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

using PkmnLib.Dynamic.Models;
using PkmnLib.Plugin.Gen7.Scripts.Moves;
using PkmnLib.Static;
using PkmnLib.Static.Species;
using PkmnLib.Static.Utils;

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

/// <summary>
/// Tests for the <see cref="MagneticFlux"/> move script.
/// Gen VII Bulbapedia behavior: "Magnetic Flux raises the Defense and Special Defense stats of allied
/// Pokémon (including the user) with the Ability Plus or Minus by one stage each."
/// </summary>
public class MagneticFluxTests
{
    private static (MagneticFlux script, IExecutingMove move, IPokemon user) CreateTestSetup(
        params IPokemon?[] sidePokemon)
    {
        var script = new MagneticFlux();

        var side = Substitute.For<IBattleSide>();
        side.Pokemon.Returns(sidePokemon);

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

        var user = Substitute.For<IPokemon>();
        user.BattleData.Returns(battleData);
        var move = Substitute.For<IExecutingMove>();
        move.User.Returns(user);

        return (script, move, user);
    }

    private static IPokemon CreatePokemonWithAbility(string? abilityName)
    {
        var pokemon = Substitute.For<IPokemon>();
        if (abilityName is null)
        {
            pokemon.ActiveAbility.Returns((IAbility?)null);
        }
        else
        {
            var ability = Substitute.For<IAbility>();
            ability.Name.Returns(new StringKey(abilityName));
            pokemon.ActiveAbility.Returns(ability);
        }

        return pokemon;
    }

    /// <summary>
    /// Helper to extract the arguments of all received ChangeStatBoost calls. Received-call inspection is
    /// used instead of NSubstitute argument matchers because the trailing <c>EventBatchId</c> parameter
    /// cannot be bound by <c>Arg.Any</c> (its parameterless constructor initializes a fresh id, so it
    /// never equals the matcher's default value).
    /// </summary>
    private static List<object?[]> GetStatBoostCalls(IPokemon pokemon) =>
        pokemon.ReceivedCalls().Where(c => c.GetMethodInfo().Name == "ChangeStatBoost").Select(c => c.GetArguments())
            .ToList();

    /// <summary>
    /// Bulbapedia: "Magnetic Flux raises the Defense and Special Defense stats of allied Pokémon
    /// (including the user) with the Ability Plus or Minus by one stage each." An ally with Plus has both
    /// its Defense and its Special Defense raised by one stage.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_AllyWithPlus_DefenseAndSpecialDefenseRaisedByOneStage()
    {
        // Arrange
        var ally = CreatePokemonWithAbility("plus");
        var (script, move, _) = CreateTestSetup(ally);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        var calls = GetStatBoostCalls(ally);
        await Assert.That(calls.Count).IsEqualTo(2);
        var boostedStats = calls.Select(args => (Statistic)args[0]!).ToList();
        await Assert.That(boostedStats.Contains(Statistic.Defense)).IsTrue();
        await Assert.That(boostedStats.Contains(Statistic.SpecialDefense)).IsTrue();
        await Assert.That(calls.All(args => (sbyte)args[1]! == 1)).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: the boost applies to allied Pokémon "with the Ability Plus or Minus" — an ally with
    /// Minus is affected just like one with Plus.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_AllyWithMinus_DefenseAndSpecialDefenseRaisedByOneStage()
    {
        // Arrange
        var ally = CreatePokemonWithAbility("minus");
        var (script, move, _) = CreateTestSetup(ally);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        var calls = GetStatBoostCalls(ally);
        await Assert.That(calls.Count).IsEqualTo(2);
        var boostedStats = calls.Select(args => (Statistic)args[0]!).ToList();
        await Assert.That(boostedStats.Contains(Statistic.Defense)).IsTrue();
        await Assert.That(boostedStats.Contains(Statistic.SpecialDefense)).IsTrue();
        await Assert.That(calls.All(args => (sbyte)args[1]! == 1)).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: only allied Pokémon "with the Ability Plus or Minus" are affected — an ally with a
    /// different ability does not have its stats raised.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_AllyWithOtherAbility_StatsNotRaised()
    {
        // Arrange
        var ally = CreatePokemonWithAbility("levitate");
        var (script, move, _) = CreateTestSetup(ally);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

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

    /// <summary>
    /// Bulbapedia: only allied Pokémon "with the Ability Plus or Minus" are affected — an ally without an
    /// active ability does not have its stats raised, and the script does not throw.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_AllyWithoutActiveAbility_StatsNotRaised()
    {
        // Arrange
        var ally = CreatePokemonWithAbility(null);
        var (script, move, _) = CreateTestSetup(ally);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

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

    /// <summary>
    /// Bulbapedia: the boost applies to allied Pokémon "(including the user)" — when the user itself has
    /// Plus, its own Defense and Special Defense are raised, and the boost counts as self-inflicted.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_UserWithPlus_BoostIsSelfInflicted()
    {
        // Arrange
        var (script, move, user) = CreateTestSetup();
        var ability = Substitute.For<IAbility>();
        ability.Name.Returns(new StringKey("plus"));
        user.ActiveAbility.Returns(ability);
        user.BattleData!.BattleSide.Pokemon.Returns(new IPokemon?[] { user });

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        var calls = GetStatBoostCalls(user);
        await Assert.That(calls.Count).IsEqualTo(2);
        await Assert.That(calls.All(args => (bool)args[2]!)).IsTrue(); // self-inflicted for the user itself
    }

    /// <summary>
    /// Bulbapedia: "Magnetic Flux raises the Defense and Special Defense stats of allied Pokémon". A boost
    /// applied to an ally other than the user is not self-inflicted.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_AllyWithPlus_BoostIsNotSelfInflicted()
    {
        // Arrange
        var ally = CreatePokemonWithAbility("plus");
        var (script, move, _) = CreateTestSetup(ally);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        var calls = GetStatBoostCalls(ally);
        await Assert.That(calls.Count).IsEqualTo(2);
        await Assert.That(calls.All(args => (bool)args[2]!)).IsFalse(); // not self-inflicted
    }

    /// <summary>
    /// Bulbapedia: the boost applies to "allied Pokémon" with Plus or Minus — when multiple eligible
    /// allies are on the user's side, every one of them is raised.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_MultipleEligibleAllies_AllAreRaised()
    {
        // Arrange
        var plusAlly = CreatePokemonWithAbility("plus");
        var minusAlly = CreatePokemonWithAbility("minus");
        var (script, move, _) = CreateTestSetup(plusAlly, minusAlly);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        await Assert.That(GetStatBoostCalls(plusAlly).Count).IsEqualTo(2);
        await Assert.That(GetStatBoostCalls(minusAlly).Count).IsEqualTo(2);
    }

    /// <summary>
    /// Technical test: empty (null) slots on the user's side are skipped without throwing, and eligible
    /// allies in other slots are still raised.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_EmptyPokemonSlot_IsSkipped()
    {
        // Arrange
        var ally = CreatePokemonWithAbility("plus");
        var (script, move, _) = CreateTestSetup(null, ally);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        await Assert.That(GetStatBoostCalls(ally).Count).IsEqualTo(2);
    }

    /// <summary>
    /// Technical test: when the user 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 = new MagneticFlux();
        var user = Substitute.For<IPokemon>();
        user.BattleData.Returns((IPokemonBattleData?)null);
        var move = Substitute.For<IExecutingMove>();
        move.User.Returns(user);

        // Act & Assert - should not throw
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);
        await Assert.That(GetStatBoostCalls(user).Count).IsEqualTo(0);
    }
}