//Dstl (c) Crown Copyright 2017
package uk.gov.dstl.baleen.contentmappers.helpers;

import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import org.apache.uima.jcas.JCas;
import org.apache.uima.jcas.tcas.Annotation;

import uk.gov.dstl.baleen.types.structure.Structure;

/**
 * Holds and constructs text and annotations whilst the HTML is being converted to JCas.
 * 
 * Note that build should only be called once (as it sets the text of the jCas).
 *
 */
public class JCasBuilder {
	private List<Annotation> annotations = new LinkedList<>();
	private StringBuilder documentText = new StringBuilder();
	private JCas jCas;

	/**
	 * Instantiates a new builder.
	 *
	 * @param jCas the jCas
	 */
	public JCasBuilder(JCas jCas) {
		this.jCas = jCas;

	}

	/**
	 * Gets the jcas.
	 *
	 * @return the jcas
	 */
	public JCas getJCas() {
		return jCas;
	}

	/**
	 * Gets the current offset within the underconstruction text buffer.
	 *
	 * @return the current offset
	 */
	public int getCurrentOffset() {
		return documentText.length();
	}

	/**
	 * Adds text.
	 *
	 * @param text the text
	 */
	public void addText(String text) {
		documentText.append(text);
	}

	/**
	 * Adds annotations.
	 *
	 * @param collection the collection
	 * @param begin the begin
	 * @param end the end
	 * @param depth the depth (within the tags)
	 */
	public void addAnnotations(Collection<Annotation> collection, int begin, int end, int depth) {
		collection.forEach(a -> {
			a.setBegin(begin);
			a.setEnd(end);
			if (a instanceof Structure) {
				((Structure) a).setDepth(depth);
			}
			annotations.add(a);
		});
	}

	/**
	 * Apply the text and annotations to the jCas.
	 * 
	 * Once call once.
	 */
	public void build() {
		jCas.setDocumentText(documentText.toString());
		for (Annotation a : annotations) {
			a.addToIndexes(jCas);
		}
	}
}