/* keyboard.c - keyboard functions */

#include <system.h>
#include <keyboard.h>
#include <console.h>

unsigned short keyflags = 0;
unsigned short key_extended_buffer;
unsigned char keybuffer[256];
unsigned char keybuffer_pointer = 0, keybuffer_count = 0;

unsigned char keydata[128] = {
	0, 0, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 0xDF, '\'', '\b', '\t',
	'q', 'w', 'e', 'r', 't', 'z', 'u', 'i', 'o', 'p', 0xFC, '+', '\n', 0, 'a', 's',
	'd', 'f', 'g', 'h', 'j', 'k', 'l', 0xF6, 0xE4, '^', 0, '#', 'y', 'x', 'c', 'v',
	'b', 'n', 'm', ',', '.', '-', 0, '*', 0, ' ', 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0x0B, 0, 0, '-', 0, 0, 0, '+', 0,
	0, 0, 0, 0, 0, 0, '<', 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

unsigned char keydata_shift[128] = {
	0, 0, '!', '"', 0xA7, '$', '%', '&', '/', '(', ')', '=', '?', '`', '\b', '\t',
	'Q', 'W', 'E', 'R', 'T', 'Z', 'U', 'I', 'O', 'P', 0xDC, '*', '\n', 0, 'A', 'S',
	'D', 'F', 'G', 'H', 'J', 'K', 'L', 0xD6, 0xC4, 0xB0, 0, '\'', 'Y', 'X', 'C', 'V',
	'B', 'N', 'M', ';', ':', '_', 0, '*', 0, ' ', 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0x0B, 0, 0, '-', 0, 0, 0, '+', 0,
	0, 0, 0, 0, 0, 0, '>', 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

unsigned char keydata_extended[128] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '\n', 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, '/', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0x0B, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

unsigned char keydata_altgr[128] = {
	0, 0, 0, 0xB2, 0xB3, 0, 0, 0, '{', '[', ']', '}', '\\', 0, '\b', '\t',
	'@', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '~', '\n', 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0xB5, 0, 0, 0, 0, '*', 0, ' ', 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0x0B, 0, 0, '-', 0, 0, 0, '+', 0,
	0, 0, 0, 0, 0, 0, '|', 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

unsigned char keydata_numlock[13] = {
	'7', '8', '9', '-', '4', '5', '6', '+', '1', '2', '3', '0', ','
};


void update_leds() {
	register unsigned char al asm("%al");
	do {
		asm (
			"in $0x64,%al\n"
			"and $0b00000010,%al\n"
		);
	} while (al);
	asm (
		"mov $0xED,%al\n"
		"out %al,$0x60\n"
	);
	do {
		asm (
			"in $0x64,%al\n"
			"and $0b00000010,%al\n"
		);
	} while (al);
	asm (
		"mov %0,%%eax\n"
		"and $0b11100000,%%al\n"
		"shr $5,%%al\n"
		"out %%al,$0x60\n"
		: : "m" (keyflags)
	);
}


void kb_write_keycode() {
	
	unsigned char keycode;
	unsigned long fullcode;
	unsigned char ansicode = 0;
	
	unsigned char *keytable = keydata;
	
	asm ("mov %%al,%0" : "=m" (keycode));
	
	fullcode = (keycode & KEY_CODE);
	
	if(keycode==ACKNOWLEDGE_CODE) return;
	
	else if(keycode==EXTENDED0_CODE) {keyflags |= FLAG_EXTENDED_KEY; key_extended_buffer = EXTENDED0_CODE;}
	
	else if(keycode==EXTENDED1_CODE) {keyflags |= FLAG_EXTENDED_KEY; key_extended_buffer = EXTENDED1_CODE;}
	
	else {
		
		if(keyflags & FLAG_EXTENDED_KEY) {
			if(key_extended_buffer==EXTENDED0_CODE) {
				fullcode = ((keycode & KEY_CODE) | (EXTENDED0_CODE << 8));
				keyflags &= ~FLAG_EXTENDED_KEY;
			}
			else if(key_extended_buffer==EXTENDED1_CODE) {
				fullcode = ((keycode & KEY_CODE) | (EXTENDED1_CODE << 8));
				key_extended_buffer = fullcode;
			}
			else {
				fullcode = ((keycode & KEY_CODE) | (((unsigned long)key_extended_buffer) << 8));
				keyflags &= ~FLAG_EXTENDED_KEY;
			}
		}
		
