//////////////////////////////////////////////////////////////
// Mapper190  Nintendo MMC3                                             //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using static VirtualNes.Core.CPU;
using INT = System.Int32;
using BYTE = System.Byte;
using System;
using Codice.CM.Client.Differences;

namespace VirtualNes.Core
{
    public class Mapper190 : Mapper
    {
        BYTE cbase;     /* PowerOn OR RESET : cbase=0 */
        BYTE mp190_lcchk;   /* PowerOn OR RESET */
        BYTE mp190_lcmd;
        BYTE mp190_cmd;

        BYTE irq_enable;
        BYTE irq_counter;
        BYTE irq_latch;
        BYTE lowoutdata;
        public Mapper190(NES parent) : base(parent)
        {
        }

        public override void Reset()

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

            //	DWORD	crc = nes.rom.GetPROM_CRC();
            //	if( crc == 0x6F3D187A ) {
            //		Temp_Buf=0;	//Kof96
            //	} else {
            //		Temp_Buf=1;	//ST97
            //	}

            irq_enable = 0;
            irq_counter = 0;
            cbase = 0;      /* PowerOn OR RESET : cbase=0 */
            mp190_lcchk = 0;    /* PowerOn OR RESET */
            mp190_lcmd = 1;
        }

        //void Mapper190::WriteLow(WORD addr, BYTE data)
        public override void WriteLow(ushort addr, byte data)
        {
            /* For Initial Copy Protect check (KOF'96) */
            if (addr == 0x5000)
            {
                mp190_lcmd = data;
                switch (data)
                {
                    case 0xE0:
                        SetPROM_32K_Bank(0);
                        break;
                    case 0xEE:
                        SetPROM_32K_Bank(3);
                        break;
                }
            }
            if ((addr == 0x5001) && (mp190_lcmd == 0x00))
            {
                SetPROM_32K_Bank(7);
            }
            if (addr == 0x5080)
            {
                switch (data)
                {
                    case 0x1: lowoutdata = 0x83; break;
                    case 0x2: lowoutdata = 0x42; break;
                    case 0x3: lowoutdata = 0x00; break;
                }
            }
            CPU_MEM_BANK[addr >> 13][addr & 0x1FFF] = data;
        }

        //BYTE Mapper190::ReadLow(WORD addr)
        public override byte ReadLow(ushort addr)
        {
            switch (addr)
            {
                case 0x5000:
                    return lowoutdata;
                default:
                    return CPU_MEM_BANK[addr >> 13][addr & 0x1FFF];
            }
        }

