// 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 System.Collections.Generic;
using Xunit;
 
namespace Microsoft.Extensions.AI;
 
public class FunctionInvocationContextTests
{
    [Fact]
    public void Constructor_PropertiesDefaultToExpectedValues()
    {
        FunctionInvocationContext ctx = new();
 
        Assert.NotNull(ctx.CallContent);
        Assert.NotNull(ctx.Messages);
        Assert.NotNull(ctx.Function);
        Assert.Equal(0, ctx.FunctionCallIndex);
        Assert.Equal(0, ctx.FunctionCount);
        Assert.Equal(0, ctx.Iteration);
        Assert.False(ctx.Terminate);
 
        Assert.Empty(ctx.Messages);
        Assert.True(ctx.Messages.IsReadOnly);
 
        Assert.Equal(nameof(FunctionInvocationContext), ctx.Function.Name);
        Assert.Empty(ctx.Function.Description);
        Assert.NotNull(ctx.Function.UnderlyingMethod);
    }
 
    [Fact]
    public void InvalidArgs_Throws()
    {
        FunctionInvocationContext ctx = new();
        Assert.Throws<ArgumentNullException>("value", () => ctx.CallContent = null!);
        Assert.Throws<ArgumentNullException>("value", () => ctx.Messages = null!);
        Assert.Throws<ArgumentNullException>("value", () => ctx.Function = null!);
    }
 
    [Fact]
    public void Properties_Roundtrip()
    {
        FunctionInvocationContext ctx = new();
 
        List<ChatMessage> messages = [];
        ctx.Messages = messages;
        Assert.Same(messages, ctx.Messages);
 
        AIFunction function = AIFunctionFactory.Create(() => { }, nameof(Properties_Roundtrip));
        ctx.Function = function;
        Assert.Same(function, ctx.Function);
 
        FunctionCallContent callContent = new(string.Empty, string.Empty, new Dictionary<string, object?>());
        ctx.CallContent = callContent;
        Assert.Same(callContent, ctx.CallContent);
 
        ctx.Iteration = 1;
        Assert.Equal(1, ctx.Iteration);
 
        ctx.FunctionCallIndex = 2;
        Assert.Equal(2, ctx.FunctionCallIndex);
 
        ctx.FunctionCount = 3;
        Assert.Equal(3, ctx.FunctionCount);
 
        ctx.Terminate = true;
        Assert.True(ctx.Terminate);
    }
}