/*
    * 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
    *
    *     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.apache.commons.configuration2.plist;
  
  import java.io.PrintWriter;
  import java.io.Reader;
  import java.io.Writer;
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.nio.charset.Charset;
  import java.nio.charset.StandardCharsets;
  import java.text.DateFormat;
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Calendar;
  import java.util.Collection;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.LinkedList;
  import java.util.List;
  import java.util.Map;
  import java.util.TimeZone;
  
  import javax.xml.parsers.SAXParser;
  import javax.xml.parsers.SAXParserFactory;
  
  import org.apache.commons.codec.binary.Base64;
  import org.apache.commons.configuration2.BaseHierarchicalConfiguration;
  import org.apache.commons.configuration2.FileBasedConfiguration;
  import org.apache.commons.configuration2.HierarchicalConfiguration;
  import org.apache.commons.configuration2.ImmutableConfiguration;
  import org.apache.commons.configuration2.MapConfiguration;
  import org.apache.commons.configuration2.ex.ConfigurationException;
  import org.apache.commons.configuration2.ex.ConfigurationRuntimeException;
  import org.apache.commons.configuration2.io.FileLocator;
  import org.apache.commons.configuration2.io.FileLocatorAware;
  import org.apache.commons.configuration2.tree.ImmutableNode;
  import org.apache.commons.configuration2.tree.InMemoryNodeModel;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.text.StringEscapeUtils;
  import org.xml.sax.Attributes;
  import org.xml.sax.EntityResolver;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  import org.xml.sax.helpers.DefaultHandler;
  
  /**
   * Property list file (plist) in XML FORMAT as used by macOS X (http://www.apple.com/DTDs/PropertyList-1.0.dtd). This
   * configuration doesn't support the binary FORMAT used in OS X 10.4.
   *
   * <p>
   * Example:
   * </p>
   *
   * <pre>
   * &lt;?xml version="1.0"?&gt;
   * &lt;!DOCTYPE plist SYSTEM "file://localhost/System/Library/DTDs/PropertyList.dtd"&gt;
   * &lt;plist version="1.0"&gt;
   *     &lt;dict&gt;
   *         &lt;key&gt;string&lt;/key&gt;
   *         &lt;string&gt;value1&lt;/string&gt;
   *
   *         &lt;key&gt;integer&lt;/key&gt;
   *         &lt;integer&gt;12345&lt;/integer&gt;
   *
   *         &lt;key&gt;real&lt;/key&gt;
   *         &lt;real&gt;-123.45E-1&lt;/real&gt;
   *
   *         &lt;key&gt;boolean&lt;/key&gt;
   *         &lt;true/&gt;
   *
   *         &lt;key&gt;date&lt;/key&gt;
   *         &lt;date&gt;2005-01-01T12:00:00Z&lt;/date&gt;
   *
   *         &lt;key&gt;data&lt;/key&gt;
   *         &lt;data&gt;RHJhY28gRG9ybWllbnMgTnVucXVhbSBUaXRpbGxhbmR1cw==&lt;/data&gt;
   *
   *         &lt;key&gt;array&lt;/key&gt;
   *         &lt;array&gt;
   *             &lt;string&gt;value1&lt;/string&gt;
   *             &lt;string&gt;value2&lt;/string&gt;
  *             &lt;string&gt;value3&lt;/string&gt;
  *         &lt;/array&gt;
  *
  *         &lt;key&gt;dictionnary&lt;/key&gt;
  *         &lt;dict&gt;
  *             &lt;key&gt;key1&lt;/key&gt;
  *             &lt;string&gt;value1&lt;/string&gt;
  *             &lt;key&gt;key2&lt;/key&gt;
  *             &lt;string&gt;value2&lt;/string&gt;
  *             &lt;key&gt;key3&lt;/key&gt;
  *             &lt;string&gt;value3&lt;/string&gt;
  *         &lt;/dict&gt;
  *
  *         &lt;key&gt;nested&lt;/key&gt;
  *         &lt;dict&gt;
  *             &lt;key&gt;node1&lt;/key&gt;
  *             &lt;dict&gt;
  *                 &lt;key&gt;node2&lt;/key&gt;
  *                 &lt;dict&gt;
  *                     &lt;key&gt;node3&lt;/key&gt;
  *                     &lt;string&gt;value&lt;/string&gt;
  *                 &lt;/dict&gt;
  *             &lt;/dict&gt;
  *         &lt;/dict&gt;
  *
  *     &lt;/dict&gt;
  * &lt;/plist&gt;
  * </pre>
  *
  * @since 1.2
  */
 public class XMLPropertyListConfiguration extends BaseHierarchicalConfiguration implements FileBasedConfiguration, FileLocatorAware {
     /** Size of the indentation for the generated file. */
     private static final int INDENT_SIZE = 4;
 
