Started implementing server deletion

MoonlightServers.Daemon/ServerSys/Abstractions/Server.cs

@@ -190,6 +190,11 @@ public class Server : IAsyncDisposable
         });
     }
 
+    public async Task Delete()
+    {
+        await FileSystem.Delete();
+    }
+
     #region State machine handlers
 
     private async Task HandleStart()

MoonlightServers.Daemon/Services/NewServerService.cs

@@ -1,11 +1,13 @@
 using System.Collections.Concurrent;
+using MoonCore.Exceptions;
 using MoonCore.Helpers;
 using MoonCore.Models;
 using MoonlightServers.Daemon.Mappers;
 using MoonlightServers.Daemon.Models.Cache;
 using MoonlightServers.Daemon.ServerSys;
-using MoonlightServers.Daemon.ServerSys.Abstractions;
+using MoonlightServers.Daemon.ServerSystem;
 using MoonlightServers.DaemonShared.PanelSide.Http.Responses;
+using Server = MoonlightServers.Daemon.ServerSys.Abstractions.Server;
 
 namespace MoonlightServers.Daemon.Services;
 
@@ -88,9 +90,68 @@ public class NewServerService : IHostedLifecycleService
         if (server == null)
             throw new ArgumentException("No server with this id found", nameof(serverId));
 
+        if (server.StateMachine.State == ServerState.Installing)
+            throw new HttpApiException("Unable to delete a server while it is installing", 400);
+
+        if (server.StateMachine.State != ServerState.Offline)
+        {
+            // If the server is not offline we need to wait until it goes offline, we
+            // do that by creating the serverOfflineWaiter task completion source which will get triggered
+            // when the event handler for state changes gets informed that the server state is now offline
+
+            var serverOfflineWaiter = new TaskCompletionSource();
+            var timeoutCancellation = new CancellationTokenSource();
+
+            // Set timeout to 10 seconds, this gives the server 10 seconds to go offline, before the request fails
+            timeoutCancellation.CancelAfter(TimeSpan.FromSeconds(10));
+
+            // Subscribe to state updates in order to get notified when the server is offline
+            server.StateMachine.OnTransitioned(transition =>
+            {
+                // Only listen for changes to offline
+                if (transition.Destination != ServerState.Offline)
+                    return;
+
+                // If the timeout has already been reached, ignore all changes
+                if (timeoutCancellation.IsCancellationRequested)
+                    return;
+
+                // Server is finally offline, notify the request that we now can delete the server
+                serverOfflineWaiter.SetResult();
+            });
+
+            // Now we trigger the kill and waiting for the server to be deleted
+            await server.StateMachine.FireAsync(ServerTrigger.Kill);
+
+            try
+            {
+                await serverOfflineWaiter.Task.WaitAsync(timeoutCancellation.Token);
+
+                await DeleteServer_Unhandled(server);
+            }
+            catch (TaskCanceledException)
+            {
+                Logger.LogWarning(
+                    "Deletion of server {id} failed because it didnt stop in time despite being killed",
+                    server.Context.Configuration.Id
+                );
+
+                throw new HttpApiException(
+                    "Could not kill the server in time for the deletion. Please try again later",
+                    500
+                );
+            }
+        }
+        else
+            await DeleteServer_Unhandled(server);
+    }
+    
+    private async Task DeleteServer_Unhandled(Server server)
+    {
+        await server.Delete();
         await server.DisposeAsync();
 
-        Servers.Remove(serverId, out _);
+        Servers.Remove(server.Context.Configuration.Id, out _);
     }
 
     #region Lifetime