/*
 *   Copyright 2013 Brian Rosenberger (Brutex Network)
 *
 *   Licensed 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 net.brutex.xservices.ws.impl;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.util.Iterator;
import java.util.List;
import java.util.StringTokenizer;

import javax.jws.WebService;
import javax.ws.rs.NotAuthorizedException;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import net.brutex.xservices.security.DirectoryPermission;
import net.brutex.xservices.types.AttributeType;
import net.brutex.xservices.types.NamespaceListType;
import net.brutex.xservices.types.NamespaceType;
import net.brutex.xservices.types.StringSplitType;
import net.brutex.xservices.types.ant.FileResource;
import net.brutex.xservices.ws.XServicesFault;
import net.brutex.xservices.ws.XmlService;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMAttribute;
import org.apache.axiom.om.OMCloneOptions;
import org.apache.axiom.om.OMComment;
import org.apache.axiom.om.OMContainer;
import org.apache.axiom.om.OMDocument;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNode;
import org.apache.axiom.om.OMProcessingInstruction;
import org.apache.axiom.om.OMText;
import org.apache.axiom.om.OMXMLBuilderFactory;
import org.apache.axiom.om.xpath.AXIOMXPath;
import org.apache.log4j.Logger;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.authz.UnauthorizedException;
import org.apache.shiro.authz.annotation.RequiresPermissions;
import org.jaxen.JaxenException;
import org.jaxen.SimpleNamespaceContext;

/**
 * @author Brian Rosenberger, bru(at)brutex.de
 * 
 */
@WebService(targetNamespace = "http://ws.xservices.brutex.net", endpointInterface = "net.brutex.xservices.ws.XmlService", serviceName = "XmlService")
public class XmlServiceImpl implements XmlService {
	final Logger logger = Logger.getLogger(XmlServiceImpl.class);

	public String insertNodesFromFile(FileResource res, NamespaceListType nsList, String xpath, String xmlFragment) throws XServicesFault {
		try {
			AXIOMXPath axp = new AXIOMXPath(xpath);
			InputStream is = res.getAntResource(null).getInputStream();
			OMDocument sourcedoc = OMXMLBuilderFactory.createOMBuilder(is)
					.getDocument();
			OMDocument fragdoc = null;
			if ((xmlFragment != null) && (new String(xmlFragment).length() > 0)) {
				fragdoc = OMXMLBuilderFactory.createOMBuilder(
						new StringReader("<XS>" + xmlFragment + "</XS>"))
						.getDocument();
			} else {
				throw new XServicesFault("No xmldata to insert.");
			}

			// Initialize XPath context
			SimpleNamespaceContext context = createContext(nsList);
			axp.setNamespaceContext(context);
			axp.addNamespaces(fragdoc.getOMDocumentElement());

			OMDocument document = insertNodes(sourcedoc, axp, fragdoc);

			StringWriter sw = new StringWriter();
			XMLOutputFactory xof = XMLOutputFactory.newInstance();
			XMLStreamWriter writer = xof.createXMLStreamWriter(sw);
			document.serialize(writer);

			this.logger.trace(sw.getBuffer().toString());
			return sw.getBuffer().toString();
		} catch (JaxenException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (IOException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (XMLStreamException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		}
	}

	public String replaceNodesFromFile(FileResource res, NamespaceListType nsList, String xpath, String xmlFragment) throws XServicesFault {
		try {
				AXIOMXPath axp = new AXIOMXPath(xpath);
				InputStream is = res.getAntResource(null).getInputStream();
				OMDocument sourcedoc = OMXMLBuilderFactory.createOMBuilder(is).getDocument();
				OMDocument fragdoc = null;
				if ((xmlFragment != null) && (new String(xmlFragment).length() > 0)) {
					fragdoc = OMXMLBuilderFactory.createOMBuilder(
							new StringReader("<XS>" + xmlFragment + "</XS>"))
							.getDocument();
				} else {
					throw new XServicesFault("No xmldata to insert.");
				}

				// Initialize XPath context
				SimpleNamespaceContext context = createContext(nsList);
				axp.setNamespaceContext(context);
				axp.addNamespaces(fragdoc.getOMDocumentElement());

				OMDocument document = replaceNodes(sourcedoc, axp, fragdoc);

