/*********************************************************************************
 *      Copyright:  (C) 2024 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  key.c
 *    Description:  This file is linux GPIO button driver test code.
 *
 ********************************************************************************/

#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <libgen.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <linux/input.h>
#include <linux/kd.h>
#include <linux/keyboard.h>

#if 0 /* Just for comment here, Reference to linux-3.3/include/linux/input.h */
struct input_event
{
    struct timeval time;
    __u16 type;  /* 0x00:EV_SYN 0x01:EV_KEY 0x04:EV_MSC 0x11:EV_LED*/
    __u16 code;  /* key value, which key */
    __s32 value; /* 1: Pressed  0:Not pressed  2:Always Pressed */
};
#endif

#define EV_RELEASED        0
#define EV_PRESSED         1
#define EV_REPEAT          2

#define BUTTON_CNT         1

#define MODE_POLL          0x01
#define MODE_NORMAL        0x02

void usage(char *name);
void display_button_event(struct input_event *ev, int cnt);

static void program_usage(const char *progname)
{
    printf("Usage: %s [OPTION]...\n", progname);
    printf(" This is linux GPIO button driver test program.\n");

    printf(" -d[device  ]  Specify input device number, such as 0\n");
    printf(" -h[help    ]  Display this help information\n");

    printf("\n");
    printf("%s program Version v1.0.0\n", progname);
    printf("Copyright (C) 2023 LingYun IoT System Studio.\n");

    return;
}

int main(int argc, char **argv)
{
    char                   *progname=NULL;
    char                    kbd_dev[128];
    char                    kbd_name[128] = "Unknown";
    int                     kbd_fd = -1;
    struct input_event      ev[BUTTON_CNT];
    int                     size = sizeof (struct input_event);

    int                     which = -1;
    int                     rv, opt;
    fd_set                  rds;

    struct option long_options[] = {
        {"device", required_argument, NULL, 'd'},
        {"help", no_argument, NULL, 'h'},
        {NULL, 0, NULL, 0}
    };

    progname = basename(argv[0]);

    /* Parser the command line parameters */
    while ((rv = getopt_long(argc, argv, "d:h", long_options, NULL)) != -1)
    {
        switch (rv)
        {
            case 'd': /*  Set infrared number, such as 0...max */
                which = atoi(optarg);
                break;

            case 'h':  /* Get help information */
                program_usage(progname);
                return 0;

            default:
                break;
        }
    }

    if( !which )
    {
        program_usage(progname);
        return 1;
    }

    if ((getuid ()) != 0)
        printf ("You are not root! This may not work...\n");

    snprintf(kbd_dev, sizeof(kbd_dev), "/dev/input/event%d", which);
    if ((kbd_fd = open(kbd_dev, O_RDONLY)) < 0)
    {
        printf("Open %s failure: %s", kbd_dev, strerror(errno));
        return -1;
    }

    ioctl (kbd_fd, EVIOCGNAME (sizeof (kbd_name)), kbd_name);
    printf ("Monitor input device %s (%s) event on poll mode:\n", kbd_dev, kbd_name);

    while (1)
    {
        FD_ZERO(&rds);
        FD_SET(kbd_fd, &rds);

        rv = select(kbd_fd + 1, &rds, NULL, NULL, NULL);
        if (rv < 0)
        {
            printf("select() system call failure: %s\n", strerror(errno));
            goto cleanup;
        }
        else if (FD_ISSET(kbd_fd, &rds))
        {
            if ((rv=read(kbd_fd, ev, size*BUTTON_CNT )) < size)
            {
                printf("Reading data from kbd_fd failure: %s\n", strerror(errno));
                break;
            }
            else
            {
                display_button_event(ev, rv/size);
            }
        }
    }

cleanup:
    close(kbd_fd);

    return 0;
}

void display_button_event(struct input_event *ev, int cnt)
{
    int i;
    struct timeval        pressed_time, duration_time;

    for(i=0; i<cnt; i++)
    {
        //printf("type:%d code:%d value:%d\n", ev[i].type, ev[i].code, ev[i].value);
        if(EV_KEY==ev[i].type && EV_PRESSED==ev[i].value)
        {
            pressed_time = ev[i].time;
            printf("Keypad[%d] pressed time: %ld.%ld\n", ev[i].code, pressed_time.tv_sec, pressed_time.tv_usec);
        }

        if(EV_KEY==ev[i].type && EV_RELEASED==ev[i].value)
        {
            timersub(&ev[i].time, &pressed_time, &duration_time);
            printf("keypad[%d] duration time: %ld.%ld\n", ev[i].code, duration_time.tv_sec, duration_time.tv_usec);
        }
    }
}