//////////////////////////////////////////////////////////////////////////
// Mapper162  Pocket Monster Gold                                       //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using static VirtualNes.Core.CPU;
using INT = System.Int32;
using BYTE = System.Byte;
using System;
using Codice.CM.Client.Differences;
using VirtualNes.Core.Debug;

namespace VirtualNes.Core
{
    public class Mapper162 : Mapper
    {
        BYTE reg5000;
        BYTE reg5100;
        BYTE reg5200;
        BYTE reg5300;
        public Mapper162(NES parent) : base(parent)
        {
        }

        public override void Reset()
        {
            reg5000 = 0;
            reg5100 = 0;
            reg5200 = 0;
            reg5300 = 7;
            SetBank_CPU();
            SetBank_PPU();
        }

        //void Mapper162::WriteLow(WORD addr, BYTE data)
        public override void WriteLow(ushort addr, byte data)
        {
            if (addr == 0x5000)
            {
                reg5000 = data;
                SetBank_CPU();
                SetBank_PPU();
            }
            else if (addr == 0x5100)
            {
                reg5100 = data;
                SetBank_CPU();
                SetBank_PPU();
            }
            else if (addr == 0x5200)
            {
                reg5200 = data;
                SetBank_CPU();
                SetBank_PPU();
            }
            else if (addr == 0x5300)
            {
                reg5300 = data;
            }
            else if (addr >= 0x6000)
            {
                CPU_MEM_BANK[addr >> 13][addr & 0x1FFF] = data;
            }
            else
            {
                Debuger.Log($"write to {addr:X4}:{data:X2}");
            }

        }

        void SetBank_CPU()
        {
            BYTE bank = 0;
            switch (reg5300)
            {
                case 4:
                    bank = (byte)((((reg5000 & 0xF) + ((reg5100 & 3) >> 1)) | ((reg5200 & 1) << 4)));
                    break;
                case 7:
                    bank = (byte)(((reg5000 & 0xF) | ((reg5200 & 1) << 4)));
                    break;
            }
            SetPROM_32K_Bank((byte)bank);
        }

        void SetBank_PPU()
        {
            SetCRAM_8K_Bank(0);
        }

        //void Mapper162::HSync(int scanline)
        public override void HSync(int scanline)
        {
            if ((reg5000 & 0x80) != 0 && nes.ppu.IsDispON())
            {
                if (scanline < 127)
                {
                    //			SetCRAM_4K_Bank(0, 0);
                    SetCRAM_4K_Bank(4, 0);
                }
                else if (scanline < 240)
                {
                    //			SetCRAM_4K_Bank(0, 1);
                    SetCRAM_4K_Bank(4, 1);
                }
            }
        }


        //void Mapper162::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            p[0] = reg5000;
            p[1] = reg5100;
            p[2] = reg5200;
            p[3] = reg5300;
        }

        //void Mapper162::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            reg5000 = p[0];
            reg5100 = p[1];
            reg5200 = p[2];
            reg5300 = p[3];
        }

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