// keyboard.c
// Author: Josh Holtrop
// Created: 04/17/03
// Modified: 08/16/04

#include "hos_defines.h"
#include "char/keyboard.h"
#include "sys/io.h"
#include "sys/pic.h"
#include "functions.h"
#include "kout.h"

#define KBD_BUFFER_LENGTH 64

u8_t	kbdFlags = 0;			// holds current keyboard flags - caps/num/scroll/shift/ctrl/alt
char	lastWasE0 = 0;			// was the last byte 0x0E ?
u32_t	kbdBuffer[KBD_BUFFER_LENGTH];	// a buffer for all keypresses
int	kbdBufferStart = 0;		// position of next key in buffer
int	kbdBufferLen = 0;		// number of keys left in the buffer
u8_t	rawIgnore = 0;			// how many signals to blatantly ignore
u8_t	ackReason = 0;			// used to record the reason why we would get an acknowledge byte (0xFA)


//these arrays convert a keyboard scan code to an ASCII character value
const u8_t SCAN2ASCII[129] =
	"\000\0331234567890-=\010\011"	// null,esc,1234567890-=,bksp,tab
	"qwertyuiop[]\n\000as"		// qwertyuiop[],enter,lctrl,as
	"dfghjkl;'`\000\\zxcv"		// dfghjkl;'`,lshift,\zxcv
	"bnm,./\000*\000 \000\000\000\000\000\000"	// bnm,./,rshift,*,alt,space,caps,f1,f2,f3,f4,f5
	"\000\000\000\000\000\000\000\000\000\000-\000\000\000+\000"		// f6,f7,f8,f9,f10,num,scrl,home,up,pgup,dash,left,center,right,plus,end
	"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"	// down,pgdn,ins,del,?,?,?,f11,f12,?,?,winL,winR,menu,?,?
	"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"	// ?
	"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000";	// ?
const u8_t SCAN2ASCII2[129] =
	"\000\033!@#$%^&*()_+\010\011"
	"QWERTYUIOP{}\n\000AS"
	"DFGHJKL:\"~\000|ZXCV"
	"BNM<>?\000*\000 \000\000\000\000\000\000"
	"\000\000\000\000\000\000\000789-456+1"
	"230.\000\000\000\000\000\000\000\000\000\000\000\000"
	"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"
	"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000";

//====FUNCTIONS:
// The Keyboard Interrupt Service Routine
void isr_keyboard()
{
	kbdScan = inportb(0x60);
	kprintf("KEYBOARD INTERRUPT: 0x%x\n", kbdScan);
	u8_t inState = inportb(0x61);
	outportb(0x61, inState|0x80);
	outportb(0x61, inState);
	return;
	
	//printf("IRQ 1: %x\n", kbdScan);

	if (kbdScan == 0xFA)	//250					//ACKnowledge
	{
		//printf("KBD_ACK 0x%x!\n", ackReason);
		if (ackReason == 0xED)					//reset LEDs
		{
			outportb(0x60, (kbdFlags & 0x07));
		}
		ackReason = 0;
	}
	if (kbdScan == 224)						// 0xE0 == extended key
	{
		kbdExt = 1;
		pic_eoi();
		return;
	}
	if (kbdScan == 225)						// 0xE1 == 2nd-set-extended key
	{
		kbdExt2 = 2;
		pic_eoi();
		return;
	}

//====handle control keys::
	kbdAscii = 2;
	switch (kbdScan)						//control keys
	{
		case KBD_SCAN_LSHIFT:
			kbdFlags |= KBD_SHIFT;
			kbdAscii = 1;
			break;
		case KBD_SCAN_RSHIFT:
			kbdFlags |= KBD_SHIFT;
			kbdAscii = 1;
			break;
		case KBD_SCAN_LCTRL:
			kbdFlags |= KBD_CTRL;
			kbdAscii = 1;
			break;
		case KBD_SCAN_LALT:
			kbdFlags |= KBD_ALT;			
			kbdAscii = 1;
			break;

		case KBD_SCAN_LSHIFT + KBD_SCAN_RELEASED:
			kbdFlags &= (KBD_SHIFT ^ 0xFF);
			kbdAscii = 1;
			break;
		case KBD_SCAN_RSHIFT + KBD_SCAN_RELEASED:
			kbdFlags &= (KBD_SHIFT ^ 0xFF);
			kbdAscii = 1;
			break;
		case KBD_SCAN_LCTRL + KBD_SCAN_RELEASED:
			kbdFlags &= (KBD_CTRL ^ 0xFF);
			kbdAscii = 1;
			break;
		case KBD_SCAN_LALT + KBD_SCAN_RELEASED:
			kbdFlags &= (KBD_ALT ^ 0xFF);
			kbdAscii = 1;
			break;

