/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2007 CaH4e3
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "mapinc.h"

static uint8 reg[4], IRQa;
static int16 IRQCount, IRQPause;

static int16 Count = 0x0000;

static SFORMAT StateRegs[] =
{
	{ reg, 4, "REGS" },
	{ &IRQa, 1, "IRQA" },
	{ &IRQCount, 2, "IRQC" },
	{ 0 }
};

static void Sync(void) {
	setprg32(0x8000, 0);
	setchr8(0);
}

/* #define Count 0x1800 */
#define Pause 0x010

static DECLFW(UNL3DBlockWrite) {
	switch (A) {
/* 4800 32 */
/* 4900 37 */
/* 4a00 01 */
/* 4e00 18 */
	case 0x4800: reg[0] = V; break;
	case 0x4900: reg[1] = V; break;
	case 0x4a00: reg[2] = V; break;
	case 0x4e00: reg[3] = V; IRQCount = Count; IRQPause = Pause; IRQa = 1; X6502_IRQEnd(FCEU_IQEXT); break;
	}
}

static void UNL3DBlockPower(void) {
	Sync();
	SetReadHandler(0x8000, 0xFFFF, CartBR);
	SetWriteHandler(0x4800, 0x4E00, UNL3DBlockWrite);
}

static void UNL3DBlockReset(void) {
	Count += 0x10;
	FCEU_printf("Count=%04x\n", Count);
}

static void FP_FASTAPASS(1) UNL3DBlockIRQHook(int a) {
	if (IRQa) {
		if (IRQCount > 0) {
			IRQCount -= a;
		} else {
			if (IRQPause > 0) {
				IRQPause -= a;
				X6502_IRQBegin(FCEU_IQEXT);
			} else {
				IRQCount = Count;
				IRQPause = Pause;
				X6502_IRQEnd(FCEU_IQEXT);
			}
		}
	}
}

static void StateRestore(int version) {
	Sync();
}

void UNL3DBlock_Init(CartInfo *info) {
	info->Power = UNL3DBlockPower;
	info->Reset = UNL3DBlockReset;
	MapIRQHook = UNL3DBlockIRQHook;
	GameStateRestore = StateRestore;
	AddExState(&StateRegs, ~0, 0, 0);
}
