/*
  Tango - Personal Media Center
  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.tango.api;

import com.google.gson.Gson;
import com.sun.net.httpserver.HttpExchange;
import de.uhilger.tango.App;
import de.uhilger.tango.Server;
import de.uhilger.tango.entity.Abspielliste;
import de.uhilger.tango.entity.Entity;
import de.uhilger.tango.entity.Titel;
import de.uhilger.tango.store.FileStorage;
import java.io.IOException;
import java.util.logging.Logger;

/**
 * Der ListHandler bearbeitet HTTP-Anfragen zu Abspiellisten
 * 
 * GET /mz/api/alist/[pl-name]          die Titel-Objekte der Liste [pl-name] liefern
 * PUT /mz/api/alist/[pl-name]          den Titel im Body anfuegen an die Liste [pl-name]
 * PUT /mz/api/alist/[pl-name]/[nr]     an der Position nr der Liste [pl-name] den Titel im Body einfuegen
 * DELETE /mz/api/alist/[pl-name]/[nr]  den Titel an der Position [nr] aus der Liste [pl-name] entfernen  
 * DELETE /mz/api/alist/[pl-name]/alle  alle Titel aus der Liste [pl-name] entfernen  
 *
 * @author Ulrich Hilger
 * @version 1, 8.4.2021
 */
public class ListHandler extends AbstractHandler {
  
  private static final Logger logger = Logger.getLogger(ListHandler.class.getName());
  
  public static final String ALLE_TITEL = "alle";


  @Override
  protected String get(HttpExchange e) {
    String path = e.getRequestURI().toString();
    String[] elems = path.split(Server.SLASH);
    String plname = elems[elems.length - 1];
    FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF)));
    String json = fs.readJson(FileStorage.ST_ABSPIELLISTE, plname);
    return embedInCustomType(json, FileStorage.ST_ABSPIELLISTE);
  }

  @Override
  protected String put(HttpExchange e) throws IOException {
    String path = e.getRequestURI().toString();
    String[] elems = path.split(Server.SLASH);
    String response = "ListHandler.put: ungueltiger URL";
    switch(elems.length) {
      case 5: // ohne nr am Ende
        response = addTitel(e, elems[4]);
        break;
        
      case 6:
        response = "Einfuegen noch nicht fertig.";
        break;
    }
    return response;
  }
  
  private String addTitel(HttpExchange e, String plname) throws IOException {
    FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF)));
    Entity entity = fs.read(FileStorage.ST_ABSPIELLISTE, plname);
    String response = "Titel konnte nicht hinzugefuegt werden.";
    if(entity instanceof Abspielliste) {
      Abspielliste aliste = (Abspielliste) entity;
      String titelJson = bodyLesen(e);
      Gson gson = new Gson();
      Object o = gson.fromJson(titelJson, fs.typeFromName(Titel.class.getSimpleName()).getType());
      if(o instanceof Titel) {
        Titel titel = (Titel) o;
        aliste.addTitel(titel);
        fs.write(aliste, true);
        response = "Titel " + titel.getName() + " der Liste " + aliste.getName() + " hinzugefuegt.";
      }
    }
    return response;
  }

  @Override
  protected String post(HttpExchange e) {
    throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
  }

  // DELETE /mz/api/alist/[pl-name]/[nr]  den Titel an der Position [nr] aus der Liste [pl-name] entfernen  
  @Override
  protected boolean delete(HttpExchange e) {
    String path = e.getRequestURI().toString();
    String[] elems = path.split(Server.SLASH);
    String listName = elems[elems.length - 2];
    FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF)));
    Entity entity = fs.read(Abspielliste.class.getSimpleName(), listName);
    if(entity instanceof Abspielliste) {
      Abspielliste liste = (Abspielliste) entity;
      String titelStr = elems[elems.length-1];
      if(titelStr.equalsIgnoreCase(ALLE_TITEL)) {
        liste.getTitel().clear();
      } else {
        liste.getTitel().remove(Integer.parseInt(elems[elems.length-1]));
      }
      fs.write(liste, true);
      return true;
    } else {
      return false;
    }
  }
  
}