Mixtape/src/main/java/xyz/etztech/mixtape/listeners/CommandPreprocessListener.java

package xyz.etztech.mixtape.listeners;

import org.apache.commons.lang.StringUtils;
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerCommandPreprocessEvent;
import org.bukkit.event.server.ServerCommandEvent;
import xyz.etztech.mixtape.Mixtape;
import xyz.etztech.mixtape.MixtapeUtil;

import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class CommandPreprocessListener implements Listener {

    private final String ERROR = "Mixtape/Error";
    private final Pattern PATTERN = Pattern.compile("<([^>]+)>");

    Mixtape plugin;

    public CommandPreprocessListener(Mixtape plugin) {
        this.plugin = plugin;
    }

    @EventHandler(priority= EventPriority.HIGH, ignoreCancelled=true)
    public void onServerCommandPreprocess(ServerCommandEvent event) {
        String command = event.getCommand();
        if (command.startsWith("/")) {
            command = command.substring(1);
        }
        String base = command.split(" ")[0];
        String[] args = command.trim().length() == base.trim().length() ? new String[0] : command.substring(base.length()+1).split(" ");

        event.setCancelled(handleEvent(Bukkit.getConsoleSender(), base, args));
    }

    @EventHandler(priority= EventPriority.HIGH, ignoreCancelled=true)
    public void onPlayerCommandPreprocess(PlayerCommandPreprocessEvent event) {

        String command = event.getMessage().substring(1); // Strip the slash
        String base = command.split(" ")[0];
        String[] args = command.trim().length() == base.trim().length() ? new String[0] : command.substring(base.length()+1).split(" ");

        event.setCancelled(handleEvent(event.getPlayer(), base, args));

    }

    private boolean handleEvent(CommandSender sender, String base, String[] args) {
        // Global aliases
        if (Mixtape.getGlobal()) {
            List<?> configs = plugin.getConfig().getList("aliases");
            for (int i = 0; i < configs.size(); i++) {
                LinkedHashMap<String, String> config = (LinkedHashMap<String, String>) configs.get(i);
                String configBase = MixtapeUtil.stripSlash(config.get("alias"));
                if (configBase.equalsIgnoreCase(base)) {
                    String configCommand = MixtapeUtil.stripSlash(config.get("command"));
                    String resolved = resolve(configCommand, args);
                    if (!ERROR.equalsIgnoreCase(resolved)) {
                        Bukkit.dispatchCommand(sender, resolved);
                    } else {
                        sender.sendMessage(ChatColor.RED + usage(base, configCommand));
                    }
                    return true;
                }
            }
        }

        // Personal aliases
        if (sender instanceof Player) {
            Player player = (Player) sender;

            // Command aliases
            Map<String, String> commands = Mixtape.getCommandAliases(player.getUniqueId().toString());
            for (String alias : commands.keySet()) {
                if (alias.equalsIgnoreCase(base)) {
                    String resolved = resolve(commands.get(alias), args);
                    if (!ERROR.equalsIgnoreCase(resolved)) {
                        Bukkit.dispatchCommand(player, resolved);
                    } else {
                        player.sendMessage(ChatColor.RED + usage(base, commands.get(alias)));
                    }
                    return true;
                }
            }

            // Chat aliases
            Map<String, String> chats = Mixtape.getChatAliases(player.getUniqueId().toString());
            for (String alias : chats.keySet()) {
                if (alias.equalsIgnoreCase(base)) {
                    String resolved = resolve(chats.get(alias), args);
                    if (!ERROR.equalsIgnoreCase(resolved)) {
                        resolved = resolved.startsWith("/") ? "." + resolved : resolved;
                        player.chat(resolved);
                    } else {
                        player.sendMessage(ChatColor.RED + usage(base, chats.get(alias)));
                    }
                    return true;
                }
            }
        }

        return false;
    }



    private String usage(String base, String template) {
        StringBuilder usage = new StringBuilder("/" + base);
        Matcher matcher = PATTERN.matcher(template);
        while (matcher.find()) {
            usage.append(" ").append(matcher.group(0));
        }
        return usage.toString();
    }

    private String resolve(String template, String... parts) {
        Matcher matcher = PATTERN.matcher(template);
        int idx = 0;
        try {
            while (matcher.find()) {
                template = template.replaceFirst(matcher.group(0), parts[idx]);
                idx++;
            }
        } catch (Exception ex) {
            return ERROR;
        }
        return template.trim() + " " + StringUtils.join(Arrays.copyOfRange(parts, idx, parts.length), " ");
    }


}