		case KBD_SCAN_CAPS+KBD_SCAN_RELEASED:
			kbdFlags ^= KBD_CAPS;
			kbdAscii = 1;
			kbd_resetLEDs();				//update LEDs
			break;
		case KBD_SCAN_SCROLL+KBD_SCAN_RELEASED:
			kbdFlags ^= KBD_SCROLL;
			kbdAscii = 1;
			kbd_resetLEDs();				//update LEDs
			break;
		case KBD_SCAN_NUM+KBD_SCAN_RELEASED:
			kbdFlags ^= KBD_NUM;
			kbdAscii = 1;
			kbd_resetLEDs();				//update LEDs
			break;
	}
	if (kbdAscii == 1)
	{
		if (kbdExt > 0)
			kbdExt--;
		pic_eoi();
		return;
	}
//====determine ASCII value of key::
	if (kbdExt > 0)						//extended key, kbdScan holds extended key
	{
		kbdExt--;
		kbdAscii = 1;
		switch (kbdScan)
		{
			case KBD_SCANE_ENTER:
				kbdAscii = '\n';	break;
			case 53:				// '/' character (divide on numpad)
				kbdAscii = '/';		break;
		}
	}
	else if (kbdExt2 > 0)					//extended key 2
	{
		kbdExt2--;
//		if (kbdScan == 69)				// (pause|break)
//			kbdAscii = 2;				//flag ascii value of 1 means control character (pausebreak)
//		else
			kbdAscii = 2;				//flag ascii value of 2 means ignore key (or unknown value)
	}
	else							//not an extended key
	{
			// if letter key
		if (((kbdScan >= 16) && (kbdScan <= 25)) || ((kbdScan >= 30) && (kbdScan <= 38)) || ((kbdScan >= 44) && (kbdScan <= 50)))
		{
			// if caps and shift are different (either one pressed, not both)
			if (((kbdFlags & KBD_SHIFT) != 0) & ((kbdFlags & KBD_CAPS) != 0))
				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
			else if (((kbdFlags & KBD_SHIFT) == 0) & ((kbdFlags & KBD_CAPS) == 0))
				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
			else
				kbdAscii = SCAN2ASCIISHIFT[kbdScan & 0x7F];
		}
			// if numpad key
		else if ((kbdScan >= 71) && (kbdScan <= 83))
		{
			// if numlock on
			if (kbdFlags & KBD_NUM)
				kbdAscii = SCAN2ASCIISHIFT[kbdScan & 0x7F];
			else
				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
		}
			// other key
		else
		{
			if ((kbdFlags & KBD_SHIFT) != 0)
				kbdAscii = SCAN2ASCIISHIFT[kbdScan & 0x7F];
			else
				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
		}
	}

//====do something with key::
//	printf("kbdScan == %d\nkbdAscii == %d\nkbdFlags == %d\n", kbdScan, kbdAscii, kbdFlags);
	if ((kbdScan == 83) && (kbdFlags & KBD_CTRL) && (kbdFlags & KBD_ALT))
	{
		kprintf("Initiating reboot.");
		restart();
	}
	if (kbdAscii == 2)							//unknown key / ignore key
	{
		pic_eoi();
		return;
	}
	if (kbdScan < KBD_SCAN_RELEASED)					//a key was pressed, save it
	{
		if (kbdBufferLen >= KBD_BUFFER_LENGTH)				//no key slots available
		{
			pic_eoi();
			return;
		}
		else
		{
			kbdBuffer[(kbdBufferStart+kbdBufferLen++)%KBD_BUFFER_LENGTH] = (u32_t) ((kbdFlags << 16) | (kbdScan << 8) | kbdAscii);
//			printf("S:%d\tL:%d\tR:%x\n", kbdBufferStart, kbdBufferLen, kbdBuffer[kbdBufferStart]);
		}
	}

	pic_eoi();

}

//Gets a key from the buffer, returns 0 if no keys available, returns immediately
u32_t kbdGetKey()
{
	if (kbdBufferLen == 0)					//buffer empty
		return 0;
	u32_t retVal = kbdBuffer[kbdBufferStart];
	kbdBufferStart++;
	kbdBufferLen--;
	if (kbdBufferStart >= KBD_BUFFER_LENGTH)
		kbdBufferStart = 0;
	return retVal;
}

//Gets a key from the buffer, if no keys available, waits for one to be entered
u32_t kbdWaitKey()
{
	for (;;)
	{
		if (kbdBufferLen != 0)					//buffer empty
			break;
	}		
	u32_t retVal = kbdBuffer[kbdBufferStart];
	kbdBufferStart++;
	kbdBufferLen--;
	if (kbdBufferStart >= KBD_BUFFER_LENGTH)
		kbdBufferStart = 0;
	return retVal;
}

//Resets the keyboard LEDs to reflect the current state of the num lock, caps lock, and scroll lock bits
void	kbd_resetLEDs()
{
	outportb(0x60, 0xED);
	ackReason = 0xED;
}