#include<stdio.h>
#include<stdlib.h>
#include<fcntl.h>
#include<unistd.h>
#include<assert.h>
#include<termios.h>
#include<string.h>
#include<sys/time.h>
#include<sys/types.h>
#include<errno.h>

static int ret;
static int fd;

/*
 * 安全读写函数
 */

ssize_t safe_write(int fd, const void *vptr, size_t n)
{
    size_t  nleft;
    ssize_t nwritten;
    const char *ptr;
    ptr = vptr;
    nleft = n;
   // printf("write:%s,len:%d\n",vptr,n );

    while(nleft > 0)
    {
    if((nwritten = write(fd, ptr, nleft)) <= 0)
        {
            if(nwritten < 0&&errno == EINTR)
                nwritten = 0;
            else
                return -1;
        }
        nleft -= nwritten;
        ptr   += nwritten;
    }
    return(n);
}

ssize_t safe_read(int fd,void *vptr,size_t n)
{
    size_t nleft;
    ssize_t nread;
    char *ptr;

    ptr=vptr;
    nleft=n;

    while(nleft > 0)
    {
        if((nread = read(fd,ptr,nleft)) < 0)
        {
            if(errno == EINTR)//被信号中断
                nread = 0;
            else
                return -1;
        }
        else
        if(nread == 0)
            break;
        nleft -= nread;
        ptr += nread;
    }
    return (n-nleft);
}

int uart_open(int fd,const char *pathname)
{
    assert(pathname);

    /*打开串口*/
    fd = open(pathname,O_RDWR|O_NOCTTY);
    if(fd <0)
    {
        perror("Open UART failed!");
        return -1;
    }

    /*清除串口非阻塞标志*/
    // if(fcntl(fd,F_SETFL,0) < 0)
    // {
    //     fprintf(stderr,"fcntl failed!\n");
    //     return -1;
    // }

    return fd;
}



int uart_set(int fd,int baude,int c_flow,int bits,char parity,int stop)
{
    struct termios options;
    bzero(&options, sizeof(options)); //clear options
    /*获取终端属性*/
    if(tcgetattr(fd,&options) < 0)
    {
        perror("tcgetattr error");
        return -1;
    }

   //printf("btnset:%d\n",baude );
    /*设置输入输出波特率，两者保持一致*/
    switch(baude)
    {
        case 4800:
            cfsetispeed(&options,B4800);
            cfsetospeed(&options,B4800);
            break;
        case 9600:
            cfsetispeed(&options,B9600);
            cfsetospeed(&options,B9600);
            break;
        case 19200:
            cfsetispeed(&options,B19200);
            cfsetospeed(&options,B19200);
            break;
        case 38400:
            cfsetispeed(&options,B38400);
            cfsetospeed(&options,B38400);
            break;
        case 57600:
            cfsetispeed(&options,B57600);
            cfsetospeed(&options,B57600);
            break;
        case 115200:
            cfsetispeed(&options,B115200);
            cfsetospeed(&options,B115200);
            break;
        default:
            fprintf(stderr,"Unkown baude!\n");
            return -1;
    }
    // options.c_cflag |= (CS8 | CLOCAL | CREAD );
    // options.c_cflag &= ~CRTSCTS;//¹Ø±ÕÓ²¼þÁ÷¿Ø          0
    // options.c_iflag = IGNPAR;
    // options.c_oflag &= ~OPOST; //启用输出处理
    // tcflush(fd, TCIFLUSH); //clear data not read
    // int err;
    // err =tcsetattr(fd, TCSANOW, &options); //chang to use now
    /*设置控制模式*/
    options.c_cflag |= CLOCAL;//保证程序不占用串口
    options.c_cflag |= CREAD;//保证程序可以从串口中读取数据

    /*设置数据流控制*/
    switch(c_flow)
    {
        case 0://不进行流控制
            options.c_cflag &= ~CRTSCTS;
            break;
        case 1://进行硬件流控制
            options.c_cflag |= CRTSCTS;
            break;
        case 2://进行软件流控制
            options.c_cflag |= IXON|IXOFF|IXANY;
            break;
        default:
            fprintf(stderr,"Unkown c_flow!\n");
            return -1;
    }