				StringWriter sw = new StringWriter();
				XMLOutputFactory xof = XMLOutputFactory.newInstance();
				XMLStreamWriter writer = xof.createXMLStreamWriter(sw);
				document.serialize(writer);

				this.logger.trace(sw.getBuffer().toString());
				return sw.getBuffer().toString();
			} catch (JaxenException e) {
				e.printStackTrace();
				throw new XServicesFault(e);
			} catch (XMLStreamException e) {
				e.printStackTrace();
				throw new XServicesFault(e);
			} catch (IOException e) {
				e.printStackTrace();
				throw new XServicesFault(e);
			}
	}

	public String replaceNodes(String source, String encoding, NamespaceListType nsList, String xpath, String xmlFragment) throws XServicesFault {
		encoding = validateEncoding(encoding);
		try {
			AXIOMXPath axp = new AXIOMXPath(xpath);
			InputStream is = new ByteArrayInputStream(source.getBytes(encoding));
			OMDocument sourcedoc = OMXMLBuilderFactory.createOMBuilder(is)
					.getDocument();
			OMDocument fragdoc = null;
			if ((xmlFragment != null) && (new String(xmlFragment).length() > 0)) {
				fragdoc = OMXMLBuilderFactory.createOMBuilder(
						new StringReader("<XS>" + xmlFragment + "</XS>"))
						.getDocument();
			} else {
				throw new XServicesFault("No xmldata to insert.");
			}

			// Initialize XPath context
			SimpleNamespaceContext context = createContext(nsList);
			axp.setNamespaceContext(context);
			axp.addNamespaces(fragdoc.getOMDocumentElement());

			OMDocument document = replaceNodes(sourcedoc, axp, fragdoc);

			StringWriter sw = new StringWriter();
			XMLOutputFactory xof = XMLOutputFactory.newInstance();
			XMLStreamWriter writer = xof.createXMLStreamWriter(sw);
			document.serialize(writer);

			this.logger.trace(sw.getBuffer().toString());
			return sw.getBuffer().toString();
		} catch (JaxenException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (XMLStreamException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (UnsupportedEncodingException e) {
			throw new XServicesFault(e);
		}
	}
	
	@RequiresPermissions("insertNodes")
	public String insertNodes(String source, String encoding, NamespaceListType nsList, String xpath, String xmlFragment) throws XServicesFault {
		encoding = validateEncoding(encoding);
		try {
			AXIOMXPath axp = new AXIOMXPath(xpath);
			InputStream is = new ByteArrayInputStream(source.getBytes(encoding));
			OMDocument sourcedoc = OMXMLBuilderFactory.createOMBuilder(is)
					.getDocument();
			OMDocument fragdoc = null;
			if ((xmlFragment != null) && (new String(xmlFragment).length() > 0)) {
				fragdoc = OMXMLBuilderFactory.createOMBuilder(
						new StringReader("<XS>" + xmlFragment + "</XS>"))
						.getDocument();
			} else {
				throw new XServicesFault("No xmldata to insert.");
			}

			// Initialize XPath context
			SimpleNamespaceContext context = createContext(nsList);
			axp.setNamespaceContext(context);
			axp.addNamespaces(fragdoc.getOMDocumentElement());

			OMDocument document = insertNodes(sourcedoc, axp, fragdoc);

			StringWriter sw = new StringWriter();
			XMLOutputFactory xof = XMLOutputFactory.newInstance();
			XMLStreamWriter writer = xof.createXMLStreamWriter(sw);
			document.serialize(writer);

			this.logger.trace(sw.getBuffer().toString());
			return sw.getBuffer().toString();
		} catch (JaxenException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (XMLStreamException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (UnsupportedEncodingException e) {
			throw new XServicesFault(e);
		}
	}

	public String wrapInCDATA(String data) throws XServicesFault {
		String result ="";
		String[] tokens = data.split("\\]\\]>", -1);
		
		for(int i=0; i<tokens.length; i++) {
			result +=  tokens[i];
			if (i+1 < tokens.length ) result += "]]]]><![CDATA[>";
		}
		
		result = "<![CDATA[" + result + "]]>";
		return result;
	}

	public StringSplitType selectXPath(String source, String encoding, NamespaceListType nsList, String xpath) throws XServicesFault {
		encoding = validateEncoding(encoding);
		try {
			StringSplitType rarray = new StringSplitType();
			AXIOMXPath axp = new AXIOMXPath(xpath);
			InputStream is = new ByteArrayInputStream(source.getBytes(encoding));
			OMDocument sourcedoc = OMXMLBuilderFactory.createOMBuilder(is).getDocument();
			
