/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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.
   *
   */
  
  package org.opencastproject.userdirectory;
  
  import static org.opencastproject.security.api.SecurityConstants.GLOBAL_ADMIN_ROLE;
  
  import org.opencastproject.security.api.JaxbOrganization;
  import org.opencastproject.security.api.JaxbRole;
  import org.opencastproject.security.api.Organization;
  import org.opencastproject.security.api.Role;
  import org.opencastproject.security.api.Role.Type;
  import org.opencastproject.security.api.RoleProvider;
  import org.opencastproject.security.api.SecurityService;
  import org.opencastproject.security.api.UserProvider;
  
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Reference;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.List;
  import java.util.regex.Pattern;
  
  /**
   * The organization role provider returning the admin and anonymous role from the current organization.
   */
  @Component(
      property = {
          "service.description=Provides the organizations role"
      },
      immediate = true,
      service = { RoleProvider.class }
  )
  public class OrganizationRoleProvider implements RoleProvider {
  
    /** The security service */
    protected SecurityService securityService = null;
  
    /**
     * @param securityService
     *          the securityService to set
     */
    @Reference
    public void setSecurityService(SecurityService securityService) {
      this.securityService = securityService;
    }
  
    private Iterator<Role> getRoles() {
      Organization organization = securityService.getOrganization();
      List<Role> roles = new ArrayList<Role>();
      // The GLOBAL_ADMIN_ROLE is provided by the InMemoryUserAndRoleProvider
      if (!GLOBAL_ADMIN_ROLE.equals(organization.getAdminRole())) {
        roles.add(new JaxbRole(
            organization.getAdminRole(),
            JaxbOrganization.fromOrganization(organization),
            "",
            Type.INTERNAL
        ));
      }
      roles.add(new JaxbRole(
          organization.getAnonymousRole(),
          JaxbOrganization.fromOrganization(organization),
          "",
          Type.SYSTEM
      ));
      return roles.iterator();
    }
  
    /**
     * @see org.opencastproject.security.api.RoleProvider#getRolesForUser(String)
     */
    @Override
    public List<Role> getRolesForUser(String userName) {
      return Collections.emptyList();
    }
  
    /**
     * @see org.opencastproject.security.api.RoleProvider#getOrganization()
    */
   @Override
   public String getOrganization() {
     return UserProvider.ALL_ORGANIZATIONS;
   }
 
   /**
    * @see org.opencastproject.security.api.RoleProvider#findRoles(String, Role.Target, int, int)
    */
   @Override
   public Iterator<Role> findRoles(String query, Role.Target target, int offset, int limit) {
     if (query == null) {
       throw new IllegalArgumentException("Query must be set");
     }
     Organization organization = securityService.getOrganization();
     HashSet<Role> foundRoles = new HashSet<Role>();
     for (Iterator<Role> it = getRoles(); it.hasNext();) {
       Role role = it.next();
       // Anonymous roles are not relevant for adding to users or groups
       if ((target == Role.Target.USER) && role.getName().equals(organization.getAnonymousRole())) {
         continue;
       }
       if (like(role.getName(), query) || like(role.getDescription(), query)) {
         foundRoles.add(role);
       }
     }
     return offsetLimitCollection(offset, limit, foundRoles).iterator();
   }
 
   private <T> HashSet<T> offsetLimitCollection(int offset, int limit, HashSet<T> entries) {
     HashSet<T> result = new HashSet<T>();
     int i = 0;
     for (T entry : entries) {
       if (limit != 0 && result.size() >= limit) {
         break;
       }
       if (i >= offset) {
         result.add(entry);
       }
       i++;
     }
     return result;
   }
 
   private boolean like(String string, final String query) {
     if (string == null) {
       return false;
     }
     String regex = query.replace("_", ".").replace("%", ".*?");
     Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
     return p.matcher(string).matches();
   }
 
 }