/*
 *  Based loosly on code from:
 *  ups.c Copyright (c) 1999-2000 Vojtech Pavlik
 *  NUT 0.44-3 nutusb.c Copyright (C) 2001  Russell Kroll <rkroll@exploits.org>
 *  includes battery date function from apcupsd
 *     Copyright (c) 2001 Vojtech Pavlik <vojtech@ucw.cz>
 *     Copyright (c) 2001 Paul Stewart <hiddev@wetlogic.net>
 *
 *  and a small amount of original code from Rob Crittenden Copyright (c) 2002
 */

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or 
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 * 
 * Should you need to contact me, the author, you can do so either by
 * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
 * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
 */

#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sys/signal.h>
#include <asm/types.h>
#include "linux/hiddev.h"

/* power device page: x84 */

#define UPS_USAGE               0x840004
#define UPS_BATTVOLT            0x840030        /* voltage * 100             */
#define UPS_LOADPCT             0x840035        /* load percentage           */
#define UPS_BELOW_RCL           0x840042        /* below remaining cap limit */
#define UPS_CHARGING            0x840044        /* 0 = no longer charging    */
#define UPS_SHUTDOWN_IMMINENT   0x840069        /* 1 = low battery           */
#define UPS_MFR                 0x8400FD        /* manufacturer              */
#define UPS_IPRODUCT            0x8400FE        /* model name                */
#define UPS_ISERIAL             0x8400FF        /* serial number             */

/* battery system page: x85 */

#define BATT_CHARGING           0x850044        /* 1 = charging, 0 = charged */
#define BATT_DISCHARGING        0x850045        /* 1 = on battery            */
#define BATT_REMAINING_CAPACITY 0x850066        /* battery percentage        */
#define BATT_RUNTIME_TO_EMPTY   0x850068        /* minutes                   */
#define BATT_MFRDATE            0x850085        /* manufacturer date         */
#define BATT_ICHEMISTRY         0x850089        /* battery type              */
#define BATT_AC_PRESENT         0x8500d0        /* 1 = on line               */
#define BATT_IOEMINFORMATION    0x85008f        /* battery OEM description   */

static char *getstring(int fd, int type)
{
        struct  hiddev_usage_ref uref;
        struct  hiddev_string_descriptor sdesc;
        static  char    str[256];

        /* TODO: build a report table so we don't need HID_REPORT_ID_UNKNOWN */

        memset(&uref, 0, sizeof(uref));
        memset(&sdesc, 0, sizeof(sdesc));
        uref.report_type = HID_REPORT_TYPE_FEATURE;
        uref.report_id = HID_REPORT_ID_UNKNOWN;
        uref.usage_code = type;

        snprintf(str, sizeof(str), "Unknown");
        if (ioctl(fd, HIDIOCGUSAGE, &uref) == 0) {
                sdesc.index = uref.value;
                if (ioctl(fd, HIDIOCGSTRING, &sdesc) > 0)
                        snprintf(str, sizeof(str), "%s", sdesc.value);
                else
                        perror("ioctl HIDIOCGSTRING");
        }

        return str;
}

int getval(int fd, int type)
{
        struct  hiddev_usage_ref uref;

        /* TODO: build a report table so we don't need HID_REPORT_ID_UNKNOWN */

        memset(&uref, 0, sizeof(uref));
        uref.report_type = HID_REPORT_TYPE_FEATURE;
        uref.report_id = HID_REPORT_ID_UNKNOWN;
        uref.field_index = 0;
        uref.usage_index = 0;
        uref.usage_code = type;
        uref.value = 0;

        if (ioctl(fd, HIDIOCGUSAGE, &uref) == 0)
                return uref.value;
        else
                return -1;
}

static inline int find_application(int fd, unsigned usage)
{
        int     i = 0, ret;

        while ((ret = ioctl(fd, HIDIOCAPPLICATION, i)) > 0 &&
               ret != usage)
                i++;

        return (ret == usage);
}

int main (int argc, char **argv) {
    int fd = -1, i;
    char name[256] = "Unknown";
    int battdate = 0;

    if (argc < 2) {
	char evdev[20];
	for (i = 0; i < 4; i++) {
	    sprintf(evdev, "/dev/usb/hid/hiddev%d", i);
	    if ((fd = open(evdev, O_RDONLY)) >= 0) {
		if (find_application(fd, UPS_USAGE)) break;
		close(fd);
	    }
	}
	if (i >= 4) {
	    fprintf(stderr, "Couldn't find UPS device.\n");
	    exit(1);
	}
        printf("Found UPS at %s\n", evdev);
    } else {
	if ((fd = open(argv[argc - 1], O_RDONLY)) < 0) {
	    perror("hiddev open");
	    exit(1);
	}
	if (!find_application(fd, UPS_USAGE)) {
	    fprintf(stderr, "%s is not a UPS\n", argv[argc - 1]);
	    exit(1);
	}
    }

    ioctl(fd, HIDIOCINITREPORT, 0);

    printf("Manufacturer: %s\n", getstring(fd, UPS_MFR));

    printf("Model: %s\n", getstring(fd, UPS_IPRODUCT));
    printf("Serial #: %s\n", getstring(fd, UPS_ISERIAL), 0, 0);
    
    printf("Battery Manufacture date: ");
    battdate = getval(fd, BATT_MFRDATE);
    printf("%4d-%02d-%02d (%d)\n", (battdate >> 9) + 1980,
                            (battdate >> 5) & 0xF, battdate & 0x1F,
                            battdate);

    printf("Battery Capacity: %d%%\n", getval(fd, BATT_REMAINING_CAPACITY));

    printf("Battery Runtime: %d\n", getval(fd, BATT_RUNTIME_TO_EMPTY));

    printf("Battery Voltage: %2.1f\n", (getval(fd, UPS_BATTVOLT) / 100.0));

    printf("UPS State: ");
    switch(getval(fd, BATT_AC_PRESENT)) {
        case 0:
            printf("On battery\n");
            break;
        case 1:
            printf("On line\n");
            break;
        default:
            printf("Unknown battery status\n");
            break;
    }
}