/*
 * 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
 *
 *      https://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.cache.interceptor;

import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;

import org.junit.Test;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.cache.annotation.AnnotationCacheOperationSource;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.cache.annotation.Caching;
import org.springframework.cache.concurrent.ConcurrentMapCache;
import org.springframework.context.expression.AnnotatedElementKey;
import org.springframework.context.support.StaticApplicationContext;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.util.ReflectionUtils;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

/**
 * @author Costin Leau
 * @author Phillip Webb
 * @author Sam Brannen
 * @author Stephane Nicoll
 */
public class ExpressionEvaluatorTests {

	private final CacheOperationExpressionEvaluator eval = new CacheOperationExpressionEvaluator();

	private final AnnotationCacheOperationSource source = new AnnotationCacheOperationSource();


	private Collection<CacheOperation> getOps(String name) {
		Method method = ReflectionUtils.findMethod(AnnotatedClass.class, name, Object.class, Object.class);
		return this.source.getCacheOperations(method, AnnotatedClass.class);
	}


	@Test
	public void testMultipleCachingSource() throws Exception {
		Collection<CacheOperation> ops = getOps("multipleCaching");
		assertEquals(2, ops.size());
		Iterator<CacheOperation> it = ops.iterator();
		CacheOperation next = it.next();
		assertTrue(next instanceof CacheableOperation);
		assertTrue(next.getCacheNames().contains("test"));
		assertEquals("#a", next.getKey());
		next = it.next();
		assertTrue(next instanceof CacheableOperation);
		assertTrue(next.getCacheNames().contains("test"));
		assertEquals("#b", next.getKey());
	}

	@Test
	public void testMultipleCachingEval() throws Exception {
		AnnotatedClass target = new AnnotatedClass();
		Method method = ReflectionUtils.findMethod(AnnotatedClass.class, "multipleCaching", Object.class,
				Object.class);
		Object[] args = new Object[] { new Object(), new Object() };
		Collection<ConcurrentMapCache> caches = Collections.singleton(new ConcurrentMapCache("test"));

		EvaluationContext evalCtx = eval.createEvaluationContext(caches, method, args,
				target, target.getClass(), null);
		Collection<CacheOperation> ops = getOps("multipleCaching");

		Iterator<CacheOperation> it = ops.iterator();

		AnnotatedElementKey key = new AnnotatedElementKey(method, AnnotatedClass.class);

		Object keyA = eval.key(it.next().getKey(), key, evalCtx);
		Object keyB = eval.key(it.next().getKey(), key, evalCtx);

		assertEquals(args[0], keyA);
		assertEquals(args[1], keyB);
	}

	@Test
	public void withReturnValue() throws Exception {
		EvaluationContext context = createEvaluationContext("theResult");
		Object value = new SpelExpressionParser().parseExpression("#result").getValue(context);
		assertThat(value, equalTo((Object) "theResult"));
	}

	@Test
	public void withNullReturn() throws Exception {
		EvaluationContext context = createEvaluationContext(null);
		Object value = new SpelExpressionParser().parseExpression("#result").getValue(context);
		assertThat(value, nullValue());
	}

	@Test
	public void withoutReturnValue() throws Exception {
		EvaluationContext context = createEvaluationContext(CacheOperationExpressionEvaluator.NO_RESULT);
		Object value = new SpelExpressionParser().parseExpression("#result").getValue(context);
		assertThat(value, nullValue());
	}

	@Test
	public void unavailableReturnValue() throws Exception {
		EvaluationContext context = createEvaluationContext(CacheOperationExpressionEvaluator.RESULT_UNAVAILABLE);
		try {
			new SpelExpressionParser().parseExpression("#result").getValue(context);
			fail("Should have failed to parse expression, result not available");
		}
		catch (VariableNotAvailableException e) {
			assertEquals("wrong variable name", "result", e.getName());
		}
	}

	@Test
	public void resolveBeanReference() throws Exception {
		StaticApplicationContext applicationContext = new StaticApplicationContext();
		BeanDefinition beanDefinition = new RootBeanDefinition(String.class);
		applicationContext.registerBeanDefinition("myBean", beanDefinition);
		applicationContext.refresh();

		EvaluationContext context = createEvaluationContext(CacheOperationExpressionEvaluator.NO_RESULT, applicationContext);
		Object value = new SpelExpressionParser().parseExpression("@myBean.class.getName()").getValue(context);
		assertThat(value, is(String.class.getName()));
	}

	private EvaluationContext createEvaluationContext(Object result) {
		return createEvaluationContext(result, null);
	}

	private EvaluationContext createEvaluationContext(Object result, BeanFactory beanFactory) {
		AnnotatedClass target = new AnnotatedClass();
		Method method = ReflectionUtils.findMethod(AnnotatedClass.class, "multipleCaching", Object.class,
				Object.class);
		Object[] args = new Object[] { new Object(), new Object() };
		Collection<ConcurrentMapCache> caches = Collections.singleton(new ConcurrentMapCache("test"));
		return eval.createEvaluationContext(caches, method, args, target, target.getClass(), result, beanFactory);
	}


	private static class AnnotatedClass {

		@Caching(cacheable = { @Cacheable(value = "test", key = "#a"), @Cacheable(value = "test", key = "#b") })
		public void multipleCaching(Object a, Object b) {
		}
	}

}
