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

namespace StellaOps.HybridLogicalClock.Tests;

public sealed partial class HybridLogicalClockTests
{
    [Fact]
    public async Task InitializeFromStateAsync_NoState_ReturnsFalseAsync()
    {
        var timeProvider = CreateTimeProvider(FixedTime);
        var clock = CreateClock(timeProvider);

        var result = await clock.InitializeFromStateAsync(CancellationToken.None);

        result.Should().BeFalse();
        clock.Current.PhysicalTime.Should().Be(0);
        clock.Current.LogicalCounter.Should().Be(0);
    }

    [Fact]
    public async Task InitializeFromStateAsync_PersistedAhead_UsesPersistedTimeAsync()
    {
        var timeProvider = CreateTimeProvider(FixedTime);
        var stateStore = new InMemoryHlcStateStore();
        var persisted = CreateRemoteTimestamp(FixedTime.AddMilliseconds(10), 3, TestNodeId);
        await stateStore.SaveAsync(persisted, CancellationToken.None);
        var clock = CreateClock(timeProvider, store: stateStore);

        var result = await clock.InitializeFromStateAsync(CancellationToken.None);

        result.Should().BeTrue();
        clock.Current.PhysicalTime.Should().Be(persisted.PhysicalTime);
        clock.Current.LogicalCounter.Should().Be(persisted.LogicalCounter + 1);
    }

    [Fact]
    public async Task InitializeFromStateAsync_PhysicalNowAhead_ResetsCounterAsync()
    {
        var physicalNow = FixedTime.AddMilliseconds(50);
        var timeProvider = CreateTimeProvider(physicalNow);
        var stateStore = new InMemoryHlcStateStore();
        var persisted = CreateRemoteTimestamp(FixedTime, 7, TestNodeId);
        await stateStore.SaveAsync(persisted, CancellationToken.None);
        var clock = CreateClock(timeProvider, store: stateStore);

        var result = await clock.InitializeFromStateAsync(CancellationToken.None);

        result.Should().BeTrue();
        clock.Current.PhysicalTime.Should().Be(physicalNow.ToUnixTimeMilliseconds());
        clock.Current.LogicalCounter.Should().Be(0);
    }
}