init structure

init protocol

api/build.gradle.kts

@@ -0,0 +1,16 @@
+plugins {
+    kotlin("jvm")
+}
+
+group = "cc.maxmc.msm.api"
+
+repositories {
+    mavenCentral()
+    maven("https://repo.papermc.io/repository/maven-public/")
+}
+
+dependencies {
+    implementation(kotlin("stdlib"))
+    @Suppress("VulnerableLibrariesLocal")
+    compileOnly("io.github.waterfallmc:waterfall-api:1.19-R0.1-SNAPSHOT")
+}

api/src/main/java/cc/maxmc/msm/api/MultiServerManAPI.java

@@ -0,0 +1,18 @@
+package cc.maxmc.msm.api;
+
+import cc.maxmc.msm.api.misc.ServerInfo;
+import net.md_5.bungee.api.connection.ProxiedPlayer;
+
+import java.util.List;
+
+@SuppressWarnings("unused") // API
+public interface MultiServerManAPI {
+    ServerInfo getServer(String type, List<ProxiedPlayer> players);
+
+    void informEnd(int id);
+
+    ServerInfo getPlayerServer(ProxiedPlayer player);
+
+    Boolean containPlayer(ProxiedPlayer player);
+
+}

api/src/main/java/cc/maxmc/msm/api/MultiServerManAPIProvider.java

@@ -0,0 +1,31 @@
+package cc.maxmc.msm.api;
+
+@SuppressWarnings("unused") // API
+public abstract class MultiServerManAPIProvider {
+    private static MultiServerManAPIProvider instance;
+
+    public static MultiServerManAPI getAPI() {
+        if (instance == null) {
+            throw new NotLoadedException();
+        }
+        return instance.provideAPI();
+    }
+
+    abstract MultiServerManAPI provideAPI();
+
+    /**
+     * 在加载 API 之前请求 API 时引发异常。
+     */
+    private static final class NotLoadedException extends IllegalStateException {
+        private static final String MESSAGE = "The MultiServerMan API isn't loaded yet!\n" +
+                "This could be because:\n" +
+                "  a) the MultiServerMan plugin is not installed or it failed to enable\n" +
+                "  b) the plugin in the stacktrace does not declare a dependency on MultiServerMan\n" +
+                "  c) the plugin in the stacktrace is retrieving the API before the plugin 'enable' phase\n" +
+                "     (call the #get method in onEnable, not the constructor!)\n";
+
+        NotLoadedException() {
+            super(MESSAGE);
+        }
+    }
+}

api/src/main/java/cc/maxmc/msm/api/misc/ServerInfo.java

@@ -0,0 +1,25 @@
+package cc.maxmc.msm.api.misc;
+
+import com.google.common.net.HostAndPort;
+import org.jetbrains.annotations.Nullable;
+
+@SuppressWarnings("unused") // API
+public class ServerInfo {
+    @Nullable
+    private final HostAndPort server;
+    private final int id;
+
+    public ServerInfo(@Nullable HostAndPort server, int id) {
+        this.server = server;
+        this.id = id;
+    }
+
+    @Nullable
+    public HostAndPort getServer() {
+        return server;
+    }
+
+    public int getId() {
+        return id;
+    }
+}