zfxaction26_2/tests/ReactorMaintenance.Simulation.Tests/SimulationEngineTests.cs

namespace ReactorMaintenance.Simulation.Tests;

public sealed class SimulationEngineTests
{
    [Fact]
    public void NetworkPropagationSuppliesBoundConsumersAndReadiesReactor()
    {
        var level = BuildReadyLevel();

        var next = m_Engine.AdvanceTurn(level);

        Assert.Equal(EConsumerServiceState.Producing, next.GetProp(new(3, 2)).ServiceState);
        Assert.Equal(EConsumerServiceState.Producing, next.GetProp(new(3, 3)).ServiceState);
        Assert.Equal(EConsumerServiceState.Producing, next.GetProp(new(3, 4)).ServiceState);
        Assert.Equal(ELevelState.Ready, next.Global.LevelState);
        Assert.Contains(next.Forecasts, forecast => forecast.Kind == EForecastKind.ReactorReady);
    }

    [Fact]
    public void ReactorActivatesOnlyAtReadyControl()
    {
        var level = m_Engine.AdvanceTurn(BuildReadyLevel()) with {
            Robot = new() { Position = new(5, 3) }
        };

        var activated = m_Engine.ActivateReactor(level);

        Assert.Equal(ELevelState.Won, activated.Global.LevelState);
        Assert.True(activated.Reactors[0].Activated);
    }

    [Fact]
    public void LeakingUndergroundCellInjectsMatchingSurfaceHazard()
    {
        var level = LevelState.Create("Leak", 6, 6);
        level = level.SetUnderground(new(2, 2), ECarrierType.Fuel, new() { State = EUndergroundState.Leaking, Amount = 5, Intensity = 5 }) with {
            Leaks = [new LeakState { Carrier = ECarrierType.Fuel, UndergroundPosition = new(2, 2), AccessPosition = new(2, 2) }]
        };
        level = level.SetProp(new(2, 2), new() { Type = EPropType.Flow, Carrier = ECarrierType.Fuel });

        var next = m_Engine.AdvanceTurn(level);

        Assert.True(next.GetSurface(new(2, 2)).Fuel > 0);
    }

    [Fact]
    public void ElementRemedyClearsHazardAndBlocksImmediateReentry()
    {
        var level = LevelState.Create("Remedy", 6, 6);
        level = level.SetUnderground(new(2, 2), ECarrierType.Fuel, new() { State = EUndergroundState.Leaking, Amount = 5, Intensity = 5 });
        level = level.SetSurface(new(2, 2), new() { Fuel = 5 }) with {
            Robot = new() { Position = new(2, 2), FuelNeutralizers = 1 },
            Leaks = [new LeakState { Carrier = ECarrierType.Fuel, UndergroundPosition = new(2, 2), AccessPosition = new(2, 2) }]
        };

        var next = m_Engine.InteractLeak(level, ECarrierType.Fuel, true);

        Assert.Equal(0, next.GetSurface(new(2, 2)).Fuel);
        Assert.True(next.GetSurface(new(2, 2)).FuelBlockTurns > 0);
        Assert.Equal(0, next.Robot.FuelNeutralizers);
    }

    [Fact]
    public void ClosedDoorBlocksAdjacentHeatFlow()
    {
        var level = LevelState.Create("Door", 6, 6);
        level = level.SetSurface(new(2, 2), new() { Heat = 8 }) with {
            Doors = [new DoorState { A = new(2, 2), B = new(3, 2), State = EDoorState.Closed }]
        };

        var next = m_Engine.AdvanceTurn(level);

        Assert.Equal(0, next.GetSurface(new(3, 2)).Heat);
    }

    [Fact]
    public void HeatShieldPreventsRobotHeatLoss()
    {
        var level = LevelState.Create("Heat shield", 6, 6);
        level = level.SetSurface(new(2, 2), new() { Heat = Balancing.Current.RobotHeatSafetyThreshold }) with {
            Robot = new() { Position = new(2, 2), HeatImmunitySteps = 1 }
        };

        var next = m_Engine.AdvanceTurn(level);

        Assert.NotEqual(ELevelState.Lost, next.Global.LevelState);
    }

    [Fact]
    public void RobotLosesOnUnsafeElementHazard()
    {
        var level = LevelState.Create("Unsafe", 6, 6);
        level = level.SetSurface(new(2, 2), new() { Electricity = Balancing.Current.MaxValue }) with {
            Robot = new() { Position = new(2, 2) }
        };

        var next = m_Engine.AdvanceTurn(level);

