Add SessionInitialize event (#3691)

* Add SessionInitialize event

* Move to using GeyserConnection instead of BedrockServerSession

* Remove redundent re-expose

* Rename geyserSession to just session

api/src/main/java/org/geysermc/geyser/api/event/bedrock/SessionInitializeEvent.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2019-2022 GeyserMC. http://geysermc.org
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * @author GeyserMC
+ * @link https://github.com/GeyserMC/Geyser
+ */
+
+package org.geysermc.geyser.api.event.bedrock;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.geysermc.geyser.api.connection.GeyserConnection;
+import org.geysermc.geyser.api.event.connection.ConnectionEvent;
+
+/**
+ * Called when Geyser initialises a session for a new bedrock client.
+ */
+public final class SessionInitializeEvent extends ConnectionEvent {
+    public SessionInitializeEvent(@NonNull GeyserConnection connection) {
+        super(connection);
+    }
+}

core/src/main/java/org/geysermc/geyser/network/GeyserServerInitializer.java

@@ -32,6 +32,8 @@ import org.cloudburstmc.protocol.bedrock.BedrockPeer;
 import org.cloudburstmc.protocol.bedrock.BedrockServerSession;
 import org.cloudburstmc.protocol.bedrock.netty.initializer.BedrockServerInitializer;
 import org.geysermc.geyser.GeyserImpl;
+import org.geysermc.geyser.api.event.bedrock.SessionInitializeEvent;
+import org.geysermc.geyser.api.event.lifecycle.GeyserPreInitializeEvent;
 import org.geysermc.geyser.session.GeyserSession;
 
 import javax.annotation.Nonnull;
@@ -49,7 +51,9 @@ public class GeyserServerInitializer extends BedrockServerInitializer {
     public void initSession(@Nonnull BedrockServerSession bedrockServerSession) {
         try {
             bedrockServerSession.setLogging(true);
-            bedrockServerSession.setPacketHandler(new UpstreamPacketHandler(this.geyser, new GeyserSession(this.geyser, bedrockServerSession, this.eventLoopGroup.next())));
+            GeyserSession session = new GeyserSession(this.geyser, bedrockServerSession, this.eventLoopGroup.next());
+            bedrockServerSession.setPacketHandler(new UpstreamPacketHandler(this.geyser, session));
+            this.geyser.eventBus().fire(new SessionInitializeEvent(session));
         } catch (Throwable e) {
             // Error must be caught or it will be swallowed
             this.geyser.getLogger().error("Error occurred while initializing player!", e);