using System;
using System.Collections.Generic;

namespace AcDream.Core.Items;

/// <summary>
/// Mutable client-side model of the 18 toolbar shortcut slots — port of retail
/// <c>ShortCutManager::shortCuts_[18]</c> (acclient.h:36492). Holds the bound object guid per
/// slot (0 = empty). Loaded from the login shortcut list, then mutated by drag-drop (lift
/// removes, drop places); the server is notified via AddShortcut/RemoveShortcut so the store
/// stays the client's source of truth within a session (retail: client owns the array).
/// Item shortcuts only — entries with ObjGuid 0 (spell-only) are skipped on Load. Pure model
/// (no Core.Net dependency): callers project their wire entries to (slot, objGuid) pairs.
/// </summary>
public sealed class ShortcutStore
{
    public const int SlotCount = 18;
    private readonly uint[] _objIds = new uint[SlotCount];

    /// <summary>Replace all slots from a (slot, objectGuid) sequence (item entries only;
    /// ObjGuid 0 and out-of-range slots are skipped).</summary>
    public void Load(IEnumerable<(int Slot, uint ObjGuid)> entries)
    {
        Array.Clear(_objIds);
        foreach (var (slot, objGuid) in entries)
            if ((uint)slot < SlotCount && objGuid != 0) _objIds[slot] = objGuid;
    }

    /// <summary>Bound object guid at <paramref name="slot"/>, or 0 (empty / out of range).</summary>
    public uint Get(int slot) => (uint)slot < SlotCount ? _objIds[slot] : 0u;
    public bool IsEmpty(int slot) => Get(slot) == 0u;
    public void Set(int slot, uint objId) { if ((uint)slot < SlotCount) _objIds[slot] = objId; }
    public void Remove(int slot) { if ((uint)slot < SlotCount) _objIds[slot] = 0u; }
}