using System;
using System.Collections.Generic;
using System.Linq;
using Indy.IL2CPU.Assembler;
using CPU = Indy.IL2CPU.Assembler;
using CPUx86 = Indy.IL2CPU.Assembler.X86;
using Indy.IL2CPU.Compiler;

namespace Indy.IL2CPU.IL.X86 {
	[OpCode(OpCodeEnum.Box)]
	public class Box: Op {
        private Type mType;
		private string mTypeId;

        public static void ScanOp(ILReader aReader, MethodInformation aMethodInfo, SortedList<string, object> aMethodData,
            IServiceProvider aServiceProvider)
        {
            Type xTypeRef = aReader.OperandValueType as Type;
            if (xTypeRef == null)
            {
                throw new Exception("Couldn't determine Type!");
            }
            aServiceProvider.GetService<IMetaDataInfoService>().GetTypeInfo(xTypeRef);
            aServiceProvider.GetService<IMetaDataInfoService>().GetMethodInfo(GCImplementationRefs.AllocNewObjectRef, false);
        }

	    public Box(ILReader aReader, MethodInformation aMethodInfo)
			: base(aReader, aMethodInfo) {
			mType = aReader.OperandValueType;
			if (mType == null) {
				throw new Exception("Couldn't determine Type!");
			}
				
		}

		public override void DoAssemble() {
            var xTheSize = GetService<IMetaDataInfoService>().GetFieldStorageSize(mType);
            mTypeId = GetService<IMetaDataInfoService>().GetTypeIdLabel(mType);
            uint xSize = xTheSize;
            if (xTheSize % 4 != 0)
            {
                xSize += 4 - (xTheSize % 4);
			}
            new CPUx86.Push { DestinationValue = (ObjectImpl.FieldDataOffset + xSize) };
            new CPUx86.Call { DestinationLabel = CPU.MethodInfoLabelGenerator.GenerateLabelName(GCImplementationRefs.AllocNewObjectRef) };
            new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
            new CPUx86.Move { DestinationReg = CPUx86.Registers.EBX, SourceRef = ElementReference.New(mTypeId), SourceIsIndirect = true };
            new CPUx86.Move { DestinationReg = CPUx86.Registers.EAX, DestinationIsIndirect = true, SourceReg = CPUx86.Registers.EBX };
            new CPUx86.Move { DestinationReg = CPUx86.Registers.EAX, DestinationIsIndirect = true, DestinationDisplacement = 4, SourceValue = (uint)InstanceTypeEnum.BoxedValueType, Size=32 };
            new CPU.Comment("xSize is " + xSize);
            for (int i = 0; i < (xSize / 4); i++)
            {
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.EDX };
                new CPUx86.Move { DestinationReg = CPUx86.Registers.EAX, DestinationIsIndirect = true, DestinationDisplacement = (ObjectImpl.FieldDataOffset + (i * 4)), SourceReg = CPUx86.Registers.EDX, Size=32 };
            }
            new CPUx86.Push { DestinationReg = CPUx86.Registers.EAX };
            Assembler.StackContents.Pop();
            Assembler.StackContents.Push(new StackContent(4, false, false, false));
		} 
	}
}