/*
    * 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;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertInstanceOf;
  import static org.junit.jupiter.api.Assertions.assertNotSame;
  import static org.junit.jupiter.api.Assertions.assertSame;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  import static org.mockito.Mockito.mock;
  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.Arrays;
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.NoSuchElementException;
  import java.util.Set;
  
  import org.apache.commons.configuration2.convert.DefaultListDelimiterHandler;
  import org.apache.commons.configuration2.convert.DisabledListDelimiterHandler;
  import org.apache.commons.configuration2.convert.ListDelimiterHandler;
  import org.apache.commons.configuration2.interpol.ConfigurationInterpolator;
  import org.apache.commons.configuration2.tree.ImmutableNode;
  import org.apache.commons.configuration2.tree.InMemoryNodeModel;
  import org.apache.commons.configuration2.tree.NodeSelector;
  import org.apache.commons.configuration2.tree.NodeStructureHelper;
  import org.apache.commons.configuration2.tree.TrackedNodeModel;
  import org.apache.commons.configuration2.tree.xpath.XPathExpressionEngine;
  import org.junit.jupiter.api.BeforeEach;
  import org.junit.jupiter.api.Test;
  
  /**
   * Test case for SubnodeConfiguration.
   */
  public class TestSubnodeConfiguration {
  
      /** The key used for the SubnodeConfiguration. */
      private static final String SUB_KEY = "tables.table(0)";
  
      /** The selector used by the test configuration. */
      private static final NodeSelector SELECTOR = new NodeSelector(SUB_KEY);
  
      /**
       * Adds a tree structure to the root node of the given configuration.
       *
       * @param configuration the configuration
       * @param root the root of the tree structure to be added
       */
      private static void appendTree(final BaseHierarchicalConfiguration configuration, final ImmutableNode root) {
          configuration.addNodes(null, Collections.singleton(root));
      }
  
      /**
       * Initializes the parent configuration. This method creates the typical structure of tables and fields nodes.
       *
       * @return the parent configuration
       */
      private static BaseHierarchicalConfiguration setUpParentConfig() {
          final BaseHierarchicalConfiguration conf = new BaseHierarchicalConfiguration();
          appendTree(conf, NodeStructureHelper.ROOT_TABLES_TREE);
          return conf;
      }
  
      /** The parent configuration. */
      private BaseHierarchicalConfiguration parent;
  
      /** The subnode configuration to be tested. */
      private SubnodeConfiguration config;
  
      /**
       * Helper method for testing interpolation facilities between a sub and its parent configuration.
       *
       * @param withUpdates the supports updates flag
       */
      private void checkInterpolationFromConfigurationAt(final boolean withUpdates) {
          parent.addProperty("base.dir", "/home/foo");
          parent.addProperty("test.absolute.dir.dir1", "${base.dir}/path1");
          parent.addProperty("test.absolute.dir.dir2", "${base.dir}/path2");
          parent.addProperty("test.absolute.dir.dir3", "${base.dir}/path3");
  
         final Configuration sub = parent.configurationAt("test.absolute.dir", withUpdates);
         for (int i = 1; i < 4; i++) {
             assertEquals("/home/foo/path" + i, parent.getString("test.absolute.dir.dir" + i));
             assertEquals("/home/foo/path" + i, sub.getString("dir" + i));
         }
     }
 
     /**
      * Checks whether the sub configuration has the expected content.
      */
     private void checkSubConfigContent() {
         assertEquals(NodeStructureHelper.table(0), config.getString("name"));
         final List<Object> fields = config.getList("fields.field.name");
 
         final List<String> expected = new ArrayList<>();
         for (int i = 0; i < NodeStructureHelper.fieldsLength(0); i++) {
             expected.add(NodeStructureHelper.field(0, i));
         }
         assertEquals(expected, fields);
     }
 
     @BeforeEach
     public void setUp() throws Exception {
         parent = setUpParentConfig();
     }
 