     /** Constant for the encoding for binary data. */
     private static final Charset DATA_ENCODING = StandardCharsets.UTF_8;
 
     /** Temporarily stores the current file location. */
     private FileLocator locator;
 
     /**
      * Creates an empty XMLPropertyListConfiguration object which can be used to synthesize a new plist file by adding
      * values and then saving().
      */
     public XMLPropertyListConfiguration() {
     }
 
     /**
      * Creates a new instance of {@code XMLPropertyListConfiguration} and copies the content of the specified configuration
      * into this object.
      *
      * @param configuration the configuration to copy
      * @since 1.4
      */
     public XMLPropertyListConfiguration(final HierarchicalConfiguration<ImmutableNode> configuration) {
         super(configuration);
     }
 
     /**
      * Creates a new instance of {@code XMLPropertyConfiguration} with the given root node.
      *
      * @param root the root node
      */
     XMLPropertyListConfiguration(final ImmutableNode root) {
         super(new InMemoryNodeModel(root));
     }
 
     private void setPropertyDirect(final String key, final Object value) {
         setDetailEvents(false);
         try {
             clearProperty(key);
             addPropertyDirect(key, value);
         } finally {
             setDetailEvents(true);
         }
     }
 
     @Override
     protected void setPropertyInternal(final String key, final Object value) {
         // special case for byte arrays, they must be stored as is in the configuration
         if (value instanceof byte[] || value instanceof List) {
             setPropertyDirect(key, value);
         } else if (value instanceof Object[]) {
             setPropertyDirect(key, Arrays.asList((Object[]) value));
         } else {
             super.setPropertyInternal(key, value);
         }
     }
 
     @Override
     protected void addPropertyInternal(final String key, final Object value) {
         if (value instanceof byte[] || value instanceof List) {
             addPropertyDirect(key, value);
         } else if (value instanceof Object[]) {
             addPropertyDirect(key, Arrays.asList((Object[]) value));
         } else {
             super.addPropertyInternal(key, value);
         }
     }
 
     /**
      * Stores the current file locator. This method is called before I/O operations.
      *
      * @param locator the current {@code FileLocator}
      */
     @Override
     public void initFileLocator(final FileLocator locator) {
         this.locator = locator;
     }
 
     @Override
     public void read(final Reader in) throws ConfigurationException {
         // set up the DTD validation
         final EntityResolver resolver = (publicId, systemId) -> new InputSource(getClass().getClassLoader().getResourceAsStream("PropertyList-1.0.dtd"));
 
         // parse the file
         final XMLPropertyListHandler handler = new XMLPropertyListHandler();
         try {
             final SAXParserFactory factory = SAXParserFactory.newInstance();
             factory.setValidating(true);
 
             final SAXParser parser = factory.newSAXParser();
             parser.getXMLReader().setEntityResolver(resolver);
             parser.getXMLReader().setContentHandler(handler);
             parser.getXMLReader().parse(new InputSource(in));
 
             getNodeModel().mergeRoot(handler.getResultBuilder().createNode(), null, null, null, this);
         } catch (final Exception e) {
             throw new ConfigurationException("Unable to parse the configuration file", e);
         }
     }
 
     @Override
     public void write(final Writer out) throws ConfigurationException {
         if (locator == null) {
             throw new ConfigurationException(
                 "Save operation not properly " + "initialized! Do not call write(Writer) directly," + " but use a FileHandler to save a configuration.");
         }
         final PrintWriter writer = new PrintWriter(out);
 
         if (locator.getEncoding() != null) {
             writer.println("<?xml version=\"1.0\" encoding=\"" + locator.getEncoding() + "\"?>");
         } else {
             writer.println("<?xml version=\"1.0\"?>");
         }
 
         writer.println("<!DOCTYPE plist SYSTEM \"file://localhost/System/Library/DTDs/PropertyList.dtd\">");
         writer.println("<plist version=\"1.0\">");
 
         printNode(writer, 1, getNodeModel().getNodeHandler().getRootNode());
 
         writer.println("</plist>");
         writer.flush();
     }
 
     /**
      * Append a node to the writer, indented according to a specific level.
      */
     private void printNode(final PrintWriter out, final int indentLevel, final ImmutableNode node) {
         final String padding = StringUtils.repeat(" ", indentLevel * INDENT_SIZE);
 
         if (node.getNodeName() != null) {
             out.println(padding + "<key>" + StringEscapeUtils.escapeXml10(node.getNodeName()) + "</key>");
         }
 
         final List<ImmutableNode> children = node.getChildren();
         if (!children.isEmpty()) {
             out.println(padding + "<dict>");
 
             final Iterator<ImmutableNode> it = children.iterator();
             while (it.hasNext()) {
                 final ImmutableNode child = it.next();
                 printNode(out, indentLevel + 1, child);
 
                 if (it.hasNext()) {
                     out.println();
                 }
             }
 
             out.println(padding + "</dict>");
         } else if (node.getValue() == null) {
             out.println(padding + "<dict/>");
         } else {
             final Object value = node.getValue();
             printValue(out, indentLevel, value);
         }
     }
 
