using System.Linq;
using Content.Shared.Access.Components;
using Content.Shared.Clothing.Components;
using Content.Shared.Contraband;
using Content.Shared.Emp;
using Content.Shared.Inventory;
using Content.Shared.Inventory.Events;
using Content.Shared.Item;
using Content.Shared.Lock;
using Content.Shared.Tag;
using Content.Shared.Verbs;
using Robust.Shared.Network;
using Robust.Shared.Prototypes;
using Robust.Shared.Random;
using Robust.Shared.Timing;
using Robust.Shared.Utility;

namespace Content.Shared.Clothing.EntitySystems;

public abstract class SharedChameleonClothingSystem : EntitySystem
{
    [Dependency] private readonly IPrototypeManager _proto = default!;
    [Dependency] private readonly ClothingSystem _clothingSystem = default!;
    [Dependency] private readonly ContrabandSystem _contraband = default!;
    [Dependency] private readonly MetaDataSystem _metaData = default!;
    [Dependency] private readonly SharedItemSystem _itemSystem = default!;
    [Dependency] private readonly SharedAppearanceSystem _appearance = default!;
    [Dependency] private readonly TagSystem _tag = default!;
    [Dependency] protected readonly IGameTiming Timing = default!;
    [Dependency] private readonly LockSystem _lock = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] protected readonly SharedUserInterfaceSystem UI = default!;
    [Dependency] private readonly INetManager _net = default!;

    private static readonly SlotFlags[] IgnoredSlots =
    {
        SlotFlags.All,
        SlotFlags.PREVENTEQUIP,
        SlotFlags.NONE
    };

    private static readonly SlotFlags[] Slots = Enum.GetValues<SlotFlags>().Except(IgnoredSlots).ToArray();

    private readonly Dictionary<SlotFlags, List<EntProtoId>> _data = new();

    public readonly Dictionary<SlotFlags, List<string>> ValidVariants = new();

    private static readonly ProtoId<TagPrototype> WhitelistChameleonTag = "WhitelistChameleon";

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<ChameleonClothingComponent, GotEquippedEvent>(OnGotEquipped);
        SubscribeLocalEvent<ChameleonClothingComponent, GotUnequippedEvent>(OnGotUnequipped);
        SubscribeLocalEvent<ChameleonClothingComponent, GetVerbsEvent<InteractionVerb>>(OnVerb);
        SubscribeLocalEvent<ChameleonClothingComponent, EmpPulseEvent>(OnEmpPulse);

        SubscribeLocalEvent<ChameleonClothingComponent, PrototypesReloadedEventArgs>(OnPrototypeReload);
        PrepareAllVariants();
    }

    private void OnPrototypeReload(EntityUid uid, ChameleonClothingComponent component, PrototypesReloadedEventArgs args)
    {
        PrepareAllVariants();
    }

    private void OnGotEquipped(EntityUid uid, ChameleonClothingComponent component, GotEquippedEvent args)
    {
        component.User = args.Equipee;
    }

    private void OnGotUnequipped(EntityUid uid, ChameleonClothingComponent component, GotUnequippedEvent args)
    {
        component.User = null;
    }

    // Updates chameleon visuals and meta information.
    // This function is called on a server after user selected new outfit.
    // And after that on a client after state was updated.
    // This 100% makes sure that server and client have exactly same data.
    protected void UpdateVisuals(EntityUid uid, ChameleonClothingComponent component)
    {
        if (string.IsNullOrEmpty(component.Default) ||
            !_proto.Resolve(component.Default, out EntityPrototype? proto))
            return;

        // world sprite icon
        UpdateSprite(uid, proto);

        // copy name and description, unless its an ID card
        if (!HasComp<IdCardComponent>(uid))
        {
            var meta = MetaData(uid);
            _metaData.SetEntityName(uid, proto.Name, meta);
            _metaData.SetEntityDescription(uid, proto.Description, meta);
        }

        // item sprite logic
        if (TryComp(uid, out ItemComponent? item) &&
            proto.TryGetComponent(out ItemComponent? otherItem, Factory))
        {
            _itemSystem.CopyVisuals(uid, otherItem, item);
        }

        // clothing sprite logic
        if (TryComp(uid, out ClothingComponent? clothing) &&
            proto.TryGetComponent(out ClothingComponent? otherClothing, Factory))
        {
            _clothingSystem.CopyVisuals(uid, otherClothing, clothing);
        }

