package org.codehaus.groovy.modules.pages;

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

/**
 * Created by IntelliJ IDEA.
 * Author: Troy Heninger
 * Date: Jan 10, 2004
 * Utility class to strip HTML from around tags that specify it.
 */
class Strip {
	private static Pattern stripTag = Pattern.compile("\\^([a-zA-Z]+)%\\{([^}]|\\}[^%])*\\}%");
	private static Pattern anyTag = Pattern.compile("((\\^[a-zA-Z])?%\\{([^}]|\\}[^%])*\\}%|[$@]\\{[^}]*\\})");

	private StringBuffer text;

	Strip(CharSequence text) {
		this.text = new StringBuffer(text.toString());
	} // Scan()

	void strip(int index) {
		Matcher match = stripTag.matcher(text);
		if (match.find(index)) {
			strip(match.end());
			String tag = match.group(1);
			int start = match.start() + 1 + tag.length(); // begin after '^tag'; at the '%{'
			int end = match.end();
			Pattern patAfter = Pattern.compile("</" + tag + "(>|[^>a-zA-Z][^>]*>)\\s*", Pattern.CASE_INSENSITIVE);
			Matcher matchAfter = patAfter.matcher(text);
			if (matchAfter.find(end)) {
				int end2 = matchAfter.end();
				Matcher matchAny = anyTag.matcher(text.subSequence(0, end2));
				if (matchAny.find(end)) end2 = matchAny.start();
				Pattern nextTagPat = Pattern.compile("<" + tag + "(\\s|>)", Pattern.CASE_INSENSITIVE);
				Matcher matchNext = nextTagPat.matcher(text.subSequence(0, end2));
				if (matchNext.find(end)) end2 = matchNext.start();
					// System.out.println("Stripping " + text.subSequence(end, end2));
				text.delete(end, end2);
			}
			Pattern patBefore = Pattern.compile(new Reverse("*s\\<" + tag).toString(),
					Pattern.CASE_INSENSITIVE);
			Matcher matchBefore = patBefore.matcher(new Reverse(text, 0, start));
			if (matchBefore.find()) {
				int start2 = start - matchBefore.end();
				Matcher matchAny = anyTag.matcher(text.subSequence(0, start));
				if (matchAny.find(start2)) start2 = matchAny.end();
					// System.out.println("Stripping " + text.subSequence(start2, start));
				text.delete(start2, start);
			}
		}
	} // strip()

	public String toString() {
		return text.toString();
	}

} // Strip