#include <exec/exec.h>
#include <dos/dos.h>
#include <intuition/intuition.h>
#include <graphics/gfx.h>
#include <graphics/gfxbase.h>
#include <devices/input.h>
#include <hardware/custom.h>
#include <hardware/dmabits.h>

#include <clib/exec_protos.h>
#include <clib/dos_protos.h>
#include <clib/graphics_protos.h>
#include <clib/intuition_protos.h>

#include "hardware.h"

static UWORD old_dmacon;
static UWORD old_intena;
static UWORD old_adkcon;
static UWORD old_intreq;

static struct MsgPort *inputmp;
static struct IOStdReq *inputreq;
static struct Interrupt inputhandler;
static BOOL	inputdeviceok;

static struct View	*oldview;
static struct Window *old_processwinptr;
static struct Process *thisprocess;

extern struct IntuitionBase *IntuitionBase;
extern struct GfxBase *GfxBase;

static LONG null_input_handler(void)
{
	// kills all input
	return 0;
}

void kill_system(void)
{
	thisprocess = (struct Process *)FindTask(0);

	// safe actual view and install null view

	oldview = GfxBase->ActiView;
	LoadView(0);
	WaitTOF();
	WaitTOF();

	// install null_input_handler() to kill all input events
	if ((inputmp = CreateMsgPort())) {
		if ((inputreq = CreateIORequest(inputmp,sizeof(*inputreq)))) {
			if (OpenDevice("input.device",0,(struct IORequest *)inputreq,0) == 0) {
				inputdeviceok = TRUE;
				inputhandler.is_Node.ln_Type = NT_INTERRUPT;
				inputhandler.is_Node.ln_Pri = 127;
				inputhandler.is_Data = 0;
				inputhandler.is_Code = (APTR) null_input_handler;
				inputreq->io_Command = IND_ADDHANDLER;
				inputreq->io_Data = &inputhandler;
				DoIO((struct IORequest *)inputreq);
			}
		}
	}

	// disable requesters for our process
	old_processwinptr = thisprocess->pr_WindowPtr;
	thisprocess->pr_WindowPtr = (APTR)-1;

	// lock blitter
	OwnBlitter();
	WaitBlit();

	// no multitasking/interrupts
	Disable();

	// save important custom registers
	old_dmacon = custom->dmaconr | 0x8000;
	old_intena = custom->intenar | 0x8000;
	old_adkcon = custom->adkconr | 0x8000;
	old_intreq = custom->intreqr | 0x8000;
}

void activate_system(void)
{
	// reset important custom registers
	custom->dmacon = 0x7FFF;
	custom->intena = 0x7FFF;
	custom->adkcon = 0x7FFF;
	custom->intreq = 0x7FFF;

	custom->dmacon = old_dmacon;
	custom->intena = old_intena;
	custom->adkcon = old_adkcon;
	custom->intreq = old_intreq;

	// enable multitasking/interrupts
	Enable();

	// unlock blitter
	WaitBlit();
	DisownBlitter();

	// enable requesters for our process
	thisprocess->pr_WindowPtr = old_processwinptr;

	// remove null inputhandler
	if (inputdeviceok)
	{
		inputreq->io_Command = IND_REMHANDLER;
		inputreq->io_Data = &inputhandler;
		DoIO((struct IORequest *)inputreq);
		CloseDevice((struct IORequest *)inputreq);
	}

	if (inputreq) DeleteIORequest(inputreq);
	if (inputmp) DeleteMsgPort(inputmp);

	// reset old view
	LoadView(oldview);
	WaitTOF();
	WaitTOF();
}

void wait_vbl(void)
{
	UBYTE b;

	b = *(UBYTE *)0xbfe801;
	while(*(UBYTE *)0xbfe801 == b) ;
}

void wait_vbeam(ULONG line)
{
	ULONG vpos;

	line *= 0x100;

	do {
        vpos = *(ULONG *)0xdff004;
	} while ((vpos & 0x1FF00) != line);
}

void hard_wait_blit(void)
{
	if (custom->dmaconr & DMAF_BLTDONE) ;
	while (custom->dmaconr & DMAF_BLTDONE) ;
}

BOOL joy_left(void) { return (custom->joy1dat & 512) ? TRUE : FALSE; }
BOOL joy_right(void) { return (custom->joy1dat & 2) ? TRUE : FALSE; }

BOOL joy_up(void)
{
	// ^ = xor
	WORD w = custom->joy1dat << 1;
	return ((w ^ custom->joy1dat) & 512) ? TRUE : FALSE;
}

BOOL joy_down(void)
{
	// ^ = xor
	WORD w = custom->joy1dat << 1;
	return ((w ^ custom->joy1dat) & 2) ? TRUE : FALSE;
}

BOOL joy_fire(void) { return ((*(UBYTE *)0xbfe001) & 128) ? FALSE : TRUE; }
BOOL lmb_down(void) { return ((*(UBYTE *)0xbfe001) & 64) ? FALSE : TRUE; }

// This is not used, but keeping it as a reference, since waiting for mouse button is
// tricky in C vs assembly
/*
void hard_wait_lmb(void)
{
	while (((*(UBYTE *)0xbfe001) & 64) != 0) ;
	while (((*(UBYTE *)0xbfe001) & 64) == 0) ;
}
*/