using System;
using System.Collections.Generic;
using Indy.IL2CPU.Assembler;


using CPUx86 = Indy.IL2CPU.Assembler.X86;
using System.Reflection;
using Indy.IL2CPU.Compiler;

namespace Indy.IL2CPU.IL.X86 {
	[OpCode(OpCodeEnum.Stsfld)]
	public class Stsfld: Op {
		private string mDataName;
		private Type mDataType;
		private bool mNeedsGC;
		private string mBaseLabel;
        private string mNextLabel;
	    private string mCurLabel;
	    private uint mCurOffset;
	    private MethodInformation mMethodInformation;

			public static void ScanOp(ILReader aReader, MethodInformation aMethodInfo, SortedList<string, object> aMethodData, IServiceProvider aProvider)
			{
				FieldInfo xField = aReader.OperandValueField;
				Engine.QueueStaticField(xField);
			}
        private FieldInfo mField;
		public Stsfld(ILReader aReader, MethodInformation aMethodInfo)
			: base(aReader, aMethodInfo) {
			mField = aReader.OperandValueField;
            mDataName = DataMember.GetStaticFieldName(mField);
			mNeedsGC = !mField.FieldType.IsValueType;
			mDataType = mField.FieldType;
			mBaseLabel = GetInstructionLabel(aReader);
             mMethodInformation = aMethodInfo;
		    mCurOffset = aReader.Position;
		    mCurLabel = IL.Op.GetInstructionLabel(aReader);
            mNextLabel = IL.Op.GetInstructionLabel(aReader.NextPosition);
		}

		public override void DoAssemble() {
            var xSize = GetService<IMetaDataInfoService>().GetFieldStorageSize(mField.FieldType);
		    var xDecRefMethodInfo = GetService<IMetaDataInfoService>().GetMethodInfo(GCImplementationRefs.DecRefCountRef,
		                                                                             false);


			if (mNeedsGC) {
                new CPUx86.Push { DestinationRef = ElementReference.New(mDataName), DestinationIsIndirect = true };
                new CPUx86.Call { DestinationLabel = xDecRefMethodInfo.LabelName};
			}
            for (int i = 0; i < (xSize / 4); i++)
            {
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
                new CPUx86.Move { DestinationRef = ElementReference.New(mDataName, i * 4), DestinationIsIndirect = true, SourceReg = CPUx86.Registers.EAX };
			}
            switch (xSize % 4)
            {
				case 1: {
                        new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
                        new CPUx86.Move { DestinationRef = ElementReference.New(mDataName, (int)((xSize / 4) * 4)), DestinationIsIndirect = true, SourceReg = CPUx86.Registers.AL };
						break;
					}
				case 2: {
                        new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
                        new CPUx86.Move { DestinationRef = ElementReference.New(mDataName, (int)((xSize / 4) * 4)), DestinationIsIndirect = true, SourceReg = CPUx86.Registers.AX };
                        break;
					}
				case 0: {
						break;
					}
				default:
                    EmitNotImplementedException(Assembler, GetServiceProvider(), "Ldsfld: Remainder size " + (xSize % 4) + " not supported!", mCurLabel, mMethodInformation, mCurOffset, mNextLabel);
                    break;

			}
			Assembler.StackContents.Pop();
		}
	}
}