/*
 * Copyright 2015 the original author or authors.
 *
 * 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.statemachine.security;

import org.springframework.security.access.expression.AbstractSecurityExpressionHandler;
import org.springframework.security.access.expression.SecurityExpressionHandler;
import org.springframework.security.access.expression.SecurityExpressionOperations;
import org.springframework.security.authentication.AuthenticationTrustResolver;
import org.springframework.security.authentication.AuthenticationTrustResolverImpl;
import org.springframework.security.core.Authentication;
import org.springframework.statemachine.transition.Transition;
import org.springframework.util.Assert;

public class DefaultTransitionSecurityExpressionHandler extends AbstractSecurityExpressionHandler<Transition<?, ?>>
		implements SecurityExpressionHandler<Transition<?, ?>> {

	private AuthenticationTrustResolver trustResolver = new AuthenticationTrustResolverImpl();
	private String defaultRolePrefix = "ROLE_";

	@Override
	protected SecurityExpressionOperations createSecurityExpressionRoot(Authentication authentication, Transition<?, ?> transition) {
		TransitionSecurityExpressionRoot root = new TransitionSecurityExpressionRoot(authentication, transition);
		root.setPermissionEvaluator(getPermissionEvaluator());
		root.setTrustResolver(trustResolver);
		root.setRoleHierarchy(getRoleHierarchy());
		root.setDefaultRolePrefix(defaultRolePrefix);
		return root;
	}

	/**
	 * Sets the {@link AuthenticationTrustResolver} to be used. The default is
	 * {@link AuthenticationTrustResolverImpl}.
	 *
	 * @param trustResolver
	 *            the {@link AuthenticationTrustResolver} to use. Cannot be
	 *            null.
	 */
	public void setTrustResolver(AuthenticationTrustResolver trustResolver) {
		Assert.notNull(trustResolver, "trustResolver cannot be null");
		this.trustResolver = trustResolver;
	}

	/**
	 * <p>
	 * Sets the default prefix to be added to
	 * {@link org.springframework.security.access.expression.SecurityExpressionRoot#hasAnyRole(String...)}
	 * or
	 * {@link org.springframework.security.access.expression.SecurityExpressionRoot#hasRole(String)}
	 * . For example, if hasRole("ADMIN") or hasRole("ROLE_ADMIN") is passed in,
	 * then the role ROLE_ADMIN will be used when the defaultRolePrefix is
	 * "ROLE_" (default).
	 * </p>
	 *
	 * <p>
	 * If null or empty, then no default role prefix is used.
	 * </p>
	 *
	 * @param defaultRolePrefix
	 *            the default prefix to add to roles. Default "ROLE_".
	 */
	public void setDefaultRolePrefix(String defaultRolePrefix) {
		this.defaultRolePrefix = defaultRolePrefix;
	}

}
