/* 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "mapinc.h"

static uint8 reg[16], IRQa;
static uint32 IRQCount;
static uint8 *WRAM=NULL;
static uint32 WRAMSIZE;

static SFORMAT StateRegs[]=
{
  {&IRQa, 1, "IRQA"},
  {&IRQCount, 4, "IRQCOUNT"},
  {reg, 16, "REGS"},
  {0}
};

static void Sync(void)
{
  setchr1(0x0000,reg[0]&0xfe);
  setchr1(0x0400,reg[1]|1);
  setchr1(0x0800,reg[2]&0xfe);
  setchr1(0x0c00,reg[3]|1);
  setchr1(0x1000,reg[4]);
  setchr1(0x1400,reg[5]);
  setchr1(0x1800,reg[6]);
  setchr1(0x1c00,reg[7]);
  setprg8r(0x10,0x6000,0);
  setprg8(0x8000,(reg[0x8]&0xf)|0x10);
  setprg8(0xA000,(reg[0x9]&0x1f));
  setprg8(0xC000,(reg[0xa]&0x1f));
  setprg8(0xE000,(reg[0xb]&0xf)|0x10);
  setmirror((reg[0xc]&1)^1);
}

static DECLFW(M106Write)
{
  A&=0xF;
  switch(A)
  {
    case 0xD: IRQa=0; IRQCount=0; X6502_IRQEnd(FCEU_IQEXT); break;
    case 0xE: IRQCount=(IRQCount&0xFF00)|V; break;
    case 0xF: IRQCount=(IRQCount&0x00FF)|(V<<8); IRQa=1; break;
    default: reg[A]=V; Sync(); break;
  }
}

static void M106Power(void)
{
  reg[8]=reg[9]=reg[0xa]=reg[0xb]=-1;
  Sync();
  SetReadHandler(0x6000,0x7FFF,CartBR);
  SetReadHandler(0x8000,0xFFFF,CartBR);
  SetWriteHandler(0x6000,0x7FFF,CartBW);
  SetWriteHandler(0x8000,0xFFFF,M106Write);
}

static void M106Reset(void)
{
}

static void M106Close(void)
{
  if(WRAM)
    FCEU_gfree(WRAM);
  WRAM=NULL;
}

void M106CpuHook(int a)
{
  if(IRQa)
  {
    IRQCount+=a;
    if(IRQCount>0x10000)
    {
      X6502_IRQBegin(FCEU_IQEXT);
      IRQa=0;
    }
  }
}

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

void Mapper106_Init(CartInfo *info)
{
  info->Reset=M106Reset;
  info->Power=M106Power;
  info->Close=M106Close;
  MapIRQHook=M106CpuHook;
  GameStateRestore=StateRestore;

  WRAMSIZE=8192;
  WRAM=(uint8*)FCEU_gmalloc(WRAMSIZE);
  SetupCartPRGMapping(0x10,WRAM,WRAMSIZE,1);
  AddExState(WRAM, WRAMSIZE, 0, "WRAM");

  AddExState(&StateRegs, ~0, 0, 0);
}