package de.mrbesen.telegram.commands;

import de.mrbesen.telegram.TelegramAPI;
import de.mrbesen.telegram.objects.TMessage;
import de.mrbesen.telegram.objects.TUser;

import java.util.ArrayList;

public class CommandManager {

	private final static String CMDPATTERN = "^[\\w-]+$";
	private final TelegramAPI api;
	
	private ArrayList<ICommandHandler> handlerlist = new ArrayList<>();//list of all registered CommandHandler

	public CommandManager(TelegramAPI a) {
		api = a;
	}
	
	public void onCommand(String line, TUser sender, TMessage json) {//called by the api (/-prefix already removed)
		line = line.trim();
		String[] split = line.split(" ",2);
		String cmd = split[0].toLowerCase();
		if(cmd.contains("@")) {
			cmd = cmd.substring(0, cmd.indexOf('@'));
		}
		boolean result = false;
		if(cmd.matches(CMDPATTERN)) {
			String[] args = new String[0];
			if(split.length == 2) {
				args = split[1].split(" ");
			}
			//call
			for(ICommandHandler cmdhand : handlerlist) {
				try {
					if(cmdhand instanceof JSONCommandHandler) {
						result = ((JSONCommandHandler) cmdhand).onCommand(sender, cmd, args, json);
					} else if( cmdhand instanceof CommandHandler){
						result = ((CommandHandler) cmdhand).onCommand(sender, cmd, args);
					}
					if(result)
						break;
				} catch(Throwable t) {
					System.err.println("Error, while performing Command. ");//TODO do loggin here
					t.printStackTrace();
				}
			}
		}
		//do smth. with result
		if(!result && json.getChatID() < 0) {
			TUser.sendMessage(api, json.getChatID(), api.getHelpMessage(), null, 0, true, null);
		}
	}

	public void registerCommand(ICommandHandler handler) {
		registerCommand(null, handler);
	}

	public void registerCommand(String cmd, ICommandHandler handler) {
		if(handler == null) {
			throw new NullPointerException("handler is not allowed to be null");
		}
		handlerlist.add(handler);
	}
}