    /*设置数据位*/
    switch(bits)
    {
        case 5:
            options.c_cflag &= ~CSIZE;//屏蔽其它标志位
            options.c_cflag |= CS5;
            break;
        case 6:
            options.c_cflag &= ~CSIZE;//屏蔽其它标志位
            options.c_cflag |= CS6;
            break;
        case 7:
            options.c_cflag &= ~CSIZE;//屏蔽其它标志位
            options.c_cflag |= CS7;
            break;
        case 8:
            options.c_cflag &= ~CSIZE;//屏蔽其它标志位
            options.c_cflag |= CS8;
            break;
        default:
            fprintf(stderr,"Unkown bits!\n");
            return -1;
    }

    /*设置校验位*/
    switch(parity)
    {
        /*无奇偶校验位*/
        case 'n':
        case 'N':
            // options.c_cflag &= ~PARENB;//PARENB：产生奇偶位，执行奇偶校验
            // options.c_cflag &= ~INPCK;//INPCK：使奇偶校验起作用
            break;
        /*设为空格,即停止位为2位*/
        case 's':
        case 'S':
            options.c_cflag &= ~PARENB;//PARENB：产生奇偶位，执行奇偶校验
            options.c_cflag &= ~CSTOPB;//CSTOPB：使用两位停止位
            break;
        /*设置奇校验*/
        case 'o':
        case 'O':
            options.c_cflag |= PARENB;//PARENB：产生奇偶位，执行奇偶校验
            options.c_cflag |= PARODD;//PARODD：若设置则为奇校验,否则为偶校验
            options.c_cflag |= INPCK;//INPCK：使奇偶校验起作用
            options.c_cflag |= ISTRIP;//ISTRIP：若设置则有效输入数字被剥离7个字节，否则保留全部8位
            break;
        /*设置偶校验*/
        case 'e':
        case 'E':
            options.c_cflag |= PARENB;//PARENB：产生奇偶位，执行奇偶校验
            options.c_cflag &= ~PARODD;//PARODD：若设置则为奇校验,否则为偶校验
            options.c_cflag |= INPCK;//INPCK：使奇偶校验起作用
            options.c_cflag |= ISTRIP;//ISTRIP：若设置则有效输入数字被剥离7个字节，否则保留全部8位
            break;
        default:
            fprintf(stderr,"Unkown parity!\n");
            return -1;
    }

    /*设置停止位*/
    switch(stop)
    {
        case 1:
            options.c_cflag &= ~CSTOPB;//CSTOPB：使用两位停止位
            break;
        case 2:
            options.c_cflag |= CSTOPB;//CSTOPB：使用两位停止位
            break;
        default:
            fprintf(stderr,"Unkown stop!\n");
            return -1;
    }

    /*设置输出模式为原始输出*/
    options.c_oflag &= ~OPOST;//OPOST：若设置则按定义的输出处理，否则所有c_oflag失效

    /*设置本地模式为原始模式*/
    options.c_lflag &= IGNPAR;//~(ICANON | ECHO | ECHOE | ISIG);
    /*
     *ICANON：允许规范模式进行输入处理
     *ECHO：允许输入字符的本地回显
     *ECHOE：在接收EPASE时执行Backspace,Space,Backspace组合
     *ISIG：允许信号
     */

    /*设置等待时间和最小接受字符*/
    options.c_cc[VTIME] = 150;//可以在select中设置
    options.c_cc[VMIN] = 0;//最少读取一个字符

    /*如果发生数据溢出，只接受数据，但是不进行读操作*/
    tcflush(fd,TCIFLUSH);

    /*激活配置*/
    if(tcsetattr(fd,TCSANOW,&options) < 0)
    {
        perror("tcsetattr failed");
        return -1;
    }

    return 0;
}

int uart_read(int fd,char *r_buf,size_t len)
{
    ssize_t cnt = 0;
    fd_set rfds;
    struct timeval time;

    /*将文件描述符加入读描述符集合*/
    FD_ZERO(&rfds);
    FD_SET(fd,&rfds);

    /*设置超时为15s*/
    time.tv_sec = 15;
    time.tv_usec = 0;

