using System;

namespace BizHawk.Emulation.Consoles.TurboGrafx
{
    public partial class PCEngine
    {
        private byte[] CdIoPorts = new byte[16];
        private ScsiCD scsi = new ScsiCD();

        private void WriteCD(int addr, byte value)
        {
            Console.WriteLine("Write to reg[{0:X4}] {1:X2}", addr&0x1FFF, value);
            switch (addr & 0x1FFF)
            {
                case 0x1800: // SCSI Drive Control Line
                    CdIoPorts[0] = value;
                //    Console.WriteLine("Write to CDC Status [0] {0:X2}", value);

                    scsi.SEL = true;
                    scsi.Think();
                    scsi.SEL = false;
                    scsi.Think();

                    // this probably does some things
                    // possibly clear irq line or trigger or who knows
                    break;

                case 0x1801: // CDC Command
                    CdIoPorts[1] = value;
                    scsi.DB = value;
                    scsi.Think();
//                    Console.WriteLine("Write to CDC Command [1] {0:X2}", value);
                    break;

                case 0x1802: // ACK and Interrupt Control
                    CdIoPorts[2] = value;
                    scsi.ACK = ((value & 0x80) != 0);
                    scsi.Think();
                    RefreshIRQ2();
                    break;

                case 0x1804: // CD Reset Command
                    CdIoPorts[4] = value;
                    scsi.RST = ((value & 0x02) != 0);
                    scsi.Think();
                    if (scsi.RST)
                    {
                        CdIoPorts[3] &= 0x8F; // Clear interrupt control bits
                        RefreshIRQ2();
                    }
                    break;

                case 0x1807: // BRAM Unlock
                    if (BramEnabled && (value & 0x80) != 0)
                    {
                        Console.WriteLine("UNLOCK BRAM!");
                        BramLocked = false;
                    }
                    break;

                case 0x180B: // ADPCM DMA Control
                    CdIoPorts[0x0B] = value;
  //                  Console.WriteLine("Write to ADPCM DMA Control [B]");
                    // TODO... there is DMA to be done 
                    break;

                case 0x180D: // ADPCM Address Control
                    CdIoPorts[0x0D] = value;
    //                Console.WriteLine("Write to ADPCM Address Control [D]");
                    break;

                case 0x180E: // ADPCM Playback Rate
                    CdIoPorts[0x0E] = value;
      //              Console.WriteLine("Write to ADPCM Address Control [E]");
                    break;

                case 0x180F: // Audio Fade Timer
                    CdIoPorts[0x0F] = value;
//                    Console.WriteLine("Write to CD Audio fade timer [F]");
                    // TODO: hook this up to audio system);
                    break;

                default:
                    Console.WriteLine("unknown write to {0:X4}:{1:X2}",addr, value);
                    break;
            }
        }

        public byte ReadCD(int addr)
        {
            byte returnValue = 0;
            switch (addr & 0x1FFF)
            {
                case 0x1800: //  SCSI Drive Control Line
                    scsi.Think();
                    if (scsi.IO)  returnValue |= 0x08;
                    if (scsi.CD)  returnValue |= 0x10;
                    if (scsi.MSG) returnValue |= 0x20;
                    if (scsi.REQ) returnValue |= 0x40;
                    if (scsi.BSY) returnValue |= 0x80;
                    //if (returnValue != 0) returnValue = 0x40;
                    Console.WriteLine("Read SCSI Drive Control Line [0]: {0:X2}   btw, pc={1:X4} ", returnValue,this.Cpu.PC);
                    return returnValue;

                case 0x1802: // ADPCM / CD Control
                    Console.WriteLine("Read 1802 {0:X2}", CdIoPorts[2]);
                    return CdIoPorts[2];

                case 0x1803: // BRAM Lock
                    if (BramEnabled)
                    {
                        Console.WriteLine("LOCKED BRAM! (read 1803)");
                        BramLocked = true;
                    }
                    return CdIoPorts[3];

                case 0x1804: // CD Reset
                    Console.WriteLine("Read 1804 {0:X2}", CdIoPorts[4]);
                    return CdIoPorts[4];

                case 0x180F: // Audio Fade Timer
                    Console.WriteLine("Read 180F {0:X2}", CdIoPorts[0xF]);
                    return CdIoPorts[0x0F];

                // These are some retarded version check
                case 0x18C1: return 0xAA;
                case 0x18C2: return 0x55;
                case 0x18C3: return 0x00;
                case 0x18C5: return 0xAA;
                case 0x18C6: return 0x55;
                case 0x18C7: return 0x03;

                default:
                    Console.WriteLine("unknown read to {0:X4}", addr);
                    return 0xFF;
            }
        }

        private void RefreshIRQ2()
        {
            int mask = CdIoPorts[2] & CdIoPorts[3] & 0x7C;
            Cpu.IRQ2Assert = (mask != 0);
        }
    }
}