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

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

/// <summary>
/// Tests for the <see cref="FalseSwipe"/> move script.
/// Gen VII Bulbapedia behavior: "False Swipe inflicts damage, but will leave the target with 1 HP if it would
/// otherwise cause it to faint. If the target has 1 HP remaining, False Swipe will hit and leave the target
/// at 1 HP."
/// </summary>
public class FalseSwipeTests
{
    /// <summary>
    /// Creates a fully mocked test setup where the target has the given current health.
    /// </summary>
    private static (FalseSwipe script, IExecutingMove move, IBattlePokemon target) CreateTestSetup(uint currentHealth)
    {
        var script = new FalseSwipe();
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IBattlePokemon>();
        target.CurrentHealth.Returns(currentHealth);
        return (script, move, target);
    }

    /// <summary>
    /// Bulbapedia: "False Swipe inflicts damage, but will leave the target with 1 HP if it would otherwise
    /// cause it to faint." — damage exactly equal to the target's remaining HP is reduced to leave 1 HP.
    /// The (1, 1, 0) row verifies "If the target has 1 HP remaining, False Swipe will hit and leave the
    /// target at 1 HP."
    /// </summary>
    [Test, Arguments(50u, 50u, 49u), Arguments(100u, 100u, 99u), Arguments(1u, 1u, 0u)]
    public async Task ChangeMoveDamage_DamageExactlyLethal_LeavesTargetWithOneHp(uint currentHealth, uint damage,
        uint expectedDamage)
    {
        // Arrange
        var (script, move, target) = CreateTestSetup(currentHealth);

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

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

    /// <summary>
    /// Bulbapedia: "False Swipe inflicts damage, but will leave the target with 1 HP if it would otherwise
    /// cause it to faint." — damage exceeding the target's remaining HP is also capped so the target is left
    /// at 1 HP.
    /// </summary>
    [Test, Arguments(50u, 100u, 49u), Arguments(1u, 5u, 0u), Arguments(30u, 4000u, 29u)]
    public async Task ChangeMoveDamage_DamageExceedsCurrentHealth_LeavesTargetWithOneHp(uint currentHealth, uint damage,
        uint expectedDamage)
    {
        // Arrange
        var (script, move, target) = CreateTestSetup(currentHealth);

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

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

    /// <summary>
    /// Bulbapedia: "False Swipe inflicts damage" — when the damage would not cause the target to faint, it
    /// is dealt in full.
    /// </summary>
    [Test, Arguments(100u, 50u), Arguments(100u, 99u), Arguments(2u, 1u)]
    public async Task ChangeMoveDamage_DamageNotLethal_DamageUnchanged(uint currentHealth, uint damage)
    {
        // Arrange
        var (script, move, target) = CreateTestSetup(currentHealth);
        var originalDamage = damage;

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

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