package net.curisit.securis;

import java.io.File;
import java.io.IOException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Signature;
import java.security.SignatureException;
import java.security.spec.InvalidKeySpecException;
import java.text.MessageFormat;
import java.util.Date;
import java.util.Map;

import net.curisit.securis.beans.LicenseBean;
import net.curisit.securis.beans.RequestBean;

import org.apache.commons.net.util.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * License generator and signer
 * 
 * @author roberto <roberto.sanchez@curisit.net>
 */
public class LicenseGenerator {

	private static final Logger log = LoggerFactory.getLogger(LicenseGenerator.class);

	private static LicenseGenerator singleton = new LicenseGenerator();

	private LicenseGenerator() {
	}

	public static LicenseGenerator getInstance() {
		return singleton;
	}

	/**
	 * Generate a license bean with the specified data
	 * 
	 * @param hw
	 * @param customerCode
	 *            - e.g: "BP"
	 * @param maxInstances
	 * @param maxUsers
	 * @param maxTimeThreshold
	 *            Max time between synchronizations expressed in days
	 * @return
	 * @throws SeCurisException
	 */
	public LicenseBean generateLicense(RequestBean req, Map<String, Object> metadata, Date expirationDate, String licenseCode) throws SeCurisException {
		log.info(MessageFormat.format("Generating license: MAC: {0}, Customer code: {1}, AppCode: {2}", req.getMacAddresses(), req.getCustomerCode(), req.getAppCode()));
		LicenseBean license = new LicenseBean(req);
		license.setLicenseCode(licenseCode);
		license.setExpirationDate(expirationDate);
		license.setMetadata(metadata);
		sign(license);

		return license;
	}

	/**
	 * TODO: This method should be removed from client code.
	 * 
	 * @param licBean
	 * @return
	 * @throws NoSuchAlgorithmException
	 * @throws IOException
	 * @throws InvalidKeySpecException
	 * @throws InvalidKeyException
	 * @throws SignatureException
	 */
	public String sign(LicenseBean licBean) throws SeCurisException {
		SignatureHelper sh = SignatureHelper.getInstance();

		Signature signature;
		try {
			signature = Signature.getInstance(SignatureHelper.SIGNATURE_GENERATION_ALGORITHM);
			signature.initSign(sh.generatePrivateKey(new File("/Users/cproberto/Documents/wsPython/doky/tests/privkey.pkcs8")));

			sh.prepareSignature(signature, licBean);

			byte[] signatureData = signature.sign();
			licBean.setSignature(Base64.encodeBase64String(signatureData));
			return licBean.getSignature();
		} catch (NoSuchAlgorithmException e) {
			log.error("Error signing license for " + licBean, e);
		} catch (InvalidKeyException e) {
			log.error("Error signing license for " + licBean, e);
		} catch (InvalidKeySpecException e) {
			log.error("Error signing license for " + licBean, e);
		} catch (IOException e) {
			log.error("Error signing license for " + licBean, e);
		} catch (SignatureException e) {
			log.error("Error signing license for " + licBean, e);
		}
		throw new SeCurisException("License could not be generated");
	}

	public static void main(String[] args) throws IOException, NoSuchAlgorithmException, InvalidKeySpecException, NoSuchProviderException, InvalidKeyException, SignatureException {

		System.out.print("os.arch: " + System.getProperty("os.arch") + " " + System.getProperty("os.name"));

	}
}