#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <linux/input.h>
#include <termios.h>
#include <errno.h>
#include <stdbool.h>
#include <string.h>

#define PROGRAM_NAME "kl"

static struct termios original_term;
const char *key_names[256] = {0};

void init_key_names() {
	key_names[KEY_Q] = "Q";
	key_names[KEY_W] = "W";
	key_names[KEY_E] = "E";
	key_names[KEY_R] = "R";
	key_names[KEY_T] = "T";
	key_names[KEY_Y] = "Y";
	key_names[KEY_U] = "U";
	key_names[KEY_I] = "I";
	key_names[KEY_O] = "O";
	key_names[KEY_P] = "P";
	key_names[KEY_A] = "A";
	key_names[KEY_S] = "S";
	key_names[KEY_D] = "D";
	key_names[KEY_F] = "F";
	key_names[KEY_G] = "G";
	key_names[KEY_H] = "H";
	key_names[KEY_J] = "J";
	key_names[KEY_K] = "K";
	key_names[KEY_L] = "L";
	key_names[KEY_Z] = "Z";
	key_names[KEY_X] = "X";
	key_names[KEY_C] = "C";
	key_names[KEY_V] = "V";
	key_names[KEY_B] = "B";
	key_names[KEY_N] = "N";
	key_names[KEY_M] = "M";

	key_names[KEY_1] = "1";
	key_names[KEY_2] = "2";
	key_names[KEY_3] = "3";
	key_names[KEY_4] = "4";
	key_names[KEY_5] = "5";
	key_names[KEY_6] = "6";
	key_names[KEY_7] = "7";
	key_names[KEY_8] = "8";
	key_names[KEY_9] = "9";
	key_names[KEY_0] = "0";

	key_names[KEY_MINUS] = "-";
	key_names[KEY_EQUAL] = "=";
	key_names[KEY_LEFTBRACE] = "[";
	key_names[KEY_RIGHTBRACE] = "]";
	key_names[KEY_SEMICOLON] = ";";
	key_names[KEY_APOSTROPHE] = "'";
	key_names[KEY_GRAVE] = "`";
	key_names[KEY_BACKSLASH] = "\\";
	key_names[KEY_COMMA] = ",";
	key_names[KEY_DOT] = ".";
	key_names[KEY_SLASH] = "/";
	key_names[KEY_SPACE] = "<SPACE>";

	key_names[KEY_ESC] = "<ESC>";
	key_names[KEY_BACKSPACE] = "<BACKSPACE>";
	key_names[KEY_TAB] = "<TAB>";
	key_names[KEY_ENTER] = "<ENTER>";
	key_names[KEY_LEFTSHIFT] = "<L_SHIFT>";
	key_names[KEY_RIGHTSHIFT] = "<R_SHIFT>";
	key_names[KEY_LEFTCTRL] = "<L_CTRL>";
	key_names[KEY_RIGHTCTRL] = "<R_CTRL>";
	key_names[KEY_LEFTALT] = "<L_ALT>";
	key_names[KEY_RIGHTALT] = "<R_ALT>";
	key_names[KEY_LEFTMETA] = "<L_META>";
	key_names[KEY_RIGHTMETA] = "<R_META>";
	key_names[KEY_CAPSLOCK] = "<CAPSLOCK>";
	key_names[KEY_NUMLOCK] = "<NUMLOCK>";
	key_names[KEY_SCROLLLOCK] = "<SCROLLLOCK>";

	key_names[KEY_F1] = "<F1>";
	key_names[KEY_F2] = "<F2>";
	key_names[KEY_F3] = "<F3>";
	key_names[KEY_F4] = "<F4>";
	key_names[KEY_F5] = "<F5>";
	key_names[KEY_F6] = "<F6>";
	key_names[KEY_F7] = "<F7>";
	key_names[KEY_F8] = "<F8>";
	key_names[KEY_F9] = "<F9>";
	key_names[KEY_F10] = "<F10>";
	key_names[KEY_F11] = "<F11>";
	key_names[KEY_F12] = "<F12>";
	key_names[KEY_F13] = "<F13>";
	key_names[KEY_F14] = "<F14>";
	key_names[KEY_F15] = "<F15>";
	key_names[KEY_F16] = "<F16>";
	key_names[KEY_F17] = "<F17>";
	key_names[KEY_F18] = "<F18>";
	key_names[KEY_F19] = "<F19>";
	key_names[KEY_F20] = "<F20>";
	key_names[KEY_F21] = "<F21>";
	key_names[KEY_F22] = "<F22>";
	key_names[KEY_F23] = "<F23>";
	key_names[KEY_F24] = "<F24>";

	key_names[KEY_KP0] = "<KP0>";
	key_names[KEY_KP1] = "<KP1>";
	key_names[KEY_KP2] = "<KP2>";
	key_names[KEY_KP3] = "<KP3>";
	key_names[KEY_KP4] = "<KP4>";
	key_names[KEY_KP5] = "<KP5>";
	key_names[KEY_KP6] = "<KP6>";
	key_names[KEY_KP7] = "<KP7>";
	key_names[KEY_KP8] = "<KP8>";
	key_names[KEY_KP9] = "<KP9>";
	key_names[KEY_KPDOT] = "<KP.>";
	key_names[KEY_KPCOMMA] = "<KP,>";
	key_names[KEY_KPENTER] = "<KPENTER>";
	key_names[KEY_KPMINUS] = "<KP->";
	key_names[KEY_KPPLUS] = "<KP+>";
	key_names[KEY_KPSLASH] = "<KP/>";
	key_names[KEY_KPASTERISK] = "<KP*>";
	key_names[KEY_KPEQUAL] = "<KP=>";

