// <copyright file="DroppedItemsDisappearedPlugIn.cs" company="MUnique">
// Licensed under the MIT License. See LICENSE file in the project root for full license information.
// </copyright>

namespace MUnique.OpenMU.GameServer.RemoteView.World;

using System.Runtime.InteropServices;
using MUnique.OpenMU.GameLogic.Views.World;
using MUnique.OpenMU.Network;
using MUnique.OpenMU.Network.Packets.ServerToClient;
using MUnique.OpenMU.PlugIns;

/// <summary>
/// The default implementation of the <see cref="IDroppedItemsDisappearedPlugIn"/> which is forwarding everything to the game client with specific data packets.
/// </summary>
[PlugIn]
[Display(Name = nameof(PlugInResources.DroppedItemsDisappearedPlugIn_Name), Description = nameof(PlugInResources.DroppedItemsDisappearedPlugIn_Description), ResourceType = typeof(PlugInResources))]
[Guid("ecd14e95-33be-44f7-bb9b-1429a57a7a94")]
public class DroppedItemsDisappearedPlugIn : IDroppedItemsDisappearedPlugIn
{
    private readonly RemotePlayer _player;

    /// <summary>
    /// Initializes a new instance of the <see cref="DroppedItemsDisappearedPlugIn"/> class.
    /// </summary>
    /// <param name="player">The player.</param>
    public DroppedItemsDisappearedPlugIn(RemotePlayer player) => this._player = player;

    /// <inheritdoc/>
    public async ValueTask DroppedItemsDisappearedAsync(IEnumerable<ushort> disappearedItemIds)
    {
        var connection = this._player.Connection;
        if (connection is null)
        {
            return;
        }

        ////C2 00 07 21 01 00 0C
        int count = disappearedItemIds.Count();

        int Write()
        {
            var size = ItemDropRemovedRef.GetRequiredSize(count);
            var span = connection.Output.GetSpan(size)[..size];
            var message = new ItemDropRemovedRef(span)
            {
                ItemCount = (byte)count,
            };

            int i = 0;
            foreach (var dropId in disappearedItemIds)
            {
                var drop = message[i];
                drop.Id = dropId;
                i++;
            }

            return size;
        }

        await connection.SendAsync(Write).ConfigureAwait(false);
    }
}