baseline: OpenMU upstream b5a0961 (fresh source)

src/GameServer/RemoteView/ViewPlugInContainer.cs

@@ -0,0 +1,105 @@
+// <copyright file="ViewPlugInContainer.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;
+
+using System.ComponentModel.Design;
+using System.Reflection;
+using Microsoft.Extensions.DependencyInjection;
+using MUnique.OpenMU.GameLogic;
+using MUnique.OpenMU.GameLogic.Views;
+using MUnique.OpenMU.Network.PlugIns;
+using MUnique.OpenMU.PlugIns;
+
+/// <summary>
+/// A plugin container which selects plugin based on the provided version/season metadata.
+/// </summary>
+/// <seealso cref="IViewPlugIn" />
+/// <remarks>
+/// Simplified example: View plugin container is meant for season 6.
+/// There are some IChatMessageViewPlugIns available for the seasons 1, 2, 6 and 7.
+/// Which one to choose?
+///   In this case, it's easy, we just select the one which is equal.
+/// Now, if we remove the plugin for season 6, so that 1, 2 and 7 are available?
+///   In this case, we assume that the last available season before the target season is the correct one, season 2.
+/// </remarks>
+internal sealed class ViewPlugInContainer : CustomPlugInContainerBase<IViewPlugIn>, IDisposable
+{
+    private readonly RemotePlayer _player;
+
+    private readonly ServiceContainer _serviceContainer;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ViewPlugInContainer"/> class.
+    /// </summary>
+    /// <param name="player">The player.</param>
+    /// <param name="clientVersion">The client information.</param>
+    /// <param name="manager">The manager.</param>
+    public ViewPlugInContainer(RemotePlayer player, ClientVersion clientVersion, PlugInManager manager)
+        : base(manager)
+    {
+        this._player = player;
+        this.Client = clientVersion;
+        this._player.ClientVersionChanged += this.OnClientVersionChanged;
+        this._serviceContainer = new ServiceContainer();
+        this._serviceContainer.AddService(typeof(RemotePlayer), this._player);
+        this.Initialize();
+    }
+
+    /// <summary>
+    /// Gets the client.
+    /// </summary>
+    /// <value>
+    /// The client.
+    /// </value>
+    public ClientVersion Client { get; private set; }
+
+    /// <inheritdoc />
+    public void Dispose()
+    {
+        this._serviceContainer.Dispose();
+        this.KnownPlugIns.OfType<IDisposable>().ForEach(d => d.Dispose());
+    }
+
+    /// <inheritdoc/>
+    /// <remarks>We look if the activated plugin is rated at a higher client version than the current one.</remarks>
+    protected override bool IsNewPlugInReplacingOld(IViewPlugIn currentEffectivePlugIn, IViewPlugIn activatedPlugIn)
+    {
+        var currentPlugInClient = currentEffectivePlugIn.GetType().GetCustomAttribute<MinimumClientAttribute>(inherit: false)?.Client ?? default;
+        var activatedPluginClient = activatedPlugIn.GetType().GetCustomAttribute<MinimumClientAttribute>(inherit: false)?.Client ?? default;
+        return currentPlugInClient.CompareTo(activatedPluginClient) < 0;
+    }
+
+    /// <inheritdoc />
+    /// <remarks>We sort by version and choose the highest one.</remarks>
+    protected override IViewPlugIn? DetermineEffectivePlugIn(Type interfaceType)
+    {
+        return this.ActivePlugIns.OrderByDescending(p => p.GetType().GetCustomAttribute(typeof(MinimumClientAttribute), inherit: false)).FirstOrDefault(interfaceType.IsInstanceOfType);
+    }
+
+    /// <inheritdoc />
+    /// <remarks>We just take the plugins which have a equal or lower version than our target <see cref="Client"/>.</remarks>
+    protected override void CreatePlugInIfSuitable(Type plugInType)
+    {
+        if (this.Client.IsPlugInSuitable(plugInType))
+        {
+            var plugIn = (IViewPlugIn)ActivatorUtilities.CreateInstance(this._serviceContainer, plugInType)!;
+            this.AddPlugIn(plugIn, true);
+        }
+    }
+
+    private void OnClientVersionChanged(object? sender, EventArgs e)
+    {
+        this.Client = this._player.ClientVersion;
+        foreach (var activePlugIn in this.ActivePlugIns)
+        {
+            if (!this.Client.IsPlugInSuitable(activePlugIn.GetType()))
+            {
+                this.DeactivatePlugIn(activePlugIn);
+            }
+        }
+
+        this.Initialize();
+    }
+}