From dd23203139747351c3f13b788050145bf5b58363 Mon Sep 17 00:00:00 2001
From: Andrew Steinborn <git@steinborn.me>
Date: Wed, 28 Oct 2020 19:02:37 -0400
Subject: [PATCH] Add some missing convenience APIs to
 MinecraftChannelIdentifier

---
 .../messages/MinecraftChannelIdentifier.java  | 34 +++++++++++++++++++
 .../MinecraftChannelIdentifierTest.java       | 22 ++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/api/src/main/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifier.java b/api/src/main/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifier.java
index b63b6b1ac..01a582035 100644
--- a/api/src/main/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifier.java
+++ b/api/src/main/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifier.java
@@ -4,6 +4,7 @@ import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
 import java.util.Objects;
 import java.util.regex.Pattern;
+import net.kyori.minecraft.Key;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -50,6 +51,35 @@ public final class MinecraftChannelIdentifier implements ChannelIdentifier {
     return new MinecraftChannelIdentifier(namespace, name);
   }
 
+  /**
+   * Creates an channel identifier from the specified Minecraft identifier.
+   *
+   * @param identifier the Minecraft identifier
+   * @return a new channel identifier
+   */
+  public static MinecraftChannelIdentifier from(String identifier) {
+    int colonPos = identifier.indexOf(':');
+    if (colonPos == -1) {
+      throw new IllegalArgumentException("Identifier does not contain a colon.");
+    }
+    if (colonPos + 1 == identifier.length()) {
+      throw new IllegalArgumentException("Identifier is empty.");
+    }
+    String namespace = identifier.substring(0, colonPos);
+    String name = identifier.substring(colonPos + 1);
+    return create(namespace, name);
+  }
+
+  /**
+   * Creates an channel identifier from the specified Minecraft identifier.
+   *
+   * @param key the Minecraft key to use
+   * @return a new channel identifier
+   */
+  public static MinecraftChannelIdentifier from(Key key) {
+    return create(key.namespace(), key.value());
+  }
+
   public String getNamespace() {
     return namespace;
   }
@@ -58,6 +88,10 @@ public final class MinecraftChannelIdentifier implements ChannelIdentifier {
     return name;
   }
 
+  public Key asKey() {
+    return Key.of(namespace, name);
+  }
+
   @Override
   public String toString() {
     return namespace + ":" + name + " (modern)";
diff --git a/api/src/test/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifierTest.java b/api/src/test/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifierTest.java
index 00699ba5e..dfa738198 100644
--- a/api/src/test/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifierTest.java
+++ b/api/src/test/java/com/velocitypowered/api/proxy/messages/MinecraftChannelIdentifierTest.java
@@ -1,7 +1,9 @@
 package com.velocitypowered.api.proxy.messages;
 
 import static com.velocitypowered.api.proxy.messages.MinecraftChannelIdentifier.create;
+import static com.velocitypowered.api.proxy.messages.MinecraftChannelIdentifier.from;
 import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
@@ -26,4 +28,24 @@ class MinecraftChannelIdentifierTest {
         () -> assertThrows(IllegalArgumentException.class, () -> create("minecraft", null))
     );
   }
+
+  @Test
+  void fromIdentifierIsCorrect() {
+    MinecraftChannelIdentifier expected = MinecraftChannelIdentifier.create("velocity", "test");
+    assertEquals(expected, MinecraftChannelIdentifier.from("velocity:test"));
+  }
+
+  @Test
+  void fromIdentifierThrowsOnBadValues() {
+    assertAll(
+        () -> assertThrows(IllegalArgumentException.class, () -> from("")),
+        () -> assertThrows(IllegalArgumentException.class, () -> from(":")),
+        () -> assertThrows(IllegalArgumentException.class, () -> from(":a")),
+        () -> assertThrows(IllegalArgumentException.class, () -> from("a:")),
+        () -> assertThrows(IllegalArgumentException.class, () -> from("hello:$$$$$$")),
+        () -> assertThrows(IllegalArgumentException.class, () -> from("hello::"))
+    );
+  }
+
+
 }
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