/*
THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.  
COPYRIGHT 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/
/*
 * $Source: f:/miner/source/bios/rcs/key.c $
 * $Revision: 1.35 $
 * $Author: john $
 * $Date: 1995/01/25 20:13:30 $
 * 
 * Functions for keyboard handler.
 * 
 * $Log: key.c $
 * Revision 1.35  1995/01/25  20:13:30  john
 * Took out not passing keys to debugger if w10.
 * 
 * Revision 1.34  1995/01/14  19:19:31  john
 * Made so when you press Shift+Baskspace, it release keys autmatically.
 * 
 * Revision 1.33  1994/12/13  09:21:48  john
 * Took out keyd_editor_mode, and KEY_DEBUGGED stuff for NDEBUG versions.
 * 
 * Revision 1.32  1994/11/12  13:52:01  john
 * Fixed bug with code that cleared bios buffer.
 * 
 * Revision 1.31  1994/10/24  15:16:16  john
 * Added code to detect KEY_PAUSE.
 * 
 * Revision 1.30  1994/10/24  13:57:53  john
 * Hacked in support for pause key onto code 0x61.
 * 
 * Revision 1.29  1994/10/21  15:18:13  john
 * *** empty log message ***
 * 
 * Revision 1.28  1994/10/21  15:17:24  john
 * Made LSHIFT+BACKSPACE do what PrtScr used to.
 * 
 * Revision 1.27  1994/09/22  16:09:18  john
 * Fixed some virtual memory lockdown problems with timer and
 * joystick.
 * 
 * Revision 1.26  1994/09/15  21:32:47  john
 * Added bounds checking for down_count scancode
 * parameter.
 * 
 * Revision 1.25  1994/08/31  12:22:20  john
 * Added KEY_DEBUGGED
 * 
 * Revision 1.24  1994/08/24  18:53:48  john
 * Made Cyberman read like normal mouse; added dpmi module; moved
 * mouse from assembly to c. Made mouse buttons return time_down.
 * 
 * Revision 1.23  1994/08/18  15:17:51  john
 * *** empty log message ***
 * 
 * Revision 1.22  1994/08/18  15:16:38  john
 * fixed some bugs with clear_key_times and then
 * removed it because i fixed key_flush to do the
 * same.
 * 
 * Revision 1.21  1994/08/17  19:01:25  john
 * Attempted to fix a bug with a key being held down
 * key_flush called, then the key released having too 
 * long of a time.
 * 
 * Revision 1.20  1994/08/08  10:43:48  john
 * Recorded when a key was pressed for key_inkey_time.
 * 
 * Revision 1.19  1994/06/22  15:00:03  john
 * Made keyboard close automatically on exit.
 * 
 * Revision 1.18  1994/06/21  09:16:29  john
 * *** empty log message ***
 * 
 * Revision 1.17  1994/06/21  09:08:23  john
 * *** empty log message ***
 * 
 * Revision 1.16  1994/06/21  09:05:01  john
 * *** empty log message ***
 * 
 * Revision 1.15  1994/06/21  09:04:24  john
 * Made PrtScreen do an int5
 * 
 * Revision 1.14  1994/06/17  17:17:06  john
 * Added keyd_time_last_key_was_pressed or something like that.
 * 
 * Revision 1.13  1994/05/14  13:55:16  matt
 * Added #define to control key passing to bios
 * 
 * Revision 1.12  1994/05/05  18:09:39  john
 * Took out BIOS to prevent stuck keys.
 * 
 * Revision 1.11  1994/05/03  17:39:12  john
 * *** empty log message ***
 * 
 * Revision 1.10  1994/04/29  12:14:20  john
 * Locked all memory used during interrupts so that program
 * won't hang when using virtual memory.
 * 
 * Revision 1.9  1994/04/28  23:49:41  john
 * Made key_flush flush more keys and also did something else but i forget what.
 * 
 * Revision 1.8  1994/04/22  12:52:12  john
 * *** empty log message ***
 * 
 * Revision 1.7  1994/04/01  10:44:59  mike
 * Change key_getch() to call getch() if our interrupt hasn't been installed.
 * 
 * Revision 1.6  1994/03/09  10:45:48  john
 * Neatend code a bit.
 * 
 * Revision 1.5  1994/02/17  17:24:16  john
 * Neatened up a bit.
 * 
 * Revision 1.4  1994/02/17  16:30:29  john
 * Put in code to pass keys when in debugger.
 * 
 * Revision 1.3  1994/02/17  15:57:59  john
 * Made handler not chain to BIOS handler.
 * 
 * Revision 1.2  1994/02/17  15:56:06  john
 * Initial version.
 * 
 * Revision 1.1  1994/02/17  15:54:07  john
 * Initial revision
 * 
 * 
 */

