namespace MyNes.Core;

[BoardInfo("Unknown", 163)]
internal class Mapper163 : Board
{
	internal byte prg_reg;

	internal byte security_reg;

	internal bool security_trigger;

	internal byte security_reg101;

	internal bool do_chr_ram;

	internal override void HardReset()
	{
		base.HardReset();
		security_reg101 = 1;
		security_trigger = false;
		do_chr_ram = true;
		Switch32KPRG(15, PRGArea.Area8000);
		Toggle08KCHR_RAM(ram: true);
	}

	internal override void WriteEX(ref ushort address, ref byte data)
	{
		if (address == 20737)
		{
			if (security_reg101 != 0 && data == 0)
			{
				security_trigger = true;
			}
			security_reg101 = data;
		}
		else
		{
			if (address < 20480)
			{
				return;
			}
			switch (address & 0x7300)
			{
			case 20480:
				prg_reg = (byte)((prg_reg & 0xF0u) | (data & 0xFu));
				Switch32KPRG(prg_reg, PRGArea.Area8000);
				do_chr_ram = (data & 0x80) != 0;
				if (!do_chr_ram && NesEmu.ppu_clock_v < 128)
				{
					Switch08KCHR(0);
				}
				break;
			case 20736:
				if (data == 6)
				{
					Switch32KPRG(3, PRGArea.Area8000);
				}
				break;
			case 20992:
				prg_reg = (byte)((prg_reg & 0xFu) | (uint)((data & 0xF) << 4));
				Switch32KPRG(prg_reg, PRGArea.Area8000);
				break;
			case 21248:
				security_reg = data;
				break;
			}
		}
	}

	internal override void ReadEX(ref ushort addr, out byte val)
	{
		val = 0;
		if (addr < 20480)
		{
			return;
		}
		switch (addr & 0x1E14)
		{
		case 20736:
			val = security_reg;
			break;
		case 21760:
			if (security_trigger)
			{
				val = security_reg;
			}
			break;
		}
	}

	internal override void OnPPUScanlineTick()
	{
		base.OnPPUScanlineTick();
		if (do_chr_ram && NesEmu.IsRenderingOn())
		{
			if (NesEmu.ppu_clock_v == 127)
			{
				Switch04KCHR(1, CHRArea.Area0000);
				Switch04KCHR(1, CHRArea.Area1000);
			}
			if (NesEmu.ppu_clock_v == 237)
			{
				Switch04KCHR(0, CHRArea.Area0000);
				Switch04KCHR(0, CHRArea.Area1000);
			}
		}
	}
}