PkmnLib.NET/Plugins/PkmnLib.Plugin.Gen7.Tests/Scripts/Moves/GravityTests.cs

using PkmnLib.Dynamic.Models;
using PkmnLib.Dynamic.ScriptHandling;
using PkmnLib.Dynamic.ScriptHandling.Registry;
using PkmnLib.Plugin.Gen7.Scripts.Moves;
using PkmnLib.Plugin.Gen7.Scripts.Pokemon;
using PkmnLib.Static.Utils;
using BattleGravity = PkmnLib.Plugin.Gen7.Scripts.Battle.Gravity;

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

/// <summary>
/// Tests for the <see cref="Gravity"/> move script.
/// Gen VII Bulbapedia behavior: "Gravity causes the field to undergo intense gravity lasting 5 turns",
/// and "Semi-invulnerable Pokémon using Fly or Bounce are immediately canceled."
/// </summary>
public class GravityTests
{
    /// <summary>
    /// Creates a fully mocked test setup for Gravity tests. The battle's volatile script set is a
    /// substitute so the addition of the battle-wide gravity script can be inspected.
    /// </summary>
    private static (Gravity script, IExecutingMove move, IPokemon target, IBattle battle, IScriptSet battleVolatile)
        CreateTestSetup(params IReadOnlyList<IPokemon?>[] sidePokemon)
    {
        var script = new Gravity();
        var move = Substitute.For<IExecutingMove>();
        move.User.Returns(Substitute.For<IPokemon>());

        var battle = Substitute.For<IBattle>();
        var battleVolatile = Substitute.For<IScriptSet>();
        battle.Volatile.Returns(battleVolatile);
        var sides = sidePokemon.Select(pokemon =>
        {
            var side = Substitute.For<IBattleSide>();
            side.Pokemon.Returns(pokemon);
            return side;
        }).ToArray();
        battle.Sides.Returns(sides);

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

        return (script, move, target, battle, battleVolatile);
    }

    /// <summary>
    /// Creates a mocked Pokémon with a real <see cref="ScriptSet"/> as its volatile set, so effects can
    /// be attached and their removal inspected.
    /// </summary>
    private static (IPokemon pokemon, ScriptSet volatileSet) CreateFieldPokemon()
    {
        var pokemon = Substitute.For<IPokemon>();
        pokemon.GetScripts().Returns(_ => new ScriptIterator(new List<IEnumerable<ScriptContainer>>()));
        var volatileSet = new ScriptSet(pokemon);
        pokemon.Volatile.Returns(volatileSet);
        return (pokemon, volatileSet);
    }

    /// <summary>
    /// Bulbapedia: "Gravity causes the field to undergo intense gravity lasting 5 turns." The battle-wide
    /// gravity effect is added to the battle's volatile script set.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_Always_AddsGravityToBattleVolatile()
    {
        // Arrange
        var (script, move, target, _, battleVolatile) = CreateTestSetup();

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

        // Assert
        battleVolatile.Received(1).StackOrAdd(new StringKey("gravity"), Arg.Any<Func<Script?>>());
        await Assert.That(battleVolatile.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "StackOrAdd")).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: the field undergoes "intense gravity" — the instantiation function passed to the
    /// battle's volatile script set creates the battle-wide <see cref="BattleGravity"/> script.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_GravityInstantiation_CreatesBattleGravityScript()
    {
        // Arrange
        var (script, move, target, battle, battleVolatile) = CreateTestSetup();
        battle.Library.Returns(LibraryHelpers.LoadLibrary());

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

        // Assert
        var call = battleVolatile.ReceivedCalls().First(c => c.GetMethodInfo().Name == "StackOrAdd");
        var instantiation = (Func<Script?>)call.GetArguments()[1]!;
        await Assert.That(instantiation() is BattleGravity).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: "Semi-invulnerable Pokémon using Fly or Bounce are immediately canceled." A Pokémon in
    /// the semi-invulnerable turn of Fly has its <see cref="ChargeFlyEffect"/> removed.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_PokemonFlying_FlyEffectRemoved()
    {
        // Arrange
        var (pokemon, volatileSet) = CreateFieldPokemon();
        volatileSet.Add(new ChargeFlyEffect(pokemon));
        var (script, move, target, _, _) = CreateTestSetup(new List<IPokemon?> { pokemon });

