aetheria-anarchy-plugin/src/main/java/cc/fascinated/placeholder/PlaceholderManager.java

package cc.fascinated.placeholder;

import cc.fascinated.Aetheria;
import lombok.extern.log4j.Log4j2;
import me.clip.placeholderapi.PlaceholderAPI;
import me.clip.placeholderapi.expansion.PlaceholderExpansion;
import org.bukkit.OfflinePlayer;
import org.bukkit.entity.Player;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.Arrays;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

@Log4j2
public class PlaceholderManager {

    private static final Map<String, AetheriaPlaceholder> PLACEHOLDERS = new ConcurrentHashMap<>();

    public PlaceholderManager() {
        new PlaceholderAdapter().register();
    }

    /**
     * Register the provided placeholder
     *
     * @param placeholder the placeholder to register
     */
    public static void registerPlaceholder(AetheriaPlaceholder placeholder) {
        PLACEHOLDERS.put(placeholder.getIdentifier(), placeholder);
        log.info("Registered placeholder " + placeholder.getIdentifier());
    }

    /**
     * Unregister the provided placeholder
     *
     * @param placeholder the placeholder to unregister
     */
    public static void unregisterPlaceholder(AetheriaPlaceholder placeholder) {
        PLACEHOLDERS.remove(placeholder.getIdentifier());
        log.info("Unregistered placeholder " + placeholder.getIdentifier());
    }

    /**
     * Replace PAPI placeholders in the given content.
     *
     * @param player the player to replace the placeholders for, null if offline
     * @param content the content to replace the placeholders in
     * @return the content with the placeholders replaced
     */
    public static String replace(@Nullable Player player, String content) {
        return PlaceholderAPI.setPlaceholders(player != null && (player.isOnline()) ? player : null, content);
    }

    static class PlaceholderAdapter extends PlaceholderExpansion {

        @Override
        public @NotNull String getIdentifier() {
            return "aetheria";
        }

        @SuppressWarnings("UnstableApiUsage")
        @Override
        public @NotNull String getAuthor() {
            return String.join(", ", Aetheria.INSTANCE.getPluginMeta().getAuthors());
        }

        @SuppressWarnings("UnstableApiUsage")
        @Override
        public @NotNull String getVersion() {
            return Aetheria.INSTANCE.getPluginMeta().getVersion();
        }

        /**
         * From PlaceholderAPI:
         * <p>
         * Expansions that do not use the e-cloud and instead register from the dependency should set this to true
         * to ensure that your placeholder expansion is not unregistered when the papi reload command is used
         */
        public boolean persist() {
            return true;
        }

        @Override
        public @Nullable String onRequest(@Nullable OfflinePlayer player, @NotNull String params) {
            String[] parameters = params.split("_");
            AetheriaPlaceholder placeholder = PLACEHOLDERS.get(parameters[0]);
            // Attempt to fetch the placeholder with the provided id
            if (placeholder == null) {
                log.error("Tried to fetch an unregistered placeholder: " + parameters[0]);
                return null;
            }
            // Ensure the correct amount of parameters is provided
            if (parameters.length - 1 < placeholder.getRequiredParameterCount()) {
                log.error("Invalid placeholders provided for {}, provided = {}, required = {}",
                        placeholder.getIdentifier(),
                        parameters.length - 1,
                        placeholder.getRequiredParameterCount());
                return null;
            }
            // Trim the placeholder identifier from the parameters before parsing
            return placeholder.parse((Player) player, parameters.length > 1 ? Arrays.copyOfRange(parameters, 1, parameters.length) : parameters);
        }
    }
}