PkmnLib.NET/Plugins/PkmnLib.Plugin.Gen7.Tests/Scripts/MoveVolatile/FireGrassPledgeMoveTests.cs

using PkmnLib.Dynamic.Models;
using PkmnLib.Dynamic.Models.Choices;
using PkmnLib.Dynamic.ScriptHandling;
using PkmnLib.Plugin.Gen7.Scripts.MoveVolatile;
using PkmnLib.Plugin.Gen7.Scripts.Side;
using PkmnLib.Static;
using PkmnLib.Static.Utils;

namespace PkmnLib.Plugin.Gen7.Tests.Scripts.MoveVolatile;

/// <summary>
/// Tests for the <see cref="FireGrassPledgeMove"/> volatile script, which implements the combined move of
/// Fire Pledge and Grass Pledge, and the <see cref="SeaOfFireEffect"/> it creates.
/// Bulbapedia (Fire Pledge): "If Fire Pledge and Grass Pledge are used in the same turn, the ally moving
/// second will use Fire Pledge with a power of 150, and create a sea of fire on the target's side of the
/// field for four turns. The sea of fire damages all non-Fire Pokémon on that side of the field for 1/8 of
/// their maximum HP at the end of each turn."
/// </summary>
public class FireGrassPledgeMoveTests
{
    /// <summary>
    /// Creates a fully mocked test setup. The target's battle side gets a real <see cref="ScriptSet"/> as
    /// its volatile script set, so the sea of fire created by the combined move can be inspected and driven.
    /// </summary>
    private static (FireGrassPledgeMove script, IExecutingMove move, IPokemon target, IBattleSide side, IScriptSet
        sideVolatile) CreateTestSetup()
    {
        var script = new FireGrassPledgeMove();
        var move = Substitute.For<IExecutingMove>();

        var side = Substitute.For<IBattleSide>();
        side.GetScripts().Returns(_ => new ScriptIterator(new List<IEnumerable<ScriptContainer>>()));
        var sideVolatile = new ScriptSet(side);
        side.VolatileScripts.Returns(sideVolatile);

        var battleData = Substitute.For<IPokemonBattleData>();
        battleData.BattleSide.Returns(side);
        var target = Substitute.For<IPokemon>();
        target.BattleData.Returns(battleData);

        return (script, move, target, side, sideVolatile);
    }

    /// <summary>
    /// Creates a Pokémon substitute of the given type with the given maximum HP, for placing on the side
    /// covered by the sea of fire.
    /// </summary>
    private static IPokemon CreateSidePokemon(string typeName, uint maxHealth)
    {
        var pokemon = Substitute.For<IPokemon>();
        pokemon.Types.Returns(new List<TypeIdentifier> { new(1, typeName) });
        pokemon.MaxHealth.Returns(maxHealth);
        return pokemon;
    }

    /// <summary>
    /// Helper to count the Damage calls a Pokémon received.
    /// </summary>
    private static int CountDamageCalls(IPokemon pokemon) =>
        pokemon.ReceivedCalls().Count(c => c.GetMethodInfo().Name == "Damage");

    /// <summary>
    /// Bulbapedia: "the ally moving second will use Fire Pledge" when Fire Pledge and Grass Pledge are
    /// combined. The marked choice's move is replaced with Fire Pledge.
    /// </summary>
    [Test]
    public async Task ChangeMove_CombinedMove_ExecutesFirePledge()
    {
        // Arrange
        var (script, _, _, _, _) = CreateTestSetup();
        var choice = Substitute.For<IMoveChoice>();
        StringKey moveName = "grass_pledge";

        // Act
        script.ChangeMove(choice, ref moveName);

        // Assert
        await Assert.That(moveName).IsEqualTo(new StringKey("fire_pledge"));
    }

    /// <summary>
    /// Bulbapedia: "the ally moving second will use Fire Pledge with a power of 150".
    /// </summary>
    [Test]
    public async Task ChangeBasePower_CombinedMove_PowerIs150()
    {
        // Arrange
        var (script, move, target, _, _) = CreateTestSetup();
        ushort basePower = 80;

        // Act
        script.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)150);
    }

    /// <summary>
    /// Bulbapedia: the combined move will "create a sea of fire on the target's side of the field for four
    /// turns." The <see cref="SeaOfFireEffect"/> is added to the target's side.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_CombinedMoveHits_AddsSeaOfFireToTargetsSide()
    {
        // Arrange
        var (script, move, target, _, sideVolatile) = CreateTestSetup();

        // Act
        script.OnSecondaryEffect(move, target, 0);

        // Assert
        await Assert.That(sideVolatile.Get<SeaOfFireEffect>()).IsNotNull();
    }