        //void Mapper190::Write(WORD addr, BYTE data)
        public override void Write(ushort addr, byte data)
        {
            switch (addr & 0xE003)
            {
                case 0x8000:
                    mp190_cmd = data;
                    if ((mp190_cmd & 0x80) != 0)
                        cbase = 1;
                    else
                        cbase = 0;
                    break;
                case 0x8003:    /* for Street Fighter Zero 2 '97 */
                    mp190_lcchk = data;
                    switch (data)
                    {
                        case 0x28:
                            SetPROM_8K_Bank(4, 0x1F);
                            SetPROM_8K_Bank(5, 0x1F);
                            SetPROM_8K_Bank(6, 0x17);
                            SetPROM_8K_Bank(7, 0x1F);
                            break;
                        case 0x2A:
                            SetPROM_8K_Bank(4, 0x1F);
                            SetPROM_8K_Bank(5, 0x0F);
                            SetPROM_8K_Bank(6, 0x17);
                            SetPROM_8K_Bank(7, 0x1F);
                            break;
                        case 0x06:
                            SetPROM_8K_Bank(4, 0x1E);
                            SetPROM_8K_Bank(5, 0x1F);
                            SetPROM_8K_Bank(6, 0x1F);
                            SetPROM_8K_Bank(7, 0x1F);
                            break;
                    }
                    break;
                case 0x8001:
                    if ((mp190_lcchk == 0x6) || (mp190_lcmd == 0x0))
                    {
                        switch (mp190_cmd & 0x07)
                        {
                            case 0:
                                if (cbase == 0)
                                {
                                    SetVROM_1K_Bank(0, data + 0x100);
                                    SetVROM_1K_Bank(1, data + 0x101);
                                }
                                else
                                {
                                    SetVROM_1K_Bank(4, data + 0x100);
                                    SetVROM_1K_Bank(5, data + 0x101);
                                }
                                break;
                            case 1:
                                if (cbase == 0)
                                {
                                    SetVROM_1K_Bank(2, data + 0x100);
                                    SetVROM_1K_Bank(3, data + 0x101);
                                }
                                else
                                {
                                    SetVROM_1K_Bank(6, data + 0x100);
                                    SetVROM_1K_Bank(7, data + 0x101);
                                }
                                break;
                            case 2:
                                if (cbase == 0)
                                {
                                    SetVROM_1K_Bank(4, data);
                                }
                                else
                                {
                                    SetVROM_1K_Bank(0, data);
                                }
                                break;
                            case 3:
                                if (cbase == 0)
                                {
                                    SetVROM_1K_Bank(5, data);
                                }
                                else
                                {
                                    SetVROM_1K_Bank(1, data);
                                }
                                break;
                            case 4:
                                if (cbase == 0)
                                {
                                    SetVROM_1K_Bank(6, data);
                                }
                                else
                                {
                                    SetVROM_1K_Bank(2, data);
                                }
                                break;
                            case 5:
                                if (cbase == 0)
                                {
                                    SetVROM_1K_Bank(7, data);
                                }
                                else
                                {
                                    SetVROM_1K_Bank(3, data);
                                }
                                break;
                            case 6:
                                data = (byte)(data & ((PROM_8K_SIZE * 2) - 1));
                                if ((mp190_lcmd & 0x40) != 0)
                                {
                                    SetPROM_8K_Bank(6, data);
                                    SetPROM_8K_Bank(4, (PROM_8K_SIZE - 1) * 2);
                                }
                                else
                                {
                                    SetPROM_8K_Bank(4, data);
                                    SetPROM_8K_Bank(6, (PROM_8K_SIZE - 1) * 2);
                                }
                                break;
                            case 7:
                                data = (byte)(data & ((PROM_8K_SIZE * 2) - 1));
                                if ((mp190_lcmd & 0x40) != 0)
                                {
                                    SetPROM_8K_Bank(5, data);
                                    SetPROM_8K_Bank(4, (PROM_8K_SIZE - 1) * 2);
                                }
                                else
                                {
                                    SetPROM_8K_Bank(5, data);
                                    SetPROM_8K_Bank(6, (PROM_8K_SIZE - 1) * 2);
                                }
                                break;
                        }
                    }
                    break;
                case 0xA000:
                    if ((data & 0x1) == 0x1)
                        SetVRAM_Mirror(VRAM_HMIRROR);
                    else
                        SetVRAM_Mirror(VRAM_VMIRROR);
                    break;
                case 0xA001:
                    break;
                case 0xC000:
                    irq_counter = (byte)(data - 1);
                    break;
                case 0xC001:
                    irq_latch = (byte)(data - 1);
                    break;
                case 0xC002:
                    irq_counter = data;
                    break;
                case 0xC003:
                    irq_latch = data;
                    break;
                case 0xE000:
                    irq_counter = irq_latch;
                    irq_enable = 0;
                    nes.cpu.ClrIRQ(IRQ_MAPPER);
                    break;
                case 0xE001:
                    irq_enable = 1;
                    break;
                case 0xE002:
                    irq_counter = irq_latch;
                    irq_enable = 0;
                    nes.cpu.ClrIRQ(IRQ_MAPPER);
                    break;
                case 0xE003:
                    irq_enable = 1;
                    irq_counter = irq_counter;
                    break;
            }
        }

        //void Mapper190::HSync(INT scanline)
        public override void HSync(int scanline)
        {
            if ((scanline >= 0 && scanline <= 239))
            {
                if (nes.ppu.IsDispON())
                {
                    if (irq_enable != 0)
                    {
                        if ((irq_counter--) == 0)
                        {
                            //					nes.cpu.IRQ_NotPending();
                            nes.cpu.SetIRQ(IRQ_MAPPER);
                        }
                    }
                }
            }
        }

        //void Mapper190::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            p[0] = irq_enable;
            p[1] = irq_counter;
            p[2] = irq_latch;

            p[3] = cbase;
            p[4] = mp190_lcchk;
            p[5] = mp190_lcmd;
            p[6] = mp190_cmd;
            p[7] = lowoutdata;
        }

        //void Mapper190::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            irq_enable = p[0];
            irq_counter = p[1];
            irq_latch = p[2];

            cbase = p[3];
            mp190_lcchk = p[4];
            mp190_lcmd = p[5];
            mp190_cmd = p[6];
            lowoutdata = p[7];
        }
        public override bool IsStateSave()
        {
            return true;
        }
    }
}