/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.user2;
  
  import java.net.URLEncoder;
  import java.nio.charset.StandardCharsets;
  import java.util.HashMap;
  import java.util.LinkedHashMap;
  import java.util.Map.Entry;
  
  import org.mycore.common.MCRConstants;
  import org.mycore.common.MCRSessionMgr;
  import org.mycore.common.config.MCRConfiguration2;
  
  /**
   * Represents a realm of users. Each user belongs to a realm. Realms are configured 
   * in the file realms.xml. A realm determines the method that is used to login the user.
   * There is always a local default realm, which is defined by the attribute local in realms.xml.
   * 
   * @author Frank L\u00fctzenkirchen
   * @author Thomas Scheffler (yagee)
   */
  public class MCRRealm {
      /** The unique ID of the realm, e.g. 'local' */
      private String id;
  
      /** The labels of the realm */
      private HashMap<String, String> labels = new HashMap<>();
  
      /** The URL where users from this realm can change their password */
      private String passwordChangeURL;
  
      /** The URL where users from this realm can login */
      private String loginURL;
  
      /** The URL where new users may create an account for this realm  */
      private String createURL;
  
      private String redirectParameter;
  
      private String realmParameter;
  
      private static String DEFAULT_LANG = MCRConfiguration2.getString("MCR.Metadata.DefaultLang")
          .orElse(MCRConstants.DEFAULT_LANG);
  
      public static final String USER_INFORMATION_ATTR = "realmId";
  
      /** 
       * Creates a new realm.
       * 
       * @param id the unique ID of the realm
       */
      MCRRealm(String id) {
          this.id = id;
      }
  
      /**
       * Returns the unique ID of the realm.
       * 
       * @return the unique ID of the realm.
       */
      public String getID() {
          return id;
      }
  
      /**
       * Returns the label in the current language
       */
      public String getLabel() {
          String lang = MCRSessionMgr.getCurrentSession().getCurrentLanguage();
          String label = labels.get(lang);
          if (label != null) {
              return label;
          }
          label = labels.get(DEFAULT_LANG);
          if (label != null) {
              return label;
          }
          return id;
      }
  
      /**
       * Sets the label for the given language
      */
     void setLabel(String lang, String label) {
         labels.put(lang, label);
     }
 
     /** 
      * Returns the URL where users from this realm can change their password 
      */
     public String getPasswordChangeURL() {
         return passwordChangeURL;
     }
 
     /** 
      * Sets the URL where users from this realm can change their password 
      */
     void setPasswordChangeURL(String url) {
         this.passwordChangeURL = url;
     }
 
     /** 
      * Returns the URL where users from this realm can login 
      */
     public String getLoginURL() {
         return loginURL;
     }
 
     /** 
      * Sets the URL where users from this realm can login 
      */
     void setLoginURL(String url) {
         this.loginURL = url;
     }
 
     /**
      * @return the createURL
      */
     public String getCreateURL() {
         return createURL;
     }
 
     /**
      * @param createURL the createURL to set
      */
     void setCreateURL(String createURL) {
         this.createURL = createURL;
     }
 
     @Override
     public boolean equals(Object obj) {
         if (obj instanceof MCRRealm) {
             return ((MCRRealm) obj).id.equals(id);
         } else {
             return false;
         }
     }
 
     @Override
     public int hashCode() {
         return id.hashCode();
     }
 
     /* (non-Javadoc)
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString() {
         return "id=" + id + ", " + (loginURL != null ? "loginURL=" + loginURL : "");
     }
 
     /**
      * Returns the URL where users from this realm can login with redirect URL attached.
      * If this realm has a attribut <code>redirectParameter</code> defined this method returns
      * a complete login URL with <code>redirectURL</code> properly configured.
      * @param redirectURL URL where to redirect to after login succeeds.
      * @return the same as {@link #getLoginURL()} if <code>redirectParameter</code> is undefined for this realm
      */
     public String getLoginURL(String redirectURL) {
         LinkedHashMap<String, String> parameter = new LinkedHashMap<>();
         String redirect = getRedirectParameter();
         if (redirect != null && redirectURL != null) {
             parameter.put(redirect, redirectURL);
         }
         String realmParameter = getRealmParameter();
         if (realmParameter != null) {
             parameter.put(realmParameter, getID());
         }
         if (parameter.isEmpty()) {
             return getLoginURL();
         }
         StringBuilder loginURL = new StringBuilder(getLoginURL());
         boolean firstParameter = !getLoginURL().contains("?");
         for (Entry<String, String> entry : parameter.entrySet()) {
             if (firstParameter) {
                 loginURL.append('?');
                 firstParameter = false;
             } else {
                 loginURL.append('&');
             }
             loginURL.append(entry.getKey()).append('=').append(URLEncoder.encode(entry.getValue(),
                 StandardCharsets.UTF_8));
         }
         return loginURL.toString();
     }
 
     /**
      * @return the redirectParameter
      */
     String getRedirectParameter() {
         return redirectParameter;
     }
 
     /**
      * @param redirectParameter the redirectParameter to set
      */
     void setRedirectParameter(String redirectParameter) {
         this.redirectParameter = redirectParameter;
     }
 
     public String getRealmParameter() {
         return realmParameter;
     }
 
     public void setRealmParameter(String realmParameter) {
         this.realmParameter = realmParameter;
     }
 
 }