package com.nokia.cpp.internal.api.utils.ui;

import java.util.ArrayList;

import java.util.List;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import org.eclipse.jface.resource.JFaceColors;

import org.eclipse.jface.viewers.StyledString;

import org.eclipse.jface.viewers.StyledString.Styler;

import org.eclipse.swt.graphics.TextStyle;

import org.eclipse.swt.widgets.Display;

public class LinkParser {

	public static class Element {

		private String text;

		public Element(String text) {

			this.text = text;

		}

		public String getText() {

			return text;

		}

	}

	public static class LinkElement extends Element {

		private String href;

		public LinkElement(String href, String text) {

			super(text);

			this.href = href;

		}

		public String getHref() {

			return href;

		}

	}

	private static final Pattern HREF_PATTERN = Pattern.compile("<a href=\"([^\"]*)\">(.*?)</a>", Pattern.CASE_INSENSITIVE);

	private static Styler hyperLinkStyler = new Styler() {

		@Override

		public void applyStyles(TextStyle textStyle) {

			textStyle.foreground = JFaceColors.getHyperlinkText(Display.getDefault());

			textStyle.underline = true;

		}

	};

	public static List<Element> parseText(String text) {

		List<Element> elements = new ArrayList<Element>();

		if (text != null) {

			Matcher m = HREF_PATTERN.matcher(text);

			int start = 0;

			int end;

			while (m.find()) {

				end = m.start();

				if (start <= end)

					elements.add(new Element(text.substring(start, end)));

				elements.add(new LinkElement(m.group(1), m.group(2)));

				start = m.end();

			}

			end = text.length();

			if (start <= end)

				elements.add(new Element(text.substring(start, end)));

		}

		return elements;

	}

	public static StyledString getStyledString(List<Element> elements) {

		StyledString styledString = new StyledString();

		for (Element element : elements) {

			styledString.append(element.getText(), element instanceof LinkElement ? hyperLinkStyler : null);

		}

		return styledString;

	}

}