//////////////////////////////////////////////////////////////////////////
// Mapper026  Konami VRC6 (PA0,PA1 reverse)                             //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using static VirtualNes.Core.CPU;
using INT = System.Int32;
using BYTE = System.Byte;
using Codice.CM.Client.Differences;

namespace VirtualNes.Core
{
	public class Mapper026 : Mapper
	{

		BYTE irq_enable;
		BYTE irq_counter;
		BYTE irq_latch;
		INT irq_clock;
		public Mapper026(NES parent) : base(parent)
		{
		}


		public override void Reset()
		{
			irq_enable = 0;
			irq_counter = 0;
			irq_latch = 0;
			irq_clock = 0;

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

			if (VROM_1K_SIZE != 0)
			{
				SetVROM_8K_Bank(0);
			}

			uint crc = nes.rom.GetPROM_CRC();
			if (crc == 0x30e64d03)
			{   // Esper Dream 2 - Aratanaru Tatakai(J)
				nes.SetRenderMethod(EnumRenderMethod.POST_ALL_RENDER);
			}
			if (crc == 0x836cc1ab)
			{   // Mouryou Senki Madara(J)
				nes.SetRenderMethod(EnumRenderMethod.POST_ALL_RENDER);
			}
			nes.apu.SelectExSound(1);
		}

		//void Mapper026::Write(WORD addr, BYTE data)
		public override void Write(ushort addr, byte data)
		{
			switch (addr & 0xF003)
			{
				case 0x8000:
					SetPROM_16K_Bank(4, data);
					break;

				case 0x9000:
				case 0x9001:
				case 0x9002:
				case 0x9003:
				case 0xA000:
				case 0xA001:
				case 0xA002:
				case 0xA003:
				case 0xB000:
				case 0xB001:
				case 0xB002:
					addr = (ushort)((addr & 0xfffc) | ((addr & 1) << 1) | ((addr & 2) >> 1));
					nes.apu.ExWrite(addr, data);
					break;

				case 0xB003:
					data = (byte)(data & 0x7F);
					if (data == 0x08 || data == 0x2C) SetVRAM_Mirror(VRAM_MIRROR4H);
					else if (data == 0x20) SetVRAM_Mirror(VRAM_VMIRROR);
					else if (data == 0x24) SetVRAM_Mirror(VRAM_HMIRROR);
					else if (data == 0x28) SetVRAM_Mirror(VRAM_MIRROR4L);
					break;

				case 0xC000:
					SetPROM_8K_Bank(6, data);
					break;

				case 0xD000:
					SetVROM_1K_Bank(0, data);
					break;

				case 0xD001:
					SetVROM_1K_Bank(2, data);
					break;

				case 0xD002:
					SetVROM_1K_Bank(1, data);
					break;

				case 0xD003:
					SetVROM_1K_Bank(3, data);
					break;

				case 0xE000:
					SetVROM_1K_Bank(4, data);
					break;

				case 0xE001:
					SetVROM_1K_Bank(6, data);
					break;

				case 0xE002:
					SetVROM_1K_Bank(5, data);
					break;

				case 0xE003:
					SetVROM_1K_Bank(7, data);
					break;

				case 0xF000:
					irq_latch = data;
					break;
				case 0xF001:
					irq_enable = (byte)((irq_enable & 0x01) * 3);
					nes.cpu.ClrIRQ(IRQ_MAPPER);
					break;
				case 0xF002:
					irq_enable = (byte)(data & 0x03);
					if ((irq_enable & 0x02) != 0)
					{
						irq_counter = irq_latch;
						irq_clock = 0;
					}
					nes.cpu.ClrIRQ(IRQ_MAPPER);
					break;
			}
		}

		//void Mapper026::Clock(INT cycles)
		public override void Clock(int cycles)
		{
			if ((irq_enable & 0x02) != 0)
			{
				if ((irq_clock += cycles) >= 0x72)
				{
					irq_clock -= 0x72;
					if (irq_counter >= 0xFF)
					{
						irq_counter = irq_latch;
						//				nes.cpu.IRQ_NotPending();
						////				nes.cpu.IRQ();
						nes.cpu.SetIRQ(IRQ_MAPPER);
					}
					else
					{
						irq_counter++;
					}
				}
			}
		}

		//void Mapper026::SaveState(LPBYTE p)
		public override void SaveState(byte[] p)
		{
			//p[0] = irq_enable;
			//p[1] = irq_counter;
			//p[2] = irq_latch;
			//*(INT*)&p[3] = irq_clock;
		}

		//void Mapper026::LoadState(LPBYTE p)
		public override void LoadState(byte[] p)
		{
			//irq_enable = p[0];
			//irq_counter = p[1];
			//irq_latch = p[2];
			//irq_clock = *(INT*)&p[3];
		}



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