package org.openslx.satellitedaemon;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.KeyFactory;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.cert.CertificateException;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.util.Properties;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;

import org.apache.log4j.Logger;

public class Globals {
	private static Logger log = Logger.getLogger(Globals.class);
	private static final Properties properties = new Properties();
	private static SSLContext context = null;
	private static final KeyFactory keyFact;

	public static final int BLOCKSIZE = 16 * 1024 * 1024; // 16 MB blocksize

	public static void init() {
	}

	/***********************************************************************************************/
	/**
	 * A call of Globals.getXXXXXX() returns the corresponding entry in config/global.properties
	 */
	
	// * Properties *//

	// Strings //
	public static String getMasterserverHost() {
		return properties.getProperty("MASTERSERVER_HOST");
	}

	public static String getKeystoreType() {
		return properties.getProperty("KEYSTORE_TYPE");
	}

	public static String getFiletransferKeystorePath() {
		return properties.getProperty("FILETRANSFER_KEYSTORE_PATH");
	}

	public static String getFiletransferKeystorePassword() {
		return properties.getProperty("FILETRANSFER_KEYSTORE_PASSWORD");
	}

	public static String getOrganizationName() {
		return properties.getProperty("ORGANIZATION_NAME");
	}

	public static String getThriftKeystoreAlias() {
		return properties.getProperty("THRIFT_KEYSTORE_ALIAS");
	}

	public static String getThriftKeystorePassword() {
		return properties.getProperty("THRIFT_KEYSTORE_PASSWORD");
	}

	public static String getThriftKeystorePath() {
		return properties.getProperty("THRIFT_KEYSTORE_PATH");
	}
	
	public static String getImageFolder() {
		return properties.getProperty("IMAGE_FOLDER");
	}

	// Integers //

	public static int getThriftPort() {
		return tryToParseInt(properties.getProperty("THRIFT_PORT"));
	}

	/**
	 * Load properties
	 */
	static {
		try {
			// Load all entries of the config file into properties
			InputStreamReader stream = new InputStreamReader(
					new FileInputStream("config/global.properties"), StandardCharsets.UTF_8);
			properties.load(stream);
			stream.close();
		} catch (IOException e) {
			log.error("Could not load properties. Exiting.");
			System.exit(2);
		}
		
		KeyFactory kf;
		try {
			kf = KeyFactory.getInstance("RSA");
		} catch (NoSuchAlgorithmException nSAE) {
			kf = null;
		}
		keyFact = kf;
		
		notNullOrEmptyFatal(getMasterserverHost(), "Masterserver Host must not be empty!");
		// TODO: check properties
	}

	/***********************************************************************************************/
	/**
	 * 
	 * @return
	 */
	public static boolean masterServerSslContextInit() {
		char[] passphrase = getFiletransferKeystorePassword().toCharArray();
		KeyStore keystore;
		try {
			keystore = KeyStore.getInstance("JKS");
			keystore.load(new FileInputStream(getFiletransferKeystorePath()),
					passphrase);
			TrustManagerFactory tmf = TrustManagerFactory
					.getInstance(TrustManagerFactory.getDefaultAlgorithm());
			tmf.init(keystore);
			context = SSLContext.getInstance("SSLv3");
			TrustManager[] trustManagers = tmf.getTrustManagers();
			context.init(null, trustManagers, null);
		} catch (KeyStoreException e) {
			log.error("KeyStoreException");
			return false;
		} catch (NoSuchAlgorithmException e) {
			log.error("NoSuchAlgorithmException");
			return false;
		} catch (CertificateException e) {
			log.error("CertificateException");
			return false;
		} catch (FileNotFoundException e) {
			log.error("Could not find the keystore for the filetransfer. Path was '" + getFiletransferKeystorePath() + "'");
			return false;
		} catch (IOException e) {
			log.error("IOException", e);
			return false;
		} catch (KeyManagementException e) {
			log.error("KeyManagementException");
			return false;
		}
		return true;
	}

	public static SSLContext getMasterServerSslContext() {
		return Globals.context;
	}

	/**
	 * Tries to parse an int. Returns 0 on error.
	 * 
	 * @param s
	 *            The strig to parse
	 * @return The parsed int or 0 on error
	 */
	public static int tryToParseInt(String s) {
		try {
			return Integer.parseInt(s);
		} catch (NumberFormatException e) {
			return 0;
		}
	}

	public static void notNullOrEmptyFatal(String something, String message) {
		if (something == null || something.isEmpty()) {
			if (message != null)
				log.fatal("[NOTNULL] " + message);
			log.warn(Thread.currentThread().getStackTrace().toString());
			System.exit(2);
		}
	}
	
	public static PrivateKey getPrivateKey() {
		PrivateKey ret;
		BufferedReader br = null;
		String modulus, exponent;
		try {
			br = new BufferedReader(new FileReader("config/private.key"));
			modulus = br.readLine();
			exponent = br.readLine();
		} catch (FileNotFoundException e) {
			log.error("File 'private.key' not found!", e);
			return null;
		} catch (IOException e) {
			log.error("File 'private.key' not correct readable.", e);
			return null;
		} finally {
			try {
				br.close();
			} catch (IOException e) {
			}
		}
		if (modulus == null || exponent == null) {
			return null;
		}
		
		try {
			BigInteger mod = new BigInteger(modulus);
			BigInteger exp = new BigInteger(exponent);
			
			RSAPrivateKeySpec keySpec = new RSAPrivateKeySpec(mod, exp);
			synchronized (keyFact) {
				ret = keyFact.generatePrivate(keySpec);
			}
		} catch (InvalidKeySpecException e) {
			log.error("Not able to build key with given numbers.", e);
			return null;
		} catch (NumberFormatException e) {
			log.error("Invalid number format.", e);
			return null;
		}
		return ret;
	}
}