//#define PASS_KEYS_TO_BIOS	1			//if set, bios gets keys

#pragma off (unreferenced)
static char rcsid[] = "$Id: key.c 1.35 1995/01/25 20:13:30 john Exp $";
#pragma on (unreferenced)

#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>
#include <i86.h>

//#define WATCOM_10

#include "error.h"
#include "key.h"
#include "timer.h"
#include "dpmi.h"

#define KEY_BUFFER_SIZE 16

//-------- Variable accessed by outside functions ---------
unsigned char 				keyd_buffer_type;		// 0=No buffer, 1=buffer ASCII, 2=buffer scans
unsigned char 				keyd_repeat;
unsigned char 				keyd_editor_mode;
volatile unsigned char 	keyd_last_pressed;
volatile unsigned char 	keyd_last_released;
volatile unsigned char	keyd_pressed[256];
volatile int				keyd_time_when_last_pressed;

typedef struct keyboard	{
	unsigned short		keybuffer[KEY_BUFFER_SIZE];
	fix					time_pressed[KEY_BUFFER_SIZE];
	fix					TimeKeyWentDown[256];
	fix					TimeKeyHeldDown[256];
	unsigned int		NumDowns[256];
	unsigned int		NumUps[256];
	unsigned int 		keyhead, keytail;
	unsigned char 		E0Flag;
	unsigned char 		E1Flag;
	int 					in_key_handler;
	void (__interrupt __far *prev_int_9)();
} keyboard;

static volatile keyboard key_data;

static unsigned char Installed=0;

unsigned char ascii_table[128] = 
{ 255, 255, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=',255,255,
  'q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p', '[', ']', 255, 255,
  'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';', 39, '`',
  255, '\\', 'z', 'x', 'c', 'v', 'b', 'n', 'm', ',', '.', '/', 255,'*',
  255, ' ', 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255,255,
  255, 255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  255,255,255,255,255,255,255,255 };

unsigned char shifted_ascii_table[128] = 
{ 255, 255, '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+',255,255,
  'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', 255, 255,
  'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '"', '~', 
  255, '|', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?', 255,255,
  255, ' ', 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255,255,
  255, 255, 255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
  255,255,255,255,255,255,255,255 };


extern char key_to_ascii(int keycode )
{
	int shifted;

	shifted = keycode & KEY_SHIFTED;
	keycode &= 0xFF;

	if ( keycode>=127 )
		return 255;

	if (shifted)
		return shifted_ascii_table[keycode];
	else
		return ascii_table[keycode];
}

void key_clear_bios_buffer_all()
{
	// Clear keyboard buffer...
	*(ushort *)0x41a=*(ushort *)0x41c;
	// Clear the status bits...
	*(ubyte *)0x417 = 0;
	*(ubyte *)0x418 = 0;
}

void key_clear_bios_buffer()
{
	// Clear keyboard buffer...
	*(ushort *)0x41a=*(ushort *)0x41c;
}

void key_flush()
{
	int i;
	fix CurTime;

	_disable();

	// Clear the BIOS buffer
	key_clear_bios_buffer();

	key_data.keyhead = key_data.keytail = 0;

	//Clear the keyboard buffer
	for (i=0; i<KEY_BUFFER_SIZE; i++ )	{
		key_data.keybuffer[i] = 0;
		key_data.time_pressed[i] = 0;
	}
	
	//Clear the keyboard array

	CurTime =timer_get_fixed_secondsX();

	for (i=0; i<256; i++ )	{
		keyd_pressed[i] = 0;
		key_data.TimeKeyWentDown[i] = CurTime;
		key_data.TimeKeyHeldDown[i] = 0;
		key_data.NumDowns[i]=0;
		key_data.NumUps[i]=0;
	}
	_enable();
}

int add_one( int n )
{
	n++;
	if ( n >= KEY_BUFFER_SIZE ) n=0;
	return n;
}

// Returns 1 if character waiting... 0 otherwise
int key_checkch()
{
	int is_one_waiting = 0;

	_disable();

	key_clear_bios_buffer();

	if (key_data.keytail!=key_data.keyhead)
		is_one_waiting = 1;
	_enable();
	return is_one_waiting;
}

int key_inkey()
{
	int key = 0;

	_disable();

	key_clear_bios_buffer();

	if (key_data.keytail!=key_data.keyhead)	{
		key = key_data.keybuffer[key_data.keyhead];
		key_data.keyhead = add_one(key_data.keyhead);
	}
	_enable();
	return key;
}

int key_inkey_time(fix * time)
{
	int key = 0;