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

        // Assert
        await Assert.That(volatileSet.Contains(ScriptUtils.ResolveName<ChargeFlyEffect>())).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "Semi-invulnerable Pokémon using Fly or Bounce are immediately canceled." A Pokémon in
    /// the semi-invulnerable turn of Bounce has its <see cref="ChargeBounceEffect"/> removed.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_PokemonBouncing_BounceEffectRemoved()
    {
        // Arrange
        var (pokemon, volatileSet) = CreateFieldPokemon();
        volatileSet.Add(new ChargeBounceEffect(pokemon));
        var (script, move, target, _, _) = CreateTestSetup(new List<IPokemon?> { pokemon });

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

        // Assert
        await Assert.That(volatileSet.Contains(ScriptUtils.ResolveName<ChargeBounceEffect>())).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: Gravity cancels Sky Drop — "Semi-invulnerable Pokémon ... are immediately canceled." A
    /// Pokémon in the semi-invulnerable turn of Sky Drop has its <see cref="ChargeSkyDropEffect"/>
    /// removed.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_PokemonInSkyDrop_SkyDropEffectRemoved()
    {
        // Arrange
        var (pokemon, volatileSet) = CreateFieldPokemon();
        volatileSet.Add(new ChargeSkyDropEffect(pokemon));
        var (script, move, target, _, _) = CreateTestSetup(new List<IPokemon?> { pokemon });

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

        // Assert
        await Assert.That(volatileSet.Contains(ScriptUtils.ResolveName<ChargeSkyDropEffect>())).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "The effect grounds all Pokémon, removing ... Telekinesis ... effects." A Pokémon under
    /// Telekinesis has its <see cref="TelekinesisEffect"/> removed.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_PokemonUnderTelekinesis_TelekinesisEffectRemoved()
    {
        // Arrange
        var (pokemon, volatileSet) = CreateFieldPokemon();
        volatileSet.Add(new TelekinesisEffect());
        var (script, move, target, _, _) = CreateTestSetup(new List<IPokemon?> { pokemon });

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

        // Assert
        await Assert.That(volatileSet.Contains(ScriptUtils.ResolveName<TelekinesisEffect>())).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "The effect grounds all Pokémon, removing ... Magnet Rise ... effects." A Pokémon under
    /// Magnet Rise should have its <see cref="MagnetRiseEffect"/> removed.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_PokemonUnderMagnetRise_MagnetRiseEffectRemoved()
    {
        // Arrange
        var (pokemon, volatileSet) = CreateFieldPokemon();
        volatileSet.Add(new MagnetRiseEffect());
        var (script, move, target, _, _) = CreateTestSetup(new List<IPokemon?> { pokemon });

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

        // Assert
        await Assert.That(volatileSet.Contains(ScriptUtils.ResolveName<MagnetRiseEffect>())).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "The effect grounds all Pokémon" — Pokémon on every side of the battle are affected,
    /// not only those on the target's side.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_FlyingPokemonOnBothSides_BothCanceled()
    {
        // Arrange
        var (allyPokemon, allyVolatile) = CreateFieldPokemon();
        allyVolatile.Add(new ChargeFlyEffect(allyPokemon));
        var (opposingPokemon, opposingVolatile) = CreateFieldPokemon();
        opposingVolatile.Add(new ChargeFlyEffect(opposingPokemon));
        var (script, move, target, _, _) = CreateTestSetup(new List<IPokemon?> { allyPokemon },
            new List<IPokemon?> { opposingPokemon });

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

        // Assert
        await Assert.That(allyVolatile.Contains(ScriptUtils.ResolveName<ChargeFlyEffect>())).IsFalse();
        await Assert.That(opposingVolatile.Contains(ScriptUtils.ResolveName<ChargeFlyEffect>())).IsFalse();
    }

    /// <summary>
    /// Technical test: empty (null) slots on a side are skipped without throwing.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_EmptyPokemonSlot_IsSkipped()
    {
        // Arrange
        var (script, move, target, _, battleVolatile) = CreateTestSetup(new List<IPokemon?> { null });

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

        // Assert
        await Assert.That(battleVolatile.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "StackOrAdd")).IsTrue();
    }

    /// <summary>
    /// Technical test: when the target has no <see cref="IPokemon.BattleData"/> (it is not in a battle),
    /// the script does nothing instead of throwing.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_NullBattleData_DoesNothing()
    {
        // Arrange
        var (script, move, target, _, battleVolatile) = CreateTestSetup();
        target.BattleData.Returns((IPokemonBattleData?)null);

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

        // Assert
        await Assert.That(battleVolatile.ReceivedCalls().Any()).IsFalse();
    }
}