package org.daisy.pipeline.common.calabash.impl;
   
   import java.util.Map;
   
   import javax.xml.namespace.QName;
   
   import com.google.common.collect.ImmutableMap;
   
   import com.xmlcalabash.core.XProcException;
  import com.xmlcalabash.core.XProcRuntime;
  import com.xmlcalabash.io.ReadablePipe;
  import com.xmlcalabash.io.WritablePipe;
  import com.xmlcalabash.library.DefaultStep;
  import com.xmlcalabash.runtime.XAtomicStep;
  
  import net.sf.saxon.s9api.SaxonApiException;
  
  import org.daisy.common.xproc.calabash.CalabashExceptionFromXProcError;
  import org.daisy.common.xproc.calabash.XMLCalabashInputValue;
  import org.daisy.common.xproc.calabash.XProcStep;
  import org.daisy.common.xproc.calabash.XProcStepProvider;
  import org.daisy.common.xproc.XProcError;
  import org.daisy.common.xproc.XProcMonitor;
  
  import org.osgi.service.component.annotations.Component;
  
  @Component(
  	name = "pxi:error",
  	service = { XProcStepProvider.class },
  	property = { "type:String={http://www.daisy.org/ns/pipeline/xproc/internal}error" }
  )
  public class Error implements XProcStepProvider {
  
  	public XProcStep newStep(XProcRuntime runtime, XAtomicStep step, XProcMonitor monitor, Map<String,String> properties) {
  		return new ErrorStep(runtime, step);
  	}
  
  	/**
  	 * Own version of <code>p:error</code> that reads one or more <code>c:errors</code> documents
  	 * with one or more <code>c:error</code> elements in each, creates {@link XProcException}s,
  	 * reports them, and throws the last one.
  	 */
  	public static class ErrorStep extends DefaultStep implements XProcStep {
  
  		private ReadablePipe errorPipe = null;
  		private XProcException lastError = null;
  
  		private ErrorStep(XProcRuntime runtime, XAtomicStep step) {
  			super(runtime, step);
  		}
  
  		@Override
  		public void setInput(String port, ReadablePipe pipe) {
  			if ("error".equals(port))
  				errorPipe = pipe;
  		}
  
  		@Override
  		public void setOutput(String port, WritablePipe pipe) {
  		}
  		
  		@Override
  		public void reset() {
  			errorPipe.resetReader();
  			lastError = null;
  		}
  		
  		@Override
  		public void run() throws SaxonApiException {
  			try {
  				lastError = null;
  				new ErrorReporter(this::report)
  					.transform(
  						ImmutableMap.of(new QName("source"), new XMLCalabashInputValue(errorPipe)),
  						ImmutableMap.of())
  					.run();
  				if (lastError != null)
  					throw lastError;
  				else
  					throw new RuntimeException("Expected c:errors document with at least one c:error");
  			} catch (Throwable e) {
  				throw XProcStep.raiseError(e, step);
  			}
  		}
  
  		private void report(XProcError error) {
  			lastError = CalabashExceptionFromXProcError.from(error);
  			step.reportError(lastError);
  		}
  	}
  }