/*
 * Copyright 2002-2019 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.test.context.support;

import java.lang.reflect.Method;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.springframework.context.ApplicationContext;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.style.ToStringCreator;
import org.springframework.lang.Nullable;
import org.springframework.test.annotation.DirtiesContext.HierarchyMode;
import org.springframework.test.context.CacheAwareContextLoaderDelegate;
import org.springframework.test.context.MergedContextConfiguration;
import org.springframework.test.context.TestContext;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;

/**
 * Default implementation of the {@link TestContext} interface.
 *
 * @author Sam Brannen
 * @author Juergen Hoeller
 * @author Rob Harrop
 * @since 4.0
 */
public class DefaultTestContext implements TestContext {

        private static final long serialVersionUID = -5827157174866681233L;

        private final Map<String, Object> attributes = new ConcurrentHashMap<>(4);

        private final CacheAwareContextLoaderDelegate cacheAwareContextLoaderDelegate;

        private final MergedContextConfiguration mergedContextConfiguration;

        private final Class<?> testClass;

        @Nullable
        private volatile Object testInstance;

        @Nullable
        private volatile Method testMethod;

        @Nullable
        private volatile Throwable testException;


        /**
         * <em>Copy constructor</em> for creating a new {@code DefaultTestContext}
         * based on the <em>attributes</em> and immutable state of the supplied context.
         * <p><em>Immutable state</em> includes all arguments supplied to the
         * {@linkplain #DefaultTestContext(Class, MergedContextConfiguration,
         * CacheAwareContextLoaderDelegate) standard constructor}.
         * @throws NullPointerException if the supplied {@code DefaultTestContext}
         * is {@code null}
         */
        public DefaultTestContext(DefaultTestContext testContext) {
                this(testContext.testClass, testContext.mergedContextConfiguration,
                        testContext.cacheAwareContextLoaderDelegate);
                this.attributes.putAll(testContext.attributes);
        }

        /**
         * Construct a new {@code DefaultTestContext} from the supplied arguments.
         * @param testClass the test class for this test context
         * @param mergedContextConfiguration the merged application context
         * configuration for this test context
         * @param cacheAwareContextLoaderDelegate the delegate to use for loading
         * and closing the application context for this test context
         */
        public DefaultTestContext(Class<?> testClass, MergedContextConfiguration mergedContextConfiguration,
                        CacheAwareContextLoaderDelegate cacheAwareContextLoaderDelegate) {

                Assert.notNull(testClass, "Test Class must not be null");
                Assert.notNull(mergedContextConfiguration, "MergedContextConfiguration must not be null");
                Assert.notNull(cacheAwareContextLoaderDelegate, "CacheAwareContextLoaderDelegate must not be null");
                this.testClass = testClass;
                this.mergedContextConfiguration = mergedContextConfiguration;
                this.cacheAwareContextLoaderDelegate = cacheAwareContextLoaderDelegate;
        }

        /**
         * Determine if the {@linkplain ApplicationContext application context} for
         * this test context is present in the context cache.
         * @return {@code true} if the application context has already been loaded
         * and stored in the context cache
         * @since 5.2
         * @see #getApplicationContext()
         * @see CacheAwareContextLoaderDelegate#isContextLoaded
         */
        @Override
        public boolean hasApplicationContext() {
                return this.cacheAwareContextLoaderDelegate.isContextLoaded(this.mergedContextConfiguration);
        }

        /**
         * Get the {@linkplain ApplicationContext application context} for this
         * test context.
         * <p>The default implementation delegates to the {@link CacheAwareContextLoaderDelegate}
         * that was supplied when this {@code TestContext} was constructed.
         * @throws IllegalStateException if the context returned by the context
         * loader delegate is not <em>active</em> (i.e., has been closed)
         * @see CacheAwareContextLoaderDelegate#loadContext
         */
        @Override
        public ApplicationContext getApplicationContext() {
                ApplicationContext context = this.cacheAwareContextLoaderDelegate.loadContext(this.mergedContextConfiguration);
                if (context instanceof ConfigurableApplicationContext) {
                        @SuppressWarnings("resource")
                        ConfigurableApplicationContext cac = (ConfigurableApplicationContext) context;
                        Assert.state(cac.isActive(), () ->
                                        "The ApplicationContext loaded for [" + this.mergedContextConfiguration +
                                        "] is not active. This may be due to one of the following reasons: " +
                                        "1) the context was closed programmatically by user code; " +
                                        "2) the context was closed during parallel test execution either " +
                                        "according to @DirtiesContext semantics or due to automatic eviction " +
                                        "from the ContextCache due to a maximum cache size policy.");
                }
                return context;
        }

        /**
         * Mark the {@linkplain ApplicationContext application context} associated
         * with this test context as <em>dirty</em> (i.e., by removing it from the
         * context cache and closing it).
         * <p>The default implementation delegates to the {@link CacheAwareContextLoaderDelegate}
         * that was supplied when this {@code TestContext} was constructed.
         * @see CacheAwareContextLoaderDelegate#closeContext
         */
        @Override
        public void markApplicationContextDirty(@Nullable HierarchyMode hierarchyMode) {
                this.cacheAwareContextLoaderDelegate.closeContext(this.mergedContextConfiguration, hierarchyMode);
        }

        @Override
        public final Class<?> getTestClass() {
                return this.testClass;
        }

        @Override
        public final Object getTestInstance() {
                Object testInstance = this.testInstance;
                Assert.state(testInstance != null, "No test instance");
                return testInstance;
        }

        @Override
        public final Method getTestMethod() {
                Method testMethod = this.testMethod;
                Assert.state(testMethod != null, "No test method");
                return testMethod;
        }

        @Override
        @Nullable
        public final Throwable getTestException() {
                return this.testException;
        }

        @Override
        public void updateState(@Nullable Object testInstance, @Nullable Method testMethod, @Nullable Throwable testException) {
                this.testInstance = testInstance;
                this.testMethod = testMethod;
                this.testException = testException;
        }

        @Override
        public void setAttribute(String name, @Nullable Object value) {
                Assert.notNull(name, "Name must not be null");
                synchronized (this.attributes) {
                        if (value != null) {
                                this.attributes.put(name, value);
                        }
                        else {
                                this.attributes.remove(name);
                        }
                }
        }

        @Override
        @Nullable
        public Object getAttribute(String name) {
                Assert.notNull(name, "Name must not be null");
                return this.attributes.get(name);
        }

        @Override
        @Nullable
        public Object removeAttribute(String name) {
                Assert.notNull(name, "Name must not be null");
                return this.attributes.remove(name);
        }

        @Override
        public boolean hasAttribute(String name) {
                Assert.notNull(name, "Name must not be null");
                return this.attributes.containsKey(name);
        }

        @Override
        public String[] attributeNames() {
                synchronized (this.attributes) {
                        return StringUtils.toStringArray(this.attributes.keySet());
                }
        }


        /**
         * Provide a String representation of this test context's state.
         */
        @Override
        public String toString() {
                return new ToStringCreator(this)
                                .append("testClass", this.testClass)
                                .append("testInstance", this.testInstance)
                                .append("testMethod", this.testMethod)
                                .append("testException", this.testException)
                                .append("mergedContextConfiguration", this.mergedContextConfiguration)
                                .append("attributes", this.attributes)
                                .toString();
        }

}