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

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

/// <summary>
/// Tests for the <see cref="FellStinger"/> move script.
/// Gen VII Bulbapedia behavior ("Generation VII onwards"): "It now raises the user's Attack stat by three
/// stages if it causes the targeted Pokémon to faint."
/// </summary>
public class FellStingerTests
{
    /// <summary>
    /// Creates a fully mocked test setup for Fell Stinger tests.
    /// </summary>
    private static (FellStinger script, IExecutingMove move, IBattlePokemon user, IBattlePokemon target)
        CreateTestSetup(bool targetFainted)
    {
        var script = new FellStinger();
        var move = Substitute.For<IExecutingMove>();
        var user = Substitute.For<IBattlePokemon>();
        move.User.Returns(user);
        var target = Substitute.For<IBattlePokemon>();
        target.IsFainted.Returns(targetFainted);
        return (script, move, user, target);
    }

    /// <summary>
    /// Helper to find the first ChangeStatBoost call received by a Pokémon substitute.
    /// </summary>
    private static object[]? GetStatBoostArguments(IBattlePokemon pokemon)
    {
        var call = pokemon.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "ChangeStatBoost");
        return call?.GetArguments()!;
    }

    /// <summary>
    /// Bulbapedia: "It now raises the user's Attack stat by three stages if it causes the targeted Pokémon
    /// to faint."
    /// When the target fainted from the hit, the user's Attack stat is boosted.
    /// </summary>
    [Test]
    public async Task OnAfterHits_TargetFainted_RaisesUserAttack()
    {
        // Arrange
        var (script, move, user, target) = CreateTestSetup(true);

        // Act
        script.OnAfterHits(move, target);

        // Assert
        var arguments = GetStatBoostArguments(user);
        await Assert.That(arguments).IsNotNull();
        await Assert.That((Statistic)arguments![0]!).IsEqualTo(Statistic.Attack);
    }

    /// <summary>
    /// Bulbapedia: "It now raises the user's Attack stat by three stages if it causes the targeted Pokémon
    /// to faint."
    /// In Generation VII the boost is three stages (up from two stages in Generation VI).
    /// </summary>
    [Test]
    public async Task OnAfterHits_TargetFainted_AttackRaisedByThreeStages()
    {
        // Arrange
        var (script, move, user, target) = CreateTestSetup(true);

        // Act
        script.OnAfterHits(move, target);

        // Assert
        var arguments = GetStatBoostArguments(user);
        await Assert.That(arguments).IsNotNull();
        await Assert.That((sbyte)arguments![1]!).IsEqualTo((sbyte)3);
    }

    /// <summary>
    /// Bulbapedia: "It now raises the user's Attack stat by three stages if it causes the targeted Pokémon
    /// to faint."
    /// The boost is applied by the user to itself, so it must be self-inflicted and not forced.
    /// </summary>
    [Test]
    public async Task OnAfterHits_TargetFainted_BoostIsSelfInflictedAndNotForced()
    {
        // Arrange
        var (script, move, user, target) = CreateTestSetup(true);

        // Act
        script.OnAfterHits(move, target);

        // Assert
        var arguments = GetStatBoostArguments(user);
        await Assert.That(arguments).IsNotNull();
        await Assert.That((bool)arguments![2]!).IsTrue();
        await Assert.That((bool)arguments[3]!).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: the Attack boost only happens "if it causes the targeted Pokémon to faint".
    /// If the target survives the hit, no stat boost is applied.
    /// </summary>
    [Test]
    public async Task OnAfterHits_TargetNotFainted_NoStatBoost()
    {
        // Arrange
        var (script, move, user, target) = CreateTestSetup(false);

        // Act
        script.OnAfterHits(move, target);

        // Assert - ChangeStatBoost should never be called. (Checked via ReceivedCalls, as arg matchers cannot
        // be used with EventBatchId parameters: its parameterless constructor generates a random Guid.)
        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "ChangeStatBoost")).IsFalse();
    }
}