import org.elasticsearch.gradle.LoggedExec
import org.elasticsearch.gradle.MavenFilteringHack
import org.elasticsearch.gradle.test.NodeInfo

import javax.net.ssl.HttpsURLConnection
import javax.net.ssl.KeyManagerFactory
import javax.net.ssl.SSLContext
import javax.net.ssl.TrustManagerFactory
import java.nio.charset.StandardCharsets
import java.security.KeyStore
import java.security.SecureRandom

// Tell the tests we're running with ssl enabled
integTestRunner {
  systemProperty 'tests.ssl.enabled', 'true'
}

// needed to be consistent with ssl host checking
Object san = new SanEvaluator()

// location of generated keystores and certificates
File keystoreDir = new File(project.buildDir, 'keystore')

// Generate the node's keystore
File nodeKeystore = new File(keystoreDir, 'test-node.jks')
task createNodeKeyStore(type: LoggedExec) {
  doFirst {
    if (nodeKeystore.parentFile.exists() == false) {
      nodeKeystore.parentFile.mkdirs()
    }
    if (nodeKeystore.exists()) {
      delete nodeKeystore
    }
  }
  executable = new File(project.runtimeJavaHome, 'bin/keytool')
  standardInput = new ByteArrayInputStream('FirstName LastName\nUnit\nOrganization\nCity\nState\nNL\nyes\n\n'.getBytes('UTF-8'))
  args '-genkey',
          '-alias', 'test-node',
          '-keystore', nodeKeystore,
          '-keyalg', 'RSA',
          '-keysize', '2048',
          '-validity', '712',
          '-dname', 'CN=smoke-test-plugins-ssl',
          '-keypass', 'keypass',
          '-storepass', 'keypass',
          '-ext', san
}

// Generate the client's keystore
File clientKeyStore = new File(keystoreDir, 'test-client.jks')
task createClientKeyStore(type: LoggedExec) {
  doFirst {
    if (clientKeyStore.parentFile.exists() == false) {
      clientKeyStore.parentFile.mkdirs()
    }
    if (clientKeyStore.exists()) {
      delete clientKeyStore
    }
  }
  executable = new File(project.runtimeJavaHome, 'bin/keytool')
  standardInput = new ByteArrayInputStream('FirstName LastName\nUnit\nOrganization\nCity\nState\nNL\nyes\n\n'.getBytes('UTF-8'))
  args '-genkey',
          '-alias', 'test-client',
          '-keystore', clientKeyStore,
          '-keyalg', 'RSA',
          '-keysize', '2048',
          '-validity', '712',
          '-dname', 'CN=smoke-test-plugins-ssl',
          '-keypass', 'keypass',
          '-storepass', 'keypass',
          '-ext', san
}

// Export the node's certificate
File nodeCertificate = new File(keystoreDir, 'test-node.cert')
task exportNodeCertificate(type: LoggedExec) {
  doFirst {
    if (nodeCertificate.parentFile.exists() == false) {
      nodeCertificate.parentFile.mkdirs()
    }
    if (nodeCertificate.exists()) {
      delete nodeCertificate
    }
  }
  executable = new File(project.runtimeJavaHome, 'bin/keytool')
  args '-export',
          '-alias', 'test-node',
          '-keystore', nodeKeystore,
          '-storepass', 'keypass',
          '-file', nodeCertificate
}

// Import the node certificate in the client's keystore
task importNodeCertificateInClientKeyStore(type: LoggedExec) {
  dependsOn exportNodeCertificate
  executable = new File(project.runtimeJavaHome, 'bin/keytool')
  args '-import',
          '-alias', 'test-node',
          '-keystore', clientKeyStore,
          '-storepass', 'keypass',
          '-file', nodeCertificate,
          '-noprompt'
}

// Export the client's certificate
File clientCertificate = new File(keystoreDir, 'test-client.cert')
task exportClientCertificate(type: LoggedExec) {
  doFirst {
    if (clientCertificate.parentFile.exists() == false) {
      clientCertificate.parentFile.mkdirs()
    }
    if (clientCertificate.exists()) {
      delete clientCertificate
    }
  }
  executable = new File(project.runtimeJavaHome, 'bin/keytool')
  args '-export',
          '-alias', 'test-client',
          '-keystore', clientKeyStore,
          '-storepass', 'keypass',
          '-file', clientCertificate
}

