package org.argeo.jcr.xml;

import java.io.IOException;
import java.io.Writer;

import javax.jcr.Node;
import javax.jcr.NodeIterator;
import javax.jcr.Property;
import javax.jcr.PropertyIterator;
import javax.jcr.RepositoryException;
import javax.jcr.Value;
import javax.jcr.nodetype.NodeType;

import org.argeo.jcr.Jcr;

/** Utilities around JCR and XML. */
public class JcrXmlUtils {
	/**
	 * Convenience method calling {@link #toXmlElements(Writer, Node, boolean)} with
	 * <code>false</code>.
	 */
	public static void toXmlElements(Writer writer, Node node) throws RepositoryException, IOException {
		toXmlElements(writer, node, false, false);
	}

	/**
	 * Write JCR properties as XML elements in a tree structure whose elements are
	 * named by node primary type.
	 * 
	 * @param writer       the writer to use
	 * @param node         the subtree
	 * @param withMetadata whether to write the primary type and mixins as elements
	 *                     jcr:primaryType (
	 */
	public static void toXmlElements(Writer writer, Node node, boolean withMetadata, boolean withPrefix)
			throws RepositoryException, IOException {
		if (withMetadata && node.hasProperty(Property.JCR_UUID)) {
			writeStart(writer, withPrefix(node.getPrimaryNodeType().getName(), withPrefix), "id",
					"urn:uuid:" + node.getProperty(Property.JCR_UUID).getString());
		} else {
			writeStart(writer, withPrefix(node.getPrimaryNodeType().getName(), withPrefix));
		}

		// name
		writeStart(writer, withPrefix ? Jcr.JCR_NAME : "name");
		writer.append(node.getName());
		writeEnd(writer, withPrefix ? Jcr.JCR_NAME : "name");

		// mixins
		if (withMetadata) {
			for (NodeType mixin : node.getMixinNodeTypes()) {
				writeStart(writer, withPrefix ? Jcr.JCR_MIXIN_TYPES : "mixinTypes");
				writer.append(mixin.getName());
				writeEnd(writer, withPrefix ? Jcr.JCR_MIXIN_TYPES : "mixinTypes");
			}
		}

		// properties
		PropertyIterator pit = node.getProperties();
		properties: while (pit.hasNext()) {
			Property p = pit.nextProperty();
			if (p.isMultiple()) {
				for (Value value : p.getValues()) {
					writeStart(writer, withPrefix(p.getName(), withPrefix));
					writer.write(value.getString());
					writeEnd(writer, withPrefix(p.getName(), withPrefix));
				}
			} else {
				Value value = p.getValue();
				String pName = p.getName();
				if (!withMetadata && (pName.equals(Jcr.JCR_PRIMARY_TYPE) || pName.equals(Jcr.JCR_UUID)
						|| pName.equals(Jcr.JCR_CREATED) || pName.equals(Jcr.JCR_CREATED_BY)
						|| pName.equals(Jcr.JCR_LAST_MODIFIED) || pName.equals(Jcr.JCR_LAST_MODIFIED_BY)))
					continue properties;
				writeStart(writer, withPrefix(p.getName(), withPrefix));
				writer.write(value.getString());
				writeEnd(writer, withPrefix(p.getName(), withPrefix));
			}
		}

		// children
		NodeIterator nit = node.getNodes();
		while (nit.hasNext()) {
			toXmlElements(writer, nit.nextNode(), withMetadata, withPrefix);
		}

		writeEnd(writer, withPrefix(node.getPrimaryNodeType().getName(), withPrefix));
	}

	private static String withPrefix(String str, boolean withPrefix) {
		if (withPrefix)
			return str;
		int index = str.indexOf(':');
		if (index < 0)
			return str;
		return str.substring(index + 1);
	}

	private static void writeStart(Writer writer, String tagName) throws IOException {
		writer.append('<');
		writer.append(tagName);
		writer.append('>');
	}

	private static void writeStart(Writer writer, String tagName, String attr, String value) throws IOException {
		writer.append('<');
		writer.append(tagName);
		writer.append(' ');
		writer.append(attr);
		writer.append("=\"");
		writer.append(value);
		writer.append("\">");
	}

	private static void writeEnd(Writer writer, String tagName) throws IOException {
		writer.append("</");
		writer.append(tagName);
		writer.append('>');
	}

	/** Singleton. */
	private JcrXmlUtils() {

	}

}