package net.curisit.securis;

import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import net.curisit.securis.ConnectionManager.Command;
import net.curisit.securis.beans.LicenseBean;
import net.curisit.securis.beans.RequestBean;
import net.curisit.securis.beans.SignedLicenseBean;
import net.curisit.securis.beans.StatusBean;
import net.curisit.securis.utils.JsonUtils;
import net.curisit.securis.utils.Params;
import net.curisit.securis.utils.SignatureHelper;

import org.apache.commons.io.FileUtils;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/**
 * Manage all licenses tasks, just like validation, renew, requesting, ...
 * 
 * @author roberto <roberto.sanchez@curisit.net>
 */
public class LicenseManager {

	private static final Logger LOG = LogManager.getLogger(LicenseManager.class);

	private static LicenseManager singleton = new LicenseManager();

	public static final String PING_MESSAGE = "SeCuris API OK";
	public static final String HEADER_LICENSE_NAME_OR_REFERENCE = "X-SECURIS-LIC-NAMEREF";
	public static final String HEADER_LICENSE_EMAIL = "X-SECURIS-LIC-EMAIL";

	private LicenseManager() {}

	public static LicenseManager getInstance() {
		return singleton;
	}

	/**
	 * Loads a license from file
	 * 
	 * @param licFile
	 * @return The license bean
	 * @throws SeCurisException
	 */
	public LicenseBean load(File licFile) throws SeCurisException {
		LicenseBean licBean;
		try {
			licBean = JsonUtils.json2object(FileUtils.readFileToString(licFile), LicenseBean.class);
		} catch (IOException e) {
			throw new SeCurisException("Error getting license data from file: " + licFile, e);
		}
		return licBean;
	}

	/**
	 * Validates the license stored in {@code licFile} and get the corresponding LicenseBean
	 * <p>
	 * The validation includes:
	 * <ul>
	 * <li>Signature</li>
	 * <li>HW data</li>
	 * <li>Logo CRC</li>
	 * </ul>
	 * </p>
	 * 
	 * @param licFile
	 * @return The license bean stored in file
	 * @throws SeCurisException
	 */
	public LicenseBean validateLicense(File licFile) throws SeCurisException {

		return validateLicense(licFile, false);
	}

	/**
	 * Validates the license stored in {@code licFile} and get the corresponding LicenseBean. The License date is not validated
	 * <p>
	 * The validation includes:
	 * <ul>
	 * <li>Signature</li>
	 * <li>HW data</li>
	 * <li>Logo CRC</li>
	 * </ul>
	 * </p>
	 * 
	 * @param licFile
	 * @return The license bean stored in file
	 * @throws SeCurisException
	 */
	public LicenseBean validateLicense(File licFile, boolean excludeDateValidation) throws SeCurisException {
		LicenseBean licBean = load(licFile);
		SignatureHelper.getInstance().validateSignature(licBean);
		LicenseValidator.getInstance().validateHW(licBean, Params.get(Params.KEYS.LIC_TYPE_CODE, Params.get(Params.KEYS.APPLICATION_CODE)), Params.get(Params.KEYS.CUSTOMER_CODE), Params.get(Params.KEYS.PACK_CODE));
		LicenseValidator.getInstance().validateLogo(licBean);

		if (!excludeDateValidation) {
			if (new Date().after(licBean.getExpirationDate())) {
				throw new ExpiredLicenseException();
			}
		}

		return licBean;
	}

	/**
	 * Request to server for a valid license
	 * 
	 * @return The license bean returned by the server
	 * @throws SeCurisException
	 */
	public SignedLicenseBean requestLicense(String nameOrReference, String email) throws SeCurisException {
		RequestBean req = ReqGenerator.getInstance().createRequest(Params.get(Params.KEYS.LIC_TYPE_CODE, Params.get(Params.KEYS.APPLICATION_CODE)), Params.get(Params.KEYS.CUSTOMER_CODE), Params.get(Params.KEYS.PACK_CODE));

		SignedLicenseBean lic = requestLicenseToServer(req, nameOrReference, email);
		return lic;
	}

	/**
	 * Generate a license file using a {@link LicenseBean}
	 * 
	 * @param license
	 * @param file
	 * @throws SeCurisException
	 */
	public void save(LicenseBean license, File file) throws SeCurisException {
		SignedLicenseBean signedLic = new SignedLicenseBean(license);
		save(signedLic, file);
	}