     /**
      * Append a value to the writer, indented according to a specific level.
      */
     private void printValue(final PrintWriter out, final int indentLevel, final Object value) {
         final String padding = StringUtils.repeat(" ", indentLevel * INDENT_SIZE);
 
         if (value instanceof Date) {
             synchronized (PListNodeBuilder.FORMAT) {
                 out.println(padding + "<date>" + PListNodeBuilder.FORMAT.format((Date) value) + "</date>");
             }
         } else if (value instanceof Calendar) {
             printValue(out, indentLevel, ((Calendar) value).getTime());
         } else if (value instanceof Number) {
             if (value instanceof Double || value instanceof Float || value instanceof BigDecimal) {
                 out.println(padding + "<real>" + value.toString() + "</real>");
             } else {
                 out.println(padding + "<integer>" + value.toString() + "</integer>");
             }
         } else if (value instanceof Boolean) {
             if (((Boolean) value).booleanValue()) {
                 out.println(padding + "<true/>");
             } else {
                 out.println(padding + "<false/>");
             }
         } else if (value instanceof List) {
             out.println(padding + "<array>");
             ((List<?>) value).forEach(o -> printValue(out, indentLevel + 1, o));
             out.println(padding + "</array>");
         } else if (value instanceof HierarchicalConfiguration) {
             // This is safe because we have created this configuration
             @SuppressWarnings("unchecked")
             final HierarchicalConfiguration<ImmutableNode> config = (HierarchicalConfiguration<ImmutableNode>) value;
             printNode(out, indentLevel, config.getNodeModel().getNodeHandler().getRootNode());
         } else if (value instanceof ImmutableConfiguration) {
             // display a flat Configuration as a dictionary
             out.println(padding + "<dict>");
 
             final ImmutableConfiguration config = (ImmutableConfiguration) value;
             final Iterator<String> it = config.getKeys();
             while (it.hasNext()) {
                 // create a node for each property
                 final String key = it.next();
                 final ImmutableNode node = new ImmutableNode.Builder().name(key).value(config.getProperty(key)).create();
 
                 // print the node
                 printNode(out, indentLevel + 1, node);
 
                 if (it.hasNext()) {
                     out.println();
                 }
             }
             out.println(padding + "</dict>");
         } else if (value instanceof Map) {
             // display a Map as a dictionary
             final Map<String, Object> map = transformMap((Map<?, ?>) value);
             printValue(out, indentLevel, new MapConfiguration(map));
         } else if (value instanceof byte[]) {
             final String base64 = new String(Base64.encodeBase64((byte[]) value), DATA_ENCODING);
             out.println(padding + "<data>" + StringEscapeUtils.escapeXml10(base64) + "</data>");
         } else if (value != null) {
             out.println(padding + "<string>" + StringEscapeUtils.escapeXml10(String.valueOf(value)) + "</string>");
         } else {
             out.println(padding + "<string/>");
         }
     }
 
     /**
      * Transform a map of arbitrary types into a map with string keys and object values. All keys of the source map which
      * are not of type String are dropped.
      *
      * @param src the map to be converted
      * @return the resulting map
      */
     private static Map<String, Object> transformMap(final Map<?, ?> src) {
         final Map<String, Object> dest = new HashMap<>();
         for (final Map.Entry<?, ?> e : src.entrySet()) {
             if (e.getKey() instanceof String) {
                 dest.put((String) e.getKey(), e.getValue());
             }
         }
         return dest;
     }
 
     /**
      * SAX Handler to build the configuration nodes while the document is being parsed.
      */
     private final class XMLPropertyListHandler extends DefaultHandler {
         /** The buffer containing the text node being read */
         private final StringBuilder buffer = new StringBuilder();
 
         /** The stack of configuration nodes */
         private final List<PListNodeBuilder> stack = new ArrayList<>();
 
         /** The builder for the resulting node. */
         private final PListNodeBuilder resultBuilder;
 
         public XMLPropertyListHandler() {
             resultBuilder = new PListNodeBuilder();
             push(resultBuilder);
         }
 
