//============================================================================
//
//   SSSS    tt          lll  lll       
//  SS  SS   tt           ll   ll        
//  SS     tttttt  eeee   ll   ll   aaaa 
//   SSSS    tt   ee  ee  ll   ll      aa
//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
//  SS  SS   tt   ee      ll   ll  aa  aa
//   SSSS     ttt  eeeee llll llll  aaaaa
//
// Copyright (c) 1995-2014 by Bradford W. Mott, Stephen Anthony
// and the Stella Team
//
// See the file "License.txt" for information on usage and redistribution of
// this file, and for a DISCLAIMER OF ALL WARRANTIES.
//
// $Id: Cart0840.cxx,v 1.0 2006/11/17
//============================================================================

#include <cassert>
#include <cstring>

#include "System.hxx"
#include "Cart0840.hxx"

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cartridge0840::Cartridge0840(const uInt8* image, uInt32 size, const Settings& settings)
  : Cartridge(settings)
{
  // Copy the ROM image into my buffer
  memcpy(myImage, image, MIN(8192u, size));
  createCodeAccessBase(8192);

  // Remember startup bank
  myStartBank = 0;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Cartridge0840::~Cartridge0840()
{
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void Cartridge0840::reset()
{
  // Upon reset we switch to the startup bank
  bank(myStartBank);
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
void Cartridge0840::install(System& system)
{
  mySystem = &system;
  uInt16 shift = mySystem->pageShift();
  uInt16 mask = mySystem->pageMask();

  // Make sure the system we're being installed in has a page size that'll work
  assert((0x1000 & mask) == 0);

  // Get the page accessing methods for the hot spots since they overlap
  // areas within the TIA we'll need to forward requests to the TIA
  myHotSpotPageAccess[0] = mySystem->getPageAccess(0x0800 >> shift);
  myHotSpotPageAccess[1] = mySystem->getPageAccess(0x0900 >> shift);
  myHotSpotPageAccess[2] = mySystem->getPageAccess(0x0A00 >> shift);
  myHotSpotPageAccess[3] = mySystem->getPageAccess(0x0B00 >> shift);
  myHotSpotPageAccess[4] = mySystem->getPageAccess(0x0C00 >> shift);
  myHotSpotPageAccess[5] = mySystem->getPageAccess(0x0D00 >> shift);
  myHotSpotPageAccess[6] = mySystem->getPageAccess(0x0E00 >> shift);
  myHotSpotPageAccess[7] = mySystem->getPageAccess(0x0F00 >> shift);

  // Set the page accessing methods for the hot spots
  System::PageAccess access(0, 0, 0, this, System::PA_READ);

  for(uInt32 i = 0x0800; i < 0x0FFF; i += (1 << shift))
    mySystem->setPageAccess(i >> shift, access);

  // Install pages for bank 0
  bank(myStartBank);
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
uInt8 Cartridge0840::peek(uInt16 address)
{
  address &= 0x1840;

  // Switch banks if necessary
  switch(address)
  {
    case 0x0800:
      // Set the current bank to the lower 4k bank
      bank(0);
      break;

    case 0x0840:
      // Set the current bank to the upper 4k bank
      bank(1);
      break;

    default:
      break;
  }

  if(!(address & 0x1000))
  {
    // Because of the way we've set up accessing above, we can only
    // get here when the addresses are from 0x800 - 0xFFF
    int hotspot = ((address & 0x0F00) >> 8) - 8;
    return myHotSpotPageAccess[hotspot].device->peek(address);
  }

  return 0;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge0840::poke(uInt16 address, uInt8 value)
{
  address &= 0x1840;

  // Switch banks if necessary
  switch(address)
  {
    case 0x0800:
      // Set the current bank to the lower 4k bank
      bank(0);
      break;

    case 0x0840:
      // Set the current bank to the upper 4k bank
      bank(1);
      break;

    default:
      break;
  }

  if(!(address & 0x1000))
  {
    // Because of the way we've set up accessing above, we can only
    // get here when the addresses are from 0x800 - 0xFFF
    int hotspot = ((address & 0x0F00) >> 8) - 8;
    myHotSpotPageAccess[hotspot].device->poke(address, value);
  }
  return false;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge0840::bank(uInt16 bank)
{ 
  if(bankLocked()) return false;

  // Remember what bank we're in
  myCurrentBank = bank;
  uInt16 offset = myCurrentBank << 12;
  uInt16 shift = mySystem->pageShift();

  // Setup the page access methods for the current bank
  System::PageAccess access(0, 0, 0, this, System::PA_READ);

  // Map ROM image into the system
  for(uInt32 address = 0x1000; address < 0x2000; address += (1 << shift))
  {
    access.directPeekBase = &myImage[offset + (address & 0x0FFF)];
    access.codeAccessBase = &myCodeAccessBase[offset + (address & 0x0FFF)];
    mySystem->setPageAccess(address >> shift, access);
  }
  return myBankChanged = true;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
uInt16 Cartridge0840::bank() const
{
  return myCurrentBank;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
uInt16 Cartridge0840::bankCount() const
{
  return 2;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge0840::patch(uInt16 address, uInt8 value)
{
  myImage[(myCurrentBank << 12) + (address & 0x0fff)] = value;
  return myBankChanged = true;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
const uInt8* Cartridge0840::getImage(int& size) const
{
  size = 8192;
  return myImage;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge0840::save(Serializer& out) const
{
   out.putString(name());
   out.putShort(myCurrentBank);

   return true;
}

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
bool Cartridge0840::load(Serializer& in)
{
   if(in.getString() != name())
      return false;

   myCurrentBank = in.getShort();

   // Remember what bank we were in
   bank(myCurrentBank);

   return true;
}
