package lu.technolink.vaadin.theme.precompiler;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileFilter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class VaadinThemePreCompiler {

	/**
	 * @param args
	 * 
	 * Prepare the Vaadin themes by changing the url paths in order to make them work with the SASS/Compass compiler
	 * 
	 */
	
	private static final String[] VAADIN_THEMES = new String[] { "base", "chameleon", "liferay", "reindeer", "runo" };
	private static final String PATTERN = "(.+) url\\(([\\w/\\.-]+)\\)(.+)";
	
	public static void main(String[] args) {
		VaadinThemePreCompiler compiler = new VaadinThemePreCompiler();
		compiler.compile();
	}
	
	public void compile() {
		for (String theme : VaadinThemePreCompiler.VAADIN_THEMES) {
			System.out.println("Pre-compiling the theme --- " + theme + " ---");
			compileTheme("VAADIN" + File.separator + theme);
		}
		
		System.out.println("Done.");
	}

	private void compileTheme(final String theme) {
		File themeRoot = new File(theme);
		if (themeRoot != null && themeRoot.isDirectory()) {
			processDirectory(themeRoot);
		}
	}
	
	private void processDirectory(final File directory) {
		System.out.println("\tProcessing directory --- " + directory.getName() + "---");
		File[] listFiles = directory.listFiles(new FileFilter() {

			@Override
			public boolean accept(File pathname) {
				return pathname.isDirectory() || pathname.getName().toLowerCase().endsWith(".scss");
			}
		});
		
		for (File file : listFiles) {
			if (file.isDirectory()) {
				processDirectory(file);
			} else {
				processFile(file);
			}
		}
		
	}

	private void processFile(final File file) {
		System.out.println("\t\tProcessing file --- " + file.getName() + "---");
		StringBuffer buffer = new StringBuffer();
		String currentLine;
		Pattern pattern = Pattern.compile(VaadinThemePreCompiler.PATTERN);
		try {
			BufferedReader br = new BufferedReader(new FileReader(file));
			while ((currentLine = br.readLine()) != null) {
				Matcher matcher = pattern.matcher(currentLine);
				
				if (matcher.matches()) {
					String parent = file.getParent().replaceFirst("VAADIN", "..");
					String path = matcher.group(2);
					while (path.startsWith("..")) {
						path = path.substring(path.indexOf("/") + 1);
						parent = parent.substring(0, parent.lastIndexOf("/"));
					}
					String newPath = "url(" + parent + "/" + path + ")";
					currentLine = matcher.replaceAll("$1 " + newPath + "$3");
				}
				buffer.append(currentLine).append("\n");
			}
			br.close();
			BufferedWriter bw = new BufferedWriter(new FileWriter(file, false));
			bw.append(buffer);
			bw.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
}