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

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

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

/// <summary>
/// Tests for the <see cref="FlareBlitz"/> move script.
/// Gen VII Bulbapedia behavior: "Flare Blitz inflicts damage, and the user receives recoil damage equal to
/// ⅓ of the damage done to the target. This move has a 10% chance of burning the target."
/// </summary>
public class FlareBlitzTests
{
    /// <summary>
    /// Creates a fully mocked test setup for Flare Blitz tests, where the hit dealt
    /// <paramref name="damage"/> damage to the target.
    /// </summary>
    private static (FlareBlitz script, IExecutingMove move, IPokemon user, IPokemon target, IBattleRandom random)
        CreateTestSetup(uint damage, Script[]? moveScripts = null)
    {
        var script = new FlareBlitz();
        var move = Substitute.For<IExecutingMove>();
        var user = Substitute.For<IPokemon>();
        var target = Substitute.For<IPokemon>();

        var hitData = Substitute.For<IHitData>();
        hitData.Damage.Returns(damage);
        move.GetHitData(target, 0).Returns(hitData);

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

        // RunScriptHook iterates the move's scripts; give the mock a real iterator so the hook pass runs
        // (empty unless the test attaches scripts such as Rock Head).
        var containers = (moveScripts ?? []).Select(IEnumerable<ScriptContainer> (s) => new ScriptContainer(s))
            .ToArray();
        move.GetScripts().Returns(_ => new ScriptIterator(containers));

        move.User.Returns(user);

        return (script, move, user, target, random);
    }

    /// <summary>
    /// Helper to extract the damage amount from a Pokémon's received Damage calls, or 0 if none was received.
    /// </summary>
    private static uint GetDamageAmount(IPokemon pokemon)
    {
        var call = pokemon.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "Damage");
        return call != null ? (uint)call.GetArguments()[0]! : 0;
    }

    /// <summary>
    /// Helper to extract the damage source from a Pokémon's received Damage calls.
    /// </summary>
    private static DamageSource? GetDamageSource(IPokemon pokemon)
    {
        var call = pokemon.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "Damage");
        return call != null ? (DamageSource)call.GetArguments()[1]! : null;
    }

    /// <summary>
    /// Helper that checks whether a Pokémon received a SetStatus call for the given status.
    /// </summary>
    private static bool ReceivedSetStatus(IPokemon pokemon, string status) =>
        pokemon.ReceivedCalls().Any(c =>
            c.GetMethodInfo().Name == "SetStatus" && (StringKey)c.GetArguments()[0]! == new StringKey(status));

    /// <summary>
    /// Bulbapedia: "the user receives recoil damage equal to ⅓ of the damage done to the target."
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_DamageDealt_UserTakesOneThirdRecoil()
    {
        // Arrange
        var (script, move, user, target, _) = CreateTestSetup(90);

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

        // Assert - 90 / 3 = 30
        await Assert.That(GetDamageAmount(user)).IsEqualTo(30u);
    }

    /// <summary>
    /// Bulbapedia: "the user receives recoil damage equal to ⅓ of the damage done to the target."
    /// Tests various damage values to ensure proper integer truncation of the one-third amount.
    /// </summary>
    [Test, Arguments(90u, 30u), Arguments(100u, 33u), Arguments(120u, 40u), Arguments(2u, 0u), Arguments(301u, 100u)]
    public async Task OnSecondaryEffect_DamageDealt_RecoilCalculation(uint damage, uint expectedRecoil)
    {
        // Arrange
        var (script, move, user, target, _) = CreateTestSetup(damage);

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

        // Assert
        await Assert.That(GetDamageAmount(user)).IsEqualTo(expectedRecoil);
    }

    /// <summary>
    /// Bulbapedia: "the user receives recoil damage". Recoil is indirect damage, so it is dealt with
    /// <see cref="DamageSource.Misc"/> rather than move damage.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_DamageDealt_RecoilUsesMiscDamageSource()
    {
        // Arrange
        var (script, move, user, target, _) = CreateTestSetup(90);

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

        // Assert
        await Assert.That(GetDamageSource(user)!.Value).IsEqualTo(DamageSource.Misc);
    }

    /// <summary>
    /// Bulbapedia: "This move has a 10% chance of burning the target."
    /// When the effect chance roll succeeds, the target is burned.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_EffectChanceSucceeds_BurnsTarget()
    {
        // Arrange
        var (script, move, _, target, random) = CreateTestSetup(90);
        random.EffectChance(10f, move, target, 0).Returns(true);

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

        // Assert
        await Assert.That(ReceivedSetStatus(target, "burned")).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: "This move has a 10% chance of burning the target."
    /// When the effect chance roll fails, the target is not burned.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_EffectChanceFails_DoesNotBurnTarget()
    {
        // Arrange
        var (script, move, _, target, random) = CreateTestSetup(90);
        random.EffectChance(10f, move, target, 0).Returns(false);

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

        // Assert
        await Assert.That(ReceivedSetStatus(target, "burned")).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "This move has a 10% chance of burning the target."
    /// The 10% chance is rolled through the battle's <see cref="IBattleRandom.EffectChance"/> so that
    /// effect-chance-modifying effects (such as Serene Grace) apply.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_DamageDealt_RollsTenPercentEffectChance()
    {
        // Arrange
        var (script, move, _, target, random) = CreateTestSetup(90);

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

        // Assert
        random.Received(1).EffectChance(10f, move, target, 0);
    }

    /// <summary>
    /// The recoil can be prevented by recoil-negating effects (Bulbapedia: Rock Head "prevents the Pokémon
    /// from taking recoil damage from most moves"). When a script such as <see cref="RockHead"/> flags the
    /// recoil as prevented, the user takes no recoil damage.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_RecoilPrevented_UserTakesNoRecoilDamage()
    {
        // Arrange
        var (script, move, user, target, _) = CreateTestSetup(90, [new RockHead()]);

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

        // Assert
        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Damage")).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "This move has a 10% chance of burning the target." The burn chance is independent of the
    /// recoil: Rock Head only "prevents the Pokémon from taking recoil damage", so preventing the recoil must
    /// not suppress the burn chance.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_RecoilPrevented_BurnChanceStillApplies()
    {
        // Arrange
        var (script, move, _, target, random) = CreateTestSetup(90, [new RockHead()]);
        random.EffectChance(10f, move, target, 0).Returns(true);

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

        // Assert
        await Assert.That(ReceivedSetStatus(target, "burned")).IsTrue();
    }

    /// <summary>
    /// Technical test: when the target has no <see cref="IPokemon.BattleData"/>, the script does nothing;
    /// no recoil is taken and no burn is rolled.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_TargetHasNoBattleData_NoRecoilOrBurn()
    {
        // Arrange
        var (script, move, user, target, _) = CreateTestSetup(90);
        target.BattleData.Returns((IPokemonBattleData?)null);

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

        // Assert
        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Damage")).IsFalse();
        await Assert.That(ReceivedSetStatus(target, "burned")).IsFalse();
    }
}