// Import the client certificate in the node's keystore
task importClientCertificateInNodeKeyStore(type: LoggedExec) {
  dependsOn exportClientCertificate
  executable = new File(project.runtimeJavaHome, 'bin/keytool')
  args '-import',
          '-alias', 'test-client',
          '-keystore', nodeKeystore,
          '-storepass', 'keypass',
          '-file', clientCertificate,
          '-noprompt'
}

forbiddenPatterns {
  exclude '**/*.cert'
}

// Add keystores to test classpath: it expects it there
sourceSets.test.resources.srcDir(keystoreDir)
processTestResources.dependsOn(
        createNodeKeyStore, createClientKeyStore,
        importNodeCertificateInClientKeyStore, importClientCertificateInNodeKeyStore
)

integTestCluster.dependsOn(importClientCertificateInNodeKeyStore)


integTestCluster {
  // The setup that we actually want
  setting 'xpack.security.http.ssl.enabled', 'true'
  setting 'xpack.security.transport.ssl.enabled', 'true'

  // ceremony to set up ssl
  setting 'xpack.ssl.keystore.path', 'test-node.jks'
  keystoreSetting 'xpack.ssl.keystore.secure_password', 'keypass'

  // copy keystores into config/
  extraConfigFile nodeKeystore.name, nodeKeystore
  extraConfigFile clientKeyStore.name, clientKeyStore

  // Override the wait condition to work properly with security and SSL
  waitCondition = { NodeInfo node, AntBuilder ant ->
    File tmpFile = new File(node.cwd, 'wait.success')
    KeyStore keyStore = KeyStore.getInstance("JKS");
    keyStore.load(clientKeyStore.newInputStream(), 'keypass'.toCharArray());
    KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
    kmf.init(keyStore, 'keypass'.toCharArray());
    TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
    tmf.init(keyStore);
    SSLContext sslContext = SSLContext.getInstance("TLSv1.2");
    sslContext.init(kmf.getKeyManagers(), tmf.getTrustManagers(), new SecureRandom());
    for (int i = 0; i < 10; i++) {
      // we use custom wait logic here for HTTPS
      HttpsURLConnection httpURLConnection = null;
      try {
        httpURLConnection = (HttpsURLConnection) new URL("https://${node.httpUri()}/_cluster/health?wait_for_nodes=${numNodes}&wait_for_status=yellow").openConnection();
        httpURLConnection.setSSLSocketFactory(sslContext.getSocketFactory());
        httpURLConnection.setRequestProperty("Authorization", "Basic " +
                Base64.getEncoder().encodeToString("test_admin:x-pack-test-password".getBytes(StandardCharsets.UTF_8)));
        httpURLConnection.setRequestMethod("GET");
        httpURLConnection.connect();
        if (httpURLConnection.getResponseCode() == 200) {
          tmpFile.withWriter StandardCharsets.UTF_8.name(), {
            it.write(httpURLConnection.getInputStream().getText(StandardCharsets.UTF_8.name()))
          }
        }
      } catch (IOException e) {
        if (i == 9) {
          logger.error("final attempt of calling cluster health failed", e)
        } else {
          logger.debug("failed to call cluster health", e)
        }
      } finally {
        if (httpURLConnection != null) {
          httpURLConnection.disconnect();
        }
      }

      // did not start, so wait a bit before trying again
      Thread.sleep(500L);
    }

    return tmpFile.exists()
  }
}




/** A lazy evaluator to find the san to use for certificate generation. */
class SanEvaluator {

  private static String san = null

  String toString() {
    synchronized (SanEvaluator.class) {
      if (san == null) {
        san = getSubjectAlternativeNameString()
      }
    }
    return san
  }

  // Code stolen from NetworkUtils/InetAddresses/NetworkAddress to support SAN
  /** Return all interfaces (and subinterfaces) on the system */
  private static List<NetworkInterface> getInterfaces() throws SocketException {
    List<NetworkInterface> all = new ArrayList<>();
    addAllInterfaces(all, Collections.list(NetworkInterface.getNetworkInterfaces()));
    Collections.sort(all, new Comparator<NetworkInterface>() {
      @Override
      public int compare(NetworkInterface left, NetworkInterface right) {
        return Integer.compare(left.getIndex(), right.getIndex());
      }
    });
    return all;
  }

