using PkmnLib.Dynamic.Models;
using PkmnLib.Dynamic.ScriptHandling;
using PkmnLib.Dynamic.ScriptHandling.Registry;
using PkmnLib.Plugin.Gen7.Scripts.Moves;
using PkmnLib.Plugin.Gen7.Scripts.Side;
using PkmnLib.Static;
using PkmnLib.Static.Utils;

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

/// <summary>
/// Tests for the <see cref="HealingWish"/> move script and its side effect script
/// <see cref="HealingWishEffect"/>.
/// Gen VII Bulbapedia behavior: "Healing Wish causes the user to faint, then switches in the new Pokémon.
/// The new Pokémon's HP is restored and it is cured of any status conditions upon being sent out.", where
/// from Generation V to VII "The receiving Pokémon is now sent out at the end of the turn rather than
/// immediately."
/// </summary>
public class HealingWishTests
{
    /// <summary>
    /// Creates a fully mocked test setup for the <see cref="HealingWish"/> move script, with the user at
    /// side 0 and the given position, and the side's volatile scripts backed by a real
    /// <see cref="ScriptSet"/>.
    /// </summary>
    private static (HealingWish script, IExecutingMove move, IPokemon user, IScriptSet sideVolatile) CreateMoveSetup(
        byte position = 1, bool hasUsablePartyMembers = true)
    {
        var script = new HealingWish();
        var move = Substitute.For<IExecutingMove>();

        var side = Substitute.For<IBattleSide>();
        // ScriptSet.Add runs the IScriptPreventVolatileAdd hook over the owner's scripts; give the mock a
        // real (empty) iterator so the hook pass runs.
        side.GetScripts().Returns(_ => new ScriptIterator(Array.Empty<IEnumerable<ScriptContainer>>()));
        IScriptSet sideVolatile = new ScriptSet(side);
        side.VolatileScripts.Returns(sideVolatile);

        var party = Substitute.For<IBattleParty>();
        party.IsResponsibleForIndex(Arg.Any<ResponsibleIndex>()).Returns(true);
        party.HasUsablePokemonNotInField().Returns(hasUsablePartyMembers);

        var battle = Substitute.For<IBattle>();
        battle.Sides.Returns(new[] { side });
        battle.Parties.Returns(new[] { party });

        var battleData = Substitute.For<IPokemonBattleData>();
        battleData.Battle.Returns(battle);
        battleData.SideIndex.Returns((byte)0);
        battleData.Position.Returns(position);

        var user = Substitute.For<IPokemon>();
        user.BattleData.Returns(battleData);
        move.User.Returns(user);

        return (script, move, user, sideVolatile);
    }

    /// <summary>
    /// Creates a mocked replacement Pokémon with the given maximum HP for
    /// <see cref="HealingWishEffect"/> tests.
    /// </summary>
    private static IPokemon CreateReplacement(uint maxHp = 200)
    {
        var pokemon = Substitute.For<IPokemon>();
        pokemon.BoostedStats.Returns(new StatisticSet<uint>(maxHp, 0, 0, 0, 0, 0));
        return pokemon;
    }

    /// <summary>
    /// Helper to extract the heal amount from a substitute's received Heal calls, or null when Heal was
    /// never called.
    /// </summary>
    private static uint? GetHealAmount(IPokemon pokemon)
    {
        var call = pokemon.ReceivedCalls().FirstOrDefault(c => c.GetMethodInfo().Name == "Heal");
        return call != null ? (uint)call.GetArguments()[0]! : null;
    }

    /// <summary>
    /// Bulbapedia: "Healing Wish causes the user to faint".
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_UserInBattle_UserFaints()
    {
        // Arrange
        var (script, move, user, _) = CreateMoveSetup();

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Faint")).IsTrue();
    }

    /// <summary>
    /// Bulbapedia (Generations V to VII): "The receiving Pokémon is now sent out at the end of the turn
    /// rather than immediately." — using the move leaves a pending <see cref="HealingWishEffect"/> on the
    /// user's side instead of healing anything directly.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_UserInBattle_AddsHealingWishEffectToUserSide()
    {
        // Arrange
        var (script, move, _, sideVolatile) = CreateMoveSetup();

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        await Assert.That(sideVolatile.Contains(ScriptUtils.ResolveName<HealingWishEffect>())).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: the wish benefits the Pokémon "sent out" in the user's place — the pending effect is
    /// bound to the position the user fainted at, so a replacement entering that position is healed.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_UserAtPosition_EffectTargetsUsersPosition()
    {
        // Arrange
        var (script, move, _, sideVolatile) = CreateMoveSetup(1);
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);
        var effect = (HealingWishEffect)sideVolatile.Get(new StringKey("healing_wish"))!.Script!;
        var replacement = CreateReplacement();

        // Act
        effect.OnSwitchIn(replacement, 1);

        // Assert
        await Assert.That(GetHealAmount(replacement)).IsNotNull();
    }