	key_names[KEY_UP] = "<UP>";
	key_names[KEY_DOWN] = "<DOWN>";
	key_names[KEY_LEFT] = "<LEFT>";
	key_names[KEY_RIGHT] = "<RIGHT>";
	key_names[KEY_HOME] = "<HOME>";
	key_names[KEY_END] = "<END>";
	key_names[KEY_PAGEUP] = "<PAGEUP>";
	key_names[KEY_PAGEDOWN] = "<PAGEDOWN>";
	key_names[KEY_INSERT] = "<INSERT>";
	key_names[KEY_DELETE] = "<DELETE>";

	key_names[KEY_MUTE] = "<MUTE>";
	key_names[KEY_VOLUMEDOWN] = "<VOLUMEDOWN>";
	key_names[KEY_VOLUMEUP] = "<VOLUMEUP>";
	key_names[KEY_POWER] = "<POWER>";
	key_names[KEY_SLEEP] = "<SLEEP>";
	key_names[KEY_WAKEUP] = "<WAKEUP>";
	key_names[KEY_PLAY] = "<PLAY>";
	key_names[KEY_PAUSE] = "<PAUSE>";
	key_names[KEY_PLAYPAUSE] = "<PLAYPAUSE>";
	key_names[KEY_STOPCD] = "<STOP>";
	key_names[KEY_PREVIOUSSONG] = "<PREVIOUS>";
	key_names[KEY_NEXTSONG] = "<NEXT>";
	key_names[KEY_REWIND] = "<REWIND>";
	key_names[KEY_FASTFORWARD] = "<FASTFORWARD>";
	key_names[KEY_RECORD] = "<RECORD>";
	key_names[KEY_EJECTCD] = "<EJECT>";

	key_names[KEY_SYSRQ] = "<SYSRQ>";
	key_names[KEY_PAUSE] = "<PAUSE>";
	key_names[KEY_MENU] = "<MENU>";
	key_names[KEY_CALC] = "<CALC>";
	key_names[KEY_MAIL] = "<MAIL>";
	key_names[KEY_WWW] = "<WWW>";
	key_names[KEY_SEARCH] = "<SEARCH>";
	key_names[KEY_BACK] = "<BACK>";
	key_names[KEY_FORWARD] = "<FORWARD>";
	key_names[KEY_REFRESH] = "<REFRESH>";
	key_names[KEY_STOP] = "<STOP>";
	key_names[KEY_COPY] = "<COPY>";
	key_names[KEY_CUT] = "<CUT>";
	key_names[KEY_PASTE] = "<PASTE>";
	key_names[KEY_UNDO] = "<UNDO>";
	key_names[KEY_REDO] = "<REDO>";
	key_names[KEY_FIND] = "<FIND>";
	key_names[KEY_HELP] = "<HELP>";
	key_names[KEY_FILE] = "<FILE>";
	key_names[KEY_SAVE] = "<SAVE>";
	key_names[KEY_NEW] = "<NEW>";
	key_names[KEY_OPEN] = "<OPEN>";
	key_names[KEY_CLOSE] = "<CLOSE>";
	key_names[KEY_EXIT] = "<EXIT>";
	key_names[KEY_PRINT] = "<PRINT>";
	key_names[KEY_BRIGHTNESSDOWN] = "<BRIGHTNESSDOWN>";
	key_names[KEY_BRIGHTNESSUP] = "<BRIGHTNESSUP>";
	key_names[KEY_DISPLAY_OFF] = "<DISPLAYOFF>";
	key_names[KEY_MICMUTE] = "<MICMUTE>";
	key_names[KEY_WLAN] = "<WLAN>";
	key_names[KEY_BLUETOOTH] = "<BLUETOOTH>";
}

void usage() {
	printf("Usage: %s <EVENT_FILE_PATH>.\n", PROGRAM_NAME);
}

void disable_term_echo() {
	struct termios new_setting, init_setting;
	tcgetattr(0, &init_setting);
	new_setting = init_setting;

	new_setting.c_lflag&=~ECHO;
	tcsetattr(0, TCSANOW, &new_setting);
}

void enable_term_echo() {
	tcsetattr(0, TCSANOW, &original_term);
}

int main(int argc,  char** argv) {
	if (argc != 2 || strcmp(argv[1], "--help") == 0) {
		usage();
		return -1;
	}

	disable_term_echo();

	struct input_event ie;
	int fd = open(argv[1], O_RDONLY);

	if (fd == -1 && errno == EACCES) {
		printf("Permission denied: please run %s with sudo.\n", PROGRAM_NAME);
		return -1;
	}

	init_key_names();

	while (1) {
		read(fd, &ie, sizeof(ie));

		if (ie.type == EV_KEY && ie.value == 2)  {
			continue;
		}

		if (key_names[ie.code] != NULL && ie.value == 1) {
			printf("%s\n", key_names[ie.code]);
		}

	}

	enable_term_echo();
	return 0;
}