#include <stdint.h>

#include "kernel.h"
#include "kbd.h"
#include "interrupt.h"
#include "tty.h"
#include "pic.h"
#include "ioport.h"

static struct interrupt_handler keyboard;

static unsigned char keymap[128] = {
  0, 27, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', '\b',
  '\t', 'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n',
  0, 'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', '\'', '`',
  0, '\\', 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/', 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
};

static unsigned char keymap_shift[128] = {
  0, 27, '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', '\b',
  '\t', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '\n',
  0, 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~',
  0, '|', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?', 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
};

static unsigned int kbd_state = 0;

static unsigned char keyboard_decode(unsigned char scancode) {
	if (scancode & 0x80) {
		/* break */
		scancode = scancode & 0x7F;
		if (scancode == 0x2A || scancode == 0x36) {
			/* left or right shift */
			kbd_state = 0;
		}
		return 0;
	} else {
		if (scancode == 0x2A || scancode == 0x36) {
			kbd_state = 1;
			return 0;
		}
    
		if (kbd_state == 1) {
			return keymap_shift[scancode];
		} else {
			return keymap[scancode];
		}
	}
}

static void keyboard_handler(struct interrupt_context *c, void *unused) {
	unsigned char code;
	unsigned char scancode;

	scancode = inport8(0x60);

	code = keyboard_decode(scancode);

	/* TODO deliver to process with console open */
	/* will need a notion of 'foreground' and 'background' processes */
	/* might make sense to just hand it off to whatever terminal it is
	 * attached to
	 */
	if(code) {
		printk("%c", code);
	}
	code = scancode;
}

void init_keyboard() {
	keyboard.handler = keyboard_handler;
	keyboard.context = 0;

	interrupt_add_handler(IRQ1, &keyboard);
}