/*
 * Copyright 2002-2016 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.security.access.expression.method;

import static org.assertj.core.api.Assertions.assertThat;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;

import org.aopalliance.intercept.MethodInvocation;
import org.junit.Test;
import org.springframework.security.access.AccessDecisionVoter;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.access.expression.method.PreInvocationExpressionAttribute;
import org.springframework.security.access.prepost.PreInvocationAuthorizationAdviceVoter;
import org.springframework.security.authentication.TestingAuthenticationToken;
import org.springframework.security.util.SimpleMethodInvocation;

@SuppressWarnings("unchecked")
public class MethodExpressionVoterTests {
	private TestingAuthenticationToken joe = new TestingAuthenticationToken("joe",
			"joespass", "ROLE_blah");
	private PreInvocationAuthorizationAdviceVoter am = new PreInvocationAuthorizationAdviceVoter(
			new ExpressionBasedPreInvocationAdvice());

	@Test
	public void hasRoleExpressionAllowsUserWithRole() throws Exception {
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingAnArray());
		assertThat(am.vote(joe, mi,
				createAttributes(new PreInvocationExpressionAttribute(null, null,
						"hasRole('blah')")))).isEqualTo(AccessDecisionVoter.ACCESS_GRANTED);
	}

	@Test
	public void hasRoleExpressionDeniesUserWithoutRole() throws Exception {
		List<ConfigAttribute> cad = new ArrayList<ConfigAttribute>(1);
		cad.add(new PreInvocationExpressionAttribute(null, null, "hasRole('joedoesnt')"));
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingAnArray());
		assertThat(am.vote(joe, mi, cad)).isEqualTo(AccessDecisionVoter.ACCESS_DENIED);
	}

	@Test
	public void matchingArgAgainstAuthenticationNameIsSuccessful() throws Exception {
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingAString(), "joe");
		assertThat(am.vote(joe, mi,
				createAttributes(new PreInvocationExpressionAttribute(null, null,
						"(#argument == principal) and (principal == 'joe')"))))
			.isEqualTo(AccessDecisionVoter.ACCESS_GRANTED);
	}

	@Test
	public void accessIsGrantedIfNoPreAuthorizeAttributeIsUsed() throws Exception {
		Collection arg = createCollectionArg("joe", "bob", "sam");
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingACollection(), arg);
		assertThat(am.vote(joe, mi,
				createAttributes(new PreInvocationExpressionAttribute(
						"(filterObject == 'jim')", "collection", null))))
			.isEqualTo(AccessDecisionVoter.ACCESS_GRANTED);
		// All objects should have been removed, because the expression is always false
		assertThat(arg).isEmpty();
	}

	@Test
	public void collectionPreFilteringIsSuccessful() throws Exception {
		List arg = createCollectionArg("joe", "bob", "sam");
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingACollection(), arg);
		am.vote(joe, mi, createAttributes(new PreInvocationExpressionAttribute(
				"(filterObject == 'joe' or filterObject == 'sam')", "collection",
				"permitAll")));
		assertThat(arg).containsExactly("joe","sam");
	}

	@Test(expected = IllegalArgumentException.class)
	public void arraysCannotBePrefiltered() throws Exception {
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingAnArray(), createArrayArg("sam", "joe"));
		am.vote(joe, mi, createAttributes(new PreInvocationExpressionAttribute(
				"(filterObject == 'jim')", "someArray", null)));
	}

	@Test(expected = IllegalArgumentException.class)
	public void incorrectFilterTargetNameIsRejected() throws Exception {
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingACollection(), createCollectionArg("joe", "bob"));
		am.vote(joe, mi, createAttributes(new PreInvocationExpressionAttribute(
				"(filterObject == 'joe')", "collcetion", null)));
	}

	@Test(expected = IllegalArgumentException.class)
	public void nullNamedFilterTargetIsRejected() throws Exception {
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingACollection(), new Object[] { null });
		am.vote(joe, mi, createAttributes(new PreInvocationExpressionAttribute(
				"(filterObject == 'joe')", "collection", null)));
	}

	@Test
	public void ruleDefinedInAClassMethodIsApplied() throws Exception {
		MethodInvocation mi = new SimpleMethodInvocation(new TargetImpl(),
				methodTakingAString(), "joe");
		assertThat(

		am.vote(joe, mi,
				createAttributes(new PreInvocationExpressionAttribute(null, null,
						"T(org.springframework.security.access.expression.method.SecurityRules).isJoe(#argument)"))))
								.isEqualTo(AccessDecisionVoter.ACCESS_GRANTED);
	}

	private List<ConfigAttribute> createAttributes(ConfigAttribute... attributes) {
		return Arrays.asList(attributes);
	}

	private List createCollectionArg(Object... elts) {
		ArrayList result = new ArrayList(elts.length);
		result.addAll(Arrays.asList(elts));
		return result;
	}

	private Object createArrayArg(Object... elts) {
		ArrayList result = new ArrayList(elts.length);
		result.addAll(Arrays.asList(elts));
		return result.toArray(new Object[0]);
	}

	private Method methodTakingAnArray() throws Exception {
		return Target.class.getMethod("methodTakingAnArray", Object[].class);
	}

	private Method methodTakingAString() throws Exception {
		return Target.class.getMethod("methodTakingAString", String.class);
	}

	private Method methodTakingACollection() throws Exception {
		return Target.class.getMethod("methodTakingACollection", Collection.class);
	}

	// ~ Inner Classes
	// ==================================================================================================

	private interface Target {
		void methodTakingAnArray(Object[] args);

		void methodTakingAString(String argument);

		Collection methodTakingACollection(Collection collection);
	}

	private static class TargetImpl implements Target {
		public void methodTakingAnArray(Object[] args) {
		}

		public void methodTakingAString(String argument) {
		};

		public Collection methodTakingACollection(Collection collection) {
			return collection;
		}
	}
}
