/*
 *   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.emitter;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.Iterator;
import java.util.List;
import java.util.UUID;

import javax.xml.stream.XMLStreamException;

import net.brutex.svn.SVNCommitInfo;
import net.brutex.svn.SVNLookExecutor;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMComment;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNamespace;
import org.apache.axiom.om.OMNode;
import org.apache.axiom.om.OMText;
import org.apache.axiom.om.OMXMLBuilderFactory;
import org.apache.axiom.om.xpath.AXIOMXPath;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.BasicParser;
import org.apache.commons.cli.ParseException;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.apache.http.client.ClientProtocolException;
import org.apache.log4j.Logger;
import org.jaxen.JaxenException;


/**
 * The Class ALFEmitter.
 *
 * @author Brian Rosenberger, bru(at)brutex.de
 * @since 0.1
 */
public class ALFEmitter {
	
	private static final String version = "0.1";
	static Logger logger = Logger.getRootLogger();
	private static final String PARAM_REPOS = "repos";
	private static final String PARAM_TXN = "txn";
	private static final String PARAM_REV = "rev";
	private static final String PARAM_CONFIG = "conf";

	/**
	 * The main method.
	 *
	 * @param args the arguments
	 */
	public static void main(String[] args) {
		long startTime = System.currentTimeMillis();
		CommandLineParser parser = new BasicParser();
		CommandLine cmd = null;;
		try {
			cmd = parser.parse( getOptions(), args);
		} catch (ParseException e1) {
			logger.error(e1.getMessage());
			printHelp();
			System.exit(1);
		}
		ALFEmitter emitter = new ALFEmitter(cmd, startTime);
		long endTime = System.currentTimeMillis();
		logger.debug("Total execution took '"+(endTime-startTime)+"' milliseconds.");
		System.exit(0);
	}
	
	private final String repos;
	private final String txn;
	private final String rev;
	private SVNCommitInfo info;
	private OMElement template;
	private Configuration config;
	private final String nss;
	private final long startTime;
		
	private ALFEmitter(CommandLine cmd, long startTime) {
		this.startTime = startTime;
		repos = cmd.getOptionValue(PARAM_REPOS);
		txn = cmd.getOptionValue(PARAM_TXN);
		rev = cmd.getOptionValue(PARAM_REV);
		String config_file = cmd.getOptionValue(PARAM_CONFIG, "emitter.properties");

		logger.debug(String.format("Using REPOS='%s' and TXN='%s'.", repos, txn));
	
		config = null;
		try {
			config = new PropertiesConfiguration(config_file);
		} catch (ConfigurationException e) {
			logger.error("Could not find/ load '"+config_file+"' file.", e);
			System.exit(1);
		}
		
		/*
		 * Load Properties from Configuration file
		 */
		
		//it might be interesting to look into SVNKit
		//for a pure Java implementation in future
		final String svnlook = config.getString("svnlook"); 
		logger.debug("Using svnlook at '" + svnlook +"'.");
		
		final String[] issuepatterns = config.getStringArray("issuepattern");
		StringBuilder sb = new StringBuilder(); for(String s : issuepatterns) sb.append(s);
		logger.debug(String.format("Using issue id patterns: '%s'.", sb.toString()));
		
		final String eventtemplate = config.getString("eventtemplate");
		logger.debug("Using alf event template at '" + eventtemplate +"'.");
		
		nss = config.getString("eventnamespace", "http://www.eclipse.org/alf/schema/EventBase/1");
		logger.debug("Using alf event namespace '" + nss +"'.");
		
		final String marker_logmessage = config.getString("marker.logmessage", "@@logmessage@@");
		logger.debug("Using comment marker '<!-- " + marker_logmessage +" -->' in event template for logmessage.");
		
		final String marker_author = config.getString("marker.author", "@@author@@");
		logger.debug("Using comment marker '<!-- " + marker_author +" -->' with event template for author.");
		
