/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.commons.configuration2.builder.combined;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertInstanceOf;
import static org.junit.jupiter.api.Assertions.assertSame;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.reset;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import static org.mockito.Mockito.when;

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

import org.apache.commons.configuration2.XMLConfiguration;
import org.apache.commons.configuration2.builder.BasicBuilderParameters;
import org.apache.commons.configuration2.builder.FileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.ReloadingFileBasedConfigurationBuilder;
import org.apache.commons.configuration2.builder.XMLBuilderParametersImpl;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.reloading.ReloadingController;
import org.apache.commons.configuration2.tree.ExpressionEngine;
import org.apache.commons.configuration2.tree.xpath.XPathExpressionEngine;
import org.junit.jupiter.api.Test;

/**
 * Test class for {@code ReloadingMultiFileConfigurationBuilder}.
 */
public class TestReloadingMultiFileConfigurationBuilder extends AbstractMultiFileConfigurationBuilderTest {

    /**
     * A test implementation of the class under test which allows access to reloading controllers of managed configuration
     * builders.
     */
    private static final class ReloadingMultiFileConfigurationBuilderTestImpl extends ReloadingMultiFileConfigurationBuilder<XMLConfiguration> {

        /**
         * A list with mocks for reloading controllers created by this instance.
         */
        private final List<ReloadingController> reloadingControllers;

        public ReloadingMultiFileConfigurationBuilderTestImpl() {
            super(XMLConfiguration.class, createTestBuilderParameters(null).getParameters());
            reloadingControllers = new ArrayList<>();
        }

        /**
         * {@inheritDoc} This implementation creates a specialized reloading builder which is associated with a mock reloading
         * controller.
         */
        @Override
        protected FileBasedConfigurationBuilder<XMLConfiguration> createManagedBuilder(final String fileName, final Map<String, Object> params)
            throws ConfigurationException {
            final ReloadingController ctrl = mock(ReloadingController.class);
            reloadingControllers.add(ctrl);
            return new ReloadingFileBasedConfigurationBuilder<XMLConfiguration>(getResultClass(), params) {
                @Override
                public ReloadingController getReloadingController() {
                    return ctrl;
                }
            };
        }

        /**
         * Returns the list with the mock reloading controllers for the managed configuration builders created by this instance.
         *
         * @return the list with mock reloading controllers
         */
        public List<ReloadingController> getReloadingControllers() {
            return reloadingControllers;
        }
    }

    /**
     * Tests whether correct managed builders are created.
     */
    @Test
    void testCreateManagedBuilder() throws ConfigurationException {
        final ReloadingMultiFileConfigurationBuilder<XMLConfiguration> builder = new ReloadingMultiFileConfigurationBuilder<>(XMLConfiguration.class);
        final FileBasedConfigurationBuilder<XMLConfiguration> managedBuilder = builder.createManagedBuilder("test.xml",
            createTestBuilderParameters(null).getParameters());
        assertInstanceOf(ReloadingFileBasedConfigurationBuilder.class, managedBuilder);
        assertFalse(managedBuilder.isAllowFailOnInit());
    }

    /**
     * Tests whether the allowFailOnInit flag is passed to newly created managed builders.
     */
    @Test
    void testCreateManagedBuilderWithAllowFailFlag() throws ConfigurationException {
        final ReloadingMultiFileConfigurationBuilder<XMLConfiguration> builder = new ReloadingMultiFileConfigurationBuilder<>(XMLConfiguration.class, null,
            true);
        final FileBasedConfigurationBuilder<XMLConfiguration> managedBuilder = builder.createManagedBuilder("test.xml",
            createTestBuilderParameters(null).getParameters());
        assertTrue(managedBuilder.isAllowFailOnInit());
    }

    /**
     * Tests whether parameters passed to the constructor are passed to the super class.
     */
    @Test
    void testInitWithParameters() throws ConfigurationException {
        final ExpressionEngine engine = new XPathExpressionEngine();
        final BasicBuilderParameters params = createTestBuilderParameters(new XMLBuilderParametersImpl().setExpressionEngine(engine));
        final ReloadingMultiFileConfigurationBuilder<XMLConfiguration> builder = new ReloadingMultiFileConfigurationBuilder<>(XMLConfiguration.class,
            params.getParameters());
        switchToConfig(1);
        final XMLConfiguration config = builder.getConfiguration();
        assertSame(engine, config.getExpressionEngine());
    }

    /**
     * Tests whether a reloading check works correctly.
     */
    @Test
    void testReloadingControllerCheck() throws ConfigurationException {
        final ReloadingMultiFileConfigurationBuilderTestImpl builder = new ReloadingMultiFileConfigurationBuilderTestImpl();
        switchToConfig(1);
        builder.getConfiguration();
        switchToConfig(2);
        builder.getConfiguration();
        final List<ReloadingController> controllers = builder.getReloadingControllers();
        assertEquals(2, controllers.size());

        for (final ReloadingController c : controllers) {
            reset(c);
            when(c.checkForReloading(null)).thenReturn(Boolean.FALSE);
        }

        assertFalse(builder.getReloadingController().checkForReloading(this));

        for (final ReloadingController c : controllers) {
            verify(c).checkForReloading(null);
            verifyNoMoreInteractions(c);
        }
    }

    /**
     * Tests a reloading check which detects the need to reload.
     */
    @Test
    void testReloadingControllerCheckReloadingRequired() throws ConfigurationException {
        final ReloadingMultiFileConfigurationBuilderTestImpl builder = new ReloadingMultiFileConfigurationBuilderTestImpl();
        for (int i = 1; i <= 3; i++) {
            switchToConfig(i);
            builder.getConfiguration();
        }
        final List<ReloadingController> controllers = builder.getReloadingControllers();

        reset(controllers.toArray());
        when(controllers.get(0).checkForReloading(null)).thenReturn(Boolean.FALSE);
        when(controllers.get(1).checkForReloading(null)).thenReturn(Boolean.TRUE);
        when(controllers.get(2).checkForReloading(null)).thenReturn(Boolean.FALSE);

        assertTrue(builder.getReloadingController().checkForReloading(this));

        for (final ReloadingController c : controllers) {
            verify(c).checkForReloading(null);
            verifyNoMoreInteractions(c);
        }
    }

    /**
     * Tests whether the reloading state of the reloading controller can be reset.
     */
    @Test
    void testReloadingControllerResetReloadingState() throws ConfigurationException {
        final ReloadingMultiFileConfigurationBuilderTestImpl builder = new ReloadingMultiFileConfigurationBuilderTestImpl();
        switchToConfig(1);
        builder.getConfiguration();
        switchToConfig(2);
        builder.getConfiguration();
        final List<ReloadingController> controllers = builder.getReloadingControllers();

        reset(controllers.toArray());
        for (final ReloadingController c : controllers) {
            when(c.checkForReloading(null)).thenReturn(Boolean.TRUE);
        }

        builder.getReloadingController().checkForReloading(null);
        builder.getReloadingController().resetReloadingState();

        for (final ReloadingController c : controllers) {
            verify(c).checkForReloading(null);
            verify(c).resetReloadingState();
            verifyNoMoreInteractions(c);
        }
    }
}
