/*********************************************************************************
 *      Copyright:  (C) 2024 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  can_test.c
 *    Description:  This file is socket CAN loop test program
 *
 *        Version:  1.0.0(05/26/2024)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "05/26/2024 05:42:49 PM"
 *
 ********************************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <sys/socket.h>
#include <linux/can.h>
#include <linux/can/raw.h>
#include <getopt.h>

// 打印使用帮助信息
void print_usage(const char *progname)
{
    printf("Usage: %s -i <can_interface> -m <mode>\n", progname);
    printf("Options:\n");
    printf("  -i, --interface    CAN interface (e.g., can0)\n");
    printf("  -m, --mode         Mode: send or receive\n");
    printf("  -h, --help         Display this help message\n");
}

void send_can_message(const char *ifname)
{
    int                     fd;
    struct sockaddr_can     addr;
    struct ifreq            ifr;
    struct can_frame        frame;

    // 创建socket
    fd = socket(PF_CAN, SOCK_RAW, CAN_RAW);
    if (fd < 0)
    {
        perror("socket");
        exit(1);
    }

    // 指定CAN接口
    strcpy(ifr.ifr_name, ifname);
    ioctl(fd, SIOCGIFINDEX, &ifr);
    addr.can_family = AF_CAN;
    addr.can_ifindex = ifr.ifr_ifindex;

    // 绑定socket到CAN接口
    if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
    {
        perror("bind");
        exit(1);
    }

    // 构造CAN帧
    frame.can_id = 0x123; // 设置CAN ID
    frame.can_dlc = 2;    // 数据长度
    frame.data[0] = 0x11; // 数据
    frame.data[1] = 0x22; // 数据

    // 发送CAN帧
    if (write(fd, &frame, sizeof(struct can_frame)) != sizeof(struct can_frame))
    {
        perror("write");
        exit(1);
    }

    // 关闭socket
    close(fd);
}

void receive_can_message(const char *ifname)
{
    int                     fd;
    struct sockaddr_can     addr;
    struct ifreq            ifr;
    struct can_frame        frame;

    // 创建socket
    fd = socket(PF_CAN, SOCK_RAW, CAN_RAW);
    if (fd < 0) {
        perror("socket");
        exit(1);
    }

    // 指定CAN接口
    strcpy(ifr.ifr_name, ifname);
    ioctl(fd, SIOCGIFINDEX, &ifr);
    addr.can_family = AF_CAN;
    addr.can_ifindex = ifr.ifr_ifindex;

    // 绑定socket到CAN接口
    if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0)
    {
        perror("bind");
        exit(1);
    }

    // 接收CAN帧
    while (1)
    {
        int nbytes = read(fd, &frame, sizeof(struct can_frame));
        if (nbytes < 0)
        {
            perror("read");
            exit(1);
        }

        if (nbytes < sizeof(struct can_frame))
        {
            fprintf(stderr, "read: incomplete CAN frame\n");
            exit(1);
        }

        // 打印接收到的CAN帧
        printf("Received CAN frame: ID=0x%X DLC=%d data=", frame.can_id, frame.can_dlc);
        for (int i = 0; i < frame.can_dlc; i++)
            printf("%02X ", frame.data[i]);

        printf("\n");
    }

    // 关闭socket
    close(fd);
}

int main(int argc, char **argv)
{
    int              opt, index = 0;
    const char      *ifname = NULL;
    const char      *mode = NULL;

    // 定义长选项
    static struct option long_options[] =
    {
        {"interface", required_argument, 0, 'i'},
        {"mode",      required_argument, 0, 'm'},
        {"help",      no_argument,       0, 'h'},
        {0, 0, 0, 0}
    };

    while ((opt = getopt_long(argc, argv, "i:m:h", long_options, &index)) != -1)
    {
        switch (opt) {
            case 'i':
                ifname = optarg;
                break;
            case 'm':
                mode = optarg;
                break;
            case 'h':
                print_usage(argv[0]);
                return 0;
            default:
                print_usage(argv[0]);
                return 1;
        }
    }

    if (ifname == NULL || mode == NULL)
    {
        print_usage(argv[0]);
        return 1;
    }

    if (strcmp(mode, "send") == 0)
    {
        send_can_message(ifname);
    }
    else if (strcmp(mode, "receive") == 0)
    {
        receive_can_message(ifname);
    }
    else
    {
        fprintf(stderr, "Invalid mode: %s\n", mode);
        print_usage(argv[0]);
        return 1;
    }

    return 0;
}