         /**
          * Gets the builder for the result node.
          *
          * @return the result node builder
          */
         public PListNodeBuilder getResultBuilder() {
             return resultBuilder;
         }
 
         /**
          * Return the node on the top of the stack.
          */
         private PListNodeBuilder peek() {
             if (!stack.isEmpty()) {
                 return stack.get(stack.size() - 1);
             }
             return null;
         }
 
         /**
          * Returns the node on top of the non-empty stack. Throws an exception if the stack is empty.
          *
          * @return the top node of the stack
          * @throws ConfigurationRuntimeException if the stack is empty
          */
         private PListNodeBuilder peekNE() {
             final PListNodeBuilder result = peek();
             if (result == null) {
                 throw new ConfigurationRuntimeException("Access to empty stack!");
             }
             return result;
         }
 
         /**
          * Remove and return the node on the top of the stack.
          */
         private PListNodeBuilder pop() {
             if (!stack.isEmpty()) {
                 return stack.remove(stack.size() - 1);
             }
             return null;
         }
 
         /**
          * Put a node on the top of the stack.
          */
         private void push(final PListNodeBuilder node) {
             stack.add(node);
         }
 
         @Override
         public void startElement(final String uri, final String localName, final String qName, final Attributes attributes) throws SAXException {
             if ("array".equals(qName)) {
                 push(new ArrayNodeBuilder());
             } else if ("dict".equals(qName) && peek() instanceof ArrayNodeBuilder) {
                 // push the new root builder on the stack
                 push(new PListNodeBuilder());
             }
         }
 
         @Override
         public void endElement(final String uri, final String localName, final String qName) throws SAXException {
             if ("key".equals(qName)) {
                 // create a new node, link it to its parent and push it on the stack
                 final PListNodeBuilder node = new PListNodeBuilder();
                 node.setName(buffer.toString());
                 peekNE().addChild(node);
                 push(node);
             } else if ("dict".equals(qName)) {
                 // remove the root of the XMLPropertyListConfiguration previously pushed on the stack
                 final PListNodeBuilder builder = pop();
                 assert builder != null : "Stack was empty!";
                 if (peek() instanceof ArrayNodeBuilder) {
                     // create the configuration
                     final XMLPropertyListConfiguration config = new XMLPropertyListConfiguration(builder.createNode());
 
                     // add it to the ArrayNodeBuilder
                     final ArrayNodeBuilder node = (ArrayNodeBuilder) peekNE();
                     node.addValue(config);
                 }
             } else {
                 if ("string".equals(qName)) {
                     peekNE().addValue(buffer.toString());
                 } else if ("integer".equals(qName)) {
                     peekNE().addIntegerValue(buffer.toString());
                 } else if ("real".equals(qName)) {
                     peekNE().addRealValue(buffer.toString());
                 } else if ("true".equals(qName)) {
                     peekNE().addTrueValue();
                 } else if ("false".equals(qName)) {
                     peekNE().addFalseValue();
                 } else if ("data".equals(qName)) {
                     peekNE().addDataValue(buffer.toString());
                 } else if ("date".equals(qName)) {
                     try {
                         peekNE().addDateValue(buffer.toString());
                     } catch (final IllegalArgumentException iex) {
                         getLogger().warn("Ignoring invalid date property " + buffer);
                     }
                 } else if ("array".equals(qName)) {
                     final ArrayNodeBuilder array = (ArrayNodeBuilder) pop();
                     peekNE().addList(array);
                 }
 
                 // remove the plist node on the stack once the value has been parsed,
                 // array nodes remains on the stack for the next values in the list
                 if (!(peek() instanceof ArrayNodeBuilder)) {
                     pop();
                 }
             }
 
             buffer.setLength(0);
         }
 
         @Override
         public void characters(final char[] ch, final int start, final int length) throws SAXException {
             buffer.append(ch, start, length);
         }
     }
 
     /**
      * A specialized builder class with addXXX methods to parse the typed data passed by the SAX handler. It is used for
      * creating the nodes of the configuration.
      */
     private static class PListNodeBuilder {
         /**
          * The MacOS FORMAT of dates in plist files. Note: Because {@code SimpleDateFormat} is not thread-safe, each access has
          * to be synchronized.
          */
         private static final DateFormat FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
         static {
             FORMAT.setTimeZone(TimeZone.getTimeZone("UTC"));
         }
 
         /**
          * The GNUstep FORMAT of dates in plist files. Note: Because {@code SimpleDateFormat} is not thread-safe, each access
          * has to be synchronized.
          */
         private static final DateFormat GNUSTEP_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z");
 
