neon-sprawl/server/NeonSprawl.Server.Tests/Game/Npc/NpcRuntimeOperationsTests.cs

using NeonSprawl.Server.Game.Npc;
using Xunit;

namespace NeonSprawl.Server.Tests.Game.Npc;

public sealed class NpcRuntimeOperationsTests
{
    private static readonly DateTimeOffset T0 =
        new(2026, 5, 27, 12, 0, 0, TimeSpan.Zero);

    private static (INpcRuntimeStateStore Runtime, IThreatStateStore Threat, INpcBehaviorDefinitionRegistry Behavior)
        CreateFixture()
    {
        return (
            new InMemoryNpcRuntimeStateStore(),
            new InMemoryThreatStateStore(),
            PrototypeNpcTestFixtures.CreateBehaviorRegistry());
    }

    private static void SetHolder(IThreatStateStore threatStore, string npcId, string playerId = "dev-local-1") =>
        _ = threatStore.TrySetHolder(npcId, playerId);

    private static void Advance(
        DateTimeOffset nowUtc,
        INpcRuntimeStateStore runtimeStore,
        IThreatStateStore threatStore,
        INpcBehaviorDefinitionRegistry behaviorRegistry,
        double maxDeltaSeconds = NpcRuntimeOperations.DefaultMaxDeltaSeconds) =>
        NpcRuntimeOperations.AdvanceAll(nowUtc, runtimeStore, threatStore, behaviorRegistry, maxDeltaSeconds);

    [Fact]
    public void AdvanceAll_ShouldKeepIdle_WhenNoAggroHolder()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        // Act
        Advance(T0, runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Idle, snapshot.BehaviorState);
        Assert.Null(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldEnterAggro_WhenHolderSetAndRowIdle()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        // Act
        Advance(T0, runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Aggro, snapshot.BehaviorState);
        Assert.Equal(T0, snapshot.PhaseStartedUtc);
        Assert.Null(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldNotTelegraph_WhenNoAggroHolder()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        runtime.LastAdvancedUtc = T0;
        // Act
        Advance(T0.AddSeconds(10), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Idle, snapshot.BehaviorState);
        Assert.Null(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldEnterTelegraphAfterMeleeAttackCooldownSeconds()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(3), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.TelegraphWindup, snapshot.BehaviorState);
        Assert.Equal(T0.AddSeconds(3), snapshot.PhaseStartedUtc);
        Assert.NotNull(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldRemainAggro_BeforeMeleeAttackCooldownCompletes()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(2.9), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Aggro, snapshot.BehaviorState);
    }

    [Fact]
    public void AdvanceAll_ShouldRemainTelegraphWindup_BeforeMeleeWindupCompletes()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        Advance(T0.AddSeconds(3), runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(4.4), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.TelegraphWindup, snapshot.BehaviorState);
    }

    [Fact]
    public void AdvanceAll_ShouldEnterRecover_WhenMeleeWindupCompletes()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        Advance(T0.AddSeconds(3), runtime, threat, behavior);
        Advance(T0.AddSeconds(4.4), runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(4.5), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Recover, snapshot.BehaviorState);
        Assert.Equal(T0.AddSeconds(4.5), snapshot.PhaseStartedUtc);
        Assert.Null(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldRunFullMeleeCycle_ToSecondTelegraph()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        Advance(T0.AddSeconds(3), runtime, threat, behavior);
        Advance(T0.AddSeconds(4.5), runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(7.5), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.TelegraphWindup, snapshot.BehaviorState);
        Assert.Equal(T0.AddSeconds(7.5), snapshot.PhaseStartedUtc);
        Assert.NotNull(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldRunFullMeleeCycle_ToSecondTelegraph_InSingleAdvanceCall()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(7.5), runtime, threat, behavior, maxDeltaSeconds: 10);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.TelegraphWindup, snapshot.BehaviorState);
        Assert.Equal(T0.AddSeconds(7.5), snapshot.PhaseStartedUtc);
        Assert.NotNull(snapshot.ActiveTelegraph);
    }

    [Fact]
    public void AdvanceAll_ShouldReturnToIdle_WhenHolderClearedMidWindup()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        Advance(T0.AddSeconds(3), runtime, threat, behavior);
        _ = threat.TryClearHolder(PrototypeNpcRegistry.PrototypeNpcMeleeId);
        // Act
        Advance(T0.AddSeconds(3.5), runtime, threat, behavior);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Idle, snapshot.BehaviorState);
        Assert.Null(snapshot.ActiveTelegraph);
    }

    [Theory]
    [InlineData("prototype_npc_ranged", 4.0)]
    [InlineData("prototype_npc_elite", 5.0)]
    public void AdvanceAll_ShouldEnterTelegraph_AtCatalogCooldownForArchetype(
        string npcInstanceId,
        double attackCooldownSeconds)
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, npcInstanceId);
        Advance(T0, runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(attackCooldownSeconds), runtime, threat, behavior);
        // Assert
        runtime.TryGet(npcInstanceId, out var snapshot);
        Assert.Equal(NpcBehaviorState.TelegraphWindup, snapshot.BehaviorState);
        Assert.Equal(T0.AddSeconds(attackCooldownSeconds), snapshot.PhaseStartedUtc);
    }

    [Theory]
    [InlineData("prototype_npc_ranged", 4.0, 2.0)]
    [InlineData("prototype_npc_elite", 5.0, 2.5)]
    public void AdvanceAll_ShouldEnterRecover_AfterCatalogWindupForArchetype(
        string npcInstanceId,
        double attackCooldownSeconds,
        double telegraphWindupSeconds)
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, npcInstanceId);
        Advance(T0, runtime, threat, behavior);
        Advance(T0.AddSeconds(attackCooldownSeconds), runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(attackCooldownSeconds + telegraphWindupSeconds), runtime, threat, behavior);
        // Assert
        runtime.TryGet(npcInstanceId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Recover, snapshot.BehaviorState);
        Assert.Equal(
            T0.AddSeconds(attackCooldownSeconds + telegraphWindupSeconds),
            snapshot.PhaseStartedUtc);
    }

    [Fact]
    public void AdvanceAll_ShouldCapSimulatedDelta_PerAdvanceCall()
    {
        // Arrange
        var (runtime, threat, behavior) = CreateFixture();
        SetHolder(threat, PrototypeNpcRegistry.PrototypeNpcMeleeId);
        Advance(T0, runtime, threat, behavior);
        // Act
        Advance(T0.AddSeconds(10), runtime, threat, behavior, maxDeltaSeconds: 5);
        // Assert
        runtime.TryGet(PrototypeNpcRegistry.PrototypeNpcMeleeId, out var snapshot);
        Assert.Equal(NpcBehaviorState.Recover, snapshot.BehaviorState);
        Assert.Equal(T0.AddSeconds(4.5), snapshot.PhaseStartedUtc);
    }
}