//////////////////////////////////////////////////////////////////////////
// Mapper068  SunSoft Mapper 4 (After Burner II)                        //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using BYTE = System.Byte;
using INT = System.Int32;


namespace VirtualNes.Core
{
    public class Mapper068 : Mapper
    {
        BYTE[] reg = new byte[4];
        BYTE coin;
        public Mapper068(NES parent) : base(parent)
        {
        }

        public override void Reset()
        {
            reg[0] = reg[1] = reg[2] = reg[3] = 0;
            coin = 0;

            SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
        }


#if FALSE //0
BYTE	Mapper068::ExRead( WORD addr )
{
	if( addr == 0x4020 ) {
DEBUGOUT( "RD $4020:%02X\n", coin );
		return	coin;
	}

	return	addr>>8;
}

void	Mapper068::ExWrite( WORD addr, BYTE data )
{
	if( addr == 0x4020 ) {
DEBUGOUT( "WR $4020:%02X\n", data );
		coin = data;
	}
}
#endif

        //void Mapper068::Write(WORD addr, BYTE data)
        public override void Write(ushort addr, byte data)
        {
            switch (addr & 0xF000)
            {
                case 0x8000:
                    SetVROM_2K_Bank(0, data);
                    break;
                case 0x9000:
                    SetVROM_2K_Bank(2, data);
                    break;
                case 0xA000:
                    SetVROM_2K_Bank(4, data);
                    break;
                case 0xB000:
                    SetVROM_2K_Bank(6, data);
                    break;

                case 0xC000:
                    reg[2] = data;
                    SetBank();
                    break;
                case 0xD000:
                    reg[3] = data;
                    SetBank();
                    break;
                case 0xE000:
                    reg[0] = (byte)((data & 0x10) >> 4);
                    reg[1] = (byte)(data & 0x03);
                    SetBank();
                    break;

                case 0xF000:
                    SetPROM_16K_Bank(4, data);
                    break;
            }
        }

        void SetBank()
        {
            if (reg[0] != 0)
            {
                switch (reg[1])
                {
                    case 0:
                        SetVROM_1K_Bank(8, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(9, (INT)reg[3] + 0x80);
                        SetVROM_1K_Bank(10, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(11, (INT)reg[3] + 0x80);
                        break;
                    case 1:
                        SetVROM_1K_Bank(8, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(9, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(10, (INT)reg[3] + 0x80);
                        SetVROM_1K_Bank(11, (INT)reg[3] + 0x80);
                        break;
                    case 2:
                        SetVROM_1K_Bank(8, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(9, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(10, (INT)reg[2] + 0x80);
                        SetVROM_1K_Bank(11, (INT)reg[2] + 0x80);
                        break;
                    case 3:
                        SetVROM_1K_Bank(8, (INT)reg[3] + 0x80);
                        SetVROM_1K_Bank(9, (INT)reg[3] + 0x80);
                        SetVROM_1K_Bank(10, (INT)reg[3] + 0x80);
                        SetVROM_1K_Bank(11, (INT)reg[3] + 0x80);
                        break;
                }
            }
            else
            {
                switch (reg[1])
                {
                    case 0:
                        SetVRAM_Mirror(VRAM_VMIRROR);
                        break;
                    case 1:
                        SetVRAM_Mirror(VRAM_HMIRROR);
                        break;
                    case 2:
                        SetVRAM_Mirror(VRAM_MIRROR4L);
                        break;
                    case 3:
                        SetVRAM_Mirror(VRAM_MIRROR4H);
                        break;
                }
            }
        }

        //void Mapper068::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            p[0] = reg[0];
            p[1] = reg[1];
            p[2] = reg[2];
            p[3] = reg[3];
        }

        //void Mapper068::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            reg[0] = p[0];
            reg[1] = p[1];
            reg[2] = p[2];
            reg[3] = p[3];
        }


        public override bool IsStateSave()
        {
            return true;
        }
    }
}