/*
  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 static de.uhilger.tango.App.RB_EP_LISTE;
import static de.uhilger.tango.App.RB_EP_LISTE_ALLES;
import de.uhilger.tango.Server;
import de.uhilger.tango.entity.Ablageort;
import de.uhilger.tango.store.FileStorage;
import de.uhilger.tango.entity.Entity;
import de.uhilger.tango.entity.Geraet;
import static de.uhilger.tango.store.FileStorage.ST_ABLAGEORT;
import static de.uhilger.tango.store.FileStorage.ST_GERAET;
import de.uhilger.tango.store.Storage;
import java.io.IOException;
import java.net.URI;
import java.util.Iterator;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import java.net.http.HttpClient;
import java.net.http.HttpClient.Version;
import java.net.http.HttpClient.Redirect;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpResponse.BodyHandlers;
import java.time.Duration;
import java.util.ArrayList;


/**
 * HttpHandler fuer die Verwaltung von Entitaeten der Mediazentrale
 * 
 * GET /mz/api/store/[typname]/[name]
 * GET /mz/api/store/[typname]/liste
 * GET /mz/api/store/[typname]/listealles  (nur Typ Geraet)
 * 
 * @author Ulrich Hilger
 * @version 1, 5.4.2021
 */
public class StorageHandler extends AbstractHandler {
  
  private static final Logger logger = Logger.getLogger(StorageHandler.class.getName());

  @Override
  protected String put(HttpExchange e) throws IOException {
    String path = e.getRequestURI().toString();
    String[] elems = path.split(Server.SLASH);
    String type = elems[elems.length - 2];
    String elemName = elems[elems.length - 1]; // alter Name, wenn Aenderung
    if(!elemName.equalsIgnoreCase(App.getRs(RB_EP_LISTE))) {
      FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF)));
      Gson gson = new Gson();
      logger.log(Level.FINE, "type: {0}, token: {1}", new Object[]{type, fs.typeFromName(type).getType().getTypeName()});
      Object o = gson.fromJson(bodyLesen(e), fs.typeFromName(type).getType());
      if(o instanceof Entity) {
        Entity entity = (Entity) o;
        if(fs.exists(type, elemName)) { // Aenderung
          fs.delete(type, elemName);
          // wenn Ablageort, hier noch alten Kontext entfernen
          if(type.equalsIgnoreCase(FileStorage.ST_ABLAGEORT)) {
            Entity aoe = fs.read(type, elemName);
            if(aoe instanceof Ablageort) {
              Ablageort ablageort = (Ablageort) aoe;
              App.getServer().ablageortEntfernen(ablageort.getUrl());      
            }
          }
          fs.write(entity, true);
          // wenn Ablageort, hier noch neuen Kontext anlegen
          if(type.equalsIgnoreCase(FileStorage.ST_ABLAGEORT)) {
            if(entity instanceof Ablageort) {
              Ablageort ablageort = (Ablageort) entity;
              App.getServer().ablageortHinzufuegen(ablageort);
            }
          }
        } else { // Neu
          fs.write(entity, false);
          // wenn Ablageort, hier noch neuen Kontext anlegen
          if(type.equalsIgnoreCase(FileStorage.ST_ABLAGEORT)) {
            if(entity instanceof Ablageort) {
              Ablageort ablageort = (Ablageort) entity;
              App.getServer().ablageortHinzufuegen(ablageort);
            }
          }
        }
        return type + Server.SLASH + entity.getName();
      } else {
        return "Ungueltiges Objekt im Body.";
      }
    } else {
      return "Ungueltiger Elementname: " + App.getRs(RB_EP_LISTE);
    }
  }
  
  private boolean loeschen(HttpExchange e) {
    String path = e.getRequestURI().toString();
    String[] elems = path.split(Server.SLASH);
    String type = elems[elems.length - 2];
    String elemName = elems[elems.length - 1];
    FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF)));
    if(type.equalsIgnoreCase(FileStorage.ST_ABLAGEORT)) {
      // im laufenden Server den Context entfernen
      Entity entity = fs.read(type, elemName);
      if(entity instanceof Ablageort) {
        Ablageort ablageort = (Ablageort) entity;
        App.getServer().ablageortEntfernen(ablageort.getUrl());      
      }
    }
    return fs.delete(type, elemName);
  }
  
  private String lesen(HttpExchange e) throws IOException, InterruptedException {
    String path = e.getRequestURI().toString();
    String[] elems = path.split(Server.SLASH);
    FileStorage fs = new FileStorage(App.getInitParameter(App.getRs(App.RB_AP_CONF)));
    if(path.endsWith(Server.SLASH)) {
      List list = null;
      if(elems[elems.length - 1].equalsIgnoreCase(App.getRs(RB_EP_LISTE_ALLES))) {
        String type = elems[elems.length - 2];
        logger.fine(type);
        if(type.equalsIgnoreCase(ST_GERAET)) {
          list = collectDeviceStatus(fs, type);
          Gson gson = new Gson();
          Object o = gson.fromJson(bodyLesen(e), fs.typeFromName(type).getType());
          return gson.toJson(list);
        }
      } else if(elems[elems.length - 1].equalsIgnoreCase(App.getRs(RB_EP_LISTE))) {
        String type = elems[elems.length - 2];
        logger.fine(type);
        list = fs.list(type);
        if(type.equalsIgnoreCase(ST_ABLAGEORT)) {
          list.add("Livestreams");
        }
      } else {
        String type = elems[elems.length - 1];
        logger.fine(type);
        list = fs.listObjects(type);
      }
      return jsonWithEnclosingType(list);
    } else {
      String type = elems[elems.length - 2];
      String elemName = elems[elems.length - 1];
      return fs.readJson(type, elemName);
    }
  }
  
  @Override
  public String get(HttpExchange e) {
    try {
      return lesen(e);
    } catch (IOException | InterruptedException ex) {
      Logger.getLogger(StorageHandler.class.getName()).log(Level.SEVERE, null, ex);
      return ex.getLocalizedMessage();
    }
  }

  @Override
  public String post(HttpExchange e) {
    return "nicht unterstuetzt";
  }

  @Override
  public boolean delete(HttpExchange e) {
    return loeschen(e);
  }
  
  private List collectDeviceStatus(Storage fs, String type) throws IOException, InterruptedException {
    List list = fs.listObjects(type);
    List<Geraet> newList = new ArrayList();
    Iterator<Entity> i = list.iterator();
    while (i.hasNext()) {
      Entity entity = i.next();
      if (entity instanceof Geraet) {
        Geraet g = (Geraet) entity;
        String statusurl = g.getStatusUrl();
        logger.info(statusurl);

        HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create(statusurl))
                .build();
        HttpClient client = HttpClient.newBuilder()
                .version(Version.HTTP_1_1)
                .followRedirects(Redirect.NORMAL)
                .connectTimeout(Duration.ofSeconds(20))
                //.proxy(ProxySelector.of(new InetSocketAddress("proxy.example.com", 80)))
                //.authenticator(Authenticator.getDefault())
                .build();
        HttpResponse<String> response = client.send(request, BodyHandlers.ofString());
        logger.finer(Integer.toString(response.statusCode()));
        logger.finer(response.body());
        // {"ison":false,"has_timer":false,"overpower":false}
        String[] parts = response.body().split(",")[0].split(":");
        logger.finer("ison: " + parts[1]);
        g.setStatus(Boolean.parseBoolean(parts[1]));
        newList.add(g);
      }
    }
    return newList;
  }
}