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

using PkmnLib.Dynamic.Models;
using PkmnLib.Dynamic.Models.Choices;
using PkmnLib.Dynamic.ScriptHandling;
using PkmnLib.Plugin.Gen7.Scripts.Moves;
using PkmnLib.Plugin.Gen7.Scripts.Pokemon;
using PkmnLib.Static.Moves;
using PkmnLib.Static.Utils;

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

/// <summary>
/// Tests for the <see cref="Imprison"/> move script and its <see cref="ImprisonEffect"/> volatile.
/// Gen VII Bulbapedia behavior: "As long as the user remains in battle, opponents cannot use any move which
/// is also known by the user. This includes opponents switched in after the move was used". Generation V
/// onwards: "Imprison still works even if no opponent has a move the user knows."
/// </summary>
public class ImprisonTests
{
    /// <summary>
    /// Creates a substitute learned move whose <see cref="IMoveData.Name"/> is the given name.
    /// </summary>
    private static ILearnedMove CreateLearnedMove(string name)
    {
        var moveData = Substitute.For<IMoveData>();
        moveData.Name.Returns(new StringKey(name));
        var learnedMove = Substitute.For<ILearnedMove>();
        learnedMove.MoveData.Returns(moveData);
        return learnedMove;
    }

    /// <summary>
    /// Creates the Pokémon that used Imprison, knowing the given moves (with an empty move slot, as real
    /// movesets can have them), and the <see cref="ImprisonEffect"/> bound to it.
    /// </summary>
    private static (ImprisonEffect effect, IBattlePokemon user) CreateImprisonUser(params string[] knownMoves)
    {
        var user = Substitute.For<IBattlePokemon>();
        var moves = knownMoves.Select(ILearnedMove? (m) => CreateLearnedMove(m)).Append(null).ToArray();
        user.Moves.Returns(moves);
        return (new ImprisonEffect(user), user);
    }

    /// <summary>
    /// Creates a move choice by the given Pokémon for a move with the given name.
    /// </summary>
    private static IMoveChoice CreateMoveChoice(IBattlePokemon chooser, string moveName)
    {
        var choice = Substitute.For<IMoveChoice>();
        choice.User.Returns(chooser);
        var learnedMove = CreateLearnedMove(moveName);
        choice.ChosenMove.Returns(learnedMove);
        return choice;
    }

    /// <summary>
    /// Bulbapedia: "As long as the user remains in battle, opponents cannot use any move which is also known
    /// by the user." This includes opponents switched in after the move was used, so using the move puts the
    /// <see cref="ImprisonEffect"/> on the battle's volatile scripts, where every move choice sees it.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_Used_AddsImprisonEffectToBattleVolatile()
    {
        // Arrange
        var script = new Imprison();
        var move = Substitute.For<IExecutingMove>();
        var user = Substitute.For<IBattlePokemon>();
        move.User.Returns(user);
        var target = Substitute.For<IBattlePokemon>();

        var battle = Substitute.For<IBattle>();
        battle.GetScripts().Returns(_ => new ScriptIterator(Array.Empty<IEnumerable<ScriptContainer>>()));
        var battleVolatile = new ScriptSet(battle);
        battle.Volatile.Returns(battleVolatile);

        target.Battle.Returns(battle);

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

        // Assert
        await Assert.That(battleVolatile.Get<ImprisonEffect>()).IsNotNull();
    }

    /// <summary>
    /// Bulbapedia: "opponents cannot use any move which is also known by the user." An opponent choosing a
    /// move the Imprison user knows has its selection prevented.
    /// </summary>
    [Test]
    public async Task PreventMoveSelection_OpponentChoosesMoveKnownByUser_SelectionPrevented()
    {
        // Arrange
        var (effect, _) = CreateImprisonUser("tackle", "imprison");
        var opponent = Substitute.For<IBattlePokemon>();
        var choice = CreateMoveChoice(opponent, "tackle");
        var prevent = false;

        // Act
        effect.PreventMoveSelection(choice, ref prevent);

        // Assert
        await Assert.That(prevent).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: only moves "also known by the user" are sealed. An opponent choosing a move the Imprison
    /// user does not know is free to use it.
    /// </summary>
    [Test]
    public async Task PreventMoveSelection_OpponentChoosesMoveNotKnownByUser_SelectionAllowed()
    {
        // Arrange
        var (effect, _) = CreateImprisonUser("tackle", "imprison");
        var opponent = Substitute.For<IBattlePokemon>();
        var choice = CreateMoveChoice(opponent, "ember");
        var prevent = false;

        // Act
        effect.PreventMoveSelection(choice, ref prevent);

        // Assert
        await Assert.That(prevent).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "opponents cannot use any move which is also known by the user" — the user itself is not
    /// restricted and can keep using its own moves.
    /// </summary>
    [Test]
    public async Task PreventMoveSelection_UsersOwnChoice_SelectionAllowed()
    {
        // Arrange
        var (effect, user) = CreateImprisonUser("tackle", "imprison");
        var choice = CreateMoveChoice(user, "tackle");
        var prevent = false;

        // Act
        effect.PreventMoveSelection(choice, ref prevent);

        // Assert
        await Assert.That(prevent).IsFalse();
    }
}