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/* bkerndev - Bran's Kernel Development Tutorial
*  By:   Brandon F. ([email protected])
*  Desc: Keyboard driver
*
*  Notes: No warranty expressed or implied. Use at own risk. */
#include <system.h>

/* KBDUS means US Keyboard Layout. This is a scancode table
*  used to layout a standard US keyboard. I have left some
*  comments in to give you an idea of what key is what, even
*  though I set it's array index to 0. You can change that to
*  whatever you want using a macro, if you wish! */
unsigned char kbdus[128] =
{
    0,  27, '1', '2', '3', '4', '5', '6', '7', '8',	/* 9 */
  '9', '0', '-', '=', '\b',	/* Backspace */
  '\t',			/* Tab */
  'q', 'w', 'e', 'r',	/* 19 */
  't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n',		/* Enter key */
    0,			/* 29   - Control */
  'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';',	/* 39 */
 '\'', '`',   0,		/* Left shift */
 '\\', 'z', 'x', 'c', 'v', 'b', 'n',			/* 49 */
  'm', ',', '.', '/',   0,					/* Right shift */
  '*',
    0,	/* Alt */
  ' ',	/* Space bar */
    0,	/* Caps lock */
    0,	/* 59 - F1 key ... > */
    0,   0,   0,   0,   0,   0,   0,   0,
    0,	/* < ... F10 */
    0,	/* 69 - Num lock*/
    0,	/* Scroll Lock */
    0,	/* Home key */
    0,	/* Up Arrow */
    0,	/* Page Up */
  '-',
    0,	/* Left Arrow */
    0,
    0,	/* Right Arrow */
  '+',
    0,	/* 79 - End key*/
    0,	/* Down Arrow */
    0,	/* Page Down */
    0,	/* Insert Key */
    0,	/* Delete Key */
    0,   0,   0,
    0,	/* F11 Key */
    0,	/* F12 Key */
    0,	/* All other keys are undefined */
};

/* Handles the keyboard interrupt */
void keyboard_handler(struct regs *r)
{
    unsigned char scancode;

    /* Read from the keyboard's data buffer */
    scancode = inportb(0x60);

    /* If the top bit of the byte we read from the keyboard is
    *  set, that means that a key has just been released */
    if (scancode & 0x80)
    {
        /* You can use this one to see if the user released the
        *  shift, alt, or control keys... */
    }
    else
    {
        /* Here, a key was just pressed. Please note that if you
        *  hold a key down, you will get repeated key press
        *  interrupts. */

        /* Just to show you how this works, we simply translate
        *  the keyboard scancode into an ASCII value, and then
        *  display it to the screen. You can get creative and
        *  use some flags to see if a shift is pressed and use a
        *  different layout, or you can add another 128 entries
        *  to the above layout to correspond to 'shift' being
        *  held. If shift is held using the larger lookup table,
        *  you would add 128 to the scancode when you look for it */
        putch(kbdus[scancode]);
    }
}

/* Installs the keyboard handler into IRQ1 */
void keyboard_install()
{
    irq_install_handler(1, keyboard_handler);
}

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#include <system.h>


unsigned char kbdusnsh[128] =
{
    -1,  27, '1', '2', '3', '4', '5', '6', '7', '8',	/* 9 */
  '9', '0', '-', '=', '\b', '\t',
  'q', 'w', 'e', 'r',
  't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n',		/* Enter key */
    0,			/* 29   - Control */
  'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';',	/* 39 */
 '\'', '`',   0,		/* Left shift */
 '\\', 'z', 'x', 'c', 'v', 'b', 'n',			/* 49 */
  'm', ',', '.', '/',   0,					/* Right shift */
  '*',
    0,	/* Alt */
  ' ',	/* Space bar */
    58,	/* Caps lock */
    0,	/* 59 - F1 key ... > */
    0,   0,   0,   0,   0,   0,   0,   0,
    0,	/* < ... F10 */
    0,	/* 69 - Num lock*/
    0,	/* Scroll Lock */
    0,	/* Home key */
    0,	/* Up Arrow */
    0,	/* Page Up */
  '-',
    0,	/* Left Arrow */
    0,
    0,	/* Right Arrow */
  '+',
    0,	/* 79 - End key*/
    0,	/* Down Arrow */
    0,	/* Page Down */
    0,	/* Insert Key */
    0,	/* Delete Key */
    0,   0,   0,
    0,	/* F11 Key */
    0,	/* F12 Key */
    0,	/* All other keys are undefined */
   
