package org.daisy.pipeline.tts;
   
   import java.net.URI;
   
   import net.sf.saxon.s9api.Axis;
   import net.sf.saxon.s9api.XdmNode;
   import net.sf.saxon.s9api.XdmNodeKind;
   import net.sf.saxon.s9api.XdmSequenceIterator;
   
  import org.daisy.pipeline.tts.calabash.impl.FormatSpecifications;
  
  import com.google.common.base.CharMatcher;
  
  public class Sentence implements FormatSpecifications {
  
  	private final String id;
  	private int size;
  	private final Iterable<Voice> voices;
  	private final XdmNode text;
  	private final TTSEngine ttsProc;
  
  	/**
  	 * @param voices Assumed to contain at least one voice.
  	 */
  	public Sentence(TTSEngine ttsProc, Iterable<Voice> voices, XdmNode text) {
  		id = text.getAttributeValue(Sentence_attr_id);
  		if (id == null)
  			throw new IllegalArgumentException("id must not be null");
  		this.voices = voices;
  		this.text = text;
  		this.ttsProc = ttsProc;
  		size = -1;
  	}
  
  	public int getSize() {
  		if (size == -1) {
  			size = 0;
  			size = computeSize(text);
  		}
  		return size;
  	}
  
  	/**
  	 * Get the preferred voice
  	 */
  	public Voice getPreferredVoice() {
  		return voices.iterator().next();
  	}
  
  	/**
  	 * Get the complete ordered set of selected voices
  	 */
  	public Iterable<Voice> getVoices() {
  		return voices;
  	}
  
  	public XdmNode getText() {
  		return text;
  	}
  
  	public TTSEngine getTTSproc() {
  		return ttsProc;
  	}
  
  	public String getID() {
  		return id;
  	}
  
  	public URI getBaseURI() {
  		return text.getBaseURI();
  	}
  
  	public static int computeSize(XdmNode node) {
  		int size = 0;
  		if (node.getNodeKind() == XdmNodeKind.TEXT) {
  			size += CharMatcher.WHITESPACE.removeFrom(node.getStringValue()).length();
  		} else {
  			XdmSequenceIterator iter = node.axisIterator(Axis.CHILD);
  			while (iter.hasNext()) {
  				size += computeSize((XdmNode) iter.next());
  			}
  		}
  		return size;
  	}
  }