using PkmnLib.Dynamic.Models;
using PkmnLib.Dynamic.ScriptHandling;
using PkmnLib.Dynamic.ScriptHandling.Registry;
using PkmnLib.Plugin.Gen7.Scripts.Moves;
using PkmnLib.Plugin.Gen7.Scripts.Pokemon;

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

/// <summary>
/// Tests for the <see cref="LaserFocus"/> move script and its volatile effect script
/// <see cref="LaserFocusEffect"/>.
/// Gen VII Bulbapedia behavior: "Laser Focus causes the user's move to result in a critical hit until the
/// end of the next turn, unless that move's target has Battle Armor, Shell Armor, or is under the effect
/// of Lucky Chant."
/// </summary>
public class LaserFocusTests
{
    /// <summary>
    /// Creates a real <see cref="ScriptSet"/> hosting the given effect, so that
    /// <see cref="Script.RemoveSelf"/> calls can be observed through <see cref="IScriptSet.Contains"/>.
    /// </summary>
    private static IScriptSet CreateHostedSet(Script effect)
    {
        var owner = Substitute.For<IPokemon>();
        owner.GetScripts().Returns(_ => new ScriptIterator(Array.Empty<IEnumerable<ScriptContainer>>()));
        IScriptSet set = new ScriptSet(owner);
        set.Add(effect);
        return set;
    }

    /// <summary>
    /// Bulbapedia: "Laser Focus causes the user's move to result in a critical hit" — using the move places
    /// the <see cref="LaserFocusEffect"/> on the target (Laser Focus targets the user itself).
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_Used_AddsLaserFocusEffectToTarget()
    {
        // Arrange
        var script = new LaserFocus();
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IPokemon>();
        var targetVolatile = Substitute.For<IScriptSet>();
        target.Volatile.Returns(targetVolatile);

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

        // Assert
        targetVolatile.Received(1).Add(Arg.Any<LaserFocusEffect>());
        await Assert.That(targetVolatile.ReceivedCalls().Count(c => c.GetMethodInfo().Name == "Add")).IsEqualTo(1);
    }

    /// <summary>
    /// Bulbapedia: the user's move will "result in a critical hit" — the effect raises the critical stage
    /// to at least 3, which the Gen 7 damage calculator treats as a guaranteed critical hit.
    /// </summary>
    [Test]
    public async Task ChangeCriticalStage_EffectActive_GuaranteesCriticalHit()
    {
        // Arrange
        var effect = new LaserFocusEffect();
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IPokemon>();
        byte stage = 0;

        // Act
        effect.ChangeCriticalStage(move, target, 0, ref stage);

        // Assert
        await Assert.That(stage).IsGreaterThanOrEqualTo((byte)3);
    }

    /// <summary>
    /// Bulbapedia: the guarantee lasts "until the end of the next turn" — it is not consumed by a single
    /// critical-stage check, so e.g. every hit of a multi-hit move is a critical hit.
    /// </summary>
    [Test]
    public async Task ChangeCriticalStage_AfterFirstCheck_EffectStillActive()
    {
        // Arrange
        var effect = new LaserFocusEffect();
        var set = CreateHostedSet(effect);
        var move = Substitute.For<IExecutingMove>();
        var target = Substitute.For<IPokemon>();
        byte stage = 0;

        // Act
        effect.ChangeCriticalStage(move, target, 0, ref stage);

        // Assert
        await Assert.That(set.Contains(ScriptUtils.ResolveName<LaserFocusEffect>())).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: the guarantee lasts "until the end of the next turn" — at the end of the turn Laser
    /// Focus was used the effect is still active, so the move used on the following turn is a critical hit.
    /// </summary>
    [Test]
    public async Task OnEndTurn_EndOfTurnUsed_EffectStillActive()
    {
        // Arrange
        var effect = new LaserFocusEffect();
        var set = CreateHostedSet(effect);

        // Act - the end of the turn Laser Focus was used
        if (effect is IScriptOnEndTurn onEndTurn)
            onEndTurn.OnEndTurn(Substitute.For<IScriptSource>(), Substitute.For<IBattle>());

        // Assert
        await Assert.That(set.Contains(ScriptUtils.ResolveName<LaserFocusEffect>())).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: the guarantee only lasts "until the end of the next turn" — if the user does not move,
    /// the effect expires at the end of the turn after it was used.
    /// </summary>
    [Test]
    public async Task OnEndTurn_EndOfNextTurn_EffectExpires()
    {
        // Arrange
        var effect = new LaserFocusEffect();
        var set = CreateHostedSet(effect);

        // Act - end of the turn Laser Focus was used, and end of the next turn
        if (effect is IScriptOnEndTurn onEndTurn)
        {
            onEndTurn.OnEndTurn(Substitute.For<IScriptSource>(), Substitute.For<IBattle>());
            onEndTurn.OnEndTurn(Substitute.For<IScriptSource>(), Substitute.For<IBattle>());
        }

        // Assert
        await Assert.That(set.Contains(ScriptUtils.ResolveName<LaserFocusEffect>())).IsFalse();
    }
}