//////////////////////////////////////////////////////////////////////////
// Mapper182  PC-SuperDonkeyKong                                        //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.Core.CPU;
using static VirtualNes.MMU;
using BYTE = System.Byte;


namespace VirtualNes.Core
{
    public class Mapper182 : Mapper
    {
        BYTE reg;
        BYTE irq_enable;
        BYTE irq_counter;
        public Mapper182(NES parent) : base(parent)
        {
        }

        public override void Reset()

        {
            SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
            SetVROM_8K_Bank(0);

            reg = 0;
            irq_enable = 0;
            irq_counter = 0;
        }

        //void Mapper182::Write(WORD addr, BYTE data)
        public override void Write(ushort addr, byte data)
        {
            switch (addr & 0xF003)
            {
                case 0x8001:
                    if ((data & 0x01) != 0) SetVRAM_Mirror(VRAM_HMIRROR);
                    else SetVRAM_Mirror(VRAM_VMIRROR);
                    break;
                case 0xA000:
                    reg = (byte)(data & 0x07);
                    break;
                case 0xC000:
                    switch (reg)
                    {
                        case 0:
                            SetVROM_1K_Bank(0, (data & 0xFE) + 0);
                            SetVROM_1K_Bank(1, (data & 0xFE) + 1);
                            break;
                        case 1:
                            SetVROM_1K_Bank(5, data);
                            break;
                        case 2:
                            SetVROM_1K_Bank(2, (data & 0xFE) + 0);
                            SetVROM_1K_Bank(3, (data & 0xFE) + 1);
                            break;
                        case 3:
                            SetVROM_1K_Bank(7, data);
                            break;
                        case 4:
                            SetPROM_8K_Bank(4, data);
                            break;
                        case 5:
                            SetPROM_8K_Bank(5, data);
                            break;
                        case 6:
                            SetVROM_1K_Bank(4, data);
                            break;
                        case 7:
                            SetVROM_1K_Bank(6, data);
                            break;
                    }
                    break;
                case 0xE003:
                    irq_enable = data;
                    irq_counter = data;
                    nes.cpu.ClrIRQ(IRQ_MAPPER);
                    break;
            }
        }

        //void Mapper182::HSync(INT scanline)
        public override void HSync(int scanline)
        {
            if (irq_enable != 0)
            {
                if ((scanline >= 0 && scanline <= 239) && nes.ppu.IsDispON())
                {
                    if ((--irq_counter) == 0)
                    {
                        irq_enable = 0;
                        irq_counter = 0;
                        //				nes.cpu.IRQ_NotPending();
                        nes.cpu.SetIRQ(IRQ_MAPPER);
                    }
                }
            }
        }

        //void Mapper182::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            p[0] = reg;
            p[1] = irq_enable;
            p[2] = irq_counter;
        }

        //void Mapper182::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            reg = p[0];
            irq_enable = p[1];
            irq_counter = p[2];
        }

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