         /** A collection with child builders of this builder. */
         private final Collection<PListNodeBuilder> childBuilders = new LinkedList<>();
 
         /** The name of the represented node. */
         private String name;
 
         /** The current value of the represented node. */
         private Object value;
 
         /**
          * Update the value of the node. If the existing value is null, it's replaced with the new value. If the existing value
          * is a list, the specified value is appended to the list. If the existing value is not null, a list with the two values
          * is built.
          *
          * @param v the value to be added
          */
         public void addValue(final Object v) {
             if (value == null) {
                 value = v;
             } else if (value instanceof Collection) {
                 // This is safe because we create the collections ourselves
                 @SuppressWarnings("unchecked")
                 final Collection<Object> collection = (Collection<Object>) value;
                 collection.add(v);
             } else {
                 final List<Object> list = new ArrayList<>();
                 list.add(value);
                 list.add(v);
                 value = list;
             }
         }
 
         /**
          * Parse the specified string as a date and add it to the values of the node.
          *
          * @param value the value to be added
          * @throws IllegalArgumentException if the date string cannot be parsed
          */
         public void addDateValue(final String value) {
             try {
                 if (value.indexOf(' ') != -1) {
                     // parse the date using the GNUstep FORMAT
                     synchronized (GNUSTEP_FORMAT) {
                         addValue(GNUSTEP_FORMAT.parse(value));
                     }
                 } else {
                     // parse the date using the MacOS X FORMAT
                     synchronized (FORMAT) {
                         addValue(FORMAT.parse(value));
                     }
                 }
             } catch (final ParseException e) {
                 throw new IllegalArgumentException(String.format("'%s' cannot be parsed to a date!", value), e);
             }
         }
 
         /**
          * Parse the specified string as a byte array in base 64 FORMAT and add it to the values of the node.
          *
          * @param value the value to be added
          */
         public void addDataValue(final String value) {
             addValue(Base64.decodeBase64(value.getBytes(DATA_ENCODING)));
         }
 
         /**
          * Parse the specified string as an Interger and add it to the values of the node.
          *
          * @param value the value to be added
          */
         public void addIntegerValue(final String value) {
             addValue(new BigInteger(value));
         }
 
         /**
          * Parse the specified string as a Double and add it to the values of the node.
          *
          * @param value the value to be added
          */
         public void addRealValue(final String value) {
             addValue(new BigDecimal(value));
         }
 
         /**
          * Add a boolean value 'true' to the values of the node.
          */
         public void addTrueValue() {
             addValue(Boolean.TRUE);
         }
 
         /**
          * Add a boolean value 'false' to the values of the node.
          */
         public void addFalseValue() {
             addValue(Boolean.FALSE);
         }
 
         /**
          * Add a sublist to the values of the node.
          *
          * @param node the node whose value will be added to the current node value
          */
         public void addList(final ArrayNodeBuilder node) {
             addValue(node.getNodeValue());
         }
 
         /**
          * Sets the name of the represented node.
          *
          * @param nodeName the node name
          */
         public void setName(final String nodeName) {
             name = nodeName;
         }
 
         /**
          * Adds the given child builder to this builder.
          *
          * @param child the child builder to be added
          */
         public void addChild(final PListNodeBuilder child) {
             childBuilders.add(child);
         }
 
         /**
          * Creates the configuration node defined by this builder.
          *
          * @return the newly created configuration node
          */
         public ImmutableNode createNode() {
             final ImmutableNode.Builder nodeBuilder = new ImmutableNode.Builder(childBuilders.size());
             childBuilders.forEach(child -> nodeBuilder.addChild(child.createNode()));
             return nodeBuilder.name(name).value(getNodeValue()).create();
         }
 
         /**
          * Gets the final value for the node to be created. This method is called when the represented configuration node is
          * actually created.
          *
          * @return the value of the resulting configuration node
          */
         protected Object getNodeValue() {
             return value;
         }
     }
 
     /**
      * Container for array elements. <b>Do not use this class !</b> It is used internally by XMLPropertyConfiguration to
      * parse the configuration file, it may be removed at any moment in the future.
      */
     private static final class ArrayNodeBuilder extends PListNodeBuilder {
         /** The list of values in the array. */
         private final List<Object> list = new ArrayList<>();
 
         /**
          * Add an object to the array.
          *
          * @param value the value to be added
          */
         @Override
         public void addValue(final Object value) {
             list.add(value);
         }
 
         /**
          * Return the list of values in the array.
          *
          * @return the {@link List} of values
          */
         @Override
         protected Object getNodeValue() {
             return list;
         }
     }
 }