package de.mrbesen.telegram;

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.URL;
import java.util.LinkedList;
import java.util.Scanner;

import javax.net.ssl.HttpsURLConnection;

import org.json.JSONArray;
import org.json.JSONObject;

import de.mrbesen.telegram.MessageBuilder.SendableMessage;
import de.mrbesen.telegram.commands.CommandManager;
import de.mrbesen.telegram.event.Event;
import de.mrbesen.telegram.event.EventManager;
import de.mrbesen.telegram.event.events.UserCallbackEvent;
import de.mrbesen.telegram.event.events.UserSendAudioEvent;
import de.mrbesen.telegram.event.events.UserSendMessageEvent;
import de.mrbesen.telegram.log.Log;
import de.mrbesen.telegram.log.Log4JLog;
import de.mrbesen.telegram.log.SimpleLog;
import de.mrbesen.telegram.objects.JSONBased.Member;
import de.mrbesen.telegram.objects.TAudio;
import de.mrbesen.telegram.objects.TMessage;
import de.mrbesen.telegram.objects.TUser;
import de.mrbesen.telegram.objects.TUser.Status;

public class TelegramAPI implements Runnable {

	private static final String API_URL = "https://api.telegram.org/bot";
	private static final String TOKENREGEX = "^\\d{4,9}:[\\w-]{12,64}$";
	public static final String APIVERSION = "3.6";//February 13, 2018

	private int msg_offset = 0;
	private int updateInterval = 1500;
	private String apikey;
	private Thread thread;
	private boolean run = true;
	private String helpmessage = "generic helppage\nuse TelegramAPI.setHelpText(java.lang.String) to change this.";

	private LinkedList<TUser> users = new LinkedList<>();
	private CommandManager cmdmgr = new CommandManager();
	private EventManager evntmgr = new EventManager();

	Log log = new Log4JLog();

	public TelegramAPI(String apikey) {
		if (!apikey.matches(TOKENREGEX) ) {
			throw new IllegalArgumentException("Invalid API key");
		}
		this.apikey = apikey;
	}

	public void start() {
		if(thread == null) {
			run = true;
			thread = new Thread(this, "TelegramAPI");
			thread.start();
		} else {
			throw new IllegalStateException("Still Running.");
		} 
	}

	public JSONObject request(String request, String parameter) throws IOException {
		//do https stuff
		URL url = new URL(API_URL + apikey + "/" + request);
		HttpsURLConnection con = (HttpsURLConnection)url.openConnection();
		con.setDoInput(true);
		con.setDoOutput(true);
		OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream());
		wr.write(parameter);
		wr.flush(); 
		
		log.log( "request: " + request + " content " + parameter + " -> " + con.getResponseCode() + ", " + con.getResponseMessage());
		
		Scanner s = new Scanner(con.getInputStream());
		StringBuilder sb_apianswer = new StringBuilder();
		while(s.hasNextLine()) {
			sb_apianswer.append(s.nextLine()).append('\n');
		}
		s.close();
		if(con.getResponseCode() == 200) {
			return new JSONObject(sb_apianswer.toString());
		} else {
			String errdesc = "";
			try {
				JSONObject returned =  new JSONObject(sb_apianswer.toString());
				errdesc = returned.getString("description");
			} catch(Throwable ignore) { } 
			throw new IOException("API request returned HTTP " + con.getResponseCode() + " (" + con.getResponseMessage() + ") for action " + request + "\nurl: " + url.toString() + "\nparams: " + parameter + "\nerror description: " + errdesc);
		}
	}

	public TMessage sendMessage(TUser user, String text) {
		MessageBuilder builder = new MessageBuilder();
		builder.setReciver(user.getID());
		builder.setText(text);
		return sendMessage(builder.build());
	}

	public TMessage sendMessage(SendableMessage msg) {
		try {
			JSONObject o = request("sendMessage", msg.getQ());
			return new TMessage(o.getJSONObject("result"), this);
		} catch(IOException e) {
			log.log("",e);
		}
		return null;
	}
	public void sendTypedMessage(final String msg, final TUser user, final int seconds) {
		new Thread(new Runnable() {
			@Override
			public void run() {
				user.sendStatus(Status.Typing);
				try {
					Thread.sleep(seconds*1000);
				} catch (InterruptedException e) {
				}
				sendMessage(new MessageBuilder().setText(msg).setReciver(user.getID()).build());

			}
		}).start();	
	}

	public void stop() {
		run = false;
		thread.interrupt();
		Thread.yield();//try to not get into that loop
		while(isRunning()) {
			thread.interrupt();
			Thread.yield();
			try {
				Thread.sleep(10);
			} catch(InterruptedException e) {}
		}
		log.log("tapi stoped.");
		thread = null;
	}

