/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2018 wcm.io
    * %%
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  package io.wcm.tooling.commons.packmgr.install.crx;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.commons.lang3.StringUtils;
  import org.json.JSONArray;
  import org.json.JSONException;
  import org.json.JSONObject;
  
  import io.wcm.tooling.commons.packmgr.PackageManagerException;
  
  /**
   * Check if given package and version is already installed by inspecting the JSON result of
   * <code>/crx/packmgr/list.jsp</code>.
   */
  class PackageInstalledChecker {
  
    private final JSONArray results;
  
    static final String PACKMGR_LIST_URL = "/crx/packmgr/list.jsp";
  
    private static final long NOT_FOUND_DATE = -1;
    private static final long NOT_UNPACKED_DATE = 0;
  
    PackageInstalledChecker(JSONObject result) {
      try {
        this.results = result.getJSONArray("results");
      }
      catch (JSONException ex) {
        throw new PackageManagerException("JSON response from " + PACKMGR_LIST_URL + " does not contain 'results' array.", ex);
      }
    }
  
    public PackageInstalledStatus getStatus(String group, String name, String version) {
      Map<String, Long> map = getVersionUnpackedDates(group, name);
  
      if (map.isEmpty()) {
        return PackageInstalledStatus.NOT_FOUND;
      }
  
      long versionUnpackDate = getVersionUnpackDate(map, version);
      if (versionUnpackDate == NOT_FOUND_DATE) {
        return PackageInstalledStatus.NOT_FOUND;
      }
      if (versionUnpackDate == NOT_UNPACKED_DATE) {
        return PackageInstalledStatus.UPLOADED;
      }
  
      long lastUnpackDate = getLastUnpackDate(map);
      if (lastUnpackDate > versionUnpackDate) {
        return PackageInstalledStatus.INSTALLED_OTHER_VERSION;
      }
      else {
        return PackageInstalledStatus.INSTALLED;
      }
    }
  
    private Map<String, Long> getVersionUnpackedDates(String group, String name) {
      Map<String, Long> map = new HashMap<>();
      for (int i = 0; i < results.length(); i++) {
        JSONObject item = results.getJSONObject(i);
        String itemGroup = item.optString("group");
        String itemName = item.optString("name");
        String itemVersion = item.optString("version");
        long itemLastUnpacked = item.optLong("lastUnpacked", NOT_UNPACKED_DATE);
        if (StringUtils.equals(group, itemGroup) && StringUtils.equals(name, itemName) && StringUtils.isNotBlank(itemVersion)) {
          map.put(itemVersion, itemLastUnpacked);
        }
      }
      return map;
    }
  
    private long getVersionUnpackDate(Map<String, Long> map, String version) {
      Long value = map.get(version);
      if (value == null) {
        return NOT_FOUND_DATE;
      }
      else {
        return value;
     }
   }
 
   private long getLastUnpackDate(Map<String, Long> map) {
     long last = 0;
     for (Long date : map.values()) {
       if (date > last) {
         last = date;
       }
     }
     return last;
   }
 
 }