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

using System.Collections.Generic;

using ILCompiler.DependencyAnalysisFramework;

namespace ILCompiler.DependencyAnalysis
{
    /// <summary>
    /// Represents an event that has metadata generated in the current compilation.
    /// This corresponds to an ECMA-335 Event record. Unlike fields and methods,
    /// events are not first-class entities in the compiler's type system (there is no
    /// interned EventDesc).
    /// </summary>
    /// <remarks>
    /// Only expected to be used during ILScanning when scanning for reflection.
    /// </remarks>
    internal sealed class EventMetadataNode : DependencyNodeCore<NodeFactory>
    {
        private readonly EventPseudoDesc _event;

        public EventMetadataNode(EventPseudoDesc @event)
        {
            _event = @event;
        }

        public EventPseudoDesc Event => _event;

        public override IEnumerable<DependencyListEntry> GetStaticDependencies(NodeFactory factory) => null;

        public override IEnumerable<CombinedDependencyListEntry> GetConditionalStaticDependencies(NodeFactory factory)
        {
            var dependencies = new List<CombinedDependencyListEntry>();
            CustomAttributeBasedDependencyAlgorithm.AddDependenciesDueToCustomAttributes(ref dependencies, factory, _event);
            return dependencies;
        }

        protected override string GetName(NodeFactory factory)
        {
            return "Event metadata: " + _event.ToString();
        }

        public override bool InterestingForDynamicDependencyAnalysis => false;
        public override bool HasDynamicDependencies => false;
        public override bool HasConditionalStaticDependencies => true;
        public override bool StaticDependenciesAreComputed => true;
        public override IEnumerable<CombinedDependencyListEntry> SearchDynamicDependencies(List<DependencyNodeCore<NodeFactory>> markedNodes, int firstNode, NodeFactory factory) => null;
    }
}