// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using Xunit;
 
namespace Microsoft.Extensions.AI;
 
public class UsageContentTests
{
    [Fact]
    public void Constructor_InvalidArg_Throws()
    {
        Assert.Throws<ArgumentNullException>("details", () => new UsageContent(null!));
    }
 
    [Fact]
    public void Constructor_Parameterless_PropsDefault()
    {
        UsageContent c = new();
        Assert.Null(c.RawRepresentation);
        Assert.Null(c.ModelId);
        Assert.Null(c.AdditionalProperties);
 
        Assert.NotNull(c.Details);
        Assert.Same(c.Details, c.Details);
        Assert.Null(c.Details.InputTokenCount);
        Assert.Null(c.Details.OutputTokenCount);
        Assert.Null(c.Details.TotalTokenCount);
        Assert.Null(c.Details.AdditionalProperties);
    }
 
    [Fact]
    public void Constructor_UsageDetails_PropsRoundtrip()
    {
        UsageDetails details = new();
 
        UsageContent c = new(details);
        Assert.Null(c.RawRepresentation);
        Assert.Null(c.ModelId);
        Assert.Null(c.AdditionalProperties);
 
        Assert.Same(details, c.Details);
 
        UsageDetails details2 = new();
        c.Details = details2;
        Assert.Same(details2, c.Details);
    }
 
    [Fact]
    public void Details_SetNull_Throws()
    {
        UsageContent c = new();
 
        UsageDetails d = c.Details;
        Assert.NotNull(d);
 
        Assert.Throws<ArgumentNullException>("value", () => c.Details = null!);
 
        Assert.Same(d, c.Details);
    }
}