#define LOG_TAG "brightnessbtn"

#include <sys/stat.h>
#include <poll.h>
#include <fcntl.h>
#include <errno.h>
#include <dirent.h>
#include <cutils/log.h>
#include <linux/input.h>
#include <linux/uinput.h>
#include <cutils/properties.h>

const int MAX_POWERBTNS = 3;  // убрал бы нафиг но дальше зачем то нужна)

int openfds(struct pollfd pfds[])  //  функция открытия девайся? о_О
{
    int cnt = 0;
    const char *dirname = "/dev/input";
    DIR *dir;
    if ((dir = opendir(dirname))) {
        int fd;
        struct dirent *de;
        while ((de = readdir(dir))) {
            if (de->d_name[0] != 'e') // eventX
                continue;
            char name[PATH_MAX];
            snprintf(name, PATH_MAX, "%s/%s", dirname, de->d_name);
            fd = open(name, O_RDWR | O_NONBLOCK);
            if (fd < 0) {
                LOGE("could not open %s, %s", name, strerror(errno));
                continue;
            }
            name[sizeof(name) - 1] = '\0';
            if (ioctl(fd, EVIOCGNAME(sizeof(name) - 1), &name) < 1) {
                LOGE("could not get device name for %s, %s\n", name, strerror(errno));
                name[0] = '\0';
            }

            // TODO: parse /etc/excluded-input-devices.xml
            if (!strcmp(name, "nvec keyboard")) {    //я так понял что он сам по имени выбирает путь девайса =)
                LOGI("open %s(%s) ok", de->d_name, name);
                pfds[cnt].events = POLLIN;
                pfds[cnt++].fd = fd;
                if (cnt < MAX_POWERBTNS)
                    continue;
                else
                    break;
            }
            close(fd);
        }
        closedir(dir);
    }

    return cnt;
}

void change_brightness(int up_down){
    int brightness

    if (up_down){
        brightness = 100;
        write_int("/sys/class/backlight/pwm-backlight/brightness", brightness);
    } else {
        brightness = 30;
        write_int("/sys/class/backlight/pwm-backlight/brightness", brightness);
    }
}

int main()
{
    struct pollfd pfds[MAX_POWERBTNS];
    int cnt = openfds(pfds);
    int timeout = -1;
    char prop[PROPERTY_VALUE_MAX];

    int ufd = open("/dev/uinput", O_WRONLY | O_NDELAY);
    if (ufd >= 0) {
        struct uinput_user_dev ud;
        memset(&ud, 0, sizeof(ud));
        strcpy(ud.name, "Android Power Button");
        write(ufd, &ud, sizeof(ud));
        ioctl(ufd, UI_SET_EVBIT, EV_KEY);
        ioctl(ufd, UI_SET_KEYBIT, KEY_POWER);
        ioctl(ufd, UI_DEV_CREATE, 0);
    } else {
        LOGE("could not open uinput device: %s", strerror(errno));
        return -1;
    }

    for (;;) {
        int i;
        int pollres = poll(pfds, cnt) ;
        LOGV("pollres=%d %d\n", pollres);
        if (pollres < 0) {
            LOGE("poll error: %s", strerror(errno));
            break;
        }

        for (i = 0; i < cnt; ++i) {
            if (pfds[i].revents & POLLIN) {
                struct input_event iev;
                size_t res = read(pfds[i].fd, &iev, sizeof(iev));
                if (res < sizeof(iev)) {
                    LOGW("insufficient input data(%d)? fd=%d", res, pfds[i].fd);
                    continue;
                }
                LOGV("type=%d scancode=%d value=%d from fd=%d", iev.type, iev.code, iev.value, pfds[i].fd);
                if (iev.type == EV_KEY && (iev.code == KEY_BRIGHTNESS_DOWN || iev.code == KEY_BRIGHTNESS_UP) && !iev.value) {
                    if (iev.code == KEY_BRIGHTNESS_DOWN) {
                        change_brightness(1);
                    } else {
                        change_brightness(0)
                    }
                }
            }
        }
    }

    return 0;
}