    /*实现串口的多路I/O*/
    ret = select(fd+1,&rfds,NULL,NULL,&time);
    switch(ret)
    {
        case -1:
            fprintf(stderr,"select error!\n");
            return -1;
        case 0:
            fprintf(stderr,"time over!\n");
            return -1;
        default:
            cnt = safe_read(fd,r_buf,len);
            if(cnt == -1)
            {
                fprintf(stderr,"read error!\n");
                return -1;
            }
            return cnt;
    }
}

int uart_write(int fd,const char *w_buf,size_t len)
{
    ssize_t cnt = 0;

    cnt = safe_write(fd,w_buf,len);
    if(cnt == -1)
    {
        fprintf(stderr,"write error!\n");
        return -1;
    }

    return cnt;
}

int uart_close(int fd)
{
    assert(fd);
    close(fd);

    /*可以在这里做些清理工作*/

    return 0;
}
void init_ttySerial(int fd,int btn)
{
    struct termios options;
    bzero(&options, sizeof(options)); //clear options

    cfsetispeed(&options,btn ); //set baudrate
    cfsetospeed(&options, btn); 
    options.c_cflag |= (CS8 | CLOCAL | CREAD );
    options.c_cflag &= ~CRTSCTS;//¹Ø±ÕÓ²¼þÁ÷¿Ø
    options.c_iflag = IGNPAR;
    options.c_oflag &= ~OPOST; //启用输出处理
    tcflush(fd, TCIFLUSH); //clear data not read
    int err;
    err =tcsetattr(fd, TCSANOW, &options); //chang to use now
    fprintf(stderr, "init tvsetattr:%d\n",err );
}

int serial_init(char *ttySx,int btn)
{
    fd = uart_open(fd,ttySx);/*串口号/dev/ttySn,USB口号/dev/ttyUSBn*/
    //init_ttySerial(fd,btn);
    // if(fd == -1)
    // {
    //     fprintf(stderr,"uart_open error\n");
    //     exit(EXIT_FAILURE);
    // }
    // //int uart_set(int fd,int baude,int c_flow,int bits,char parity,int stop)
    if(uart_set(fd,btn,0,8,'N',1) == -1)
    {
        fprintf(stderr,"uart set failed!\n");
        exit(EXIT_FAILURE);
    }
     printf("com:%s,btn:%d\n",ttySx,btn );
}

int uart_sendstr(char *str)
{
    int len=0;
    len =strlen(str);
    char strcp[len+4];
    memset(strcp,0,len+4);
    strcpy(strcp,str);
    len =strlen(strcp);
    if(strcp[len-2]!= '\r')
    {
        if(strcp[len-1]=='\n')
        {
            strcp[len-1]='\0';
            strcat(strcp,"\r\n");
        }
        else
        {
            if(strcp[len-1]!='\r')
                strcat(strcp,"\r\n");
            else
            {
                strcp[len-1]='\0';
                strcat(strcp,"\r\n"); 
            }

        }
    }
    len = strlen(strcp);
    ret = uart_write(fd,strcp,len);
    if(ret == -1)
    {
        //fprintf(stderr,"uart write failed!\n");
        exit(EXIT_FAILURE);
    }
    fprintf(stderr,"serial send:%s\n",str );
}

// char * right(char *dst,char *src, int n)
// { 
//     char *p = src; 
//     char *q = dst; 
//     int len = strlen(src); 
//     if(n>len) n = len; 
//     p += (len-n); /*从右边第n个字符开始，到0结束，很巧啊*/
//     while(*(q++) = *(p++));
//     return dst; 
// }

int uart_readline(char *str)
{
    char c[]="00000";
    int len;
    memset(str,0,sizeof(str));
    while(1)
    {
        memset(c,0,4);
        len=read(fd,c,1);
        if(len > 0)
        {
            strcat(str,c); 
        }
        else
        {
            usleep(2000);
            continue;
        }
        if(c[0]=='\n')
        {
            if(str[strlen(str)-1]!='\r')
            {
                strcat(str,"\r\n"); 
            }
            else
            {
                strcat(str,c); 
            }
            break;
        }
        if(strlen(str)>1000)
        {
            strcat(str,"\r\n"); 
            break;
        }
    }
   fprintf(stderr,"rev:%s\n",str );
}