using Content.Shared.Chemistry;
using Content.Shared.Damage;
using Content.Shared.Electrocution;
using Content.Shared.Explosion;
using Content.Shared.Eye.Blinding.Systems;
using Content.Shared.IdentityManagement.Components;
using Content.Shared.Inventory.Events;
using Content.Shared.Movement.Systems;
using Content.Shared.Overlays;
using Content.Shared.Radio;
using Content.Shared.Slippery;
using Content.Shared.Strip.Components;
using Content.Shared.Temperature;
using Content.Shared.Verbs;
using Robust.Shared.Containers;

namespace Content.Shared.Inventory;

public partial class InventorySystem
{
    public void InitializeRelay()
    {
        SubscribeLocalEvent<InventoryComponent, DamageModifyEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, ElectrocutionAttemptEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, SlipAttemptEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, RefreshMovementSpeedModifiersEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, BeforeStripEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, SeeIdentityAttemptEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, ModifyChangedTemperatureEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, GetDefaultRadioChannelEvent>(RelayInventoryEvent);

        // by-ref events
        SubscribeLocalEvent<InventoryComponent, GetExplosionResistanceEvent>(RefRelayInventoryEvent);

        // Eye/vision events
        SubscribeLocalEvent<InventoryComponent, CanSeeAttemptEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, GetEyeProtectionEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, GetBlurEvent>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, SolutionScanEvent>(RelayInventoryEvent);

        // ComponentActivatedClientSystems
        SubscribeLocalEvent<InventoryComponent, RefreshEquipmentHudEvent<ShowSecurityIconsComponent>>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, RefreshEquipmentHudEvent<ShowHungerIconsComponent>>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, RefreshEquipmentHudEvent<ShowThirstIconsComponent>>(RelayInventoryEvent);
        SubscribeLocalEvent<InventoryComponent, RefreshEquipmentHudEvent<ShowSyndicateIconsComponent>>(RelayInventoryEvent);

        SubscribeLocalEvent<InventoryComponent, GetVerbsEvent<EquipmentVerb>>(OnGetEquipmentVerbs);
    }

    protected void RefRelayInventoryEvent<T>(EntityUid uid, InventoryComponent component, ref T args) where T : IInventoryRelayEvent
    {
        RelayEvent((uid, component), args);
    }

    protected void RelayInventoryEvent<T>(EntityUid uid, InventoryComponent component, T args) where T : IInventoryRelayEvent
    {
        RelayEvent((uid, component), args);
    }

    public void RelayEvent<T>(Entity<InventoryComponent> inventory, ref T args) where T : IInventoryRelayEvent
    {
        var containerEnumerator = new ContainerSlotEnumerator(inventory, inventory.Comp.TemplateId, _prototypeManager, this, args.TargetSlots);

        // this copies the by-ref event if it is a struct
        var ev = new InventoryRelayedEvent<T>(args);

        while (containerEnumerator.MoveNext(out var container))
        {
            if (!container.ContainedEntity.HasValue)
                continue;

            RaiseLocalEvent(container.ContainedEntity.Value, ev);
        }

        // and now we copy it back
        args = ev.Args;
    }

    public void RelayEvent<T>(Entity<InventoryComponent> inventory, T args) where T : IInventoryRelayEvent
    {
        if (args.TargetSlots == SlotFlags.NONE)
            return;

        var containerEnumerator = new ContainerSlotEnumerator(inventory, inventory.Comp.TemplateId, _prototypeManager, this, args.TargetSlots);
        var ev = new InventoryRelayedEvent<T>(args);
        while (containerEnumerator.MoveNext(out var container))
        {
            if (!container.ContainedEntity.HasValue)
                continue;

            RaiseLocalEvent(container.ContainedEntity.Value, ev);
        }
    }

    private void OnGetEquipmentVerbs(EntityUid uid, InventoryComponent component, GetVerbsEvent<EquipmentVerb> args)
    {
        // Automatically relay stripping related verbs to all equipped clothing.

        if (!_prototypeManager.TryIndex(component.TemplateId, out InventoryTemplatePrototype? proto))
            return;

        if (!TryComp(uid, out ContainerManagerComponent? containers))
            return;

        var ev = new InventoryRelayedEvent<GetVerbsEvent<EquipmentVerb>>(args);
        foreach (var slotDef in proto.Slots)
        {
            if (slotDef.StripHidden && args.User != uid)
                continue;

            if (!containers.TryGetContainer(slotDef.Name, out var container))
                continue;

            if (container is not ContainerSlot slot || slot.ContainedEntity is not { } ent)
                continue;

            RaiseLocalEvent(ent, ev);
        }
    }

}

/// <summary>
///     Event wrapper for relayed events.
/// </summary>
/// <remarks>
///      This avoids nested inventory relays, and makes it easy to have certain events only handled by the initial
///      target entity. E.g. health based movement speed modifiers should not be handled by a hat, even if that hat
///      happens to be a dead mouse. Clothing that wishes to modify movement speed must subscribe to
///      InventoryRelayedEvent&lt;RefreshMovementSpeedModifiersEvent&gt;
/// </remarks>
public sealed class InventoryRelayedEvent<TEvent> : EntityEventArgs
{
    public TEvent Args;

    public InventoryRelayedEvent(TEvent args)
    {
        Args = args;
    }
}

/// <summary>
///     Events that should be relayed to inventory slots should implement this interface.
/// </summary>
public interface IInventoryRelayEvent
{
    /// <summary>
    ///     What inventory slots should this event be relayed to, if any?
    /// </summary>
    /// <remarks>
    ///     In general you may want to exclude <see cref="SlotFlags.POCKET"/>, given that those items are not truly
    ///     "equipped" by the user.
    /// </remarks>
    public SlotFlags TargetSlots { get; }
}