/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * 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.
 */
package org.springframework.security.cas.userdetails;

import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.User;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.GrantedAuthorityImpl;
import org.springframework.util.Assert;
import org.jasig.cas.client.validation.Assertion;

import java.util.List;
import java.util.ArrayList;

/**
 * Populates the {@link org.springframework.security.core.GrantedAuthority}s for a user by reading a list of attributes that were returned as
 * part of the CAS response.  Each attribute is read and each value of the attribute is turned into a GrantedAuthority.  If the attribute has no
 * value then its not added.
 *
 * @author Scott Battaglia
 * @since 3.0
 */
public final class GrantedAuthorityFromAssertionAttributesUserDetailsService extends AbstractCasAssertionUserDetailsService {

    private static final String NON_EXISTENT_PASSWORD_VALUE = "NO_PASSWORD";

    private final String[] attributes;

    private boolean convertToUpperCase = true;

    public GrantedAuthorityFromAssertionAttributesUserDetailsService(final String[] attributes) {
        Assert.notNull(attributes, "attributes cannot be null.");
        Assert.isTrue(attributes.length > 0, "At least one attribute is required to retrieve roles from.");
        this.attributes = attributes;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected UserDetails loadUserDetails(final Assertion assertion) {
        final List<GrantedAuthority> grantedAuthorities = new ArrayList<GrantedAuthority>();

        for (final String attribute : this.attributes) {
            final Object value = assertion.getPrincipal().getAttributes().get(attribute);

            if (value == null) {
                continue;
            }

            if (value instanceof List) {
                final List list = (List) value;

                for (final Object o : list) {
                    grantedAuthorities.add(new GrantedAuthorityImpl(this.convertToUpperCase ? o.toString().toUpperCase() : o.toString()));
                }

            } else {
                grantedAuthorities.add(new GrantedAuthorityImpl(this.convertToUpperCase ? value.toString().toUpperCase() : value.toString()));
            }

        }

        return new User(assertion.getPrincipal().getName(), NON_EXISTENT_PASSWORD_VALUE, true, true, true, true, grantedAuthorities);
    }

    /**
     * Converts the returned attribute values to uppercase values.
     *
     * @param convertToUpperCase true if it should convert, false otherwise.
     */
    public void setConvertToUpperCase(final boolean convertToUpperCase) {
        this.convertToUpperCase = convertToUpperCase;
    }
}
