import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.function.Consumer;
import org.bukkit.craftbukkit.libs.com.google.gson.Gson;
import org.bukkit.craftbukkit.libs.com.google.gson.GsonBuilder;
import com.mojang.util.UUIDTypeAdapter;
public class UUIDFetcher {

   /**
    * Date when name changes were introduced
    * @see UUIDFetcher#getUUIDAt(String, long)
    */
   public static final long FEBRUARY_2015 = 1422748800000L;


   private static Gson gson = new GsonBuilder().registerTypeAdapter(UUID.class, new UUIDTypeAdapter()).create();

   private static final String UUID_URL = "https://api.mojang.com/users/profiles/minecraft/%s?at=%d";
   private static final String NAME_URL = "https://api.mojang.com/user/profiles/%s/names";
   private static Map<String, UUID> uuidCache = new HashMap<String, UUID>();
   private static Map<UUID, String> nameCache = new HashMap<UUID, String>();
   private static ExecutorService pool = Executors.newCachedThreadPool();

   private String name;
   private UUID id;

   /**
    * Fetches the uuid asynchronously and passes it to the consumer
    *
    * @param name The name
    * @param action Do what you want to do with the uuid her
    */
   public static void getUUID(String name, Consumer<UUID> action) {
      pool.execute(() -> action.accept(getUUID(name)));
   }

   /**
    * Fetches the uuid synchronously and returns it
    *
    * @param name The name
    * @return The uuid
    */
   public static UUID getUUID(String name) {
      return getUUIDAt(name, System.currentTimeMillis());
   }

   /**
    * Fetches the uuid synchronously for a specified name and time and passes the result to the consumer
    *
    * @param name The name
    * @param timestamp Time when the player had this name in milliseconds
    * @param action Do what you want to do with the uuid her
    */
   public static void getUUIDAt(String name, long timestamp, Consumer<UUID> action) {
      pool.execute(() -> action.accept(getUUIDAt(name, timestamp)));
   }

   /**
    * Fetches the uuid synchronously for a specified name and time
    *
    * @param name The name
    * @param timestamp Time when the player had this name in milliseconds
    * @see UUIDFetcher#FEBRUARY_2015
    */
   public static UUID getUUIDAt(String name, long timestamp) {
      name = name.toLowerCase();
      if (uuidCache.containsKey(name)) {
         return uuidCache.get(name);
      }
      try {
         HttpURLConnection connection = (HttpURLConnection) new URL(String.format(UUID_URL, name, timestamp/1000)).openConnection();
         connection.setReadTimeout(5000);
         UUIDFetcher data = gson.fromJson(new BufferedReader(new InputStreamReader(connection.getInputStream())), UUIDFetcher.class);

         uuidCache.put(name, data.id);
         nameCache.put(data.id, data.name);
         return data.id;
      } catch (Exception e) {
         e.printStackTrace();
      }

      return null;
   }

   /**
    * Fetches the name asynchronously and passes it to the consumer
    *
    * @param uuid The uuid
    * @param action Do what you want to do with the name her
    */
   public static void getName(UUID uuid, Consumer<String> action) {
      pool.execute(() -> action.accept(getName(uuid)));
   }
   /**
    * Fetches the name synchronously and returns it
    *
    * @param uuid The uuid
    * @return The name
    */
   public static String getName(UUID uuid) {
      if (nameCache.containsKey(uuid)) {
         return nameCache.get(uuid);
      }
      try {
         HttpURLConnection connection = (HttpURLConnection) new URL(String.format(NAME_URL, UUIDTypeAdapter.fromUUID(uuid))).openConnection();
         connection.setReadTimeout(5000);
         UUIDFetcher[] nameHistory = gson.fromJson(new BufferedReader(new InputStreamReader(connection.getInputStream())), UUIDFetcher[].class);
         UUIDFetcher currentNameData = nameHistory[nameHistory.length - 1];
         uuidCache.put(currentNameData.name.toLowerCase(), uuid);
         nameCache.put(uuid, currentNameData.name);
         return currentNameData.name;
      } catch (Exception e) {
         e.printStackTrace();
      }
      return null;
   }
}