    /// <summary>
    /// Technical test: if the target has no <see cref="IPokemon.BattleData"/>, no sea of fire is created
    /// and the script does not throw.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_TargetHasNoBattleData_DoesNothing()
    {
        // Arrange
        var (script, move, target, _, sideVolatile) = CreateTestSetup();
        target.BattleData.Returns((IPokemonBattleData?)null);

        // Act
        script.OnSecondaryEffect(move, target, 0);

        // Assert
        await Assert.That(sideVolatile.Count).IsEqualTo(0);
    }

    /// <summary>
    /// Bulbapedia: "The sea of fire damages all non-Fire Pokémon on that side of the field for 1/8 of
    /// their maximum HP at the end of each turn."
    /// </summary>
    [Test, Arguments(96u, 12u), Arguments(100u, 12u), Arguments(120u, 15u)]
    public async Task SeaOfFireEffect_OnEndTurn_DamagesNonFirePokemonForOneEighthOfMaxHp(uint maxHealth,
        uint expectedDamage)
    {
        // Arrange
        var (script, move, target, side, sideVolatile) = CreateTestSetup();
        var waterPokemon = CreateSidePokemon("water", maxHealth);
        side.Pokemon.Returns(new List<IPokemon?> { waterPokemon });
        script.OnSecondaryEffect(move, target, 0);
        var seaOfFire = sideVolatile.Get<SeaOfFireEffect>()!;

        // Act
        seaOfFire.OnEndTurn(side, Substitute.For<IBattle>());

        // Assert
        var call = waterPokemon.ReceivedCalls().First(c => c.GetMethodInfo().Name == "Damage");
        await Assert.That((uint)call.GetArguments()[0]!).IsEqualTo(expectedDamage);
        await Assert.That((DamageSource)call.GetArguments()[1]!).IsEqualTo(DamageSource.Misc);
    }

    /// <summary>
    /// Bulbapedia: the sea of fire damages "all non-Fire Pokémon on that side of the field" — Fire-type
    /// Pokémon are not hurt by it.
    /// </summary>
    [Test]
    public async Task SeaOfFireEffect_OnEndTurn_DoesNotDamageFirePokemon()
    {
        // Arrange
        var (script, move, target, side, sideVolatile) = CreateTestSetup();
        var firePokemon = CreateSidePokemon("fire", 100);
        side.Pokemon.Returns(new List<IPokemon?> { firePokemon });
        script.OnSecondaryEffect(move, target, 0);
        var seaOfFire = sideVolatile.Get<SeaOfFireEffect>()!;

        // Act
        seaOfFire.OnEndTurn(side, Substitute.For<IBattle>());

        // Assert
        await Assert.That(CountDamageCalls(firePokemon)).IsEqualTo(0);
    }

    /// <summary>
    /// Bulbapedia: the sea of fire lasts "for four turns", damaging "at the end of each turn." Over any
    /// number of end-of-turns, a non-Fire Pokémon on the covered side is damaged exactly four times.
    /// </summary>
    [Test]
    public async Task SeaOfFireEffect_LastsFourTurns_DamagesExactlyFourTimes()
    {
        // Arrange
        var (script, move, target, side, sideVolatile) = CreateTestSetup();
        var waterPokemon = CreateSidePokemon("water", 96);
        side.Pokemon.Returns(new List<IPokemon?> { waterPokemon });
        script.OnSecondaryEffect(move, target, 0);
        var seaOfFire = sideVolatile.Get<SeaOfFireEffect>()!;
        var battle = Substitute.For<IBattle>();

        // Act - more end-of-turns than the sea of fire lasts
        for (var i = 0; i < 6; i++)
            seaOfFire.OnEndTurn(side, battle);

        // Assert
        await Assert.That(CountDamageCalls(waterPokemon)).IsEqualTo(4);
    }

    /// <summary>
    /// Technical test: once its duration has run out, the sea of fire removes itself from the side's
    /// volatile scripts.
    /// </summary>
    [Test]
    public async Task SeaOfFireEffect_AfterExpiry_HasRemovedItselfFromSide()
    {
        // Arrange
        var (script, move, target, side, sideVolatile) = CreateTestSetup();
        side.Pokemon.Returns(new List<IPokemon?>());
        script.OnSecondaryEffect(move, target, 0);
        var seaOfFire = sideVolatile.Get<SeaOfFireEffect>()!;
        var battle = Substitute.For<IBattle>();

        // Act
        for (var i = 0; i < 5; i++)
            seaOfFire.OnEndTurn(side, battle);

        // Assert
        await Assert.That(sideVolatile.Contains("sea_of_fire_effect")).IsFalse();
    }
}