package org.daisy.pipeline.epub.ace.impl;
   
   import java.io.File;
   import java.net.URI;
   import java.nio.file.Files;
   import java.util.Map;
   import java.util.Optional;
   
   import javax.xml.transform.stream.StreamSource;
  
  import com.xmlcalabash.core.XProcRuntime;
  import com.xmlcalabash.io.WritablePipe;
  import com.xmlcalabash.library.DefaultStep;
  import com.xmlcalabash.runtime.XAtomicStep;
  
  import net.sf.saxon.s9api.QName;
  import net.sf.saxon.s9api.SaxonApiException;
  
  import org.daisy.common.shell.BinaryFinder;
  import org.daisy.common.shell.CommandRunner;
  import org.daisy.common.xproc.calabash.XProcStep;
  import org.daisy.common.xproc.calabash.XProcStepProvider;
  import org.daisy.common.xproc.XProcMonitor;
  import static org.daisy.pipeline.file.FileUtils.cResultDocument;
  
  import org.osgi.service.component.annotations.Activate;
  import org.osgi.service.component.annotations.Component;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * <p>Accessibility Checker for EPUB (Ace) step provider</p>
   *
   * <p>This class provides a step that validates an EPUB using a system-wide install of the Ace tool
   * if it is installed.</p>
   */
  @Component(
  	name = "pxi:ace",
  	service = { XProcStepProvider.class },
  	property = { "type:String={http://www.daisy.org/ns/pipeline/xproc/internal}ace" }
  )
  public class AceProvider implements XProcStepProvider {
  
  	public XProcStep newStep(XProcRuntime runtime, XAtomicStep step, XProcMonitor monitor, Map<String,String> properties) {
  		return new AceStep(runtime, step);
  	}
  
  	private static File aceProgram = null;
  
  	/**
  	 * Retrieve the Ace executable path
  	 *
  	 * @throws RuntimeException if Ace is not found on the system
  	 */
  	@Activate
  	public void init() {
  		Optional<String> lpath = BinaryFinder.find("ace");
  		if (lpath.isPresent())
  			aceProgram = new File(lpath.get());
  		else
  			throw new RuntimeException("Ace was not found on your system");
  	}
  
  	public static class AceStep extends DefaultStep implements XProcStep {
  
  		private final static Logger mLogger = LoggerFactory.getLogger(AceStep.class);
  
  		private static final QName _epubFile = new QName("epub");
  		private static final QName _tempDir = new QName("temp-dir");
  		private static final QName _lang = new QName("lang");
  
  		private WritablePipe htmlReport = null;
  		private WritablePipe jsonReport = null;
  
  		private AceStep(XProcRuntime runtime, XAtomicStep step) {
  			super(runtime, step);
  		}
  
  		@Override
  		public void setOutput(String port, WritablePipe pipe) {
  			if ("html-report-uri".equals(port)) {
  				htmlReport = pipe;
  			} else { // json-report-uri
  				jsonReport = pipe;
  			}
  		}
  
  		@Override
  		public void reset() {
  			htmlReport.resetWriter();
  			jsonReport.resetWriter();
  		}
  
  		@Override
  		public void run() throws SaxonApiException {
  			super.run();
  			try {
  				URI epubURI = new URI(getOption(_epubFile).getString());
 				File epubFile = new File(epubURI);
 
 				// Note that this should normally never happen because init() would have thrown an Exception
 				if (aceProgram == null) throw new Exception("Ace was not found on your system");
 
 				// Output where the Ace reports (report.html and report.json) and unzipped epub will be stored
 				File tempDir;
 				if (getOption(_tempDir).getString().equals("")) {
 					tempDir = Files.createTempDirectory("ace-").toFile();
 					tempDir.deleteOnExit();
 				} else
 					tempDir = new File(new URI(getOption(_tempDir).getString()));
 
 				String language = getOption(_lang).getString();
 
 				String[] cmd = new String[] {
 					aceProgram.getAbsolutePath(),
 					"-o", tempDir.getAbsolutePath(),
 					"-t", tempDir.getAbsolutePath(),
 					"-l", language.equals("") ? "en" : language,
 					epubFile.getCanonicalPath()
 				};
 
 				new CommandRunner(cmd)
 					.consumeError(mLogger)
 					.run();
 
 				File htmlReportFile = new File(tempDir.getAbsolutePath() + File.separator + "report.html");
 				File jsonReportFile = new File(tempDir.getAbsolutePath() + File.separator + "report.json");
 
 				if (getOption(_tempDir).getString().equals("")) {
 					htmlReportFile.deleteOnExit();
 					jsonReportFile.deleteOnExit();
 				}
 
 				// write the result uris in c:result documents
 				writeCResult(htmlReport, htmlReportFile.toURI());
 				writeCResult(jsonReport, jsonReportFile.toURI());
 
 			} catch (Throwable e) {
 				throw XProcStep.raiseError(e, step);
 			}
 		}
 
 		private void writeCResult(WritablePipe port, URI uri) throws SaxonApiException {
 			port.write(runtime.getProcessor().newDocumentBuilder().build(new StreamSource(cResultDocument(uri.toString()))));
 		}
 	}
 }