package org.daisy.pipeline.file.calabash.impl;
   
   import java.io.File;
   import java.io.FileNotFoundException;
   import java.io.FileOutputStream;
   import java.io.IOException;
   import java.io.InputStream;
   import java.net.URI;
   import java.util.Map;
  
  import net.sf.saxon.s9api.QName;
  import net.sf.saxon.s9api.SaxonApiException;
  
  import org.daisy.common.file.URLs;
  import org.daisy.common.xproc.calabash.XProcStep;
  import org.daisy.common.xproc.calabash.XProcStepProvider;
  import org.daisy.common.xproc.XProcMonitor;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.google.common.io.ByteStreams;
  
  import com.xmlcalabash.core.XProcConstants;
  import com.xmlcalabash.core.XProcException;
  import com.xmlcalabash.core.XProcRuntime;
  import com.xmlcalabash.io.WritablePipe;
  import com.xmlcalabash.library.DefaultStep;
  import com.xmlcalabash.model.RuntimeValue;
  import com.xmlcalabash.runtime.XAtomicStep;
  import com.xmlcalabash.util.TreeWriter;
  
  import org.osgi.service.component.annotations.Component;
  
  /**
   * This steps allows to copy any resource from a URI to a file in the file system usign a file scheme URI 
   */
  @Component(
  	name = "pxi:copy-resource",
  	service = { XProcStepProvider.class },
  	property = { "type:String={http://www.daisy.org/ns/pipeline/xproc/internal}copy-resource" }
  )
  public class CopyResourceProvider implements XProcStepProvider {
  
  	/** The logger. */
  	Logger logger = LoggerFactory.getLogger(this.getClass());
  
  	/* (non-Javadoc)
  	 * @see org.daisy.common.xproc.calabash.XProcStepProvider#newStep(com.xmlcalabash.core.XProcRuntime, com.xmlcalabash.runtime.XAtomicStep)
  	 */
  	@Override
  	public XProcStep newStep(XProcRuntime runtime, XAtomicStep step, XProcMonitor monitor, Map<String,String> properties) {
  		return new CopyResource(runtime, step);
  	}
  
  	/**
  	 * Activate (OSGI)
  	 */
  	public void activate() {
  		logger.trace("Activating px:copy-resource provider");
  	}
  	
  	/**
  	 * Actual implementation of the CopyResource step
  	 *
  	 *
  	 */
  	public static class CopyResource extends DefaultStep implements XProcStep {
  		private static final QName _href = new QName("href");
  		private static final QName _target = new QName("target");
  		private static final QName _fail_on_error = new QName("fail-on-error");
  		private static final int bufsize = 8192;
  
  		private WritablePipe result = null;
  
  		/**
  		 * Creates a new instance of CopyResource 
  		 */
  		public CopyResource(XProcRuntime runtime, XAtomicStep step) {
  			super(runtime,step);
  		}
  
  		public void setOutput(String port, WritablePipe pipe) {
  			result = pipe;
  		}
  
  		public void reset() {
  			result.resetWriter();
  		}
  
  		public void run() throws SaxonApiException {
  			super.run();
  
  			if (runtime.getSafeMode()) {
  				throw XProcException.dynamicError(21);
  			}
  
  			boolean failOnError = getOption(_fail_on_error, true);
  
 			// Note that href.getBaseURI() always returns the absolute path of copy-resource.xpl
 			RuntimeValue href = getOption(_href);
 			URI sourceUri= URLs.resolve(href.getBaseURI(), URLs.asURI(href.getString()));
 
 			href = getOption(_target);
 			URI destUri = URLs.resolve(href.getBaseURI(), URLs.asURI(href.getString()));
 
 			File target=this.getFile(destUri,sourceUri);
 
 			TreeWriter tree = new TreeWriter(runtime);
 			tree.startDocument(step.getNode().getBaseURI());
 			tree.addStartElement(XProcConstants.c_result);
 			tree.startContent();
 
 			tree.addText(target.toURI().toASCIIString());
 
 			this.copy(sourceUri,target);
 
 			tree.addEndElement();
 			tree.endDocument();
 
 			result.write(tree.getResult());
 		}
 
 		File getFile(URI destUri,URI sourceUri){
 			File target=null;
 			if (!"file".equals(destUri.getScheme())) {
 				throw new XProcException(step, "Only file: scheme URIs are supported by taget.");
 			} else {
 				target = new File(destUri.getPath());
 			}
 
 			if (target.isDirectory()) {
 				int idx=sourceUri.getPath().lastIndexOf('/');
 				if(idx>-1){
 					target = new File(target, sourceUri.getPath().substring(idx));
 				}else{
 					target = new File(target, sourceUri.getPath());
 				}
 				if (target.isDirectory()) {
 					throw new XProcException(step, "Cannot copy: target is a directory: " + target.getAbsolutePath());
 				}
 			}
 			return target;
 
 		}
 
 		void copy(URI sourceUri,File target){
 
 			try {
 				InputStream src = sourceUri.toURL().openStream();
 				FileOutputStream dst = new FileOutputStream(target);
 				ByteStreams.copy(src,dst);
 				src.close();
 				dst.close();
 			} catch (FileNotFoundException fnfe) {
 				throw new XProcException(step, fnfe);
 			} catch (IOException ioe) {
 				throw new XProcException(step, ioe);
 			}
 		}
 	}
 
 }