	_disable();

	key_clear_bios_buffer();

	if (key_data.keytail!=key_data.keyhead)	{
		key = key_data.keybuffer[key_data.keyhead];
		*time = key_data.time_pressed[key_data.keyhead];
		key_data.keyhead = add_one(key_data.keyhead);
	}
	_enable();
	return key;
}



int key_peekkey()
{
	int key = 0;

	_disable();

	key_clear_bios_buffer();

	if (key_data.keytail!=key_data.keyhead)	{
		key = key_data.keybuffer[key_data.keyhead];
	}
	_enable();
	return key;
}

// If not installed, uses BIOS and returns getch();
//	Else returns pending key (or waits for one if none waiting).
int key_getch()
{
	int dummy=0;
	
	if (!Installed)
		return getch();

	while (!key_checkch())
		dummy++;
	return key_inkey();
}

unsigned int key_get_shift_status()
{
	unsigned int shift_status = 0;

	_disable();

	key_clear_bios_buffer();

	if ( keyd_pressed[KEY_LSHIFT] || keyd_pressed[KEY_RSHIFT] )
		shift_status |= KEY_SHIFTED;

	if ( keyd_pressed[KEY_LALT] || keyd_pressed[KEY_RALT] )
		shift_status |= KEY_ALTED;

	if ( keyd_pressed[KEY_LCTRL] || keyd_pressed[KEY_RCTRL] )
		shift_status |= KEY_CTRLED;

#ifndef NDEBUG
	if (keyd_pressed[KEY_DELETE])
		shift_status |=KEY_DEBUGGED;
#endif

	_enable();

	return shift_status;
}

// Returns the number of seconds this key has been down since last call.
fix key_down_time(int scancode)	{
	fix time_down, time;

	if ((scancode<0)|| (scancode>255)) return 0;

#ifndef NDEBUG
	if (keyd_editor_mode && key_get_shift_status() )
		return 0;  
#endif

	_disable();

	if ( !keyd_pressed[scancode] )	{
		time_down = key_data.TimeKeyHeldDown[scancode];
		key_data.TimeKeyHeldDown[scancode] = 0;
	} else	{
		time = timer_get_fixed_secondsX();
		time_down =  time - key_data.TimeKeyWentDown[scancode];
		key_data.TimeKeyWentDown[scancode] = time;
	}
	_enable();

	return time_down;
}

// Returns number of times key has went from up to down since last call.
unsigned int key_down_count(int scancode)	{
	int n;

	if ((scancode<0)|| (scancode>255)) return 0;

	_disable();
	n = key_data.NumDowns[scancode];
	key_data.NumDowns[scancode] = 0;
	_enable();

	return n;
}


// Returns number of times key has went from down to up since last call.
unsigned int key_up_count(int scancode)	{
	int n;

	if ((scancode<0)|| (scancode>255)) return 0;

	_disable();
	n = key_data.NumUps[scancode];
	key_data.NumUps[scancode] = 0;
	_enable();

	return n;
}

// Use intrinsic forms so that we stay in the locked interrup code.

void Int5();
#pragma aux Int5 = "int 5";

#pragma off (check_stack)
void __interrupt __far key_handler()
{
	unsigned char scancode, breakbit, temp;
	unsigned short keycode;

#ifndef WATCOM_10
#ifndef NDEBUG
	ubyte * MONO = (ubyte *)(0x0b0000+24*80*2);
	if (  ((MONO[0]=='D') && (MONO[2]=='B') && (MONO[4]=='G') && (MONO[6]=='>')) ||
			((MONO[14]=='<') && (MONO[16]=='i') && (MONO[18]=='>') && (MONO[20]==' ') && (MONO[22]=='-')) ||
			((MONO[0]==200 ) && (MONO[2]==27) && (MONO[4]==17) )
		)
 		_chain_intr( key_data.prev_int_9 );
#endif
#endif

	// Read in scancode
	scancode = inp( 0x60 );

	switch( scancode )	{
	case 0xE0:
		key_data.E0Flag = 0x80;
		break;
	default:
		// Parse scancode and break bit
		if (key_data.E1Flag > 0 )	{		// Special code for Pause, which is E1 1D 45 E1 9D C5
			key_data.E1Flag--;
			if ( scancode == 0x1D )	{
				scancode	= KEY_PAUSE;
				breakbit	= 0;
			} else if ( scancode == 0x9d ) {
				scancode	= KEY_PAUSE;
				breakbit	= 1;
			} else {
				break;		// skip this keycode
			}
		} else if ( scancode==0xE1 )	{
			key_data.E1Flag = 2;
			break;
		} else {
			breakbit	= scancode & 0x80;		// Get make/break bit
			scancode &= 0x7f;						// Strip make/break bit off of scancode
			scancode |= key_data.E0Flag;					// Add in extended key code
		}
		key_data.E0Flag = 0;								// Clear extended key code