    /// <summary>
    /// Technical test: outside of battle (no <see cref="IPokemon.BattleData"/>) the hook does nothing and
    /// the user does not faint.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_NoBattleData_UserDoesNotFaint()
    {
        // Arrange
        var script = new HealingWish();
        var move = Substitute.For<IExecutingMove>();
        var user = Substitute.For<IPokemon>();
        user.BattleData.Returns((IPokemonBattleData?)null);
        move.User.Returns(user);

        // Act
        script.OnSecondaryEffect(move, Substitute.For<IPokemon>(), 0);

        // Assert
        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Faint")).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "Healing Wish will fail if its Trainer has no other conscious Pokémon in their party".
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_NoOtherConsciousPartyMembers_MoveFails()
    {
        // Arrange
        var (script, move, _, _) = CreateMoveSetup(hasUsablePartyMembers: false);
        var target = Substitute.For<IPokemon>();
        var hitData = Substitute.For<IHitData>();
        move.GetHitData(target, 0).Returns(hitData);

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

        // Assert
        await Assert.That(hitData.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Fail")).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: when the move fails for lack of other conscious party members, the user does not faint
    /// and no pending effect is left on the side.
    /// </summary>
    [Test]
    public async Task OnSecondaryEffect_NoOtherConsciousPartyMembers_UserDoesNotFaint()
    {
        // Arrange
        var (script, move, user, sideVolatile) = CreateMoveSetup(hasUsablePartyMembers: false);
        var target = Substitute.For<IPokemon>();
        move.GetHitData(target, 0).Returns(Substitute.For<IHitData>());

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

        // Assert
        await Assert.That(user.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "Faint")).IsFalse();
        await Assert.That(sideVolatile.Contains(ScriptUtils.ResolveName<HealingWishEffect>())).IsFalse();
    }

    /// <summary>
    /// Bulbapedia: "The new Pokémon's HP is restored ... upon being sent out." — the replacement switching
    /// into the wisher's position is healed by its full maximum HP.
    /// </summary>
    [Test, Arguments(200u), Arguments(1u), Arguments(999u)]
    public async Task OnSwitchIn_MatchingPosition_HealsReplacementToFullHp(uint maxHp)
    {
        // Arrange
        var effect = new HealingWishEffect(1);
        var replacement = CreateReplacement(maxHp);

        // Act
        effect.OnSwitchIn(replacement, 1);

        // Assert
        await Assert.That(GetHealAmount(replacement)!.Value).IsEqualTo(maxHp);
    }

    /// <summary>
    /// Bulbapedia: "it is cured of any status conditions upon being sent out."
    /// </summary>
    [Test]
    public async Task OnSwitchIn_MatchingPosition_CuresStatus()
    {
        // Arrange
        var effect = new HealingWishEffect(1);
        var replacement = CreateReplacement();

        // Act
        effect.OnSwitchIn(replacement, 1);

        // Assert
        await Assert.That(replacement.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "ClearStatus")).IsTrue();
    }

    /// <summary>
    /// Bulbapedia: the wish applies to the Pokémon sent out in the user's place — a Pokémon switching in
    /// at a different position on the side is not healed and does not consume the effect.
    /// </summary>
    [Test]
    public async Task OnSwitchIn_DifferentPosition_DoesNotHealAndEffectPersists()
    {
        // Arrange
        var side = Substitute.For<IBattleSide>();
        side.GetScripts().Returns(_ => new ScriptIterator(Array.Empty<IEnumerable<ScriptContainer>>()));
        IScriptSet sideVolatile = new ScriptSet(side);
        var effect = new HealingWishEffect(1);
        sideVolatile.Add(effect);
        var otherPokemon = CreateReplacement();

        // Act
        effect.OnSwitchIn(otherPokemon, 0);

        // Assert
        await Assert.That(GetHealAmount(otherPokemon)).IsNull();
        await Assert.That(otherPokemon.ReceivedCalls().Any(c => c.GetMethodInfo().Name == "ClearStatus")).IsFalse();
        await Assert.That(sideVolatile.Contains(ScriptUtils.ResolveName<HealingWishEffect>())).IsTrue();
    }

    /// <summary>
    /// Bulbapedia (Generations V to VII): the wish is consumed by the Pokémon sent out at the position —
    /// unlike Generation VIII onwards there is no check on the replacement's HP or status, so the effect
    /// is removed from the side after the first switch-in even if the replacement was already at full
    /// health.
    /// </summary>
    [Test]
    public async Task OnSwitchIn_MatchingPosition_EffectIsRemovedFromSide()
    {
        // Arrange
        var side = Substitute.For<IBattleSide>();
        side.GetScripts().Returns(_ => new ScriptIterator(Array.Empty<IEnumerable<ScriptContainer>>()));
        IScriptSet sideVolatile = new ScriptSet(side);
        var effect = new HealingWishEffect(1);
        sideVolatile.Add(effect);

        // Act
        effect.OnSwitchIn(CreateReplacement(), 1);

        // Assert
        await Assert.That(sideVolatile.Contains(ScriptUtils.ResolveName<HealingWishEffect>())).IsFalse();
    }
}