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

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

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

/// <summary>
/// Tests for the <see cref="Facade"/> move script.
/// Gen VII Bulbapedia behavior: "Facade inflicts damage. Its base power doubles from 70 to 140 if the user is
/// poisoned, paralyzed, or burned." Generation VI onwards: "When using Facade, Burn's effect of halving the
/// damage done by physical moves is now ignored."
/// </summary>
public class FacadeTests
{
    /// <summary>
    /// Creates a fully mocked test setup where the user has the given (or no) non-volatile status in its
    /// <see cref="IBattlePokemon.StatusScript"/>, and is using a move of the given category.
    /// </summary>
    private static (Facade facade, IExecutingMove move, IBattlePokemon target) CreateTestSetup(Script? status,
        MoveCategory category = MoveCategory.Physical)
    {
        var facade = new Facade();
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IBattlePokemon>();
        var user = Substitute.For<IBattlePokemon>();
        user.StatusScript.Returns(status == null ? new ScriptContainer() : new ScriptContainer(status));
        move.User.Returns(user);
        var useMove = Substitute.For<IMoveData>();
        useMove.Category.Returns(category);
        move.UseMove.Returns(useMove);
        return (facade, move, target);
    }

    /// <summary>
    /// Bulbapedia: "Its base power doubles from 70 to 140 if the user is poisoned, paralyzed, or burned."
    /// The user is burned.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserBurned_BasePowerDoubles()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Burned());
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)140);
    }

    /// <summary>
    /// Bulbapedia: "Its base power doubles from 70 to 140 if the user is poisoned, paralyzed, or burned."
    /// The user is paralyzed.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserParalyzed_BasePowerDoubles()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Paralyzed());
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)140);
    }

    /// <summary>
    /// Bulbapedia: "Its base power doubles from 70 to 140 if the user is poisoned, paralyzed, or burned."
    /// The user is poisoned.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserPoisoned_BasePowerDoubles()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Poisoned());
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)140);
    }

    /// <summary>
    /// Bulbapedia: "Its base power doubles from 70 to 140 if the user is poisoned, paralyzed, or burned."
    /// Bad poison is a form of poison, so a badly poisoned user (<see cref="BadlyPoisoned"/>) also gets the
    /// doubled base power.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserBadlyPoisoned_BasePowerDoubles()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new BadlyPoisoned());
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)140);
    }

    /// <summary>
    /// Bulbapedia: the base power only doubles "if the user is poisoned, paralyzed, or burned" — with no
    /// status the base power is unchanged.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserHasNoStatus_BasePowerUnchanged()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(null);
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)70);
    }

    /// <summary>
    /// Bulbapedia: the base power only doubles "if the user is poisoned, paralyzed, or burned" — freeze is
    /// not one of the boosting statuses.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserFrozen_BasePowerUnchanged()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Frozen());
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)70);
    }

    /// <summary>
    /// Bulbapedia: the base power only doubles "if the user is poisoned, paralyzed, or burned" — sleep is
    /// not one of the boosting statuses.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserAsleep_BasePowerUnchanged()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Sleep());
        ushort basePower = 70;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

        // Assert
        await Assert.That(basePower).IsEqualTo((ushort)70);
    }

    /// <summary>
    /// Technical test: doubling a very large base power clamps at <see cref="ushort.MaxValue"/> instead of
    /// overflowing.
    /// </summary>
    [Test]
    public async Task ChangeBasePower_UserBurnedWithLargeBasePower_ClampsAtMaxValue()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Burned());
        ushort basePower = ushort.MaxValue - 100;

        // Act
        facade.ChangeBasePower(move, target, 0, ref basePower);

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

    /// <summary>
    /// Bulbapedia (Generation VI onwards): "When using Facade, Burn's effect of halving the damage done by
    /// physical moves is now ignored."
    ///
    /// <see cref="Facade"/> implements this by pre-doubling the damage so that the halving <see cref="Burned"/>
    /// applies afterwards cancels out. Both hooks are registered on the executing move, and
    /// <c>ExecutingMoveImpl.CollectScripts</c> yields the move script before the user's status script, so this
    /// drives them in that order.
    ///
    /// This test only pins the composition; that each half individually does its part is covered by
    /// <see cref="ChangeMoveDamage_BurnedUser_DamageDoubledToOffsetBurn"/> and
    /// <see cref="ChangeMoveDamage_BurnedUserPhysicalMoveWithoutFacade_DamageHalved"/>.
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_BurnedUserUsingFacade_BurnHalvingIgnored()
    {
        // Arrange
        var burned = new Burned();
        var (facade, move, target) = CreateTestSetup(burned);
        uint damage = 100;

        // Act
        facade.ChangeMoveDamage(move, target, 0, ref damage);
        burned.ChangeMoveDamage(move, target, 0, ref damage);

        // Assert
        await Assert.That(damage).IsEqualTo(100u);
    }

    /// <summary>
    /// The half of the above that belongs to <see cref="Facade"/>: a burned user's physical damage is doubled,
    /// offsetting the halving <see cref="Burned"/> applies later in the hook chain.
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_BurnedUser_DamageDoubledToOffsetBurn()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Burned());
        uint damage = 100;

        // Act
        facade.ChangeMoveDamage(move, target, 0, ref damage);

        // Assert
        await Assert.That(damage).IsEqualTo(200u);
    }

    /// <summary>
    /// The half of the above that belongs to <see cref="Burned"/>: without Facade's compensating hook, a burned
    /// user's physical damage is halved. Bulbapedia: burn "halves damage dealt by a burned Pokémon's physical
    /// moves".
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_BurnedUserPhysicalMoveWithoutFacade_DamageHalved()
    {
        // Arrange
        var burned = new Burned();
        var (_, move, target) = CreateTestSetup(burned);
        uint damage = 100;

        // Act
        burned.ChangeMoveDamage(move, target, 0, ref damage);

        // Assert
        await Assert.That(damage).IsEqualTo(50u);
    }

    /// <summary>
    /// Burn is the only status whose damage penalty Facade offsets — a paralyzed user gets the doubled base
    /// power but no damage compensation, since paralysis does not reduce damage.
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_ParalyzedUser_DamageUnchanged()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Paralyzed());
        uint damage = 100;

        // Act
        facade.ChangeMoveDamage(move, target, 0, ref damage);

        // Assert
        await Assert.That(damage).IsEqualTo(100u);
    }

    /// <summary>
    /// Burn only halves physical damage, so Facade must not compensate for a special move. Facade itself is
    /// physical; this pins the category guard rather than an in-game scenario.
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_BurnedUserSpecialMove_DamageUnchanged()
    {
        // Arrange
        var (facade, move, target) = CreateTestSetup(new Burned(), MoveCategory.Special);
        uint damage = 100;

        // Act
        facade.ChangeMoveDamage(move, target, 0, ref damage);

        // Assert
        await Assert.That(damage).IsEqualTo(100u);
    }
}