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

using PkmnLib.Dynamic.Models;
using PkmnLib.Dynamic.ScriptHandling;
using PkmnLib.Dynamic.ScriptHandling.Registry;
using PkmnLib.Plugin.Gen7.Scripts.Battle;
using PkmnLib.Plugin.Gen7.Scripts.Moves;
using PkmnLib.Static;
using PkmnLib.Static.Moves;

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

/// <summary>
/// Tests for the <see cref="MudSport"/> move script and its attached <see cref="MudSportEffect"/>.
/// Gen VII Bulbapedia behavior: "Mud Sport now reduces the base power of Electric-type moves by 67%
/// (approximated as a factor of 1352/4096) on both sides in battle." and (Generations VI and VII):
/// "Mud Sport is now active for five turns, even if the user switches out."
/// </summary>
public class MudSportTests
{
    /// <summary>
    /// Creates a fully mocked test setup where the battle has a real <see cref="ScriptSet"/> as its volatile
    /// script set.
    /// </summary>
    private static (MudSport script, IExecutingMove move, IPokemon target, IBattle battle, IScriptSet battleVolatile)
        CreateTestSetup()
    {
        var script = new MudSport();
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IPokemon>();

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

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

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

    /// <summary>
    /// Creates a mocked executing move whose used move has the given type name.
    /// </summary>
    private static IExecutingMove CreateExecutingMoveOfType(string typeName)
    {
        var executingMove = Substitute.For<IExecutingMove>();
        var moveData = Substitute.For<IMoveData>();
        moveData.MoveType.Returns(new TypeIdentifier(1, typeName));
        executingMove.UseMove.Returns(moveData);
        return executingMove;
    }

    /// <summary>
    /// Bulbapedia: Mud Sport reduces the base power of Electric-type moves "on both sides in battle" — using
    /// the move puts the <see cref="MudSportEffect"/> on the battle's volatile scripts so it affects the whole
    /// field, "even if the user switches out".
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_AddsMudSportEffectToBattleVolatile()
    {
        // Arrange
        var (script, move, target, _, battleVolatile) = CreateTestSetup();

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

        // Assert
        await Assert.That(battleVolatile.Contains(ScriptUtils.ResolveName<MudSportEffect>())).IsTrue();
    }

    /// <summary>
    /// Technical test: without battle data on the user (outside of battle) the secondary effect does nothing
    /// and does not throw.
    /// </summary>
    [Test]
    public void OnSecondaryEffect_UserHasNoBattleData_DoesNotThrow()
    {
        // Arrange
        var script = new MudSport();
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IPokemon>();
        var user = Substitute.For<IPokemon>();
        user.BattleData.Returns((IPokemonBattleData?)null);
        move.User.Returns(user);

        // Act & Assert - should not throw
        script.OnSecondaryEffect(move, target, 0);
    }

    /// <summary>
    /// Bulbapedia: "Mud Sport now reduces the base power of Electric-type moves by 67% (approximated as a
    /// factor of 1352/4096) on both sides in battle."
    /// </summary>
    [Test, Arguments((ushort)100, (ushort)33), Arguments((ushort)4096, (ushort)1352)]
    public async Task ChangeBasePower_ElectricMove_PowerReducedBySixtySevenPercent(ushort basePower,
        ushort expectedPower)
    {
        // Arrange
        var effect = new MudSportEffect();
        var electricMove = CreateExecutingMoveOfType("electric");
        var target = Substitute.For<IPokemon>();

        // Act
        effect.ChangeBasePower(electricMove, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo(expectedPower);
    }

    /// <summary>
    /// Bulbapedia: Mud Sport only "reduces the base power of Electric-type moves" — moves of other types are
    /// unaffected.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_NonElectricMove_PowerUnchanged()
    {
        // Arrange
        var effect = new MudSportEffect();
        var fireMove = CreateExecutingMoveOfType("fire");
        var target = Substitute.For<IPokemon>();
        ushort basePower = 100;

        // Act
        effect.ChangeBasePower(fireMove, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)100);
    }

    /// <summary>
    /// Bulbapedia: "Mud Sport is now active for five turns" — after four end-of-turn ticks the
    /// <see cref="MudSportEffect"/> is still on the battle.
    /// </summary>
    [Test]
    public async Task OnEndTurn_FourTurns_EffectRemains()
    {
        // Arrange
        var (script, move, target, battle, battleVolatile) = CreateTestSetup();
        script.OnSecondaryEffect(move, target, 0);
        var effect = battleVolatile.Get<MudSportEffect>()!;

        // Act
        for (var turn = 0; turn < 4; turn++)
            effect.OnEndTurn(battle, battle);

        // Assert
        await Assert.That(battleVolatile.Contains(ScriptUtils.ResolveName<MudSportEffect>())).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: "Mud Sport is now active for five turns" — after the fifth end-of-turn tick the
    /// <see cref="MudSportEffect"/> removes itself.
    /// </summary>
    [Test]
    public async Task OnEndTurn_FiveTurns_EffectRemovesItself()
    {
        // Arrange
        var (script, move, target, battle, battleVolatile) = CreateTestSetup();
        script.OnSecondaryEffect(move, target, 0);
        var effect = battleVolatile.Get<MudSportEffect>()!;

        // Act
        for (var turn = 0; turn < 5; turn++)
            effect.OnEndTurn(battle, battle);

        // Assert
        await Assert.That(battleVolatile.Contains(ScriptUtils.ResolveName<MudSportEffect>())).IsFalse();
    }
}