/**

  * SQL-DK

  * Copyright © 2014 František Kučera (frantovo.cz)

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, either version 3 of the License, or

  * (at your option) any later version.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. If not, see <http://www.gnu.org/licenses/>.

  */

 package info.globalcode.sql.dk.formatting;

 import info.globalcode.sql.dk.ColorfulPrintWriter;

 import info.globalcode.sql.dk.ColorfulPrintWriter.TerminalColor;

 import java.util.Stack;

 import javax.xml.namespace.QName;

 import static info.globalcode.sql.dk.Functions.isEmpty;

 import static info.globalcode.sql.dk.Functions.toHex;

 import info.globalcode.sql.dk.configuration.PropertyDeclaration;

 import static info.globalcode.sql.dk.formatting.CommonProperties.COLORFUL;

 import static info.globalcode.sql.dk.formatting.CommonProperties.COLORFUL_DESCRIPTION;

 import java.nio.charset.Charset;

 import java.util.EmptyStackException;

 import java.util.HashMap;

 import java.util.LinkedHashMap;

 import java.util.Map;

 import java.util.Map.Entry;

 import java.util.logging.Level;

 import java.util.logging.Logger;

 /**

  * <p>

  * Provides helper methods for printing pretty intended and optionally colorful (syntax highlighted)

  * XML output.

  * </p>

  *

  * <p>

  * Must be used with care – bad usage can lead to invalid XML (e.g. using undeclared namespaces).

  * </p>

  *

  * @author Ing. František Kučera (frantovo.cz)

  */

 @PropertyDeclaration(name = COLORFUL, type = Boolean.class, description = COLORFUL_DESCRIPTION)

 @PropertyDeclaration(name = AbstractXmlFormatter.PROPERTY_INDENT, type = String.class, description = "tab or sequence of spaces used for indentation of nested elements")

 @PropertyDeclaration(name = AbstractXmlFormatter.PROPERTY_INDENT_TEXT, type = Boolean.class, description = "whether to indent text nodes")

 public abstract class AbstractXmlFormatter extends AbstractFormatter {

 	private static final Logger log = Logger.getLogger(AbstractXmlFormatter.class.getName());

 	public static final String PROPERTY_INDENT = "indent";

 	/**

 	 * Whether text with line breaks should be indented (default). Otherwise original whitespace

 	 * will be preserved.

 	 */

 	public static final String PROPERTY_INDENT_TEXT = "indentText";

 	private static final TerminalColor ELEMENT_COLOR = TerminalColor.Magenta;

 	private static final TerminalColor ATTRIBUTE_NAME_COLOR = TerminalColor.Green;

 	private static final TerminalColor ATTRIBUTE_VALUE_COLOR = TerminalColor.Yellow;

 	private static final TerminalColor XML_DECLARATION_COLOR = TerminalColor.Red;

 	private static final TerminalColor XML_DOCTYPE_COLOR = TerminalColor.Cyan;

 	private Stack<QName> treePosition = new Stack<>();

 	private final ColorfulPrintWriter out;

 	private final String indent;

 	private final boolean indentText;

 	public AbstractXmlFormatter(FormatterContext formatterContext) {

 		super(formatterContext);

 		boolean colorful = formatterContext.getProperties().getBoolean(COLORFUL, false);

 		out = new ColorfulPrintWriter(formatterContext.getOutputStream(), false, colorful);

 		indent = formatterContext.getProperties().getString(PROPERTY_INDENT, "\t");

 		indentText = formatterContext.getProperties().getBoolean(PROPERTY_INDENT_TEXT, true);

 		if (!indent.matches("\\s*")) {

 			log.log(Level.WARNING, "Setting indent to „{0}“ is weird & freaky; in hex: {1}", new Object[]{indent, toHex(indent.getBytes())});

 		}

 	}

 	protected void printStartDocument() {

 		out.print(XML_DECLARATION_COLOR, "<?xml version=\"1.0\" encoding=\"" + Charset.defaultCharset().name() + "\"?>");

 	}

 	protected void printDoctype(String doctype) {

 		out.print(XML_DOCTYPE_COLOR, "\n<!DOCTYPE " + doctype + ">");

 	}

 	protected void printEndDocument() {

 		out.println();

 		out.flush();

 		if (!treePosition.empty()) {

 			throw new IllegalStateException("Some elements are not closed: " + treePosition);