     /**
      * Performs a standard initialization of the subnode config to test.
      */
     private void setUpSubnodeConfig() {
         setUpSubnodeConfig(SUB_KEY);
     }
 
     /**
      * Initializes the test configuration using the specified key.
      *
      * @param key the key
      */
     private void setUpSubnodeConfig(final String key) {
         config = (SubnodeConfiguration) parent.configurationAt(key, true);
     }
 
     /**
      * Sets up the tracked model for the sub configuration.
      *
      * @param selector the selector
      * @return the tracked model
      */
     private TrackedNodeModel setUpTrackedModel(final NodeSelector selector) {
         final InMemoryNodeModel parentModel = (InMemoryNodeModel) parent.getModel();
         parentModel.trackNode(selector, parent);
         return new TrackedNodeModel(parent, selector, true);
     }
 
     /**
      * Tests adding of properties.
      */
     @Test
     void testAddProperty() {
         setUpSubnodeConfig();
         config.addProperty("[@table-type]", "test");
         assertEquals("test", parent.getString("tables.table(0)[@table-type]"));
 
         parent.addProperty("tables.table(0).fields.field(-1).name", "newField");
         final List<Object> fields = config.getList("fields.field.name");
         assertEquals(NodeStructureHelper.fieldsLength(0) + 1, fields.size());
         assertEquals("newField", fields.get(fields.size() - 1));
     }
 
     /**
      * Tests whether a clone of a sub configuration can be created.
      */
     @Test
     void testClone() {
         setUpSubnodeConfig();
         final SubnodeConfiguration copy = (SubnodeConfiguration) config.clone();
         assertNotSame(config.getModel(), copy.getModel());
         final TrackedNodeModel subModel = (TrackedNodeModel) copy.getModel();
         assertEquals(SELECTOR, subModel.getSelector());
         final InMemoryNodeModel parentModel = (InMemoryNodeModel) parent.getModel();
         assertEquals(parentModel, subModel.getParentModel());
 
         // Check whether the track count was increased
         parentModel.untrackNode(SELECTOR);
         parentModel.untrackNode(SELECTOR);
         assertTrue(subModel.isReleaseTrackedNodeOnFinalize());
     }
 
     /**
      * Tests whether the configuration can be closed.
      */
     @Test
     void testClose() {
         final TrackedNodeModel model = mock(TrackedNodeModel.class);
 
         when(model.getSelector()).thenReturn(SELECTOR);
 
         final SubnodeConfiguration config = new SubnodeConfiguration(parent, model);
         config.close();
 
         verify(model).getSelector();
         verify(model).close();
         verifyNoMoreInteractions(model);
     }
 
     /**
      * Tests the configurationAt() method if updates are not supported.
      */
     @Test
     void testConfiguarationAtNoUpdates() {
         setUpSubnodeConfig();
         final HierarchicalConfiguration<ImmutableNode> sub2 = config.configurationAt("fields.field(1)");
         assertEquals(NodeStructureHelper.field(0, 1), sub2.getString("name"));
         parent.setProperty("tables.table(0).fields.field(1).name", "otherName");
         assertEquals(NodeStructureHelper.field(0, 1), sub2.getString("name"));
     }
 
     /**
      * Tests configurationAt() if updates are supported.
      */
     @Test
     void testConfigurationAtWithUpdateSupport() {
         setUpSubnodeConfig();
         final SubnodeConfiguration sub2 = (SubnodeConfiguration) config.configurationAt("fields.field(1)", true);
         assertEquals(NodeStructureHelper.field(0, 1), sub2.getString("name"));
         assertEquals(config, sub2.getParent());
     }
 
     /**
      * Tests listing the defined keys.
      */
     @Test
     void testGetKeys() {
         setUpSubnodeConfig();
         final Set<String> keys = new HashSet<>(ConfigurationAssert.keysToList(config));
         assertEquals(new HashSet<>(Arrays.asList("name", "fields.field.name")), keys);
     }
 
