using System.IO;

namespace MyNes.Core;

[BoardInfo("Sunsoft 4", 68)]
internal class Mapper068 : Board
{
	private bool flag_r;

	private bool flag_m;

	private int nt_reg0;

	private int nt_reg1;

	private int temp;

	internal override void HardReset()
	{
		base.HardReset();
		Switch16KPRG(PRG_ROM_16KB_Mask, PRGArea.AreaC000);
	}

	internal override void WritePRG(ref ushort address, ref byte data)
	{
		switch (address & 0xF000)
		{
		case 32768:
			Switch02KCHR(data, CHRArea.Area0000);
			break;
		case 36864:
			Switch02KCHR(data, CHRArea.Area0800);
			break;
		case 40960:
			Switch02KCHR(data, CHRArea.Area1000);
			break;
		case 45056:
			Switch02KCHR(data, CHRArea.Area1800);
			break;
		case 49152:
			nt_reg0 = (data & 0x7F) | 0x80;
			break;
		case 53248:
			nt_reg1 = (data & 0x7F) | 0x80;
			break;
		case 57344:
			flag_r = (data & 0x10) == 16;
			flag_m = (data & 1) == 1;
			Switch01KNMTFromMirroring(flag_m ? Mirroring.Horz : Mirroring.Vert);
			break;
		case 61440:
			Switch16KPRG(data, PRGArea.Area8000);
			break;
		}
	}

	internal override void ReadNMT(ref ushort address, out byte data)
	{
		if (!flag_r)
		{
			data = NMT_RAM[NMT_AREA_BLK_INDEX[(address >> 10) & 3]][address & 0x3FF];
			return;
		}
		switch ((address >> 10) & 3)
		{
		case 0:
			data = CHR_ROM[nt_reg0][address & 0x3FF];
			break;
		case 1:
			data = CHR_ROM[flag_m ? nt_reg0 : nt_reg1][address & 0x3FF];
			break;
		case 2:
			data = CHR_ROM[flag_m ? nt_reg1 : nt_reg0][address & 0x3FF];
			break;
		case 3:
			data = CHR_ROM[nt_reg1][address & 0x3FF];
			break;
		default:
			data = 0;
			break;
		}
	}

	internal override void WriteNMT(ref ushort address, ref byte data)
	{
		if (!flag_r)
		{
			base.WriteNMT(ref address, ref data);
		}
	}

	internal override void WriteStateData(ref BinaryWriter stream)
	{
		base.WriteStateData(ref stream);
		stream.Write(flag_r);
		stream.Write(flag_m);
		stream.Write(nt_reg0);
		stream.Write(nt_reg1);
		stream.Write(temp);
	}

	internal override void ReadStateData(ref BinaryReader stream)
	{
		base.ReadStateData(ref stream);
		flag_r = stream.ReadBoolean();
		flag_m = stream.ReadBoolean();
		nt_reg0 = stream.ReadInt32();
		nt_reg1 = stream.ReadInt32();
		temp = stream.ReadInt32();
	}
}