import java.util.List;
import java.lang.StringBuilder;

import java.util.regex.Pattern;
import java.util.regex.Matcher;

/**
 * String related stuff
 */
public class StringHelper {

	/*
	 * Regex Constants.
	 * 
	 * Hints:
	 * 
	 * \\\\[^\\rn] match the concator. concator must not be appended with \n \r or
	 * \\.
	 * 
	 * [^\\r\\n]*[\\r\\n]+ is match to line breaker.
	 * 
	 */

	private static final Pattern gRegStrCctor = Pattern.compile("\\\\[^\\\\rn][^\\r\\n]*[\\r\\n]+");
	private static final Pattern gRegDoubleQuote = Pattern.compile("\\\"\\\"");
	// private static final Pattern gRegEscSlash = Pattern.compile("\\\\\\\\");
	private static final Pattern gRegEscTab = Pattern.compile("\\t");
	private static final Pattern gRegEscEol = Pattern.compile("\\r?\\n");

	public static String cutLanguageHead(String strl) {
		return strl.substring("Language:".length());
	}

	public static String cutSectionHead(String strl) {
		return strl.substring(1, strl.length() - 1);
	}

	public static String cutString(String strl) {
		return strl.substring(1, strl.length() - 1);
	}

	public static String regulateString(String strl) {
		// remove string concator
		strl = gRegStrCctor.matcher(strl).replaceAll(Matcher.quoteReplacement(""));

		// replace "" with "
		strl = gRegDoubleQuote.matcher(strl).replaceAll(Matcher.quoteReplacement("\""));

		// leave double back slash alone. we still need it.
//		strl = gRegEscSlash.matcher(strl).replaceAll(Matcher.quoteReplacement("\\"));

		// replace real escape to escape char
		strl = gRegEscTab.matcher(strl).replaceAll(Matcher.quoteReplacement("\\t"));
		strl = gRegEscEol.matcher(strl).replaceAll(Matcher.quoteReplacement("\\n"));

		return strl;
	}

	public static String processString(String strl) {
		return regulateString(cutString(strl));
	}

	public static String processConcatedString(List<String> ls) {
		StringBuilder sb = new StringBuilder();
		for (String node : ls) {
			sb.append(regulateString(cutString(node)));
		}

		return sb.toString();
	}

}