// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
namespace Microsoft.CodeAnalysis.Shared.Extensions;
 
internal readonly struct KnownTaskTypes(Compilation compilation)
{
    public readonly INamedTypeSymbol? TaskType = compilation.TaskType();
    public readonly INamedTypeSymbol? TaskOfTType = compilation.TaskOfTType();
    public readonly INamedTypeSymbol? ValueTaskType = compilation.ValueTaskType();
    public readonly INamedTypeSymbol? ValueTaskOfTType = compilation.ValueTaskOfTType();
 
    public readonly INamedTypeSymbol? IEnumerableOfTType = compilation.IEnumerableOfTType();
    public readonly INamedTypeSymbol? IEnumeratorOfTType = compilation.IEnumeratorOfTType();
 
    public readonly INamedTypeSymbol? IAsyncEnumerableOfTType = compilation.IAsyncEnumerableOfTType();
    public readonly INamedTypeSymbol? IAsyncEnumeratorOfTType = compilation.IAsyncEnumeratorOfTType();
 
    public bool IsTaskLike(ITypeSymbol returnType)
    {
        if (returnType.Equals(this.TaskType))
            return true;
 
        if (returnType.Equals(this.ValueTaskType))
            return true;
 
        if (returnType.OriginalDefinition.Equals(this.TaskOfTType))
            return true;
 
        if (returnType.OriginalDefinition.Equals(this.ValueTaskOfTType))
            return true;
 
        if (returnType.IsErrorType())
            return returnType.Name is "Task" or "ValueTask";
 
        return false;
    }
}