package at.gv.egovernment.moa.spss.util;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Iterator;
import java.util.List;

import at.gv.egovernment.moa.spss.MOAApplicationException;
import at.gv.egovernment.moa.spss.server.config.ConfigurationException;
import at.gv.egovernment.moa.spss.server.config.ConfigurationProvider;
import at.gv.egovernment.moaspss.logging.LogMsg;
import at.gv.egovernment.moaspss.logging.Logger;

public class ExternalURIVerifier {

  public static void verify(String host, int port) throws MOAApplicationException {

    if (host == null) {
      return;
    }
    if (host.equalsIgnoreCase("")) {
      return;
    }

    try {
      final ConfigurationProvider config = ConfigurationProvider.getInstance();

      final boolean allowExternalUris = config.getAllowExternalUris();
      final List blacklist = config.getBlackListedUris();
      final List whitelist = config.getWhiteListedUris();

      final InetAddress hostInetAddress = InetAddress.getByName(host);
      final String ip = hostInetAddress.getHostAddress();

      if (allowExternalUris) {
        // external URIs are allowed - check blacklist
        final Iterator it = blacklist.iterator();
        while (it.hasNext()) {
          final String[] array = (String[]) it.next();
          final String bhost = array[0];
          final String bport = array[1];
          if (bport == null || port == -1) {
            // check only host
            if (ip.startsWith(bhost)) {
              Logger.debug(new LogMsg("Blacklist check: " + host + " (" + ip + ") blacklisted"));
              throw new MOAApplicationException("4002", new Object[] { host + "(" + ip + ")" });
            }
          } else {
            // check host and port
            final int iport = new Integer(bport).intValue();
            if (ip.startsWith(bhost) && iport == port) {
              Logger.debug(new LogMsg("Blacklist check: " + host + ":" + port + " (" + ip + ":" + port
                  + " blacklisted"));
              throw new MOAApplicationException("4002", new Object[] { host + ":" + port + " (" + ip + ":"
                  + port + ")" });
            }

          }
        }
      } else {
        // external uris are forbidden - check whitelist
        final Iterator it = whitelist.iterator();
        boolean allowed = false;
        while (it.hasNext()) {
          final String[] array = (String[]) it.next();
          final String bhost = array[0];
          final String bport = array[1];
          if (bport == null || port == -1) {
            // check only host
            if (ip.startsWith(bhost)) {
              Logger.debug(new LogMsg("Whitelist check: " + host + " (" + ip + ") whitelisted"));
              allowed = true;
              // throw new MOAApplicationException("4002", new Object[]{host + "(" + ip +
              // ")"});
            }
          } else {
            // check host and port
            final int iport = new Integer(bport).intValue();
            if (ip.startsWith(bhost) && iport == port) {
              Logger.debug(new LogMsg("Whitelist check: " + host + ":" + port + " (" + ip + ":" + port
                  + " whitelisted"));
              // throw new MOAApplicationException("4002", new Object[]{host + ":" + port + "
              // (" + ip + ":" + port + ")"});
              allowed = true;
            }

          }
        }

        if (!allowed) {
          if (port != -1) {
            Logger.debug(new LogMsg("No external URIs allowed (" + host + ")"));
            throw new MOAApplicationException("4001", new Object[] { host + "(" + ip + ")" });
          } else {
            Logger.debug(new LogMsg("No external URIs allowed (" + host + ":" + port + ")"));
            throw new MOAApplicationException("4001", new Object[] { host + ":" + port + " (" + ip + ":"
                + port + ")" });
          }

        }

      }

      Logger.debug(new LogMsg("URI allowed: " + ip + ":" + port));

    } catch (final ConfigurationException e) {
      throw new MOAApplicationException("config.10", null);
    } catch (final UnknownHostException e) {
      throw new MOAApplicationException("4003", new Object[] { host });
    }

  }

}