/*
    * Licensed under the GPL License. You may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *   https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
    *
    * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
    * WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
    * PURPOSE.
   */
  package psiprobe.controllers.certificates;
  
  import jakarta.servlet.http.HttpServletRequest;
  import jakarta.servlet.http.HttpServletResponse;
  
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.lang.reflect.InvocationTargetException;
  import java.net.URI;
  import java.net.URL;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.security.KeyStore;
  import java.security.cert.Certificate;
  import java.security.cert.X509Certificate;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  
  import javax.management.ObjectName;
  
  import org.apache.catalina.connector.Connector;
  import org.apache.coyote.ProtocolHandler;
  import org.apache.coyote.http11.AbstractHttp11Protocol;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.stereotype.Controller;
  import org.springframework.web.bind.annotation.RequestMapping;
  import org.springframework.web.servlet.ModelAndView;
  
  import psiprobe.controllers.AbstractTomcatContainerController;
  import psiprobe.model.certificates.Cert;
  import psiprobe.model.certificates.CertificateInfo;
  import psiprobe.model.certificates.ConnectorInfo;
  import psiprobe.model.certificates.SslHostConfigInfo;
  
  /**
   * The Class ListCertificatesController.
   */
  @Controller
  public class ListCertificatesController extends AbstractTomcatContainerController {
  
    /** The Constant logger. */
    private static final Logger logger = LoggerFactory.getLogger(ListCertificatesController.class);
  
    @RequestMapping(path = "/certificates.htm")
    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response)
        throws Exception {
      return super.handleRequest(request, response);
    }
  
    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest request,
        HttpServletResponse response) throws Exception {
  
      ModelAndView modelAndView = new ModelAndView(getViewName());
  
      try {
        List<Connector> connectors = getContainerWrapper().getTomcatContainer().findConnectors();
        List<ConnectorInfo> infos = getConnectorInfos(connectors);
  
        for (ConnectorInfo info : infos) {
          List<Cert> certs;
  
          List<SslHostConfigInfo> sslHostConfigInfos = info.getSslHostConfigInfos();
          for (SslHostConfigInfo sslHostConfigInfo : sslHostConfigInfos) {
            if (sslHostConfigInfo.getTruststoreFile() != null) {
              certs = getCertificates(sslHostConfigInfo.getTruststoreType(),
                  sslHostConfigInfo.getTruststoreFile(), sslHostConfigInfo.getTruststorePassword());
              sslHostConfigInfo.setTrustStoreCerts(certs);
            }
  
            List<CertificateInfo> certificateInfos = sslHostConfigInfo.getCertificateInfos();
            for (CertificateInfo certificateInfo : certificateInfos) {
              if (certificateInfo.getCertificateKeystoreFile() != null) {
                certs = getCertificates(certificateInfo.getCertificateKeystoreType(),
                    certificateInfo.getCertificateKeystoreFile(),
                    certificateInfo.getCertificateKeystorePassword());
                certificateInfo.setKeyStoreCerts(certs);
              }
            }
            sslHostConfigInfo.setCertificateInfos(certificateInfos);
          }
          info.setSslHostConfigInfos(sslHostConfigInfos);
        }
 
       modelAndView.addObject("connectors", infos);
     } catch (Exception e) {
       logger.error("There was an exception listing certificates", e);
     }
 
     return modelAndView;
 
   }
 
   /**
    * Gets the certificates.
    *
    * @param storeType the store type
    * @param storeFile the store file
    * @param storePassword the store password
    *
    * @return the certificates
    *
    * @throws Exception the exception
    */
   public List<Cert> getCertificates(String storeType, String storeFile, String storePassword)
       throws Exception {
     KeyStore keyStore;
 
     // Get key store
     if (storeType != null) {
       keyStore = KeyStore.getInstance(storeType);
     } else {
       keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
     }
 
     // Get password
     char[] password = null;
     if (storePassword != null) {
       password = storePassword.toCharArray();
     }
 
     // Load key store from file
     try (InputStream storeInput = getStoreInputStream(storeFile)) {
       keyStore.load(storeInput, password);
     } catch (IOException e) {
       logger.error("Error loading store file {}", storeFile, e);
       return Collections.emptyList();
     }
 