	/**
	 * Generate a license file using a {@link LicenseBean}
	 * 
	 * @param license
	 * @param file
	 * @throws SeCurisException
	 */
	public void save(SignedLicenseBean signedLic, File file) throws SeCurisException {
		byte[] json;
		try {
			json = JsonUtils.toPrettyJSON(signedLic).getBytes("utf-8");
			Files.write(Paths.get(file.toURI()), json, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
		} catch (UnsupportedEncodingException e) {
			LOG.error("Error creating json doc from license: " + signedLic, e);
			throw new SeCurisException("Error creating json doc from license: " + signedLic, e);
		} catch (IOException e) {
			LOG.error("Error creating license file: " + file, e);
			throw new SeCurisException("Error creating json doc from license: " + signedLic, e);
		}

		LOG.debug("License saved in {}", file);

	}

	private SignedLicenseBean requestLicenseToServer(RequestBean req, String nameOrReference, String email) throws SeCurisException {
		Map<String, String> headers = new HashMap<String, String>();
		headers.put(HEADER_LICENSE_NAME_OR_REFERENCE, nameOrReference);
		headers.put(HEADER_LICENSE_EMAIL, email);
		SignedLicenseBean lic = ConnectionManager.getInstance().executePost(Command.CREATE_LIC, SignedLicenseBean.class, req, headers);

		return lic;
	}

	/**
	 * Creates a new request file with current hardware in the File passed as parameter
	 * 
	 * @param outputRequestFile
	 *            File where the request data will be saved
	 * @return The generated request bean
	 * @throws SeCurisException
	 */
	public RequestBean createRequestFile(File outputRequestFile) throws SeCurisException {
		RequestBean req = ReqGenerator.getInstance().createRequest(Params.get(Params.KEYS.LIC_TYPE_CODE, Params.get(Params.KEYS.APPLICATION_CODE)), Params.get(Params.KEYS.CUSTOMER_CODE), Params.get(Params.KEYS.PACK_CODE));

		ReqGenerator.getInstance().save(req, outputRequestFile);

		return req;
	}

	/**
	 * Send the current license file to server, which is previously validated, to get a renewed one if it is prepared in server side.
	 * 
	 * @param licenseFile
	 *            Current and valid License file
	 * @return New license bean if server creates a new one, otherwise the same current License bean will be returned
	 * @throws SeCurisException
	 */
	public SignedLicenseBean renew(File licenseFile) throws SeCurisException {
		LicenseBean lic = validateLicense(licenseFile, true);

		SignedLicenseBean newLic = ConnectionManager.getInstance().executePost(Command.RENEW_LIC, SignedLicenseBean.class, lic);

		return newLic;
	}

	/**
	 * Check on SeCuris server if current license is still valid in server DB.
	 * 
	 * @param licenseFile
	 * @throws SeCurisException
	 */
	public void assertLicenseIsValid(File licenseFile) throws SeCurisException, IOException {
		LicenseBean lic = validateLicense(licenseFile);
		// We need to snd the signed version to validate signature on server
		ConnectionManager.getInstance().executePost(Command.VALIDATE, LicenseBean.class, new SignedLicenseBean(lic));
	}

	public void testServer() throws SeCurisException {
		StatusBean status = ConnectionManager.getInstance().executeGet(Command.TEST, StatusBean.class);
		if (!PING_MESSAGE.equals(status.getMessage())) {
			throw new SeCurisException("SeCuris Server is not running in given URL");
		}
	}

	public static void main(String[] args) throws SeCurisException {
		String filename  = "/Users/rob/.doxr/doxr.lic";

		if (filename == null)
			filename = "./license.req";
		File file = new File(filename);
		LicenseManager.getInstance().validateLicense(file);
		LOG.info("Validation Ok");
		String r = "{\"licenseTypeCode\":\"DX01\",\"packCode\":\"DEVDX01\",\"arch\":\"x86_64\",\"osName\":\"darwin\",\"customerCode\":\"CIT\",\"macAddresses\":[\"60:c5:47:03:cf:c8\",\"b2:00:12:b6:88:e0\"]}";
		RequestBean rb = JsonUtils.json2object(r, RequestBean.class);
		System.out.println(rb);
		LOG.info("Request file {} generated OK", file.getAbsolutePath());

	}
}