// <copyright file="InMemoryHlcStateStoreTests.Load.cs" company="StellaOps">
// Copyright (c) StellaOps. Licensed under BUSL-1.1.
// </copyright>
using FluentAssertions;
using System;
using System.Threading;
using Xunit;

namespace StellaOps.HybridLogicalClock.Tests;

public sealed partial class InMemoryHlcStateStoreTests
{
    [Fact]
    public async Task LoadAsync_NoState_ReturnsNullAsync()
    {
        var store = new InMemoryHlcStateStore();

        var result = await store.LoadAsync("node1", CancellationToken.None);

        result.Should().BeNull();
    }

    [Fact]
    public async Task LoadAsync_NullNodeId_ThrowsArgumentNullExceptionAsync()
    {
        var store = new InMemoryHlcStateStore();

        var act = () => store.LoadAsync(null!, CancellationToken.None);

        await act.Should().ThrowAsync<ArgumentNullException>();
    }

    [Fact]
    public async Task LoadAsync_WhitespaceNodeId_ThrowsArgumentExceptionAsync()
    {
        var store = new InMemoryHlcStateStore();

        var act = () => store.LoadAsync("   ", CancellationToken.None);

        await act.Should().ThrowAsync<ArgumentException>();
    }

    [Fact]
    public async Task LoadAsync_Cancelled_ThrowsOperationCanceledExceptionAsync()
    {
        var store = new InMemoryHlcStateStore();
        using var cts = new CancellationTokenSource();
        cts.Cancel();

        var act = () => store.LoadAsync("node1", cts.Token);

        await act.Should().ThrowAsync<OperationCanceledException>();
    }
}