package org.daisy.pipeline.nlp.lexing;
   
   import java.util.List;
   import java.util.regex.Matcher;
   import java.util.regex.Pattern;
   
   import org.daisy.pipeline.nlp.lexing.LexService.Sentence;
   import org.daisy.pipeline.nlp.lexing.LexService.TextBoundaries;
   
  /**
   * Convert one Lexer's result to formatted text. Likely to be used for testing.
   */
  public class LexResultPrettyPrinter {
  
  	private String mWordSeparator = "/";
  	private boolean mTrimming = false;
  
  	public void setWordSeperator(String wordSeparator) {
  		mWordSeparator = wordSeparator;
  	}
  
  	public void enableTrimming(boolean mode) {
  		mTrimming = mode;
  	}
  
  	public String convert(Object result, String lexerInput) {
  		StringBuilder sb = new StringBuilder();
  		dispatch(result, sb, lexerInput);
  		return sb.toString();
  	}
  
  	private void dispatch(Object v, StringBuilder sb, String reference) {
  		if (v instanceof List) {
  			visit((List<Sentence>) v, sb, reference);
  		} else if (v instanceof Sentence) {
  			visit((Sentence) v, sb, reference);
  		} else if (v instanceof TextBoundaries) {
  			visit((TextBoundaries) v, sb, reference, mWordSeparator, mWordSeparator);
  		}
  	}
  
  	private void visit(TextBoundaries t, StringBuilder sb, String reference,
  	        String separatorLeft, String separatorRight) {
  		String v = reference.substring(t.left, t.right);
  		if (mTrimming) {
  			Matcher m = Pattern.compile("^\\s+").matcher(v);
  			if (m.find()) {
  				sb.append(m.group()); //move the white spaces before the separator
  				if (m.group().length() == v.length()) {
  					//empty word
  					return;
  				}
  				v = v.substring(m.end());
  			}
  			m = Pattern.compile("\\s+$").matcher(v);
  			if (m.find()) {
  				if (m.start() != 0) {
  					sb.append(separatorLeft);
  					sb.append(v.substring(0, m.start()));
  					sb.append(separatorRight);
  					sb.append(m.group()); //move the white spaces after the separator
  				} else
  					sb.append(v); //empty word: only white spaces
  			} else {
  				sb.append(separatorLeft);
  				sb.append(v);
  				sb.append(separatorRight);
  			}
  		} else {
  			sb.append(separatorLeft);
  			sb.append(v);
  			sb.append(separatorRight);
  		}
  	}
  
  	private void visit(List<Sentence> sentences, StringBuilder sb, String references) {
  		for (Sentence s : sentences)
  			dispatch(s, sb, references);
  	}
  
  	private void visit(Sentence s, StringBuilder sb, String reference) {
  		if (s.words == null || s.words.isEmpty()) {
  			sb.append("{");
  			String v = reference.substring(s.boundaries.left, s.boundaries.right);
  			if (mTrimming)
  				v = v.trim();
  			sb.append(v);
  			sb.append("}");
  		} else {
  			int lastPos = s.boundaries.left;
  			if (mTrimming) {
  				String v = reference.substring(lastPos, s.words.get(0).left);
  				Matcher m = Pattern.compile("^\\s+").matcher(v);
  				if (m.find()) {
  					//sb.append(m.group()); //would move the white spaces before the {
  					lastPos += m.end();
  				}
  			}
  			sb.append("{");
 			for (TextBoundaries word : s.words) {
 				sb.append(reference.substring(lastPos, word.left));
 				lastPos = word.right;
 				visit(word, sb, reference, mWordSeparator, mWordSeparator);
 			}
 			String v = reference.substring(lastPos, s.boundaries.right);
 			Matcher m = Pattern.compile("\\s+$").matcher(v);
 			if (mTrimming && m.find()) {
 				sb.append(v.substring(0, m.start()));
 				sb.append("}");
 				//sb.append(m.group()); //would move the white spaces after the }
 			} else {
 				sb.append(v);
 				sb.append("}");
 			}
 		}
 	}
 }