/*
    AV-Direktor - Control OMXPlayer on Raspberry Pi via HTTP
    Copyright (C) 2021  Ulrich Hilger

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

package de.uhilger.avdirektor.handler;

import de.uhilger.avdirektor.App;
import de.uhilger.avdirektor.MeldeThread;
import de.uhilger.avdirektor.ProzessLauscher;
import java.io.BufferedWriter;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Methoden zur Ausfuehrung des Programmes omxplayer des Raspberry Pi 
 * sowie zum Senden von Kommandos an eine laufende Instanz des 
 * omxplayer.
 * 
 * Die Klasse OMXPlayer stellt als abstrakte Basisklasse ihre Methoden 
 * den Handler-Klassen zur Verfuegung.
 *
 * @author ulrich
 */
public class OMXPlayer implements Player , ProzessLauscher {
  
  private static final Logger logger = Logger.getLogger(OMXPlayer.class.getName());
  
  public static final String NAME = "omxplayer";
  
  public static final String BLANK = " ";
  public static final String CMD_DEC_SPEED = "1";
  public static final String CMD_DEC_VOL = "-";
  public static final String CMD_INC_SPEED = "2";
  public static final String CMD_INC_VOL = "+";
  public static final String CMD_NEXT_AUDIO = "k";
  public static final String CMD_NEXT_CHAPTER = "o";
  public static final String CMD_NEXT_SUB = "m";
  public static final String CMD_PAUSE_RESUME = "p";
  public static final String CMD_PREV_AUDIO = "j";
  public static final String CMD_PREV_CHAPTER = "i";
  public static final String CMD_PREV_SUB = "n";
  public static final String CMD_STOP = "q";
  public static final String CMD_TOGGLE_SUB = "s";
  public static final String F_PING = "ping";
  public static final String F_PLAY = "play";
  public static final String F_PLAY_ON = "playon";
  public static final String F_SEEK = "seek";
  public static final String OPT_HDMI_AUDIO = "-o%20hdmi";
  public static final String OPT_LOCAL_AUDIO = "-o%20local";
  public static final String PFEIL_HERAUF = "5b41";
  public static final String PFEIL_HERUNTER = "5b42";
  public static final String PFEIL_LINKS = "5b44";
  public static final String PFEIL_RECHTS = "5b43";
  public static final String SP_RUECK_30 = "rueck30";
  public static final String SP_RUECK_600 = "rueck600";
  public static final String SP_VOR_30 = "rueck30";
  public static final String SP_VOR_600 = "vor600";

  @Override
  public String abspielen(String urlStr, String parameter, String meldeUrlStr, String token) {
    String antwort;// = null;
    try {
      Process o = App.getPlayerProcess();
      if(o != null) {
        tilgen();        
      }
      List<String> kommando = new ArrayList();
      kommando.add(NAME);
      kommando.addAll(Arrays.asList(parameter.split(BLANK)));
      if(urlStr.startsWith("http")) {
        kommando.add(urlStr.replace(" ", "%20"));
      } else {
        kommando.add(App.getInitParameter("nfs-prefix") + urlStr);        
      }      
      logger.log(Level.FINE, "parameter: {0}", parameter);
      logger.log(Level.FINE, "kommando: {0}", kommando.toString());
      ProcessBuilder pb = new ProcessBuilder(kommando);
      pb.directory(new File(System.getProperty("omx.wd")));
      Process player_process = pb.start();
      if(meldeUrlStr != null) {
        MeldeThread mt = new MeldeThread();
        mt.setProcess(player_process);
        mt.lauscherHinzufuegen(this);
        mt.setMeldeUrl(meldeUrlStr);
        mt.start();
      }
      App.setPlayerProcess(player_process);
      antwort = "Abspielen gestartet, url: " + urlStr;
    }
    catch(IOException ex) {
      antwort = "Fehler: " + ex.getMessage();
    }
    return antwort;
  }
    
  /**
   * Einen eventuell laufenden Abspielprozess beenden und den 
   * Servlet-Kontext bereinigen.Diese Methode kann auch verwendet werden, wenn es beim normalen
 Abspielen zu Fehlern kommt und womoeglich der Servlet-Kontext noch 
 eine Referenz zu einem Abspielprozess enthaelt, die nicht mehr 
 aktuell ist.
   * 
   * Mit der Methode tilgen kann man eine solche Referenz 
 entfernen und gibt so das Objekt wieder frei fuer die Ausfuehrung 
 weiterer Kommandos.
   *
   * @return die Antwort des Servers
   */
  @Override
  public String tilgen() {
    String antwort; // = null;
    try {
      Process o = App.getPlayerProcess();
      if(o == null) {
        antwort = "Es ist kein Player zum Beenden vorhanden, aber der Servlet-Kontext wurde bereinigt.";
        App.setPlayerProcess(null);
      } else {
        kommando(CMD_STOP); // setzt den Prozess der App auf null
        antwort = "Player gestoppt, Kontext bereinigt.";
      }
    } 
    catch(Exception ex) {
      antwort = "Fehler: " + ex.getMessage();
    }
    return antwort;
  }
  
  
  /**
   * Dem laufenden Abspielprozess ein Kommando uebermitteln
   * @param k  das Kommando laut 
   * <a href="https://github.com/huceke/omxplayer/blob/master/README.md" target="_blank">Liste der Kommandos</a>
   * @return die Antwort des Servers
   */
  @Override
  public String kommando(String k) {
    String antwort; // = null;
    try {
      //Object o = t.getAttribute(App.PI_PLAYER);
      Process o = App.getPlayerProcess();
      if(o == null) {
        App.setPlayerProcess(null);
        //servletContext.removeAttribute(PI_PLAYER);
        //t.setAttribute(App.PI_PLAYER, null);
        antwort = "Es wird nichts abgespielt dem ein Kommando gesendet werden kann.";
      } else {
        Process player_process = o;
        OutputStream os = player_process.getOutputStream();
        Writer out = new BufferedWriter(new OutputStreamWriter(os));
        out.write(k);
        out.flush();
        if(k.equals(CMD_STOP)) {
          out.close();
          App.setPlayerProcess(null);
          //player_process.destroy();
          //player_process = null;
          //t.setAttribute(App.PI_PLAYER, null);
          //servletContext.removeAttribute(PI_PLAYER);
        }
        antwort = "Kommando '" + k + "' ausgefuehrt.";
      }
    } 
    catch(IOException ex) {
      antwort = "Fehler: " + ex.getMessage();
    }
    return antwort;
  }
  
  /* ------ Implementierung ProzessLauscher ----------------- */
  
  @Override
  public void prozessBeendet(String meldeUrlStr) {
    try {
      HttpURLConnection conn = (HttpURLConnection) new URL(meldeUrlStr).openConnection();
      conn.setRequestMethod("GET");
      conn.connect();
      int status = conn.getResponseCode();
      logger.log(Level.INFO, 
              "Abspielen beendet, Meldung an {0} mit Statuscode {1} gesendet.", 
              new Object[]{meldeUrlStr, status});
      App.setPlayerProcess(null);
    } catch(IOException ex) {
      logger.log(Level.INFO, ex.getMessage(), ex);
    }
  }
  
}