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="GuardianOfAlola"/> move script.
/// Gen VII Bulbapedia behavior: "Guardian of Alola deals damage equal to 75% of the target's remaining HP
/// (rounded down, but no less than 1)."
/// </summary>
public class GuardianOfAlolaTests
{
    private static (GuardianOfAlola script, IExecutingMove move, IBattlePokemon target) CreateTestSetup(uint maxHp,
        uint currentHp)
    {
        var script = new GuardianOfAlola();
        var move = Substitute.For<IExecutingMove>();

        var target = Substitute.For<IBattlePokemon>();
        target.BoostedStats.Returns(new StatisticSet<uint>(maxHp, 100, 100, 100, 100, 100));
        target.CurrentHealth.Returns(currentHp);

        return (script, move, target);
    }

    /// <summary>
    /// Bulbapedia: "Guardian of Alola deals damage equal to 75% of the target's remaining HP". A target
    /// at full HP takes 75% of that HP as damage.
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_TargetAtFullHp_DamageIsThreeQuartersOfHp()
    {
        // Arrange
        var (script, move, target) = CreateTestSetup(400, 400);
        uint damage = 10;

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

        // Assert
        await Assert.That(damage).IsEqualTo(300u);
    }

    /// <summary>
    /// Bulbapedia: the damage is "equal to 75% of the target's remaining HP", not its maximum HP. A
    /// target with 400 max HP but only 100 remaining takes 75 damage.
    /// </summary>
    [Test, Arguments(400u, 100u, 75u), Arguments(400u, 200u, 150u), Arguments(300u, 50u, 37u)]
    public async Task ChangeMoveDamage_TargetDamaged_DamageIsThreeQuartersOfRemainingHp(uint maxHp, uint currentHp,
        uint expectedDamage)
    {
        // Arrange
        var (script, move, target) = CreateTestSetup(maxHp, currentHp);
        uint damage = 10;

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

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

    /// <summary>
    /// Bulbapedia: the damage is "rounded down, but no less than 1" — a target with a single HP remaining
    /// still takes 1 damage instead of 0.
    /// </summary>
    [Test]
    public async Task ChangeMoveDamage_TargetAtOneHp_DamageIsAtLeastOne()
    {
        // Arrange
        var (script, move, target) = CreateTestSetup(400, 1);
        uint damage = 10;

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

        // Assert
        await Assert.That(damage).IsEqualTo(1u);
    }
}