		if (breakbit)	{
			// Key going up
			keyd_last_released = scancode;
			keyd_pressed[scancode] = 0;
			key_data.NumUps[scancode]++;
			temp = 0;
			temp |= keyd_pressed[KEY_LSHIFT] || keyd_pressed[KEY_RSHIFT];
			temp |= keyd_pressed[KEY_LALT] || keyd_pressed[KEY_RALT];
			temp |= keyd_pressed[KEY_LCTRL] || keyd_pressed[KEY_RCTRL];
#ifndef NDEBUG
			temp |= keyd_pressed[KEY_DELETE];
			if ( !(keyd_editor_mode && temp) )
#endif		// NOTICE LINK TO ABOVE IF!!!!
				key_data.TimeKeyHeldDown[scancode] += timer_get_fixed_secondsX() - key_data.TimeKeyWentDown[scancode];
		} else {
			// Key going down
			keyd_last_pressed = scancode;
			keyd_time_when_last_pressed = timer_get_fixed_secondsX();
			if (!keyd_pressed[scancode])	{
				// First time down
				key_data.TimeKeyWentDown[scancode] = timer_get_fixed_secondsX();
				keyd_pressed[scancode] = 1;
				key_data.NumDowns[scancode]++;
#ifndef NDEBUG
				if ( (keyd_pressed[KEY_LSHIFT]) && (scancode == KEY_BACKSP) ) 	{
					keyd_pressed[KEY_LSHIFT] = 0;
					Int5();
				}
#endif
			} else if (!keyd_repeat) {
				// Don't buffer repeating key if repeat mode is off
				scancode = 0xAA;		
			} 

			if ( scancode!=0xAA ) {
				keycode = scancode;

				if ( keyd_pressed[KEY_LSHIFT] || keyd_pressed[KEY_RSHIFT] )
					keycode |= KEY_SHIFTED;

				if ( keyd_pressed[KEY_LALT] || keyd_pressed[KEY_RALT] )
					keycode |= KEY_ALTED;

				if ( keyd_pressed[KEY_LCTRL] || keyd_pressed[KEY_RCTRL] )
					keycode |= KEY_CTRLED;

#ifndef NDEBUG
				if ( keyd_pressed[KEY_DELETE] )
					keycode |= KEY_DEBUGGED;
#endif

				temp = key_data.keytail+1;
				if ( temp >= KEY_BUFFER_SIZE ) temp=0;

				if (temp!=key_data.keyhead)	{
					key_data.keybuffer[key_data.keytail] = keycode;
					key_data.time_pressed[key_data.keytail] = keyd_time_when_last_pressed;
					key_data.keytail = temp;
				}
			}
		}
	}

#ifndef NDEBUG
#ifdef PASS_KEYS_TO_BIOS
	_chain_intr( key_data.prev_int_9 );
#endif
#endif

	temp = inp(0x61);		// Get current port 61h state
	temp |= 0x80;			// Turn on bit 7 to signal clear keybrd
	outp( 0x61, temp );	// Send to port
	temp &= 0x7f;			// Turn off bit 7 to signal break
	outp( 0x61, temp );	// Send to port
	outp( 0x20, 0x20 );	// Reset interrupt controller
}

#pragma on (check_stack)

void key_handler_end()	{		// Dummy function to help calculate size of keyboard handler function
}

void key_init()
{
	// Initialize queue

	keyd_time_when_last_pressed = timer_get_fixed_seconds();
	keyd_buffer_type = 1;
	keyd_repeat = 1;
	key_data.in_key_handler = 0;
	key_data.E0Flag = 0;
	key_data.E1Flag = 0;

	// Clear the keyboard array
	key_flush();

	if (Installed) return;
	Installed = 1;

	//--------------- lock everything for the virtal memory ----------------------------------
	if (!dpmi_lock_region ((void near *)key_handler, (char *)key_handler_end - (char near *)key_handler))	{
		printf( "Error locking keyboard handler!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&key_data, sizeof(keyboard)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_buffer_type, sizeof(char)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_repeat, sizeof(char)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_editor_mode, sizeof(char)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_last_pressed, sizeof(char)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_last_released, sizeof(char)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_pressed, sizeof(char)*256))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}
	if (!dpmi_lock_region (&keyd_time_when_last_pressed, sizeof(int)))	{
		printf( "Error locking keyboard handler's data!\n" );
		exit(1);
	}

	key_data.prev_int_9 = _dos_getvect( 9 );
	_dos_setvect( 9, key_handler );

	atexit( key_close );
}

void key_close()
{
	if (!Installed) return;
	Installed = 0;
	
	_dos_setvect( 9, key_data.prev_int_9 );

	_disable();
	key_clear_bios_buffer_all();
	_enable();

}