        // appearance data logic
        if (TryComp(uid, out AppearanceComponent? appearance) &&
            proto.TryGetComponent(out AppearanceComponent? appearanceOther, Factory))
        {
            _appearance.AppendData(appearanceOther, uid);
            Dirty(uid, appearance);
        }

        // properly mark contraband
        if (proto.TryGetComponent(out ContrabandComponent? contra, Factory))
        {
            EnsureComp<ContrabandComponent>(uid, out var current);
            _contraband.CopyDetails(uid, contra, current);
        }
        else
        {
            RemComp<ContrabandComponent>(uid);
        }
    }

    private void OnVerb(Entity<ChameleonClothingComponent> ent, ref GetVerbsEvent<InteractionVerb> args)
    {
        if (!args.CanAccess || !args.CanInteract || _lock.IsLocked(ent.Owner))
            return;

        // Can't pass args from a ref event inside of lambdas
        var user = args.User;

        args.Verbs.Add(new InteractionVerb()
        {
            Text = Loc.GetString("chameleon-component-verb-text"),
            Icon = new SpriteSpecifier.Texture(new("/Textures/Interface/VerbIcons/settings.svg.192dpi.png")),
            Act = () => UI.TryToggleUi(ent.Owner, ChameleonUiKey.Key, user)
        });
    }

    private void OnEmpPulse(EntityUid uid, ChameleonClothingComponent component, ref EmpPulseEvent args)
    {
        if (!component.AffectedByEmp)
            return;

        if (component.EmpContinuous)
            component.NextEmpChange = Timing.CurTime + TimeSpan.FromSeconds(1f / component.EmpChangeIntensity);

        if (_net.IsServer) // needs RandomPredicted
        {
            var pick = GetRandomValidPrototype(component.Slot, component.RequireTag);
            SetSelectedPrototype(uid, pick, component: component);
        }

        args.Affected = true;
        args.Disabled = true;
    }

    protected virtual void UpdateSprite(EntityUid uid, EntityPrototype proto) { }

    /// <summary>
    ///     Check if this entity prototype is valid target for chameleon item.
    /// </summary>
    public bool IsValidTarget(EntityPrototype proto, SlotFlags chameleonSlot = SlotFlags.NONE, string? requiredTag = null)
    {
        // check if entity is valid
        if (proto.Abstract || proto.HideSpawnMenu)
            return false;

        // check if it is marked as valid chameleon target
        if (!proto.TryGetComponent(out TagComponent? tag, Factory) || !_tag.HasTag(tag, WhitelistChameleonTag))
            return false;

        if (requiredTag != null && !_tag.HasTag(tag, requiredTag))
            return false;

        // check if it's valid clothing
        if (!proto.TryGetComponent(out ClothingComponent? clothing, Factory))
            return false;
        if (!clothing.Slots.HasFlag(chameleonSlot))
            return false;

        return true;
    }

    /// <summary>
    ///     Get a list of valid chameleon targets for these slots.
    /// </summary>
    public IEnumerable<EntProtoId> GetValidTargets(SlotFlags slot, string? tag = null)
    {
        var validTargets = new List<EntProtoId>();
        if (tag != null)
        {
            foreach (var proto in _data[slot])
            {
                if (IsValidTarget(_proto.Index(proto), slot, tag))
                    validTargets.Add(proto);
            }
        }
        else
        {
            validTargets = _data[slot];
        }

        return validTargets;
    }

    /// <summary>
    ///     Get a random prototype for a given slot.
    /// </summary>
    public string GetRandomValidPrototype(SlotFlags slot, string? tag = null)
    {
        return _random.Pick(GetValidTargets(slot, tag).ToList());
    }

    protected void PrepareAllVariants()
    {
        _data.Clear();
        var prototypes = _proto.EnumeratePrototypes<EntityPrototype>();

        foreach (var proto in prototypes)
        {
            // check if this is valid clothing
            if (!IsValidTarget(proto))
                continue;
            if (!proto.TryGetComponent(out ClothingComponent? item, Factory))
                continue;

            // sort item by their slot flags
            // one item can be placed in several buckets
            foreach (var slot in Slots)
            {
                if (!item.Slots.HasFlag(slot))
                    continue;

                if (!_data.ContainsKey(slot))
                {
                    _data.Add(slot, new List<EntProtoId>());
                }
                _data[slot].Add(proto.ID);
            }
        }
    }

    // TODO: Predict and use component states for the UI
    public virtual void SetSelectedPrototype(EntityUid uid, string? protoId, bool forceUpdate = false,
        ChameleonClothingComponent? component = null)
    { }
}