Introduce a priority for persistent CPE message lines

MCGalaxy/Chat/Chat.cs

@@ -14,6 +14,7 @@ permissions and limitations under the Licenses.
  */
 using System;
 using System.Text;
+using System.Collections.Generic;
 using MCGalaxy.Commands;
 using MCGalaxy.Events.ServerEvents;
 
@@ -238,5 +239,57 @@ namespace MCGalaxy {
             isCommand = true;
             return text.Substring(1);
         }
+
+        public class PersistentMessage {
+            public enum Priority { Lowest, Low, Default, High, Highest }
+
+            public string message;
+            public Priority priority;
+            public PersistentMessage(string message, Priority priority) {
+                this.message = message; this.priority = priority;
+            }
+
+            /// <summary>
+            /// Returns false if no persistent message was handled, otherwise true.
+            /// </summary>
+            internal static bool Handle(Player p, CpeMessageType type, string message, Priority priority) {
+                if (!IsPersistent(type)) return false;
+                if (!p.fields.ContainsKey(type)) {
+                    p.fields[type] = new List<PersistentMessage>();
+                }
+                var field = p.fields[type];
+
+                PersistentMessage thisMsg = null;
+                foreach (var persMsg in field) { //Find an existing message with same priority
+                    if (persMsg.priority == priority) { thisMsg = persMsg; break; }
+                }
+
+                if (string.IsNullOrEmpty(message)) { //Clearing the message case
+                    if (thisMsg == null) { return true; } //No message exists with this priority, meaning no action needs to be taken when clearing it
+                    field.Remove(thisMsg);
+                    PersistentMessage highestRemainingMsg = null;
+                    foreach (var persMsg in field) {
+                        if (highestRemainingMsg == null || persMsg.priority > highestRemainingMsg.priority) { highestRemainingMsg = persMsg; }
+                    }
+                    if (highestRemainingMsg == null) { p.Session.SendMessage(type, ""); return true; } //No messages remain, clear field and quit
+
+                    p.Session.SendMessage(type, highestRemainingMsg.message); //reveal highest remaining message
+                    return true;
+                }
+
+
+                if (thisMsg == null) { thisMsg = new PersistentMessage(message, priority); field.Add(thisMsg); } else { thisMsg.message = message; }
+
+                foreach (var persMsg in field) {
+                    if (persMsg.priority > priority) { return true; } //If any other message in this field has higher priority, do not send to client
+                }
+                p.Session.SendMessage(type, message);
+                return true;
+            }
+            static bool IsPersistent(CpeMessageType type) {
+                return type == CpeMessageType.Status1 || type == CpeMessageType.Status2 || type == CpeMessageType.Status3 ||
+                    type == CpeMessageType.BottomRight1 || type == CpeMessageType.BottomRight2 || type == CpeMessageType.BottomRight3;
+            }
+        }
     }
 }

MCGalaxy/Network/Player.Networking.cs

@@ -56,13 +56,14 @@ namespace MCGalaxy
             }
         }
 
-        public void SendCpeMessage(CpeMessageType type, string message) {
+        public void SendCpeMessage(CpeMessageType type, string message, Chat.PersistentMessage.Priority priority = Chat.PersistentMessage.Priority.Default) {
             if (type != CpeMessageType.Normal && !Supports(CpeExt.MessageTypes)) {
-                if (type == CpeMessageType.Announcement) type = CpeMessageType.Normal;
+                if (type >= CpeMessageType.Announcement) type = CpeMessageType.Normal;
                 else return;
             }
             
             message = Chat.Format(message, this);
+            if (Chat.PersistentMessage.Handle(this, type, message, priority)) { return; }
             Session.SendMessage(type, message);
         }
 

MCGalaxy/Player/Player.Fields.cs

@@ -31,6 +31,7 @@ namespace MCGalaxy {
 
         public PlayerIgnores Ignores = new PlayerIgnores();
         public static string lastMSG = "";
+        internal Dictionary<CpeMessageType, List<Chat.PersistentMessage>> fields = new Dictionary<CpeMessageType, List<Chat.PersistentMessage>>();
         public Zone ZoneIn;
         
         //TpA