using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Cosmos.Compiler.Assembler;
using Cosmos.Compiler.Assembler.X86;

namespace Cosmos.Compiler.XSharp {
    public abstract class CodeBlock {
        public enum Flags { 
            Zero, Equal // Zero is synonym for Equal
            , NotZero, NotEqual // Synonyms
            , GreaterThanOrEqualTo
            , LessThan
        };

        //TODO: Add registers as needed, not all are here yet
        public RegisterEAX EAX = RegisterEAX.Instance;
        public RegisterAX AX = RegisterAX.Instance;
        public RegisterAL AL = RegisterAL.Instance;
        
        public RegisterEBX EBX = RegisterEBX.Instance;
        public RegisterBL BL = RegisterBL.Instance;

        public RegisterECX ECX = RegisterECX.Instance;

        public RegisterEDX EDX = RegisterEDX.Instance;
        public RegisterDX DX = RegisterDX.Instance;

        public RegisterEBP EBP = RegisterEBP.Instance;
        public RegisterESP ESP = RegisterESP.Instance;
        public RegisterESI ESI = RegisterESI.Instance;
        public RegisterEDI EDI = RegisterEDI.Instance;

        public readonly Ports Port = new Ports();
        public readonly Memory Memory = new Memory();

        public abstract void Assemble();

        static public string MakeLabel(Type aType) {
            var xParts = aType.FullName.Split('.');
            string xLabel = xParts[xParts.Length - 1];
            return xLabel.Replace('+', '_');
        }

        public string Label {
            set { 
                new Cosmos.Compiler.Assembler.Label(value); 
            }
        }

        private uint mLabelCounter = 0;
        public string NewLabel() {
            mLabelCounter++;
            return GetType().Name + mLabelCounter.ToString("X8").ToUpper();
        }

        public void Call(Type aType) {
            new Call { DestinationLabel = MakeLabel(aType) };
        }
        public void Call(string aLabel) {
            new Call { DestinationLabel = aLabel };
        }

        public void Define(string aSymbol) {
            new Define( aSymbol );
        }

        public void IfDefined(string aSymbol) {
            new IfDefined(aSymbol);
        }

        public void EndIfDefined() {
            new EndIfDefined();
        }

        public void CallIf(Flags aFlags, string aLabel) {
            CallIf(aFlags, aLabel, "");
        }

        public void CallIf(Flags aFlags, string aLabel, string aJumpAfter) {
            // TODO: This is inefficient - lots of jumps
            // Maybe make an invert function for Flags
            var xLabelIf = NewLabel();
            var xLabelExit = NewLabel();

            JumpIf(aFlags, xLabelIf);
            Jump(xLabelExit);

            Label = xLabelIf;
            Call(aLabel);
            if (aJumpAfter != "") {
                Jump(aJumpAfter);
            }

            Label = xLabelExit;
        }

        public void Jump(string aLabel) {
            new Jump { DestinationLabel = aLabel };
        }

        public void JumpIf(Flags aFlags, string aLabel) {
            switch (aFlags) {
                case Flags.Zero:
                case Flags.Equal:
                    new ConditionalJump { Condition = ConditionalTestEnum.Zero, DestinationLabel = aLabel };
                    break;
                case Flags.NotZero:
                case Flags.NotEqual:
                    new ConditionalJump { Condition = ConditionalTestEnum.NotZero, DestinationLabel = aLabel };
                    break;
                case Flags.LessThan:
                    new ConditionalJump { Condition = ConditionalTestEnum.LessThan, DestinationLabel = aLabel };
                    break;
                case Flags.GreaterThanOrEqualTo:
                    new ConditionalJump { Condition = ConditionalTestEnum.GreaterThanOrEqualTo, DestinationLabel = aLabel };
                    break;
            }
        }

        public void Push(UInt32 aValue) {
            Push(aValue, 32);
        }
        public void Push(UInt32 aValue, byte aSize) {
            new Push { DestinationValue = aValue, Size = aSize };
        }

        public void PopAll32() {
            new Popad();
        }

        public void PushAll32() {
            new Pushad();
        }
        
        public void Return() {
            new Return();
        }
        
        public void Return(UInt16 aBytes) {
            new Return { DestinationValue = aBytes };
        }

        public void EnableInterrupts() {
            new Sti();
        }

        public void DisableInterrupts() {
            new ClrInterruptFlag();
        }

        public ElementReference AddressOf(string aDataName) {
            return ElementReference.New(aDataName);
        }
    }
}