//////////////////////////////////////////////////////////////////////////
// Mapper091  PC-HK-SF3                                                 //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.Core.CPU;
using static VirtualNes.MMU;
using BYTE = System.Byte;


namespace VirtualNes.Core
{
    public class Mapper091 : Mapper
    {
        BYTE irq_enable;
        BYTE irq_counter;
        public Mapper091(NES parent) : base(parent)
        {
        }

        public override void Reset()
        {
            SetPROM_32K_Bank(PROM_8K_SIZE - 2, PROM_8K_SIZE - 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);

            if (VROM_8K_SIZE != 0)
            {
                SetVROM_8K_Bank(0, 0, 0, 0, 0, 0, 0, 0);
            }

            irq_enable = 0;
            irq_counter = 0;

            nes.SetRenderMethod(EnumRenderMethod.POST_ALL_RENDER);
        }

        //void Mapper091::WriteLow(WORD addr, BYTE data)
        public override void WriteLow(ushort addr, byte data)
        {
            //DEBUGOUT( "$%04X:$%02X(%3d) L=%3d\n", addr, data, data, nes.GetScanline() );
            switch (addr & 0xF003)
            {
                case 0x6000:
                case 0x6001:
                case 0x6002:
                case 0x6003:
                    SetVROM_2K_Bank((byte)((addr & 0x03) * 2), data);
                    break;

                case 0x7000:
                    SetPROM_8K_Bank(4, data);
                    break;
                case 0x7001:
                    SetPROM_8K_Bank(5, data);
                    break;

                case 0x7002:
                    irq_enable = 0;
                    irq_counter = 0;
                    nes.cpu.ClrIRQ(IRQ_MAPPER);
                    break;
                case 0x7003:
                    irq_enable = 1;
                    break;
            }
        }

        //void Mapper091::HSync(INT scanline)
        public override void HSync(int scanline)
        {
            if ((scanline >= 0 && scanline < 240) && nes.ppu.IsDispON())
            {
                if (irq_enable != 0)
                {
                    irq_counter++;
                }
                if (irq_counter >= 8)
                {
                    //			nes.cpu.IRQ_NotPending();
                    nes.cpu.SetIRQ(IRQ_MAPPER);
                }
            }
        }

        //void Mapper091::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            p[0] = irq_enable;
            p[1] = irq_counter;
        }

        //void Mapper091::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            irq_enable = p[0];
            irq_counter = p[1];
        }


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