/*
    * 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.access.mcrimpl;
  
  import java.util.Optional;
  import java.util.regex.Pattern;
  
  import org.jdom2.Element;
  import org.mycore.common.MCRSessionMgr;
  import org.mycore.common.MCRUserInformation;
  import org.mycore.parsers.bool.MCRCondition;
  
  /**
   * Implementation of a (user xy) clause
   * 
   * @author Matthias Kramm
   */
  class MCRUserClause implements MCRCondition<Object> {
      private String user;
  
      private Pattern userRegEx;
  
      private boolean not;
  
      MCRUserClause(String user, boolean not) {
          if (user.contains("*")) {
              userRegEx = toRegex(user);
          }
          this.user = user;
          this.not = not;
      }
  
      private Pattern toRegex(String userExp) {
          StringBuilder regex = new StringBuilder("^");
  
          for (int i = 0; i < userExp.length(); i++) {
              char c = userExp.charAt(i);
              if (c == '*') {
                  regex.append(".*");
              } else {
                  regex.append(c);
              }
          }
  
          regex = regex.append('$');
          return Pattern.compile(regex.toString());
      }
  
      public boolean evaluate(Object o) {
          MCRUserInformation userInformation = Optional.ofNullable(o)
              .filter(obj -> obj instanceof MCRAccessData)
              .map(MCRAccessData.class::cast)
              .map(MCRAccessData::getUserInformation)
              .orElseGet(MCRSessionMgr.getCurrentSession()::getUserInformation);
          if (userRegEx != null) {
              return userRegEx.matcher(userInformation.getUserID()).matches() ^ not;
          }
          return user.equals(userInformation.getUserID()) ^ not;
      }
  
      @Override
      public String toString() {
          return "user" + (not ? " != " : " = ") + user + " ";
      }
  
      public Element toXML() {
          Element cond = new Element("condition");
          cond.setAttribute("field", "user");
          cond.setAttribute("operator", (not ? "!=" : "="));
          cond.setAttribute("value", user);
          return cond;
      }
  }