     /**
      * Tests whether a correct node model is returned for the sub configuration. This test is related to CONFIGURATION-670.
      */
     @Test
     void testGetNodeModel() {
         setUpSubnodeConfig();
         final InMemoryNodeModel nodeModel = config.getNodeModel();
 
         assertEquals("table", nodeModel.getNodeHandler().getRootNode().getNodeName());
     }
 
     /**
      * Tests if properties of the sub node can be accessed.
      */
     @Test
     void testGetProperties() {
         setUpSubnodeConfig();
         checkSubConfigContent();
     }
 
     /**
      * Tests creation of a subnode config.
      */
     @Test
     void testInitSubNodeConfig() {
         setUpSubnodeConfig();
         assertSame(NodeStructureHelper.nodeForKey(parent.getModel().getNodeHandler().getRootNode(), "tables/table(0)"),
                 config.getModel().getNodeHandler().getRootNode());
         assertSame(parent, config.getParent());
     }
 
     /**
      * Tests constructing a subnode configuration with a null node model. This should cause an exception.
      */
     @Test
     void testInitSubNodeConfigWithNullNode() {
         assertThrows(IllegalArgumentException.class, () -> new SubnodeConfiguration(parent, null));
     }
 
     /**
      * Tests constructing a subnode configuration with a null parent. This should cause an exception.
      */
     @Test
     void testInitSubNodeConfigWithNullParent() {
         final TrackedNodeModel model = setUpTrackedModel(SELECTOR);
         assertThrows(IllegalArgumentException.class, () -> new SubnodeConfiguration(null, model));
     }
 
     /**
      * Tests interpolation features. The subnode config should use its parent for interpolation.
      */
     @Test
     void testInterpolation() {
         parent.addProperty("tablespaces.tablespace.name", "default");
         parent.addProperty("tablespaces.tablespace(-1).name", "test");
         parent.addProperty("tables.table(0).tablespace", "${tablespaces.tablespace(0).name}");
         assertEquals("default", parent.getString("tables.table(0).tablespace"));
 
         setUpSubnodeConfig();
         assertEquals("default", config.getString("tablespace"));
     }
 
     /**
      * Tests whether interpolation works for a sub configuration obtained via configurationAt() if updates are not
      * supported.
      */
     @Test
     void testInterpolationFromConfigurationAtNoUpdateSupport() {
         checkInterpolationFromConfigurationAt(false);
     }
 
     /**
      * Tests whether interpolation works for a sub configuration obtained via configurationAt() if updates are supported.
      */
     @Test
     void testInterpolationFromConfigurationAtWithUpdateSupport() {
         checkInterpolationFromConfigurationAt(true);
     }
 
     /**
      * Tests manipulating the interpolator.
      */
     @Test
     void testInterpolator() {
         parent.addProperty("tablespaces.tablespace.name", "default");
         parent.addProperty("tablespaces.tablespace(-1).name", "test");
 
         setUpSubnodeConfig();
         InterpolationTestHelper.testGetInterpolator(config);
     }
 
     /**
      * An additional test for interpolation when the configurationAt() method is involved for a local interpolation.
      */
     @Test
     void testLocalInterpolationFromConfigurationAt() {
         parent.addProperty("base.dir", "/home/foo");
         parent.addProperty("test.absolute.dir.dir1", "${base.dir}/path1");
         parent.addProperty("test.absolute.dir.dir2", "${dir1}");
 
         final Configuration sub = parent.configurationAt("test.absolute.dir");
         assertEquals("/home/foo/path1", sub.getString("dir1"));
         assertEquals("/home/foo/path1", sub.getString("dir2"));
     }
 
