// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using ILLink.Shared.DataFlow;
using ILLink.Shared.TypeSystemProxy;
using Mono.Cecil;
using Mono.Linker;
using Mono.Linker.Dataflow;
using TypeReference = Mono.Cecil.TypeReference;


namespace ILLink.Shared.TrimAnalysis
{
    /// <summary>
    /// Return value from a method
    /// </summary>
    internal partial record MethodReturnValue
    {
        public static MethodReturnValue Create(MethodProxy method, bool isNewObj, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes, ITryResolveMetadata resolver)
        {
            Debug.Assert(!isNewObj || method.Definition.IsConstructor, "isNewObj can only be true for constructors");
            var methodRef = method.Method;
            var staticType = isNewObj ? methodRef.DeclaringType : methodRef.ReturnType.InflateFrom(methodRef as IGenericInstance ?? methodRef.DeclaringType as IGenericInstance);
            return new MethodReturnValue(staticType, method, dynamicallyAccessedMemberTypes, resolver);
        }

        private MethodReturnValue(TypeReference? staticType, MethodProxy method, DynamicallyAccessedMemberTypes dynamicallyAccessedMemberTypes, ITryResolveMetadata resolver)
        {
            StaticType = staticType == null ? null : new(staticType, resolver);
            MethodDefinition = method.Definition;
            Method = method;
            DynamicallyAccessedMemberTypes = dynamicallyAccessedMemberTypes;
        }

        public readonly MethodDefinition MethodDefinition;

        public override DynamicallyAccessedMemberTypes DynamicallyAccessedMemberTypes { get; }

        public override IEnumerable<string> GetDiagnosticArgumentsForAnnotationMismatch()
            => new string[] { DiagnosticUtilities.GetMethodSignatureDisplayName(MethodDefinition) };

        public override SingleValue DeepCopy() => this; // This value is immutable

        public override string ToString() => this.ValueToString(MethodDefinition, DynamicallyAccessedMemberTypes);
    }
}