < 0){
        MSG("Failed to open 98 value!\n");  
        return -1;  
    }
    addFdToEpoll( g_epollFd, gpioUp.fd );
    
    struct epoll_event events;
    int value;
    gpio_info *gpioTmp;
    while(1){
        ret = epoll_wait( g_epollFd, &events, 1, 500 );
        if( ret < 0 ){
            MSG("epoll_wait %s err %s\n", __func__, strerror(errno));
            break;
        }
        else if( ret == 0 ){
            /* MSG("epoll_wait timeout\n"); */
            long int nowTime = getNowTime();
            if( ( gpioCall.press_key ) && 
                ( !gpioCall.lift_key ) &&
                ( (nowTime - gpioCall.press_time) > 1000 ) ){
                MSG("Press the CALL button continuously\n");
            }
            if( ( gpioUp.press_key ) && 
                ( !gpioUp.lift_key ) &&
                ( (nowTime - gpioUp.press_time) > 1000 ) ){
                MSG("Press the VOL UP button continuously\n");
            }
            if( ( gpioDown.press_key ) && 
                ( !gpioDown.lift_key ) &&
                ( (nowTime - gpioDown.press_time) > 1000 ) ){
                MSG("Press the VOL DOWN button continuously\n");
            }
        }
        else{
            lseek( events.data.fd, 0, SEEK_SET );
            memset( buff, 0, sizeof(buff) );
            ret = read( events.data.fd, buff, sizeof(buff) );
            if( ret <= 0 ){
                MSG_E("read error, %d, %s\n", errno, strerror(errno));
                continue;
            }

            /* MSG("ret = %d, buff : %s\n", ret, buff ); */
            /* MSG("ret = %d, buff : %s\n", ret, buff ); */
            value = atoi( buff );

            if( events.data.fd == gpioUp.fd){
                MSG( "push vol up, %s", buff );
                gpioTmp = &gpioUp;
            }
            else if( events.data.fd == gpioCall.fd){
                MSG( "push call, %s", buff );
                gpioTmp = &gpioCall;
            }
            else if( events.data.fd == gpioDown.fd){
                MSG( "push vol down, %s", buff );
                gpioTmp = &gpioDown;
            }

            if( value == 0 ){ // 按键按下
                gpioTmp->press_key = true;
                gpioTmp->press_time = getNowTime();
            }else if ( gpioTmp->press_key ){ // 已经按下了
                gpioTmp->lift_key = true;
            }
            else{
                gpioTmp->press_key = false;
                gpioTmp->lift_key = false;
            }

            // 当按下标志位和按键弹起标志位都为 1 时候，才执行回调
            if( gpioTmp->press_key & gpioTmp->lift_key ){
                gpioTmp->press_key = false;
                gpioTmp->lift_key = false;

                long int nowTime = getNowTime();
                if( ( nowTime - gpioTmp->press_time  ) > 1000 ){ // 长按
                    MSG("long pasaa!!!\n");
                }else if( ( nowTime - gpioTmp->press_time  ) < 10 ){ // 抖动
                    MSG("shake!!!\n");
                }else{
                    MSG("sort pasaa!!!\n");
                }
                MSG("nowTime: %ld, press_time: %ld, %ld\n", nowTime, gpioTmp->press_time, nowTime - gpioTmp->press_time);

            }
                
        }
    }
    return 0;
}