using PkmnLib.Dynamic.Models;
using PkmnLib.Static;
using PkmnLib.Static.Species;
using PkmnLib.Tests.Integration;

namespace PkmnLib.Tests.Dynamic;

/// <summary>
/// Tests for the ephemeral <see cref="IBattlePokemon"/> wrapper. Battle-only state must live on the wrapper
/// and never leak into the underlying <see cref="IPokemon"/>; dropping the wrapper is all the cleanup a
/// battle needs.
/// </summary>
public class BattlePokemonTests
{
    private static (IBattle battle, IBattlePokemon wrapper, IPokemon inner) CreateBattleWithWrapper(
        string heldItem = "oran_berry")
    {
        var library = LibraryHelpers.LoadLibrary();
        if (!library.StaticLibrary.Species.TryGet("bulbasaur", out var bulbasaur))
            throw new InvalidOperationException("Failed to load bulbasaur species.");
        if (!library.StaticLibrary.Species.TryGet("charmander", out var charmander))
            throw new InvalidOperationException("Failed to load charmander species.");
        if (!library.StaticLibrary.Items.TryGet(heldItem, out var item))
            throw new InvalidOperationException($"Failed to load item {heldItem}.");

        var pokemon = new PokemonImpl(library, bulbasaur, bulbasaur.GetDefaultForm(), new AbilityIndex
        {
            Index = 0,
            IsHidden = false,
        }, 50, 0, Gender.Male, 0, "hardy");
        pokemon.LearnMove("tackle", MoveLearnMethod.LevelUp, 0);
        _ = pokemon.ForceSetHeldItem(item);

        var opponent = new PokemonImpl(library, charmander, charmander.GetDefaultForm(), new AbilityIndex
        {
            Index = 0,
            IsHidden = false,
        }, 50, 0, Gender.Male, 0, "hardy");

        var party1 = new PokemonPartyImpl(6);
        party1.SwapInto(pokemon, 0);
        var party2 = new PokemonPartyImpl(6);
        party2.SwapInto(opponent, 0);
        var parties = new[]
        {
            new BattlePartyImpl(party1, [new ResponsibleIndex(0, 0)]),
            new BattlePartyImpl(party2, [new ResponsibleIndex(1, 0)]),
        };
        var battle = new BattleImpl(library, parties, false, 2, 1, false, "grass", 0);
        var wrapper = parties[0].GetBattlePokemon(pokemon) ??
                      throw new InvalidOperationException("Wrapper not created.");
        return (battle, wrapper, pokemon);
    }

    [Test]
    public async Task PersistentMembersAreProxiedToUnderlyingPokemon()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();

        await Assert.That(wrapper.UnderlyingPokemon).IsSameReferenceAs(inner);
        await Assert.That(wrapper.Species).IsSameReferenceAs(inner.Species);
        await Assert.That(wrapper.Form).IsSameReferenceAs(inner.Form);
        await Assert.That(wrapper.Level).IsEqualTo(inner.Level);
        await Assert.That(wrapper.CurrentHealth).IsEqualTo(inner.CurrentHealth);
        await Assert.That(wrapper.Nature).IsSameReferenceAs(inner.Nature);
        await Assert.That(wrapper.OriginalSpecies).IsSameReferenceAs(inner.Species);
        await Assert.That(wrapper.OriginalForm).IsSameReferenceAs(inner.Form);
    }

    [Test]
    public async Task TypeOverlayDoesNotTouchUnderlyingPokemon()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();
        var originalTypes = inner.Types.ToList();

        wrapper.SetTypes([new TypeIdentifier(18, "water")]);

        await Assert.That(wrapper.Types.Count).IsEqualTo(1);
        await Assert.That(inner.Types.SequenceEqual(originalTypes)).IsTrue();

        wrapper.OnSwitchedOut();
        await Assert.That(wrapper.Types.SequenceEqual(inner.Form.Types)).IsTrue();
    }

    [Test]
    public async Task TemporaryMoveOverlayDoesNotTouchUnderlyingPokemonAndResetsOnSwitchOut()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();

        wrapper.LearnTemporaryMove("swords_dance", MoveLearnMethod.Mimic, 0);

        await Assert.That(wrapper.Moves[0]!.MoveData.Name.ToString()).IsEqualTo("swords_dance");
        await Assert.That(wrapper.BaseMoves[0]!.MoveData.Name.ToString()).IsEqualTo("tackle");
        await Assert.That(inner.Moves[0]!.MoveData.Name.ToString()).IsEqualTo("tackle");

        wrapper.OnSwitchedOut();
        await Assert.That(wrapper.Moves[0]!.MoveData.Name.ToString()).IsEqualTo("tackle");
    }

