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

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

/// <summary>
/// Tests for the <see cref="FinalGambit"/> move script.
/// Bulbapedia: "Final Gambit causes the user to faint, and the target receives damage equal to the user's
/// remaining HP before using Final Gambit."
/// </summary>
public class FinalGambitTests
{
    /// <summary>
    /// Creates a fully mocked test setup for Final Gambit tests.
    /// </summary>
    private static (FinalGambit script, IExecutingMove move, IPokemon user, IPokemon target) CreateTestSetup(
        uint userCurrentHealth)
    {
        var script = new FinalGambit();
        var move = Substitute.For<IExecutingMove>();
        var user = Substitute.For<IPokemon>();
        user.CurrentHealth.Returns(userCurrentHealth);
        move.User.Returns(user);
        var target = Substitute.For<IPokemon>();
        return (script, move, user, target);
    }

    /// <summary>
    /// Helper to extract the damage amount from the user's received Damage calls.
    /// </summary>
    private static uint? GetDamageAmount(IPokemon pokemon)
    {
        var call = pokemon.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "Damage");
        return call != null ? (uint)call.GetArguments()[0]! : null;
    }

    /// <summary>
    /// Helper to extract the damage source from the user'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>
    /// Bulbapedia: "the target receives damage equal to the user's remaining HP before using Final Gambit."
    /// The move damage is replaced with the user's current HP, regardless of what the damage formula produced.
    /// </summary>
    [Test, Arguments(1u), Arguments(150u), Arguments(400u)]
    public async Task ChangeMoveDamage_SetsDamageToUserRemainingHp(uint userCurrentHealth)
    {
        // Arrange
        var (script, move, _, target) = CreateTestSetup(userCurrentHealth);
        uint damage = 9999;

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

        // Assert
        await Assert.That(damage).IsEqualTo(userCurrentHealth);
    }

    /// <summary>
    /// Bulbapedia: "Final Gambit causes the user to faint".
    /// After the move hits, the user takes at least its full remaining HP as damage, so it always faints.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_MoveHits_UserTakesAtLeastItsRemainingHpAsDamage()
    {
        // Arrange
        const uint currentHealth = 100;
        var (script, move, user, target) = CreateTestSetup(currentHealth);

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

        // Assert - the self-damage is at least the user's remaining HP, so the user faints
        var damage = GetDamageAmount(user);
        await Assert.That(damage).IsNotNull();
        await Assert.That(damage!.Value >= currentHealth).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: "The move's side effect is not considered as inflicting damage to the user, and so if the
    /// user is holding a Focus Band, Focus Sash, or has Sturdy, they will not activate and the user will
    /// still faint."
    /// The self-inflicted faint is therefore indirect damage (<see cref="DamageSource.Misc"/>), not move damage.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_MoveHits_SelfFaintUsesMiscDamageSource()
    {
        // Arrange
        var (script, move, user, target) = CreateTestSetup(100);

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

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