		final String marker_addedfiles = config.getString("marker.addedfiles", "@@addedfiles@@");
		logger.debug("Using comment marker '<!-- " + marker_addedfiles +" -->' with event template for files added during commit.");
		
		final String marker_deletedfiles = config.getString("marker.deletedfiles", "@@deletedfiles@@");
		logger.debug("Using comment marker '<!-- " + marker_deletedfiles +" -->' with event template for files deleted during commit.");
		
		final String marker_changedfiles = config.getString("marker.changedfiles", "@@changedfiles@@");
		logger.debug("Using comment marker '<!-- " + marker_changedfiles +" -->' with event template for files changed during commit.");
		
		final String marker_fileselementname = config.getString("marker.fileselementname", "file");
		logger.debug("Using element name '" +marker_fileselementname +"' to wrap files list.");
		
		final String marker_issues = config.getString("marker.issues", "@@issues@@");
		logger.debug("Using comment marker '<!-- " + marker_issues +" -->' with event template for issue list.");
		
		final String marker_issueselementname = config.getString("marker.issueselementname", "issue");
		logger.debug("Using element name '" +marker_issueselementname +"' to wrap issue list.");
		
		final String eventmanager = config.getString("eventmanager");
		logger.debug("Using eventmanager at '" +eventmanager +"'.");
		
		final String eventmanager_user = config.getString("eventmanager.user");
		final String eventmanager_pass = config.getString("eventmanager.password");
		logger.debug("Using username '" +eventmanager_user +"' and a password.");
		
		final boolean isSoapEnabled = config.getBoolean("isSoapEnabled", true);
		logger.debug("Sending soap message is enabled='" +isSoapEnabled +"'.");
		
		final boolean isDropResponse = config.getBoolean("isDropResponse", true);
		logger.debug("Receiving the soap response is enabled='" +isDropResponse +"'.");
		
		
		try {
			template = OMXMLBuilderFactory.createOMBuilder(new FileInputStream(new File(eventtemplate)))
					.getDocument().getOMDocumentElement();
		} catch (FileNotFoundException e1) {
			logger.error(String.format("Could not load XML event template from file '%s'.", eventtemplate), e1);
			System.exit(1);
		}
		
		/*
		 * 
		 */
		SVNLookExecutor exec = new SVNLookExecutor(new File(svnlook), repos);
		if(cmd.hasOption(PARAM_TXN)) exec.setTXN(txn);
		if(cmd.hasOption(PARAM_REV)) exec.setRev(rev);
		info = exec.getCommitInfo();
		
		info.parseIssues(issuepatterns);
		
		logger.debug("SVNCommitInfo author: "+ info.getAuthor());
		SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
		String datestring = f.format(info.getDate());
		datestring= datestring.substring(0, 26) + ":" + datestring.substring(26); //hack into ISO 8601 format
		logger.debug("SVNCommitInfo date: "+ datestring);
		logger.debug("SVNCommitInfo log message: "+ info.getLogmessage());
		logger.debug("SVNCommitInfo file list: "+ info.getChangeFileListAsString());
		
		
		/**
		 * Event XML Erzeugen
		 */
		try {
			addElement( marker_logmessage, info.getLogmessage(), true);
			addElement(marker_author, info.getAuthor(), false);
			addElement("@@timestamp@@", datestring, false);
			addElements(marker_changedfiles, info.getChangedFiles(), marker_fileselementname);
			addElements(marker_deletedfiles, info.getDeletedFiles(), marker_fileselementname);
			addElements(marker_addedfiles, info.getAddedFiles(), marker_fileselementname);
			addElements(marker_issues, info.getIssues(), marker_issueselementname);
			