};

	unsigned char kbdusysh[128] =
{
 0,  0, '!', '"', '£', '$', '%', '^', '&', '*',	/* 9 */
  '(', ')', '_', '+', '\b', '\t',
  'Q', 'W', 'E', 'R',
  'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '\n',		/* Enter key */
    0,			/* 29   - Control */
  'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ';',	/* 39 */
 '|', '¬',   42,		/* Left shift */
 '\\', 'Z', 'X', 'C', 'V', 'B', 'N',			/* 49 */
  'M', '<', '>', '?',   0,					/* Right shift */
  0,
    0,	/* Alt */
  ' ',	/* Space bar */
    58,	/* Caps lock */
    0,	/* 59 - F1 key ... > */
    0,   0,   0,   0,   0,   0,   0,   0,
    0,	/* < ... F10 */
    0,	/* 69 - Num lock*/
    0,	/* Scroll Lock */
    0,	/* Home key */
    0,	/* Up Arrow */
    0,	/* Page Up */
  '-',
    0,	/* Left Arrow */
    0,
    0,	/* Right Arrow */
  '+',
    0,	/* 79 - End key*/
    0,	/* Down Arrow */
    0,	/* Page Down */
    0,	/* Insert Key */
    0,	/* Delete Key */
    0,   0,   0,
    0,	/* F11 Key */
    0,	/* F12 Key */
    0,	/* All other keys are undefined */
};

/* Handles the keyboard interrupt */
void keyboard_handler(struct regs *r)
{
    unsigned char scancode;
    int lshiftpress;
    /* Read from the keyboard's data buffer */
    scancode = inportb(0x60);

    /* If the top bit of the byte we read from the keyboard is
    *  set, that means that a key has just been released */
    while ((scancode == 42) & 0x1C)
    {
        lshiftpress = 1;

    }
    while ((scancode == 42) & 0x80)
	{
		lshiftpress = 0;
	}
	
    if (scancode & 0x80)
	{
	}
    {
        /* Here, a key was just pressed. Please note that if you
        *  hold a key down, you will get repeated key press
        *  interrupts. */

        /* Just to show you how this works, we simply translate
        *  the keyboard scancode into an ASCII value, and then
        *  display it to the screen. You can get creative and
        *  use some flags to see if a shift is pressed and use a
        *  different layout, or you can add another 128 entries
        *  to the above layout to correspond to 'shift' being
        *  held. If shift is held using the larger lookup table,
        *  you would add 128 to the scancode when you look for it */

	if (lshiftpress == 1)
	{
        putch(kbdusysh[scancode]);
	
	}
	else if (lshiftpress == 0)
	{
	putch(kbdusnsh[scancode]);
	}
    }
}

/* Installs the keyboard handler into IRQ1 */
void keyboard_install()
{
    irq_install_handler(1, keyboard_handler);
}

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/* Handles the keyboard interrupt */
void keyboard_handler(struct regs *r)
{
    unsigned char scancode;
    static int lshiftpress = 0; // will persist across all calls of the handler
	
    /* Read from the keyboard's data buffer */
    scancode = inportb(0x60);

    /* If the top bit of the byte we read from the keyboard is
     *  set, that means that a key has just been released 
	 */
	if(scancode & 0x1C)
	{
		if(scancode == 42)
			lshiftpress = 1;
	}
	
	if(scancode & 0x80)
	{
		if(scancode == 42)
		{
			lshiftpress = 0;
		}
		else
		{
			if(lshiftpress)
				putch(kbdusysh[scancode]);
			else
				putch(kbdusnsh[scancode]);
		}
	}
}

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void key_handler()
{
    static int lshiftpressed = 0;
    unsigned char scancode;

    scancode = inb(0x60);

    if(scancode & 0x80)
    {
        // Handle key up event - check that SHIFT isn't pressed anymore
    }
    else
    {
        // Handle key down event - check for SHIFT for example
    }
}