        Assert.Equal(ELevelState.Lost, next.Global.LevelState);
    }

    [Fact]
    public void RuleEventCanCreateTerminalLossForecast()
    {
        var level = LevelState.Create("Rule", 6, 6) with {
            RuleEvents = [
                new RuleEventState {
                    Phase = ERuleEventPhase.EndOfTurn,
                    ForecastText = "containment failure",
                    Predicates = [new RulePredicate { Kind = ERulePredicateKind.TurnAtLeast, Turn = 0 }],
                    Effects = [new RuleEffect { Kind = ERuleEffectKind.MarkTerminalLoss, Message = "CONTAINMENT FAILURE" }]
                }
            ]
        };

        var forecasts = m_Engine.Forecast(level);

        Assert.Contains(forecasts, forecast => forecast.Kind == EForecastKind.RuleEvent && forecast.Message == "containment failure");
        Assert.Contains(forecasts, forecast => forecast.Kind == EForecastKind.TerminalLoss);
    }

    [Fact]
    public void ValidatorRejectsWallHazardsAndInvalidReactorBinding()
    {
        var level = LevelState.Create("Invalid", 6, 6);
        level = level.SetTerrain(new(2, 2), ECellTerrain.Wall);
        level = level with {
            Surface = level.Surface.ToArray(),
            Reactors = [new ReactorBinding { ControlPosition = new(3, 3), FuelConsumerPosition = new(1, 1), CoolantConsumerPosition = new(1, 1), ElectricityConsumerPosition = new(1, 1) }]
        };
        level.Surface[level.Index(new(2, 2))] = new() { Heat = 1 };

        var report = new LevelValidator().Validate(level);

        Assert.False(report.IsValid);
        Assert.Contains(report.Errors, error => error.Message.Contains("Wall cell", StringComparison.Ordinal));
        Assert.Contains(report.Errors, error => error.Message.Contains("Reactor binding", StringComparison.Ordinal));
    }

    [Fact]
    public void LevelSerializationRoundTripsCurrentSchemaOnly()
    {
        var level = BuildReadyLevel();

        var json = LevelSerializer.Serialize(level);
        var loaded = LevelSerializer.Deserialize(json);

        Assert.Contains("\"Version\": 2", json);
        Assert.Equal(level.Name, loaded.Name);
        Assert.Equal(EPropType.Flow, loaded.GetProp(new(2, 2)).Type);
    }

    [Fact]
    public void LevelSerializationRejectsOldSchema()
    {
        var json = """
                   {
                     "Version": 1,
                     "Level": {}
                   }
                   """;

        var exception = Assert.Throws<InvalidOperationException>(() => LevelSerializer.Deserialize(json));

        Assert.Contains("Unsupported level file version 1", exception.Message);
    }

    private static LevelState BuildReadyLevel()
    {
        var level = LevelState.Create("Ready", 8, 7);
        level = AddLine(level, ECarrierType.Fuel, new(2, 2), new(3, 2));
        level = AddLine(level, ECarrierType.Coolant, new(2, 3), new(3, 3));
        level = AddLine(level, ECarrierType.Electricity, new(2, 4), new(3, 4));
        level = level.SetProp(new(2, 2), new() { Type = EPropType.Flow, Carrier = ECarrierType.Fuel });
        level = level.SetProp(new(2, 3), new() { Type = EPropType.Flow, Carrier = ECarrierType.Coolant });
        level = level.SetProp(new(2, 4), new() { Type = EPropType.Flow, Carrier = ECarrierType.Electricity });
        level = level.SetProp(new(3, 2), new() { Type = EPropType.Consumer, Carrier = ECarrierType.Fuel });
        level = level.SetProp(new(3, 3), new() { Type = EPropType.Consumer, Carrier = ECarrierType.Coolant });
        level = level.SetProp(new(3, 4), new() { Type = EPropType.Consumer, Carrier = ECarrierType.Electricity });
        level = level.SetProp(new(5, 3), new() { Type = EPropType.ReactorControl, ReactorId = 1 });
        return level with {
            Robot = new() { Position = new(5, 3) },
            Reactors = [
                new ReactorBinding {
                    ReactorId = 1,
                    ControlPosition = new(5, 3),
                    FuelConsumerPosition = new(3, 2),
                    CoolantConsumerPosition = new(3, 3),
                    ElectricityConsumerPosition = new(3, 4)
                }
            ]
        };
    }

    private static LevelState AddLine(LevelState level, ECarrierType carrier, GridPosition a, GridPosition b)
    {
        level = level.SetUnderground(a, carrier, new() { State = EUndergroundState.Intact });
        level = level.SetUnderground(b, carrier, new() { State = EUndergroundState.Intact });
        return level;
    }

    private readonly SimulationEngine m_Engine = new();
}