    [Test]
    public async Task StatBoostLivesOnWrapperAndResetsOnSwitchOut()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();
        var innerFlatAttack = inner.FlatStats.Attack;

        var changed = wrapper.ChangeStatBoost(Statistic.Attack, 2, true, false);

        await Assert.That(changed).IsTrue();
        await Assert.That(wrapper.StatBoost.Attack).IsEqualTo((sbyte)2);
        await Assert.That(wrapper.BoostedStats.Attack > wrapper.FlatStats.Attack).IsTrue();
        await Assert.That(inner.FlatStats.Attack).IsEqualTo(innerFlatAttack);

        wrapper.OnSwitchedOut();
        await Assert.That(wrapper.StatBoost.Attack).IsEqualTo((sbyte)0);
        await Assert.That(wrapper.BoostedStats.Attack).IsEqualTo(wrapper.FlatStats.Attack);
    }

    [Test]
    public async Task HeldItemOverlayDoesNotTouchUnderlyingPokemon()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();
        var innerItem = inner.HeldItem;
        await Assert.That(innerItem).IsNotNull();

        var removed = wrapper.RemoveHeldItemForBattle();

        await Assert.That(removed).IsSameReferenceAs(innerItem);
        await Assert.That(wrapper.HeldItem).IsNull();
        await Assert.That(wrapper.HasItemBeenRemovedForBattle).IsTrue();
        await Assert.That(inner.HeldItem).IsSameReferenceAs(innerItem);

        wrapper.RestoreRemovedHeldItem();
        await Assert.That(wrapper.HeldItem).IsSameReferenceAs(innerItem);
        await Assert.That(wrapper.HasItemBeenRemovedForBattle).IsFalse();
    }

    [Test]
    public async Task StealingHeldItemDoesNotTouchUnderlyingPokemon()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();
        var innerItem = inner.HeldItem;

        var stolen = wrapper.TryStealHeldItem(out var item);

        await Assert.That(stolen).IsTrue();
        await Assert.That(item).IsSameReferenceAs(innerItem);
        await Assert.That(wrapper.HeldItem).IsNull();
        await Assert.That(inner.HeldItem).IsSameReferenceAs(innerItem);
    }

    [Test]
    public async Task MarkAsCaughtOnlyAffectsWrapper()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();

        wrapper.MarkAsCaught();

        await Assert.That(wrapper.IsCaught).IsTrue();
        await Assert.That(wrapper.IsUsable).IsFalse();
        await Assert.That(inner.IsUsable).IsTrue();
    }

    [Test]
    public async Task AbilityOverrideAndSuppressionLiveOnWrapper()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();
        var naturalAbility = inner.Ability;
        await Assert.That(naturalAbility).IsNotNull();

        wrapper.SuppressAbility();
        await Assert.That(wrapper.AbilitySuppressed).IsTrue();
        await Assert.That(wrapper.ActiveAbility).IsNull();
        await Assert.That(inner.Ability).IsSameReferenceAs(naturalAbility);

        wrapper.OnSwitchedOut();
        await Assert.That(wrapper.AbilitySuppressed).IsFalse();
        await Assert.That(wrapper.ActiveAbility).IsSameReferenceAs(naturalAbility);
    }

    [Test]
    public async Task GetOwnScriptsUsesUnderlyingStatusScript()
    {
        var (_, wrapper, inner) = CreateBattleWithWrapper();

        var scripts = new List<IEnumerable<PkmnLib.Dynamic.ScriptHandling.ScriptContainer>>();
        wrapper.GetOwnScripts(scripts);

        await Assert.That(scripts.Count).IsEqualTo(4);
        await Assert.That(scripts[0]).IsSameReferenceAs(wrapper.HeldItemTriggerScript);
        await Assert.That(scripts[1]).IsSameReferenceAs(wrapper.AbilityScript);
        await Assert.That(scripts[2]).IsSameReferenceAs(inner.StatusScript);
        await Assert.That(scripts[3]).IsSameReferenceAs(wrapper.Volatile);
    }

    [Test]
    public async Task GetBattlePokemonFindsWrapperByInnerAndByWrapper()
    {
        var (battle, wrapper, inner) = CreateBattleWithWrapper();
        var party = battle.Parties[0];

        await Assert.That(party.GetBattlePokemon(inner)).IsSameReferenceAs(wrapper);
        await Assert.That(party.GetBattlePokemon(wrapper)).IsSameReferenceAs(wrapper);
        await Assert.That(battle.Parties[1].GetBattlePokemon(inner)).IsNull();
    }

    [Test]
    public async Task OnSwitchedInTracksTurnAndPosition()
    {
        var (_, wrapper, _) = CreateBattleWithWrapper();
        await Assert.That(wrapper.IsOnBattlefield).IsFalse();

        wrapper.OnSwitchedIn(0);

        await Assert.That(wrapper.IsOnBattlefield).IsTrue();
        await Assert.That(wrapper.Position).IsEqualTo((byte)0);
        // Bulbasaur's ability (Overgrow) has no script in the Gen7 plugin, so the ability script stays empty.
        await Assert.That(wrapper.AbilityScript.IsEmpty).IsTrue();
    }
}