/*
Jazzy - a Java library for Spell Checking
Copyright (C) 2001 Mindaugas Idzelis
Full text of license can be found in LICENSE.txt

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
//{{{ package and imports
//:folding=explicit:
package com.swabunga.spell.event;

import java.util.Collection;
import java.util.HashSet;

/**
 * A word finder for TeX and LaTeX documents, which searches text for sequences of letters, but ignores any commands and environments as
 * well as Math environments.
 * 
 * @author Anthony Roy (ajr@antroy.co.uk)
 */

// }}}

public class TeXWordFinder extends AbstractWordFinder {

	// {{{ ~ Instance/static variables ...............................................

	private boolean IGNORE_COMMENTS = true;
	private HashSet user_defined_ignores = new HashSet();
	private int regex_user_defined_ignores = STRING_EXPR;
	public static final int STRING_EXPR = 0;
	public static final int REG_EXPR = 1;

	// public static final int GLOB_EXPR = 2;
	// }}}
	// {{{ ~ Constructors ............................................................

	/**
	 * Creates a new DefaultWordFinder object.
	 * 
	 * @param inText
	 *            the text to search.
	 */
	public TeXWordFinder(String inText) {
		super(inText);
	}

	public TeXWordFinder() {
		super();
	}

	// }}}
	// {{{ ~ Methods .................................................................

	/**
	 * This method scans the text from the end of the last word, and returns a new Word object corresponding to the next word.
	 * 
	 * @return the next word.
	 * @throws WordNotFoundException
	 *             search string contains no more words.
	 */
	@Override
	public Word next() {
		// {{{

		if (!hasNext()) {
			throw new WordNotFoundException("No more words found.");
		}

		currentWord.copy(nextWord);
		setSentenceIterator(currentWord);

		int i = currentWord.getEnd();
		boolean finished = false;
		boolean started = false;

		search: while (i < text.length() && !finished) {

			// {{{ Find words.
			if (!started && isWordChar(i)) {
				nextWord.setStart(i++);
				started = true;
				continue search;
			} else if (started) {
				if (isWordChar(i)) {
					i++;
					continue search;
				} else {
					nextWord.setText(text.substring(nextWord.getStart(), i));
					finished = true;
					break search;
				}
			} // }}}
				// Ignores should be in order of importance and then specificity.
			int j = i;
			// Ignore Comments:
			j = ignore(j, '%', '\n');

			// Ignore Maths:
			j = ignore(j, "$$", "$$");
			j = ignore(j, '$', '$');

			// Ignore user defined.
			j = ignoreUserDefined(j);

			// Ignore certain command parameters.
			j = ignore(j, "\\newcommand", "}");
			j = ignore(j, "\\documentclass", "}");
			j = ignore(j, "\\usepackage", "}");
			j = ignore(j, "\\newcounter{", "}");
			j = ignore(j, "\\setcounter{", "}");
			j = ignore(j, "\\addtocounter{", "}");
			j = ignore(j, "\\value{", "}");
			j = ignore(j, "\\arabic{", "}");
			j = ignore(j, "\\usecounter{", "}");
			j = ignore(j, "\\newenvironment", "}");
			j = ignore(j, "\\setlength", "}");
			j = ignore(j, "\\setkeys", "}");

			// Ignore environment names.
			j = ignore(j, "\\begin{", "}");
			j = ignore(j, "\\end{", "}");
			if (i != j) {
				i = j;
				continue search;
			}

			// Ignore commands.
			j = ignore(j, '\\');

			if (i != j) {
				i = j;
				continue search;
			}
			i++;
		}

		if (!started) {
			nextWord = null;
		} else if (!finished) {
			nextWord.setText(text.substring(nextWord.getStart(), i));
		}

		return currentWord;
	}

	// }}}
	/**
	 * This method is used to import a user defined set of either strings or regular expressions to ignore.
	 * 
	 * @param expressions
	 *            a collection of of Objects whose toString() value should be the expression. Typically String objects.
	 * @param regex
	 *            is an integer specifying the type of expression to use. e.g. REG_EXPR, STRING_EXPR.
	 */
	public void addUserDefinedIgnores(Collection expressions, int regex) {
		user_defined_ignores.addAll(expressions);
		regex_user_defined_ignores = regex;
	}

	private int ignoreUserDefined(int i) {
		return i;
	}

	public void setIgnoreComments(boolean ignore) {
		IGNORE_COMMENTS = ignore;
	}
	// }}}
}