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

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

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

/// <summary>
/// Tests for the <see cref="Metronome"/> script, which implements Metronome.
/// Behavior is verified against the Bulbapedia page for Metronome (Generation VII).
/// </summary>
public class MetronomeTests
{
    /// <summary>
    /// Creates a fully mocked test setup for Metronome tests. The user's move library and battle random are
    /// mocked so that tests control which move <see cref="Metronome.ChangeMove"/> "randomly" rolls.
    /// </summary>
    private static (Metronome metronome, IMoveChoice choice, IPokemon user, IReadOnlyMoveLibrary moveLibrary,
        IBattleRandom random) CreateTestSetup()
    {
        var metronome = new Metronome();
        var user = Substitute.For<IPokemon>();
        var choice = Substitute.For<IMoveChoice>();
        choice.User.Returns(user);

        var battle = Substitute.For<IBattle>();
        var random = Substitute.For<IBattleRandom>();
        battle.Random.Returns(random);
        var battleData = Substitute.For<IPokemonBattleData>();
        battleData.Battle.Returns(battle);
        user.BattleData.Returns(battleData);

        var moveLibrary = Substitute.For<IReadOnlyMoveLibrary>();
        var staticLibrary = Substitute.For<IStaticLibrary>();
        staticLibrary.Moves.Returns(moveLibrary);
        var dynamicLibrary = Substitute.For<IDynamicLibrary>();
        dynamicLibrary.StaticLibrary.Returns(staticLibrary);
        user.Library.Returns(dynamicLibrary);

        return (metronome, choice, user, moveLibrary, random);
    }

    /// <summary>
    /// Creates a mocked <see cref="IMoveData"/> with the given name.
    /// </summary>
    private static IMoveData CreateMoveData(string name)
    {
        var moveData = Substitute.For<IMoveData>();
        moveData.Name.Returns(new StringKey(name));
        return moveData;
    }

    /// <summary>
    /// Bulbapedia: "The Metronome user executes a randomly selected move."
    /// The move rolled from the move library replaces the used move name.
    /// </summary>
    [Test]
    public async Task ChangeMove_SelectableMoveRolled_MoveNameChangesToRolledMove()
    {
        // Arrange
        var (metronome, choice, _, moveLibrary, random) = CreateTestSetup();
        var tackle = CreateMoveData("tackle");
        moveLibrary.GetRandom(random).Returns(tackle);
        var moveName = new StringKey("metronome");

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

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

    /// <summary>
    /// Technical test: if the user has no <see cref="IPokemon.BattleData"/>, the script cannot roll a random
    /// move and must leave the move name unchanged.
    /// </summary>
    [Test]
    public async Task ChangeMove_UserHasNoBattleData_MoveNameUnchanged()
    {
        // Arrange
        var (metronome, choice, user, moveLibrary, random) = CreateTestSetup();
        user.BattleData.Returns((IPokemonBattleData?)null);
        var tackle = CreateMoveData("tackle");
        moveLibrary.GetRandom(random).Returns(tackle);
        var moveName = new StringKey("metronome");

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

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

    /// <summary>
    /// Bulbapedia: "Metronome cannot select a Max Move, a Z-Move, or any of the moves" in its list of
    /// unselectable moves. When an unselectable move is rolled, the script rerolls until it finds a
    /// selectable one.
    /// </summary>
    [Test]
    public async Task ChangeMove_UnselectableMoveRolledFirst_RerollsUntilSelectableMove()
    {
        // Arrange
        var (metronome, choice, _, moveLibrary, random) = CreateTestSetup();
        var protect = CreateMoveData("protect");
        var tackle = CreateMoveData("tackle");
        moveLibrary.GetRandom(random).Returns(protect, tackle);
        var moveName = new StringKey("metronome");

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

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

    /// <summary>
    /// Bulbapedia: "Metronome cannot select a Max Move, a Z-Move, or any of the moves" in its list of
    /// unselectable moves. A sample of moves that are unselectable in Generation VII (including Metronome
    /// itself) is rolled first; the script must skip them and use the next (selectable) roll instead.
    /// </summary>
    [Test, Arguments("metronome"), Arguments("protect"), Arguments("detect"), Arguments("endure"), Arguments("counter"),
     Arguments("mirror_coat"), Arguments("mirror_move"), Arguments("mimic"), Arguments("sketch"),
     Arguments("sleep_talk"), Arguments("struggle"), Arguments("transform"), Arguments("destiny_bond"),
     Arguments("focus_punch"), Arguments("helping_hand"), Arguments("assist"), Arguments("copycat"),
     Arguments("chatter"), Arguments("after_you"), Arguments("quash"), Arguments("wide_guard"),
     Arguments("quick_guard"), Arguments("instruct"), Arguments("spectral_thief"), Arguments("crafty_shield"),
     Arguments("snore")]
    public async Task ChangeMove_Gen7UnselectableMoveRolled_IsNeverSelected(string unselectableMove)
    {
        // Arrange
        var (metronome, choice, _, moveLibrary, random) = CreateTestSetup();
        var rolled = CreateMoveData(unselectableMove);
        var tackle = CreateMoveData("tackle");
        moveLibrary.GetRandom(random).Returns(rolled, tackle);
        var moveName = new StringKey("metronome");

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

        // Assert - the unselectable move was skipped in favor of the next roll.
        await Assert.That(moveName).IsEqualTo(new StringKey("tackle"));
    }

    /// <summary>
    /// Bulbapedia: "The Metronome user executes a randomly selected move." Moves such as Dig, Fly, and Roar do
    /// not appear in the Generation VII column of Bulbapedia's list of moves Metronome cannot select, so
    /// Metronome must be able to call them (they are only excluded for other copying moves such as Assist).
    /// </summary>
    [Test, Arguments("dig"), Arguments("fly"), Arguments("roar")]
    public async Task ChangeMove_MoveSelectableByMetronomeButBannedForAssistRolled_IsSelected(string selectableMove)
    {
        // Arrange
        var (metronome, choice, _, moveLibrary, random) = CreateTestSetup();
        var rolled = CreateMoveData(selectableMove);
        var tackle = CreateMoveData("tackle");
        moveLibrary.GetRandom(random).Returns(rolled, tackle);
        var moveName = new StringKey("metronome");

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

        // Assert - the first roll is selectable by Metronome in Generation VII, so it must be used.
        await Assert.That(moveName).IsEqualTo(new StringKey(selectableMove));
    }
}