  /** Helper for getInterfaces, recursively adds subinterfaces to {@code target} */
  private static void addAllInterfaces(List<NetworkInterface> target, List<NetworkInterface> level) {
    if (!level.isEmpty()) {
      target.addAll(level);
      for (NetworkInterface intf : level) {
        addAllInterfaces(target, Collections.list(intf.getSubInterfaces()));
      }
    }
  }

  private static String getSubjectAlternativeNameString() {
    List<InetAddress> list = new ArrayList<>();
    for (NetworkInterface intf : getInterfaces()) {
      if (intf.isUp()) {
        // NOTE: some operating systems (e.g. BSD stack) assign a link local address to the loopback interface
        // while technically not a loopback address, some of these treat them as one (e.g. OS X "localhost") so we must too,
        // otherwise things just won't work out of box. So we include all addresses from loopback interfaces.
        for (InetAddress address : Collections.list(intf.getInetAddresses())) {
          if (intf.isLoopback() || address.isLoopbackAddress()) {
            list.add(address);
          }
        }
      }
    }
    if (list.isEmpty()) {
      throw new IllegalArgumentException("no up-and-running loopback addresses found, got " + getInterfaces());
    }

    StringBuilder builder = new StringBuilder("san=");
    for (int i = 0; i < list.size(); i++) {
      InetAddress address = list.get(i);
      String hostAddress;
      if (address instanceof Inet6Address) {
        hostAddress = compressedIPV6Address((Inet6Address)address);
      } else {
        hostAddress = address.getHostAddress();
      }
      builder.append("ip:").append(hostAddress);
      String hostname = address.getHostName();
      if (hostname.equals(address.getHostAddress()) == false) {
        builder.append(",dns:").append(hostname);
      }

      if (i != (list.size() - 1)) {
        builder.append(",");
      }
    }

    return builder.toString();
  }

  private static String compressedIPV6Address(Inet6Address inet6Address) {
    byte[] bytes = inet6Address.getAddress();
    int[] hextets = new int[8];
    for (int i = 0; i < hextets.length; i++) {
      hextets[i] =  (bytes[2 * i] & 255) << 8 | bytes[2 * i + 1] & 255;
    }
    compressLongestRunOfZeroes(hextets);
    return hextetsToIPv6String(hextets);
  }

  /**
   * Identify and mark the longest run of zeroes in an IPv6 address.
   *
   * <p>Only runs of two or more hextets are considered.  In case of a tie, the
   * leftmost run wins.  If a qualifying run is found, its hextets are replaced
   * by the sentinel value -1.
   *
   * @param hextets {@code int[]} mutable array of eight 16-bit hextets
   */
  private static void compressLongestRunOfZeroes(int[] hextets) {
    int bestRunStart = -1;
    int bestRunLength = -1;
    int runStart = -1;
    for (int i = 0; i < hextets.length + 1; i++) {
      if (i < hextets.length && hextets[i] == 0) {
        if (runStart < 0) {
          runStart = i;
        }
      } else if (runStart >= 0) {
        int runLength = i - runStart;
        if (runLength > bestRunLength) {
          bestRunStart = runStart;
          bestRunLength = runLength;
        }
        runStart = -1;
      }
    }
    if (bestRunLength >= 2) {
      Arrays.fill(hextets, bestRunStart, bestRunStart + bestRunLength, -1);
    }
  }

  /**
   * Convert a list of hextets into a human-readable IPv6 address.
   *
   * <p>In order for "::" compression to work, the input should contain negative
   * sentinel values in place of the elided zeroes.
   *
   * @param hextets {@code int[]} array of eight 16-bit hextets, or -1s
   */
  private static String hextetsToIPv6String(int[] hextets) {
    /*
     * While scanning the array, handle these state transitions:
     *   start->num => "num"     start->gap => "::"
     *   num->num   => ":num"    num->gap   => "::"
     *   gap->num   => "num"     gap->gap   => ""
     */
    StringBuilder buf = new StringBuilder(39);
    boolean lastWasNumber = false;
    for (int i = 0; i < hextets.length; i++) {
      boolean thisIsNumber = hextets[i] >= 0;
      if (thisIsNumber) {
        if (lastWasNumber) {
          buf.append(':');
        }
        buf.append(Integer.toHexString(hextets[i]));
      } else {
        if (i == 0 || lastWasNumber) {
          buf.append("::");
        }
      }
      lastWasNumber = thisIsNumber;
    }
    return buf.toString();
  }
}