namespace Theriapolis.Core.Items;

/// <summary>
/// Equipment slot a single <see cref="ItemInstance"/> occupies when worn or
/// wielded. Each slot holds at most one item. Two-handed weapons clear the
/// OffHand slot when equipped.
///
/// Natural-weapon enhancers (Fang Caps, Claw Sheaths, Hoof Plates, Antler Tips,
/// Horn Rings) attach to a *specific* anatomical slot — they do not share with
/// general-purpose worn items, so each gets its own enum entry.
/// </summary>
public enum EquipSlot : byte
{
    MainHand                = 0,
    OffHand                 = 1,
    Body                    = 2,
    Helm                    = 3,
    Cloak                   = 4,
    Boots                   = 5,
    AdaptivePack            = 6,
    NaturalWeaponFang       = 7,
    NaturalWeaponClaw       = 8,
    NaturalWeaponHoof       = 9,
    NaturalWeaponAntler     = 10,
    NaturalWeaponHorn       = 11,
}

public static class EquipSlotExtensions
{
    /// <summary>
    /// Maps an <see cref="Data.ItemDef.EnhancerSlot"/> string ("fang", "claw",
    /// "hoof", "antler", "horn") to the corresponding NaturalWeapon* slot.
    /// Returns null if the string isn't a recognized natural-weapon location.
    /// </summary>
    public static EquipSlot? FromEnhancerSlot(string? raw) => raw?.ToLowerInvariant() switch
    {
        "fang"   => EquipSlot.NaturalWeaponFang,
        "claw"   => EquipSlot.NaturalWeaponClaw,
        "hoof"   => EquipSlot.NaturalWeaponHoof,
        "antler" => EquipSlot.NaturalWeaponAntler,
        "horn"   => EquipSlot.NaturalWeaponHorn,
        _        => null,
    };

    /// <summary>Parses a snake_case JSON value (e.g. "main_hand") into an EquipSlot.</summary>
    public static EquipSlot? FromJson(string? raw) => raw?.ToLowerInvariant() switch
    {
        "main_hand"              => EquipSlot.MainHand,
        "off_hand"               => EquipSlot.OffHand,
        "body"                   => EquipSlot.Body,
        "helm"                   => EquipSlot.Helm,
        "cloak"                  => EquipSlot.Cloak,
        "boots"                  => EquipSlot.Boots,
        "adaptive_pack"          => EquipSlot.AdaptivePack,
        "natural_weapon_fang"    => EquipSlot.NaturalWeaponFang,
        "natural_weapon_claw"    => EquipSlot.NaturalWeaponClaw,
        "natural_weapon_hoof"    => EquipSlot.NaturalWeaponHoof,
        "natural_weapon_antler"  => EquipSlot.NaturalWeaponAntler,
        "natural_weapon_horn"    => EquipSlot.NaturalWeaponHorn,
        _                        => null,
    };
}