add server pinger

src/main/java/cc.fascinated/service/ServerService.java

@@ -0,0 +1,64 @@
+package cc.fascinated.service;
+
+import cc.fascinated.EnumUtils;
+import cc.fascinated.common.DNSUtils;
+import cc.fascinated.common.WebRequest;
+import cc.fascinated.exception.impl.BadRequestException;
+import cc.fascinated.model.cache.CachedMinecraftServer;
+import cc.fascinated.model.mojang.MojangProfile;
+import cc.fascinated.model.mojang.MojangUsernameToUuid;
+import cc.fascinated.model.server.MinecraftServer;
+import cc.fascinated.repository.MinecraftServerCacheRepository;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+import java.net.InetSocketAddress;
+import java.util.Optional;
+
+@Service @Log4j2
+public class ServerService {
+
+    private final MinecraftServerCacheRepository serverCacheRepository;
+
+    @Autowired
+    public ServerService(MinecraftServerCacheRepository serverCacheRepository) {
+        this.serverCacheRepository = serverCacheRepository;
+    }
+
+    /**
+     * Ping a server to get the server information.
+     *
+     * @param platformName the name of the platform
+     * @param hostname the hostname of the server
+     * @param port the port of the server
+     * @return the server
+     */
+    public CachedMinecraftServer getServer(String platformName, String hostname, int port) {
+        MinecraftServer.Platform platform = EnumUtils.getEnumConstant(MinecraftServer.Platform.class, platformName.toUpperCase());
+        if (platform == null) {
+            throw new BadRequestException("Invalid platform: %s".formatted(platformName));
+        }
+        String key = "%s-%s:%s".formatted(platformName, hostname, port);
+
+        Optional<CachedMinecraftServer> cached = serverCacheRepository.findById(key);
+        if (cached.isPresent()) {
+            return cached.get();
+        }
+
+        InetSocketAddress address = platform == MinecraftServer.Platform.JAVA ? DNSUtils.resolveSRV(hostname) : null;
+        if (address != null) {
+            port = port != -1 ? port : platform.getDefaultPort(); // If the port is -1, set it to the default port
+            hostname = address.getHostName();
+        }
+
+        CachedMinecraftServer server = new CachedMinecraftServer(
+                key,
+                platform.getPinger().ping(hostname, port),
+                System.currentTimeMillis()
+        );
+        serverCacheRepository.save(server);
+        return server;
+    }
+}