package spiversioning;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileFilter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;



public class SPIVersioning {
	
	/**
	 * alter this to your own environment. The format must match the systems canonical filename form.
	 */
	static final String sourceRoot = "C:\\Dev3\\SCA\\modules\\";
	
	public static void main(String[] args) throws Throwable {
	

		File root = new File(sourceRoot);
		File rootf =root.getAbsoluteFile();
		File[] contents = rootf.listFiles();

		SPIVersioning hs = new SPIVersioning();
		
		System.out.println("<spifiles>");
		for (File file : contents) {
			hs.analyseProjectDir(file);
		}
		System.out.println("</spifiles>");
			
				
	}

	private void analyseProjectDir(File pdir) {
		
		try {
			File javaSrc = new File(pdir.getAbsolutePath() + "/src/main/java");
			File jsrcdir = javaSrc.getAbsoluteFile();
			File[] pkgRoots = jsrcdir.listFiles();


			for (File proot : pkgRoots) {
				analyzeJavaFiles(proot);
			}

		} catch (Exception e) {
			// TODO: handle exception
		}
		
		
		
	}
	
	String fileToString (File f) throws java.io.IOException{
        StringBuffer sb = new StringBuffer(1000);
        BufferedReader reader = new BufferedReader(new FileReader(f));
        char[] buf = new char[1024];
        int count = 0;
        while((count=reader.read(buf)) != -1){
            String readData = String.valueOf(buf, 0, count);
            sb.append(readData);
            buf = new char[1024];
        }
        reader.close();
        return sb.toString();
    }
    
	static class PkgDirFilter implements FileFilter {

		public boolean accept(File pathname) {
			boolean rv = false;
			if (pathname.isDirectory()) {
				rv = true;
			} else if(pathname.getName().endsWith(".java")) {
				rv = true;
			} else if (pathname.getName().equals("package.html")) {
				rv = true;
			}
			
			return rv;
		}
	
	}
	private void analyzeJavaFiles(File proot) throws Exception {
		

		File[] filesOfInterest = proot.listFiles(new PkgDirFilter());
		for (File file : filesOfInterest) {
			if(file.isDirectory()) {
				analyzeJavaFiles(file);
			} else if (file.getName().equals("package.html")) {
				// TODO decide if this means every java file in this package is implicitly spi
			} else {
				String fcontents = fileToString(file);
				if(fcontents.contains("@tuscany.spi.extension")) {
					String digest = md5(file);
					String cpath = file.getCanonicalPath();
					cpath = cpath.replace(sourceRoot, "");
					System.out.println("    <file path=\""+cpath+"\" md5=\"" +digest + "\"/>");
				}


			}
			
		}
		
	}

	private static String md5(File f) {
		MessageDigest digest = null;
		try {
			digest = MessageDigest.getInstance("MD5");
		} catch (NoSuchAlgorithmException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}

		InputStream is = null;
		String output = null;
		try {
			is = new FileInputStream(f);
		} catch (FileNotFoundException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}				
		byte[] buffer = new byte[8192];
		int read = 0;
		try {
			while( (read = is.read(buffer)) > 0) {
				digest.update(buffer, 0, read);
			}		
			byte[] md5sum = digest.digest();
			BigInteger bigInt = new BigInteger(1, md5sum);
			output = bigInt.toString(16);
		}
		catch(IOException e) {
			throw new RuntimeException("Unable to process file for MD5", e);
		}
		finally {
			try {
				is.close();
			}
			catch(IOException e) {
				throw new RuntimeException("Unable to close input stream for MD5 calculation", e);
			}
		}		
		return output;
	}




}