using System;
using System.Collections.Generic;
using System.Reflection;
using Cosmos.Assembler.x86;

namespace XSharp.Compiler
{
  public static class XSRegisters
  {
    public enum RegisterSize: byte
    {
      Byte8 = 8,
      Short16 = 16,
      Int32 = 32
    }

    public abstract class Register
    {
      public readonly RegisterSize Size;
      public readonly string Name;
      public readonly RegistersEnum RegEnum;

      protected Register(string name, RegistersEnum regEnum, RegisterSize size)
      {
        Size = size;
        Name = name;
        RegEnum = regEnum;
      }
    }

    private static readonly Dictionary<string, Register> mRegisters;

    static XSRegisters()
    {
      mRegisters = new Dictionary<string, Register>();
      foreach (var xField in typeof(XSRegisters).GetFields(BindingFlags.Static | BindingFlags.Public))
      {
        mRegisters.Add(xField.Name, (Register)xField.GetValue(null));
      }
    }

    public static Register OldToNewRegister(RegistersEnum register)
    {
      Register xResult;
      if (!mRegisters.TryGetValue(register.ToString(), out xResult))
      {
        throw new NotImplementedException($"Register {register} not yet implemented!");
      }
      return xResult;
    }

    public class Register8: Register
    {
      public Register8(string name, RegistersEnum regEnum) : base(name, regEnum, RegisterSize.Byte8)
      {
      }
    }

    public class Register16 : Register
    {
      public Register16(string name, RegistersEnum regEnum) : base(name, regEnum, RegisterSize.Short16)
      {
      }
    }

    public class Register32 : Register
    {
      public Register32(string name, RegistersEnum regEnum) : base(name, regEnum, RegisterSize.Int32)
      {
      }
    }

    public class RegisterSegment: Register
    {
      public RegisterSegment(string name, RegistersEnum regEnum): base(name, regEnum, RegisterSize.Int32)
      {
      }
    }

    public static readonly Register AL = new Register8(nameof(AL), RegistersEnum.AL);
    public static readonly Register AH = new Register8(nameof(AH), RegistersEnum.AH);
    public static readonly Register AX = new Register16(nameof(AX), RegistersEnum.AX);
    public static readonly Register EAX = new Register32(nameof(EAX), RegistersEnum.EAX);

    public static readonly Register BL = new Register8(nameof(BL), RegistersEnum.BL);
    public static readonly Register BH = new Register8(nameof(BH), RegistersEnum.BH);
    public static readonly Register BX = new Register16(nameof(BX), RegistersEnum.BX);
    public static readonly Register EBX = new Register32(nameof(EBX), RegistersEnum.EBX);

    public static readonly Register CL = new Register8(nameof(CL), RegistersEnum.CL);
    public static readonly Register CH = new Register8(nameof(CH), RegistersEnum.CH);
    public static readonly Register CX = new Register16(nameof(CX), RegistersEnum.CX);
    public static readonly Register ECX = new Register32(nameof(ECX), RegistersEnum.ECX);

    public static readonly Register DL = new Register8(nameof(DL), RegistersEnum.DL);
    public static readonly Register DH = new Register8(nameof(DH), RegistersEnum.DH);
    public static readonly Register DX = new Register16(nameof(DX), RegistersEnum.DX);
    public static readonly Register EDX = new Register32(nameof(EDX), RegistersEnum.EDX);

    public static readonly Register EBP = new Register32(nameof(EBP), RegistersEnum.EBP);
    public static readonly Register ESP = new Register32(nameof(ESP), RegistersEnum.ESP);
    public static readonly Register ESI = new Register32(nameof(ESI), RegistersEnum.ESI);
    public static readonly Register EDI = new Register32(nameof(EDI), RegistersEnum.EDI);

    // Segment registers
    public static readonly RegisterSegment CS = new RegisterSegment(nameof(CS), RegistersEnum.CS);
    public static readonly RegisterSegment DS = new RegisterSegment(nameof(DS), RegistersEnum.DS);
    public static readonly RegisterSegment ES = new RegisterSegment(nameof(ES), RegistersEnum.ES);
    public static readonly RegisterSegment FS = new RegisterSegment(nameof(FS), RegistersEnum.FS);
    public static readonly RegisterSegment GS = new RegisterSegment(nameof(GS), RegistersEnum.GS);
    public static readonly RegisterSegment SS = new RegisterSegment(nameof(SS), RegistersEnum.SS);
  }
}