			AXIOMXPath path = new AXIOMXPath("//bru1:User");
			OMNamespace ns = template.findNamespace(nss, null);
			path.addNamespace("bru1", nss);
			OMElement n = (OMElement) path.selectSingleNode(template);
			if(n== null) { 
				logger.warn( String.format("<User> element was not found in namespace '%s'. Cannot add ALFSecurity elements. This is required since SBM 10.1.x.", nss));
			} else {
				/*
				 *  <ns:User>
            		<!--Optional:-->
               		<ns:ALFSecurity>
                  		<ns:UsernameToken>
                     		<ns:Username>admin</ns:Username>
                     		<ns:Password></ns:Password>
                  		</ns:UsernameToken>
               		</ns:ALFSecurity>
					</ns:User> 
				 */
				n.removeChildren();
				OMFactory fac = n.getOMFactory();
				fac.createOMComment(n, "Generated by SVN-ALFEmitter");
				OMElement sec = fac.createOMElement("ALFSecurity", ns);
				OMElement token = fac.createOMElement("UsernameToken", ns);
				OMElement user = fac.createOMElement("Username", ns);
				user.addChild( fac.createOMText(eventmanager_user));
				OMElement pass = fac.createOMElement("Password", ns);
				pass.addChild(fac.createOMText(eventmanager_pass, OMNode.CDATA_SECTION_NODE));
				token.addChild( user );
				token.addChild( pass);
				sec.addChild(token);
				n.addChild(sec);				
			}
			
			path = new AXIOMXPath("//bru1:Base/bru1:EventId");
			path.addNamespace("bru1",  nss);
			n = (OMElement) path.selectSingleNode(template);
			if(n==null) {
				logger.error("<Base> element in message is incomplete. <EventId> is missing.");
			} else {
				n.addChild( n.getOMFactory().createOMText(UUID.randomUUID().toString() ));
			}
			
			path = new AXIOMXPath("//bru1:Base/bru1:ObjectId");
			path.addNamespace("bru1",  nss);
			n = (OMElement) path.selectSingleNode(template);
			if(n==null) {
				logger.error("<Base> element in message is incomplete. <ObjectId> is missing.");
			} else {
				n.addChild( n.getOMFactory().createOMText(info.getTxn() ));
			}

			StringWriter out = new StringWriter();
			template.getParent().serialize(out);
			out.flush();
			
			String resultxml =  out.getBuffer().toString();
			logger.debug("ALFEvent result:\n"+resultxml);
			
			if(isSoapEnabled) {
				SimpleHttpEvent sender = new SimpleHttpEvent(eventmanager, resultxml);
				sender.sendSoap(isDropResponse);
				logger.debug(String.format("Sending/ receiving the soap message took '%s' milliseconds.", sender.getDuration()));
			} else {
				logger.warn("Sending soap message is deactivated.");
			}
			
			
		} catch (FileNotFoundException e) {
			logger.error(e.getMessage(), e);
			System.exit(1);
		} catch (ClientProtocolException e) {
			logger.error(e.getMessage(), e);
			System.exit(1);
		} catch (IOException e) {
			logger.error(e.getMessage(), e);
			System.exit(1);
		} catch (XMLStreamException e) {
			logger.error(e.getMessage(), e);
			System.exit(1);
		} catch (JaxenException e) {
			logger.error(e.getMessage(), e);
			System.exit(1);
		} finally {
			logger.debug("Total execution took '"+(System.currentTimeMillis()-startTime)+"' milliseconds.");
			String forcefail = config.getString("forcefail", "");
			if(forcefail.length()>0) {
				logger.warn("Force fail is active. All commits will be blocked.");
				System.exit(1);
			}
			
