// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Linq;
using System.Reflection;

namespace Microsoft.CSharp.RuntimeBinder.Semantics
{
    internal sealed class ExprProperty : ExprWithArgs
    {
        // If we have this.prop = 123, but the implementation of the property is in the
        // base class, then the object is of the base class type. Note that to get
        // the object, we must go through the MEMGRP.
        //
        // "throughObject" is
        // of the type we are actually calling through.  (We need to know the
        // "through" type to ensure that protected semantics are correctly enforced.)

        public ExprProperty(CType type, Expr pOptionalObjectThrough, Expr pOptionalArguments, ExprMemberGroup pMemberGroup, PropWithType pwtSlot, MethWithType mwtSet)
            : base(ExpressionKind.Property, type)
        {
            OptionalObjectThrough = pOptionalObjectThrough;
            OptionalArguments = pOptionalArguments;
            MemberGroup = pMemberGroup;

            if (pwtSlot != null)
            {
                PropWithTypeSlot = pwtSlot;
            }

            if (mwtSet != null)
            {
                MethWithTypeSet = mwtSet;
                if (!HasIsExternalInitModifier(mwtSet))
                {
                    Flags = EXPRFLAG.EXF_LVALUE;
                }
            }
        }

        public Expr OptionalObjectThrough { get; }

        public PropWithType PropWithTypeSlot { get; }

        public MethWithType MethWithTypeSet { get; }

        public override SymWithType GetSymWithType() => PropWithTypeSlot;

        internal static bool HasIsExternalInitModifier(MethWithType mwtSet)
        {
            var types = (mwtSet.Meth()?.AssociatedMemberInfo as MethodInfo)?.ReturnParameter.GetRequiredCustomModifiers();
            return types != null &&
                types.Any(type => type.Name == "IsExternalInit" && !type.IsNested && type.Namespace == "System.Runtime.CompilerServices");
        }
    }
}