     @Test
     void testLocalLookupsInInterpolatorAreInherited() {
         parent.addProperty("tablespaces.tablespace.name", "default");
         parent.addProperty("tablespaces.tablespace(-1).name", "test");
         parent.addProperty("tables.table(0).var", "${brackets:x}");
 
         final ConfigurationInterpolator interpolator = parent.getInterpolator();
         interpolator.registerLookup("brackets", key -> "(" + key + ")");
         setUpSubnodeConfig();
         assertEquals("(x)", config.getString("var", ""));
     }
 
     /**
      * Tests a manipulation of the parent configuration that causes the subnode configuration to become invalid. In this
      * case the sub config should be detached and keep its old values.
      */
     @Test
     void testParentChangeDetach() {
         setUpSubnodeConfig();
         parent.clear();
         checkSubConfigContent();
     }
 
     /**
      * Tests detaching a subnode configuration if an exception is thrown during reconstruction. This can happen for example if the
      * expression engine is changed for the parent.
      */
     @Test
     void testParentChangeDetatchException() {
         setUpSubnodeConfig();
         parent.setExpressionEngine(new XPathExpressionEngine());
         parent.addProperty("newProp", "value");
         checkSubConfigContent();
     }
 
     /**
      * Tests changing the expression engine.
      */
     @Test
     void testSetExpressionEngine() {
         parent.setExpressionEngine(new XPathExpressionEngine());
         setUpSubnodeConfig("tables/table[1]");
         assertEquals(NodeStructureHelper.field(0, 1), config.getString("fields/field[2]/name"));
         final Set<String> keys = ConfigurationAssert.keysToSet(config);
         assertEquals(new HashSet<>(Arrays.asList("name", "fields/field/name")), keys);
         config.setExpressionEngine(null);
         assertInstanceOf(XPathExpressionEngine.class, parent.getExpressionEngine());
     }
 
     /**
      * Tests manipulating the list delimiter handler. This object is derived from the parent.
      */
     @Test
     void testSetListDelimiterHandler() {
         final ListDelimiterHandler handler1 = new DefaultListDelimiterHandler('/');
         final ListDelimiterHandler handler2 = new DefaultListDelimiterHandler(';');
         parent.setListDelimiterHandler(handler1);
         setUpSubnodeConfig();
         parent.setListDelimiterHandler(handler2);
         assertEquals(handler1, config.getListDelimiterHandler());
         config.addProperty("newProp", "test1,test2/test3");
         assertEquals("test1,test2", parent.getString("tables.table(0).newProp"));
         config.setListDelimiterHandler(DisabledListDelimiterHandler.INSTANCE);
         assertEquals(handler2, parent.getListDelimiterHandler());
     }
 
     /**
      * Tests setting of properties in both the parent and the subnode configuration and whether the changes are visible to
      * each other.
      */
     @Test
     void testSetProperty() {
         setUpSubnodeConfig();
         config.setProperty(null, "testTable");
         config.setProperty("name", NodeStructureHelper.table(0) + "_tested");
         assertEquals("testTable", parent.getString("tables.table(0)"));
         assertEquals(NodeStructureHelper.table(0) + "_tested", parent.getString("tables.table(0).name"));
 
         parent.setProperty("tables.table(0).fields.field(1).name", "testField");
         assertEquals("testField", config.getString("fields.field(1).name"));
     }
 
     /**
      * Tests setting the exception on missing flag. The subnode config obtains this flag from its parent.
      */
     @Test
     void testSetThrowExceptionOnMissing() {
         parent.setThrowExceptionOnMissing(true);
         setUpSubnodeConfig();
         assertTrue(config.isThrowExceptionOnMissing());
         assertThrows(NoSuchElementException.class, () -> config.getString("non existing key"));
     }
 
     /**
      * Tests whether the exception flag can be set independently from the parent.
      */
     @Test
     void testSetThrowExceptionOnMissingAffectsParent() {
         parent.setThrowExceptionOnMissing(true);
         setUpSubnodeConfig();
         config.setThrowExceptionOnMissing(false);
         assertTrue(parent.isThrowExceptionOnMissing());
     }
 }