		}
		
	}
	
	
		private void addElement(String pattern, String newCdata, boolean wrapCDATA) throws JaxenException {
			OMComment comment = findComment(pattern);
			if(comment!=null) {
				OMFactory fac = OMAbstractFactory.getOMFactory();
				int type = OMNode.TEXT_NODE;
				if(wrapCDATA) {
					type = OMNode.CDATA_SECTION_NODE;
				}
				OMText text = fac.createOMText(newCdata, type);
				comment.insertSiblingAfter(text);
			}			
		}
		
		private void addElements(String pattern, List<String> files, String elementName) throws JaxenException {
			if(files.size()<=0) return;
			OMComment comment = findComment(pattern);
			if(comment!=null) {
				OMFactory fac = OMAbstractFactory.getOMFactory();
				OMNamespace ns = template.findNamespace(nss, null);
				if(ns == null) logger.error(String.format("The namespace '%s' is not defined in the template.", nss));
				for(String s : files) {
					OMElement e = fac.createOMElement(elementName, ns);
					OMText text = fac.createOMText(s, OMNode.TEXT_NODE);
					e.addChild(text);
					comment.insertSiblingAfter(e);
				}				
			}
		}
		
	
		private OMComment findComment(String pattern) throws JaxenException {
			AXIOMXPath path = new AXIOMXPath("//comment()[. = '"+pattern+"'][1]");
			//OMNamespace ns = template.findNamespace(nss, null);
			path.addNamespace("bru1", nss);
			OMComment n = (OMComment) path.selectSingleNode(template);
			if(n!=null) return n;
			logger.warn("Comment '"+pattern+"' was not found in the XML template.");
			return null;
		}
		/*
		private static OMComment findComment(OMElement element, String pattern) {
			logger.trace( String.format("Searching for comment pattern '%s' in element with name '%s'.", pattern, element.getLocalName()));
			Iterator iter = element.getChildren();

			while(iter.hasNext()) {
				Object o = iter.next(); 
				if(o instanceof OMNode) {
					OMNode node =  ((OMNode)o);
					
					switch (node.getType() ) {
					case OMNode.COMMENT_NODE:
						OMComment comment = ((OMComment)node);
						String value = comment.getValue().trim();
						if(value.equals(pattern)) {
							logger.debug("Found comment '" + pattern + "' in event template.");
							return comment;
						}
						break;
						

					case OMNode.ELEMENT_NODE:
						//traverse
						OMComment result = findComment( (OMElement)node, pattern);
						if(result!=null) return result;
						break;
						
					default:
						break;
					}
				}
			}
			//logger.info("Comment '" + pattern + "' was not found in event template.");
			return null;
		}
		*/
		
	
	@SuppressWarnings("static-access")
	private static Options getOptions() {
		Option repository = OptionBuilder.withArgName( "repository" )
											.hasArg()
											.withLongOpt("repository")
											.withDescription(  "Path or URL to the SVN repository." )
											.create( PARAM_REPOS );
		repository.setRequired(true);
		
		Option txn = OptionBuilder.withArgName( "transactionid" )
											.hasArg()
											.withLongOpt("transaction")
											.withDescription(  "The SVN transaction id to examine (TXN). You cannot combine txn with -rev. "
													+ "When a txn is given, the repository path must be a local path.")
											.create( PARAM_TXN );
		Option rev = OptionBuilder.withArgName( "revision" )
				.hasArg()
				.withDescription(  "A revision to examine. You cannot combine revision with -txn." )
				.create( PARAM_REV );
		Option config = OptionBuilder.withArgName( "config_file" )
				.hasArg()
				.withLongOpt("config")
				.withDescription(  "The configuration file to use. Defaults to 'emitter.properties'.")
				.create( PARAM_CONFIG );
		
		Options options = new Options();
		options.addOption(repository);
		options.addOption(txn);
		options.addOption(rev);
		options.addOption(config);
		return options;
	}
	
	private static void printHelp() {
		// automatically generate the help statement
		HelpFormatter formatter = new HelpFormatter();
		String header = "\nSVN-ALFEventEmitter " + version +", a SVN hook implemented in Java to emit Eclipse ALFEvents on commit.\n\n";
		String footer = "Please send bug reports to bru@brutex.de.\n(c)2013 Brian Rosenberger";
		formatter.printHelp("java -jar SVN-ALFEventEmitter", header, getOptions(), footer, true);
	}
	
	
}