 		}

 	}

 	protected void printStartElement(QName element) {

 		printStartElement(element, null);

 	}

 	protected Map<QName, String> singleAttribute(QName name, String value) {

 		Map<QName, String> attributes = new HashMap<>(2);

 		attributes.put(name, value);

 		return attributes;

 	}

 	protected void printStartElement(QName element, Map<QName, String> attributes) {

 		printStartElement(element, attributes, false);

 	}

 	/**

 	 * @param empty whether element should be closed <codfe>… /&gt;</code> (has no content, do not

 	 * call {@linkplain #printEndElement()})

 	 */

 	private void printStartElement(QName element, Map<QName, String> attributes, boolean empty) {

 		printIndent();

 		out.print(ELEMENT_COLOR, "<" + toString(element));

 		if (attributes != null) {

 			for (Entry<QName, String> attribute : attributes.entrySet()) {

 				out.print(" ");

 				out.print(ATTRIBUTE_NAME_COLOR, toString(attribute.getKey()));

 				out.print("=");

 				out.print(ATTRIBUTE_VALUE_COLOR, '"' + escapeXmlAttribute(attribute.getValue()) + '"');

 			}

 		}

 		if (empty) {

 			out.print(ELEMENT_COLOR, "/>");

 		} else {

 			out.print(ELEMENT_COLOR, ">");

 			treePosition.add(element);

 		}

 		out.flush();

 	}

 	/**

 	 * Prints text node wrapped in given element without indenting the text and adding line breaks

 	 * (useful for short texts).

 	 *

 	 * @param attributes use {@linkplain  LinkedHashMap} to preserve attributes order

 	 */

 	protected void printTextElement(QName element, Map<QName, String> attributes, String text) {

 		printStartElement(element, attributes);

 		String[] lines = text.split("\\n");

 		if (indentText && lines.length > 1) {

 			for (String line : lines) {

 				printText(line, true);

 			}

 			printEndElement(true);

 		} else {

 			/*

 			 * line breaks at the end of the text will be eaten – if you need them, use indentText = false

 			 */

 			if (lines.length == 1 && text.endsWith("\n")) {

 				text = text.substring(0, text.length() - 1);

 			}

 			printText(text, false);

 			printEndElement(false);

 		}

 	}

 	protected void printEmptyElement(QName element, Map<QName, String> attributes) {

 		printStartElement(element, attributes, true);

 	}

 	protected void printEndElement() {

 		printEndElement(true);

 	}

 	private void printEndElement(boolean indent) {

 		try {

 			QName name = treePosition.pop();

 			if (indent) {

 				printIndent();

 			}

 			out.print(ELEMENT_COLOR, "</" + toString(name) + ">");

 			out.flush();

 		} catch (EmptyStackException e) {

 			throw new IllegalStateException("No more elements to end.", e);

 		}

 	}

 	protected void printText(String s, boolean indent) {

 		if (indent) {

 			printIndent();

 		}

 		out.print(escapeXmlText(s));

 		out.flush();

 	}

 	protected void printIndent() {

 		out.println();

 		for (int i = 0; i < treePosition.size(); i++) {

 			out.print(indent);

 		}

 	}

 	protected static QName qname(String name) {

 		return new QName(name);

 	}

 	protected static QName qname(String prefix, String name) {

 		return new QName(null, name, prefix);

 	}

 	private String toString(QName name) {

 		if (isEmpty(name.getPrefix(), true)) {

 			return escapeName(name.getLocalPart());

 		} else {

 			return escapeName(name.getPrefix()) + ":" + escapeName(name.getLocalPart());

 		}

 	}

 	private String escapeName(String s) {

 		// TODO: avoid ugly values in <name name="…"/>		

 		return s;

 	}

 	private static String escapeXmlText(String s) {

 		return s.replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;");

 		// Not needed:

 		// return s.replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;").replaceAll("\"", "&quot;").replaceAll("'", "&apos;");

 	}

 	/**

 	 * Expects attribute values enclosed in "quotes" not 'apostrophes'.

 	 */

 	private static String escapeXmlAttribute(String s) {

 		return s.replaceAll("&", "&amp;").replaceAll("<", "&lt;").replaceAll(">", "&gt;").replaceAll("\"", "&quot;");

 	}

 }