			// Initialize XPath context
			SimpleNamespaceContext context = createContext(nsList);
			
			axp.setNamespaceContext(context);
			List results = axp.selectNodes(sourcedoc);
			for(Object o : results) {
				String text = null;
				
				if(o instanceof OMNode) {
					switch (((OMNode)o).getType()) {
						case OMNode.TEXT_NODE:
							text = ((OMText)o).getText();
							break;
						case OMNode.COMMENT_NODE:
							text = ((OMComment)o).getValue();
							break;
						case OMNode.PI_NODE:
							text = ((OMProcessingInstruction)o).getValue();
							break;
						default:
							StringWriter sw = new StringWriter();
							XMLOutputFactory xof = XMLOutputFactory.newInstance();
							XMLStreamWriter writer = xof.createXMLStreamWriter(sw);
							((OMNode)o).serialize(writer);
							writer.flush();
							text = sw.toString();							
					}					
				} else if(o instanceof OMAttribute) {
					text = ((OMAttribute)o).getAttributeValue();
				} else {
					text = String.valueOf(o);
				}
				rarray.addStringMatch(text);
			}
			

			return rarray;
			} catch (JaxenException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (XMLStreamException e) {
				// TODO Auto-generated catch block
			throw new XServicesFault(e.getMessage());
			} catch (UnsupportedEncodingException e) {
				throw new XServicesFault(e);
		}
	}
	
	public String setAttribute(String source, String encoding, NamespaceListType nsList, String xpath, AttributeType attr) throws XServicesFault {
		encoding = validateEncoding(encoding);
		try {
			StringSplitType rarray = new StringSplitType();
			AXIOMXPath axp = new AXIOMXPath(xpath);
			InputStream is = new ByteArrayInputStream(source.getBytes(encoding));
			OMDocument sourcedoc = OMXMLBuilderFactory.createOMBuilder(is).getDocument();
			OMFactory fac = OMAbstractFactory.getOMFactory();
			
			// Initialize XPath context
			SimpleNamespaceContext context = createContext(nsList);
			
			axp.setNamespaceContext(context);
			List results = axp.selectNodes(sourcedoc);
			for(Object o : results) {
				String text = null;
				
				if(o instanceof OMNode) {
					switch (((OMNode)o).getType()) {
						case OMNode.ELEMENT_NODE:
							OMElement node = ((OMElement)o);
							if(attr.value == null) {
								node.removeAttribute( node.getAttribute(new QName(attr.name)));
							} else {
								node.addAttribute(attr.name, attr.value, node.getNamespace());
							}
							break;
						default:
							throw new XServicesFault("XPath expression did not match an element node.");
					}
				} else {
					throw new XServicesFault("XPath expression did not match a node.");
				}
			}
						
			StringWriter sw = new StringWriter();
			XMLOutputFactory xof = XMLOutputFactory.newInstance();
			XMLStreamWriter writer = xof.createXMLStreamWriter(sw);
			sourcedoc.serialize(writer);
			writer.flush();
			return sw.toString();	
			} catch (JaxenException e) {
			e.printStackTrace();
			throw new XServicesFault(e);
		} catch (XMLStreamException e) {
				// TODO Auto-generated catch block
			throw new XServicesFault(e.getMessage());
			} catch (UnsupportedEncodingException e) {
				throw new XServicesFault(e);
		}
	}
	
	private OMDocument insertNodes(OMDocument xmldocument, AXIOMXPath axp,OMDocument xmlfragment) throws XServicesFault {
		List<?> olist = null;
		try {
			olist = axp.selectNodes(xmldocument.getOMDocumentElement());
			this.logger.debug("XPath '" + axp.toString() + "' has "
					+ olist.size() + " matches.");
			this.logger.trace("XPath root expression is: '" + axp.debug()
					+ "'.");
		} catch (JaxenException e) {
			throw new XServicesFault(e.getMessage(), e);
		}
		if (olist.size() == 0)
			throw new XServicesFault(Messages.getString("XmlService.no_match",
					new Object[] { axp.toString() }));

		// Prepare children to insert
		xmlfragment.build();

