package credence;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class IntegrityBD {

	private static byte[] hashFile(int clientId) {
		File yourFile = new File("voteList" + clientId + ".txt");

		MessageDigest md = MessageDigest.getInstance("SHA-256");

		FileInputStream iFile = new FileInputStream(yourFile);
		BufferedReader reader = new BufferedReader(new InputStreamReader(iFile));

		String text;

		String line;
		while((line= reader.readLine())!=null){
			String parts[] = line.split(" ");
			for(int i = 0; i < parts.length; i++){
				text += parts[i];
				text += clientId;
			}
		}

		reader.close();
		iFile.close();

		md.update(text.getBytes("UTF-8")); // Change this to "UTF-16" if needed
		byte[] digest = md.digest();


//Double Digest just to be super safe
/*
		String digestedOnce = new String(digest,"UTF-8");

		md = MessageDigest.getInstance("SHA-256");
		md.update(text.getBytes("UTF-8")); // Change this to "UTF-16" if needed
		* need to mixup some more secrets into the string
		byte[] finalDigest = md.digest();
*/
		return digest;
	}


	public static void saveHashFile(int clientId){
		byte[] digest = hashFile (int clientId);
		FileOutputStream out = new FileOutputStream("digested" + clientId + ".txt");
		out.write(digest);
		out.close();
	}

	public static boolean checkIntegrity(int clientId) {
		byte[] savedDigest;

		/*TODO STUFF*/
		return Arrays.equals(hashFile(int clientId),savedDigest);
	}


}