     List<Cert> certs = new ArrayList<>();
 
     for (String alias : Collections.list(keyStore.aliases())) {
 
       Certificate[] certificateChains = keyStore.getCertificateChain(alias);
 
       if (certificateChains != null) {
         for (Certificate certificateChain : certificateChains) {
           X509Certificate x509Cert = (X509Certificate) certificateChain;
           addToStore(certs, alias, x509Cert);
         }
       } else {
         X509Certificate x509Cert = (X509Certificate) keyStore.getCertificate(alias);
         addToStore(certs, alias, x509Cert);
       }
     }
     return certs;
   }
 
   /**
    * Gets the connector infos.
    *
    * @param connectors the connectors
    *
    * @return the connector infos
    *
    * @throws IllegalAccessException the illegal access exception
    * @throws InvocationTargetException the invocation target exception
    */
   private List<ConnectorInfo> getConnectorInfos(Collection<Connector> connectors)
       throws IllegalAccessException, InvocationTargetException {
     List<ConnectorInfo> infos = new ArrayList<>();
     for (Connector connector : connectors) {
       if (!connector.getSecure()) {
         continue;
       }
 
       ProtocolHandler protocolHandler = connector.getProtocolHandler();
 
       if (protocolHandler instanceof AbstractHttp11Protocol protocol) {
         if (!protocol.getSecure()) {
           continue;
         }
         infos.add(toConnectorInfo(protocol));
       }
     }
     return infos;
   }
 
   /**
    * Tries to open a InputStream the same way as Tomcat ConfigFileLoader
    * {@link org.apache.tomcat.util.file.ConfigFileLoader#getSource()
    * getSource.getResource(String).getInputStream()}.
    *
    * @param path the path of a store file (absolute or relative to CATALINA.BASE), or URI to store
    *        file (absolute or relative to CATALINA.BASE).
    *
    * @return the input stream of the path file
    *
    * @throws IOException if path can not be resolved
    */
   private InputStream getStoreInputStream(String path) throws IOException {
     File file = Path.of(path).toFile();
     if (file.exists()) {
       return Files.newInputStream(file.toPath());
     }
 
     File catalinaBaseFolder = Path.of(System.getProperty("catalina.base")).toFile();
     file = Path.of(catalinaBaseFolder.getPath(), path).toFile();
     if (file.exists()) {
       return Files.newInputStream(file.toPath());
     }
 
     URI uri = catalinaBaseFolder.toURI().resolve(path);
 
     URL url = uri.toURL();
 
     return url.openConnection().getInputStream();
   }
 
   /**
    * To connector info.
    *
    * @param protocol the protocol
    *
    * @return the connector info
    *
    * @throws IllegalAccessException the illegal access exception
    * @throws InvocationTargetException the invocation target exception
    */
   private ConnectorInfo toConnectorInfo(AbstractHttp11Protocol<?> protocol)
       throws IllegalAccessException, InvocationTargetException {
     ConnectorInfo info = new ConnectorInfo();
     info.setName(ObjectName.unquote(protocol.getName()));
 
     String defaultSslHostConfigName = protocol.getDefaultSSLHostConfigName();
     if (defaultSslHostConfigName == null) {
       logger.error("Cannot determine defaultSslHostConfigName");
       return info;
     }
     info.setDefaultSslHostConfigName(defaultSslHostConfigName);
     new SslHostConfigHelper(protocol, info);
 
     return info;
   }
 
   /**
    * Adds the to store.
    *
    * @param certs the certs
    * @param alias the alias
    * @param x509Cert the x509 cert
    */
   private void addToStore(Collection<Cert> certs, String alias, X509Certificate x509Cert) {
     Cert cert = new Cert();
 
     cert.setAlias(alias);
     cert.setSubjectDistinguishedName(x509Cert.getSubjectX500Principal().toString());
     cert.setNotBefore(x509Cert.getNotBefore().toInstant());
     cert.setNotAfter(x509Cert.getNotAfter().toInstant());
     cert.setIssuerDistinguishedName(x509Cert.getIssuerX500Principal().toString());
 
     certs.add(cert);
   }
 
   @Value("certificates")
   @Override
   public void setViewName(String viewName) {
     super.setViewName(viewName);
   }
 
 }