Add PlayerData JSON serialization

extension/src/main/java/de/jeremystartm/pickshadow/api/entity/player/PlayerData.java

@@ -20,16 +20,27 @@
 package de.jeremystartm.pickshadow.api.entity.player;
 
 
+import com.google.gson.Gson;
+import com.google.gson.JsonSyntaxException;
+import com.google.gson.reflect.TypeToken;
 import de.jeremystartm.pickshadow.misc.TabListHandler;
 import de.staropensource.sosengine.base.logging.LoggerInstance;
 import fr.mrmicky.fastboard.adventure.FastBoard;
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.Setter;
+import org.bukkit.Bukkit;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.NotNull;
 
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.Map;
+import java.util.UUID;
+
+import static java.util.Map.entry;
+
 @Setter
 @Getter
 @SuppressWarnings({ "JavadocDeclaration" })
@@ -72,16 +83,97 @@ public final class PlayerData {
     @ApiStatus.Experimental
     private @NotNull FastBoard playerListScoreboard;
 
+    /**
+     * Contains when the player has
+     * first been seen on the server.
+     *
+     * @since v1-release0
+     * -- GETTER --
+     * Returns when the player has
+     * first been seen on the server.
+     *
+     * @return first played date and time
+     * @since v1-release0
+     */
+    private ZonedDateTime firstSeen;
+
     /**
      * Creates and initializes an instance of this class.
+     * <p>
+     * This constructor creates a completely
+     * new instance without any data.
      *
      * @param player {@link Player} to use
      * @since v1-release0
      */
-    PlayerData(Player player) {
+    PlayerData(@NotNull Player player) {
         this.player = player;
         this.logger = new LoggerInstance.Builder().setClazz(getClass()).setOrigin("PSSE").setMetadata(player.getName()).build();
 
         //TabListHandler.getInstance().initializeTabList(this);
+        firstSeen = ZonedDateTime.now();
+    }
+
+    /**
+     * Creates and initializes an instance of this class.
+     * <p>
+     * This constructor creates a new instance
+     * from already existing player data.
+     *
+     * @param player    {@link Player} to use
+     * @param firstSeen when the player was first seen
+     * @since v1-release0
+     */
+    private PlayerData(@NotNull Player player, @NotNull ZonedDateTime firstSeen) {
+        this.player = player;
+        this.logger = new LoggerInstance.Builder().setClazz(getClass()).setOrigin("PSSE").setMetadata(player.getName()).build();
+
+        TabListHandler.getInstance().initializeTabList(this);
+        this.firstSeen = firstSeen;
+    }
+
+    /**
+     * Deserializes a JSON object and creates
+     * a new {@link PlayerData} instance.
+     *
+     * @param jsonString JSON string
+     * @throws JsonSyntaxException on invalid JSON
+     * @throws RuntimeException on invalid PlayerData serialization
+     * @since v1-release0
+     */
+    public static @NotNull PlayerData fromJSON(@NotNull String jsonString) throws JsonSyntaxException, NullPointerException {
+        try {
+            Map<@NotNull String, @NotNull String> data = new Gson().fromJson(jsonString, new TypeToken<Map<@NotNull String, @NotNull String>>() {
+            }.getType());
+            Player player = Bukkit.getPlayer(UUID.fromString(data.get("playerUUID")));
+
+            if (player == null)
+                throw new NullPointerException("Player is null");
+
+            return new PlayerData(
+                    player,
+                    ZonedDateTime.parse(data.get("firstPlayed"))
+            );
+        } catch (Exception exception) {
+            if (exception instanceof JsonSyntaxException)
+                throw exception;
+            else
+                throw new RuntimeException("A conversion method failed", exception);
+        }
+    }
+
+    /**
+     * Serializes this instance into a JSON object.
+     *
+     * @return serialized {@link PlayerData} instance in JSON
+     * @since v1-release0
+     */
+    public @NotNull String toJSON() {
+        return new Gson().toJson(
+                Map.ofEntries(
+                        entry("playerUUID", player.getUniqueId().toString()),
+                        entry("firstPlayed", firstSeen.format(DateTimeFormatter.ISO_ZONED_DATE_TIME))
+                ),
+                new TypeToken<Map<@NotNull String, @NotNull String>>(){}.getType());
     }
 }