using NUnit.Framework;
using SVSim.BattleNode.Bridge;
using SVSim.BattleNode.Sessions;
using SVSim.EmulatedEntrypoint.Matching;

namespace SVSim.UnitTests.Matching;

[TestFixture]
public class InProcessPairUpTests
{
    [Test]
    public async Task TryPairAsync_on_empty_slot_returns_null_and_parks()
    {
        var bridge = new MatchingBridge(new InMemoryBattleSessionStore(), new BattleNodeOptions());
        var svc = new InProcessPairUp(bridge);

        var match = await svc.TryPairAsync("tk2", new BattlePlayer(1, Ctx()), CancellationToken.None);

        Assert.That(match, Is.Null);
    }

    [Test]
    public async Task TryPairAsync_with_waiting_partner_pairs_and_returns_match()
    {
        var bridge = new MatchingBridge(new InMemoryBattleSessionStore(), new BattleNodeOptions());
        var svc = new InProcessPairUp(bridge);

        await svc.TryPairAsync("tk2", new BattlePlayer(1, Ctx()), CancellationToken.None);
        var match = await svc.TryPairAsync("tk2", new BattlePlayer(2, Ctx()), CancellationToken.None);

        Assert.That(match, Is.Not.Null);
        Assert.That(match!.BattleId, Is.Not.Empty);
    }

    [Test]
    public async Task First_arrivers_next_poll_returns_cached_match_then_evicts()
    {
        var bridge = new MatchingBridge(new InMemoryBattleSessionStore(), new BattleNodeOptions());
        var svc = new InProcessPairUp(bridge);

        await svc.TryPairAsync("tk2", new BattlePlayer(1, Ctx()), CancellationToken.None);  // park
        var secondPaired = await svc.TryPairAsync("tk2", new BattlePlayer(2, Ctx()), CancellationToken.None);  // pair
        var firstCached = await svc.TryPairAsync("tk2", new BattlePlayer(1, Ctx()), CancellationToken.None);   // consume
        var firstAgain = await svc.TryPairAsync("tk2", new BattlePlayer(1, Ctx()), CancellationToken.None);    // post-consume

        Assert.That(firstCached, Is.Not.Null);
        Assert.That(firstCached!.BattleId, Is.EqualTo(secondPaired!.BattleId));
        Assert.That(firstAgain, Is.Null, "Consumed entry must be evicted; next call re-parks.");
    }

    [Test]
    public async Task Different_modes_do_not_pair_across_slots()
    {
        var bridge = new MatchingBridge(new InMemoryBattleSessionStore(), new BattleNodeOptions());
        var svc = new InProcessPairUp(bridge);

        await svc.TryPairAsync("tk2", new BattlePlayer(1, Ctx()), CancellationToken.None);
        var rankMatch = await svc.TryPairAsync("rank_rotation", new BattlePlayer(2, Ctx()), CancellationToken.None);

        Assert.That(rankMatch, Is.Null, "Different mode shouldn't pair with tk2's waiting viewer.");
    }

    private static MatchContext Ctx() => new(
        SelfDeckCardIds: Enumerable.Range(1, 30).Select(_ => 100_011_010L).ToList(),
        ClassId: "1", CharaId: "1", CardMasterName: "card_master_node_10015",
        CountryCode: "KOR", UserName: "Player", SleeveId: "3000011",
        EmblemId: "701441011", DegreeId: "300003", FieldId: 43, IsOfficial: 0,
        BattleType: 11);
}