		
		if(keycode & KEY_RELEASE) {
			switch(fullcode) {
				case NUMLOCK_CODE:
					keyflags &= ~FLAG_NUMLOCK_PRESSED;
					break;
				case SCROLLLOCK_CODE:
					keyflags &= ~FLAG_SCROLLLOCK_PRESSED;
					break;
				case CAPSLOCK_CODE:
					keyflags &= ~FLAG_CAPSLOCK_PRESSED;
					break;
				case LSHIFT_CODE:
					keyflags &= ~FLAG_LSHIFT_PRESSED;
					break;
				case RSHIFT_CODE:
					keyflags &= ~FLAG_RSHIFT_PRESSED;
					break;
				case LALT_CODE:
					keyflags &= ~FLAG_LALT_PRESSED;
					break;
				case RALT_CODE:
					keyflags &= ~FLAG_RALT_PRESSED;
					break;
				case LCTRL_CODE:
					keyflags &= ~FLAG_LCTRL_PRESSED;
					break;
				case RCTRL_CODE:
					keyflags &= ~FLAG_RCTRL_PRESSED;
					break;
				default:
					if((keyflags & FLAG_NUMLOCK_ACTIVE) && (0x47 <= (fullcode & ~KEY_RELEASE)) && ((fullcode & ~KEY_RELEASE) <= 0x53))
						ansicode = keydata_numlock[(keycode & KEY_CODE) - 0x47];
					else {
						if((fullcode & (EXTENDED0_CODE << 8)) == (EXTENDED0_CODE << 8)) keytable = keydata_extended;
						else if(keyflags & FLAG_RALT_PRESSED) keytable = keydata_altgr;
						else if((keyflags & FLAG_LALT_PRESSED)/* && ((keyflags & FLAG_RCTRL_PRESSED)
							|| (keyflags & FLAG_LCTRL_PRESSED))*/) keytable = keydata_altgr;
						else if(keyflags & (FLAG_LSHIFT_PRESSED | FLAG_RSHIFT_PRESSED | FLAG_CAPSLOCK_ACTIVE))
							keytable = keydata_shift;
						ansicode = keytable[keycode & KEY_CODE];
					}
			}
		}
		else {
			switch(fullcode) {
				case NUMLOCK_CODE:
					if(keyflags & FLAG_NUMLOCK_PRESSED) return;
					else {
						keyflags |= FLAG_NUMLOCK_PRESSED;
						if(keyflags & FLAG_NUMLOCK_ACTIVE) keyflags &= ~FLAG_NUMLOCK_ACTIVE;
						else keyflags |= FLAG_NUMLOCK_ACTIVE;
						update_leds();
					}
					break;
				case SCROLLLOCK_CODE:
					if(keyflags & FLAG_SCROLLLOCK_PRESSED) return;
					else {
						keyflags |= FLAG_SCROLLLOCK_PRESSED;
						if(keyflags & FLAG_SCROLLLOCK_ACTIVE) keyflags &= ~FLAG_SCROLLLOCK_ACTIVE;
						else keyflags |= FLAG_SCROLLLOCK_ACTIVE;
						update_leds();
					}
					break;
				case CAPSLOCK_CODE:
					if(keyflags & FLAG_CAPSLOCK_PRESSED) return;
					else {
						keyflags |= FLAG_CAPSLOCK_PRESSED;
						if(keyflags & FLAG_CAPSLOCK_ACTIVE) keyflags &= ~FLAG_CAPSLOCK_ACTIVE;
						else keyflags |= FLAG_CAPSLOCK_ACTIVE;
						update_leds();
					}
					break;
				case LSHIFT_CODE:
					keyflags |= FLAG_LSHIFT_PRESSED;
					break;
				case RSHIFT_CODE:
					keyflags |= FLAG_RSHIFT_PRESSED;
					break;
				case LALT_CODE:
					keyflags |= FLAG_LALT_PRESSED;
					break;
				case RALT_CODE:
					keyflags |= FLAG_RALT_PRESSED;
					break;
				case LCTRL_CODE:
					keyflags |= FLAG_LCTRL_PRESSED;
					break;
				case RCTRL_CODE:
					keyflags |= FLAG_RCTRL_PRESSED;
					break;
				default:
					if((keyflags & FLAG_NUMLOCK_ACTIVE) && (0x47 <= fullcode) && (fullcode <= 0x53))
						ansicode = keydata_numlock[keycode - 0x47];
					else {
						if((fullcode & (EXTENDED0_CODE << 8)) == (EXTENDED0_CODE << 8)) keytable = keydata_extended;
						else if(keyflags & FLAG_RALT_PRESSED) keytable = keydata_altgr;
						else if(keyflags & (FLAG_LSHIFT_PRESSED | FLAG_RSHIFT_PRESSED | FLAG_CAPSLOCK_ACTIVE))
							keytable = keydata_shift;
						ansicode = keytable[keycode];
					}
			}
		}
	}
	if(keyflags & FLAG_BUFFER_FULL) return;
	keybuffer[(keybuffer_pointer + keybuffer_count++) & 0xFF] = keycode;
	keybuffer[(keybuffer_pointer + keybuffer_count++) & 0xFF] = ansicode;
	if(keybuffer_count==0) keyflags |= FLAG_BUFFER_FULL;
}


void kb_read_keycode() {
	unsigned long keycode = 0;
	unsigned char ansicode = 0;
	
	if((keybuffer_count != 0) || (keyflags & FLAG_BUFFER_FULL)) {
		keycode = keybuffer[keybuffer_pointer++];
		ansicode = keybuffer[keybuffer_pointer++];
		keybuffer_count-=2;
		keyflags &= ~FLAG_BUFFER_FULL;
		if(keycode == EXTENDED0_CODE) {
			if(keybuffer_count != 0) {
				keycode <<= 8;
				keycode |= keybuffer[keybuffer_pointer++];
				ansicode = keybuffer[keybuffer_pointer++];
				keybuffer_count-=2;
			}
		}
		else if(keycode == EXTENDED1_CODE) {
			if(keybuffer_count != 0) {
				keycode <<= 8;
				keycode |= keybuffer[keybuffer_pointer++];
				ansicode = keybuffer[keybuffer_pointer++];
				keybuffer_count-=2;
				if(keybuffer_count != 0) {
					keycode <<= 8;
					keycode |= keybuffer[keybuffer_pointer++];
					ansicode = keybuffer[keybuffer_pointer++];
					keybuffer_count-=2;
				}
			}
		}
	}
	asm ("mov %0,%%eax; mov %1,%%dl" : : "m" (keycode), "m" (ansicode));
}