/*
    * Copyright 2015 Mark Prins, GeoDienstenCentrum
    *
    * 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 nl.geodienstencentrum.maven.plugin.sass.report;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.StringWriter;
  import javax.xml.transform.Result;
  import javax.xml.transform.Source;
  import javax.xml.transform.SourceLocator;
  import javax.xml.transform.Templates;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerConfigurationException;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.stream.StreamResult;
  import javax.xml.transform.stream.StreamSource;
  import org.apache.maven.doxia.sink.Sink;
  import org.apache.maven.plugin.logging.Log;
  
  /**
   * Converts the xml report into a maven site html report.
   * @author mprins
   */
  public class SCSSLintReportGenerator {
  
  	private final Sink sink;
  	private final String description;
  	private final File xmlFile;
  	private final Log log;
  
  	/**
  	 * Construct a configured instance of the report generator.
  	 *
  	 * @param sink (html) doxia sink to use
  	 * @param description description for the report
  	 * @param xmlFile input xml file to convert
  	 * @param log maven log
  	 */
  	public SCSSLintReportGenerator(final Sink sink, final String description,
  	        final File xmlFile, final Log log) {
  		this.sink = sink;
  		this.description = description;
  		this.xmlFile = xmlFile;
  		this.log = log;
  	}
  
  	/**
  	 * translate the xml report to the format of the sink (html).
  	 */
  	public void generateReport() {
  		sink.head();
  		sink.title();
  		sink.text(description);
  		sink.title_();
  		sink.head_();
  		sink.body();
  		sink.rawText(this.translateXML());
  		sink.body_();
  		sink.flush();
  		sink.close();
  	}
  
  	/**
  	 * translate the xml using xslt.
  	 * @return the transformed xml as string
  	 */
  	private String translateXML() {
  		String translated = null;
  		try {
  			final TransformerFactory factory = TransformerFactory.newInstance();
  			final Templates template = factory.newTemplates(
  			    new StreamSource(
  			        this.getClass().getClassLoader().getResourceAsStream("scss-report.xsl")));
  			final Transformer xformer = template.newTransformer();
  			log.info("Transforming scss-lint xml results file: " + xmlFile.getAbsolutePath());
  			final Source source = new StreamSource(new FileInputStream(this.xmlFile));
  			final StringWriter outWriter = new StringWriter();
  			final Result result = new StreamResult(outWriter);
  			xformer.transform(source, result);
  			translated = outWriter.toString();
  		} catch (FileNotFoundException | TransformerConfigurationException e) {
  			// error in the XSL file
  			log.error("Error during xml conversion of " + this.xmlFile, e);
  		} catch (TransformerException e) {
 			// error while applying the XSL file
 			final SourceLocator locator = e.getLocator();
 			final int col = locator.getColumnNumber();
 			final int line = locator.getLineNumber();
 			log.error("Error during xml transformation of " + this.xmlFile
 					+ "line: " + line + ", col: " + col, e);
 		}
 
 		log.debug("Transformed scss-lint xml:\n" + translated);
 		return translated;
 	}
 }