		// Determine what has been matched
		OMContainer match = null;
		for (Object o : olist) {
			Iterator<?> children = xmlfragment.getOMDocumentElement()
					.getChildren();
			if ((o instanceof OMNode)) {
				OMNode node = (OMNode) o;
				switch (node.getType()) {
				case OMNode.ELEMENT_NODE:
					if ((o instanceof OMElement))
						match = (OMElement) o;
					if ((o instanceof OMDocument))
						match = ((OMDocument) o).getOMDocumentElement();
					this.logger.debug(Messages.getString("XmlService.8"));
					break;
				case OMNode.TEXT_NODE:
					match = ((OMText) o).getParent();
					this.logger.debug(Messages.getString("XmlService.9"));
					break;
				case OMNode.COMMENT_NODE:
					// match = node.getParent();
					match = (OMContainer) node;
					this.logger.debug(Messages.getString("XmlService.10"));
					break;
				default:
					this.logger.error("XPath matched "
							+ o.getClass().getCanonicalName() + " Node Type:"
							+ node.getType());
					this.logger.error(Messages.getString("XmlService.11"));
					throw new XServicesFault(
							Messages.getString("XmlService.12"));
				}
			} else {
				this.logger.error("XPath matched "
						+ o.getClass().getCanonicalName());
				this.logger.error(Messages.getString("XmlService.11"));
				throw new XServicesFault(Messages.getString("XmlService.12"));
			}

			while (children.hasNext()) {
				OMNode container = (OMNode) children.next();
				match.addChild((OMNode) container.clone(new OMCloneOptions()));
			}
		}

		xmldocument.build();
		return xmldocument;
	}


	private OMDocument replaceNodes(OMDocument xmldocument, AXIOMXPath axp, OMDocument xmlfragment) throws XServicesFault {
		
		List<?> olist = null;
		try {
			olist = axp.selectNodes(xmldocument.getOMDocumentElement());
			this.logger.debug("XPath '" + axp.toString() + "' has "
					+ olist.size() + " matches.");
			this.logger.trace("XPath root expression is: '" + axp.debug()
					+ "'.");
		} catch (JaxenException e) {
			throw new XServicesFault(e.getMessage(), e);
		}
		if (olist.size() == 0)
			throw new XServicesFault(Messages.getString("XmlService.no_match",
					new Object[] { axp.toString() }));

		// Prepare children to insert
		xmlfragment.build();

		// Determine what has been matched
		OMNode match = null;
		for (Object o : olist) {
			Iterator<?> children = xmlfragment.getOMDocumentElement()
					.getChildren();
			if ((o instanceof OMNode)) {
				OMNode node = (OMNode) o;
				switch (node.getType()) {
				case OMNode.ELEMENT_NODE:
					if ((o instanceof OMElement))
						match = (OMElement) o;
					if ((o instanceof OMDocument))
						match = ((OMDocument) o).getOMDocumentElement();
					this.logger.debug(Messages.getString("XmlService.8"));
					break;
				default:
					this.logger.error("XPath matched "
							+ o.getClass().getCanonicalName() + " Node Type:"
							+ node.getType());
					this.logger.error(Messages.getString("XmlService.11"));
					throw new XServicesFault(
							Messages.getString("XmlService.12"));
				}
			} else {
				this.logger.error("XPath matched "
						+ o.getClass().getCanonicalName());
				this.logger.error(Messages.getString("XmlService.11"));
				throw new XServicesFault(Messages.getString("XmlService.12"));
			}

			while (children.hasNext()) {
				OMNode container = (OMNode) children.next();
				match.insertSiblingBefore((OMNode) container.clone(new OMCloneOptions()));
			}
			match.detach();
		}
		xmldocument.build();
		return xmldocument;
	}

	private SimpleNamespaceContext createContext(NamespaceListType nsList) {
		// Initialize XPath context
		SimpleNamespaceContext context = new SimpleNamespaceContext();
		if(nsList != null) {
			for (NamespaceType ns : nsList.getNamespaces()) {
				context.addNamespace(ns.getPrefix(), ns.getUri().toString());
				this.logger.debug(Messages.getString("XmlService.0")
						+ ns.getPrefix() + "=\"" + ns.getUri().toString()
						+ "\"'");
			}
		} else {
			logger.debug("No namespaces defined.");
		}
		return context;
	}

	private String validateEncoding(String encoding) throws XServicesFault {
		if(encoding == null || encoding.equals("")) { encoding=Charset.defaultCharset().displayName(); }
		try { 
			Charset.isSupported(encoding);
		} catch (IllegalCharsetNameException e) {
			throw new XServicesFault("Endcoding '"+encoding+"' is not supported by this JRE.");
		}
		logger.debug("Setting source xml string encoding to '"+encoding+"'");
		return encoding;
	}
	

}