	@Override
	public void run() {
		while(run) {
			fetchUpdates();
			try {
				Thread.sleep(updateInterval);
			} catch (InterruptedException e) {
				break;
			}
		}
	}

	public boolean isRunning() {
		return thread.isAlive();
	}

	private void fetchUpdates() {
		try {
			processUpdates(request("getUpdates", "offset=" + msg_offset));
		} catch (IOException e) {
			log.log("error getting updates.", e);
		}
	}

	private void processUpdates(JSONObject object) {
		if(object == null)
			return;
		JSONArray arr_results = object.getJSONArray("result");
		for(int i = 0; !arr_results.isNull(i); i++) {
			JSONObject entry = arr_results.getJSONObject(i);
			TelegramAPIUpdate upd = new TelegramAPIUpdate(entry, this);
			msg_offset = (upd.update_id+1 > msg_offset ? upd.update_id+1 : msg_offset);
		}
	}

	public TUser getUser(String name) {
		for(TUser us : users) {
			if(us.getName().equals(name))
				return us;
		}
		return null;
	}

	public TUser getUser(int id) {
		for(TUser us : users) {
			if(us.getID() == id)
				return us;
		}
		TUser u = new TUser(id, this);
		users.add(u);
		return u;
	}

	/**
	 * gets a user by id from the known user lists,
	 * if no user found, it creates a new User and adds it to the list.
	 * @param json
	 * @return
	 */
	public TUser getUser(JSONObject json) {
		int id = json.getInt("id");
		TUser user = getUser(id);
		if(user != null)
			return user;
		user = new TUser(json, this);
		users.add(user);
		return user;
	}

	public void setHelpText(String helptext) {
		helpmessage = ( helptext == null ? "" : helptext);
	}

	/**
	 * Set the logging method, use {@link Log4JLog} for usage of LOG4J,
	 * or {@link SimpleLog} for usage of System.out.println();
	 * use Null t odisable logging the default is {@link SimpleLog}
	 * @param l
	 */
	public void setLog(Log l) {
		if(l == null)
			log = new Log();
		else
			log = l;
	}

	public CommandManager getCommandManager() {
		return cmdmgr;
	}

	public EventManager getEventManager() {
		return evntmgr;
	}

	public void setUpdateInterval(int d) {
		if(d < 0)
			throw new IllegalArgumentException("UpdateInterval is not allowed to be negative.");
		updateInterval = d;
	}

	public String getHelpMessage() {
		return helpmessage;
	}

	public int getupdateInterval() {
		return updateInterval;
	}

	protected class TelegramAPIUpdate {
		protected int update_id = 0;
		private TMessage msg = null;
		private boolean isCommand = false;

		protected TelegramAPIUpdate(JSONObject json, TelegramAPI api) {
			update_id = json.getInt("update_id");

			if(json.has("message")) {
				msg = new TMessage(json.getJSONObject("message"), api);

				String text = msg.getText();
				if(text != null) {
					if(text.startsWith("/" )) {
						text = text.substring(1);//remove '/'
						isCommand = true;
						cmdmgr.onCommand(text, msg.getFrom(), json.getJSONObject("message"));
					} else {
						Event e = null;
						if(getMsg().has(Member.audio)) {
							e = new UserSendAudioEvent(getUser(), new TAudio((JSONObject) getMsg().get(Member.audio)));
						} else if(getMsg().has(Member.video)) {

						} else if(getMsg().has(Member.document)) {

						} else if(getMsg().has(Member.invoice)) {

						} else if(getMsg().has(Member.location)) {

						} else if(getMsg().has(Member.video_note)) {

						} else if(getMsg().has(Member.game)) {

						} else if(getMsg().has(Member.contact)) {

						} else if(getMsg().has(Member.sticker)) {

						} else {
							e = new UserSendMessageEvent(getMsg());
						}
						getEventManager().callEvent(e);
					}
				}
			} else if(json.has("callback_query")) {
				JSONObject cbq = json.getJSONObject("callback_query");
				TUser from = api.getUser(cbq.getJSONObject("from"));
				String data = cbq.getString("data");
				getEventManager().callEvent(new UserCallbackEvent(from, data));
			}
		}

		protected int getUpdate_id() {
			return update_id;
		}

		protected TMessage getMsg() {
			return msg;
		}

		protected TUser getUser() {
			return msg.getFrom();
		}

		protected boolean isCommand() {
			return isCommand;
		}
	}

	public enum JSONObjectType {
		User,
		Chat,
		Message,
		MessageEntity,
		Audio,
		Document,
		Game,
		Sticker,
		Video,
		Voice,
		Videonote,
		Location,
		Venue,
		Contact;

		boolean isArray = false;
		void setArray(boolean b) {
			isArray = b;
		}
	}

}