package com.nilhcem.fakesmtp.core;

 import ch.qos.logback.classic.Level;

 import ch.qos.logback.classic.Logger;

 import com.nilhcem.fakesmtp.model.UIModel;

 import org.apache.commons.cli.CommandLine;

 import org.apache.commons.cli.CommandLineParser;

 import org.apache.commons.cli.GnuParser;

 import org.apache.commons.cli.HelpFormatter;

 import org.apache.commons.cli.Options;

 import org.apache.commons.cli.ParseException;

 import org.slf4j.LoggerFactory;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.List;

 import java.util.Locale;

 /**

  * Handles command line arguments.

  *

  * @author Nilhcem

  * @since 1.3

  */

 public enum ArgsHandler {

         INSTANCE;

         private static final String OPT_EMAILS_DIR_SHORT = "o";

         private static final String OPT_EMAILS_DIR_LONG = "output-dir";

         private static final String OPT_EMAILS_DESC = "Emails output directory";

         private static final String OPT_AUTOSTART_SHORT = "s";

         private static final String OPT_AUTOSTART_LONG = "start-server";

         private static final String OPT_AUTOSTART_DESC = "Automatically starts the SMTP server at launch";

         private static final String OPT_PORT_SHORT = "p";

         private static final String OPT_PORT_LONG = "port";

         private static final String OPT_PORT_DESC = "SMTP port number";

         private static final String OPT_BACKGROUNDSTART_SHORT = "b";

         private static final String OPT_BACKGROUNDSTART_LONG = "background";

         private static final String OPT_BACKGROUNDSTART_DESC = "If specified, does not start the GUI. Must be used with the -" + OPT_AUTOSTART_SHORT + " (--" +  OPT_AUTOSTART_LONG + ") argument";

         private static final String OPT_RELAYDOMAINS_SHORT = "r";

         private static final String OPT_RELAYDOMAINS_LONG = "relay-domains";

         private static final String OPT_RELAYDOMAINS_DESC = "Comma separated email domain(s) for which relay is accepted. If not specified, relays to any domain. If specified, relays only emails matching these domain(s), dropping (not saving) others";

         private static final String OPT_RELAYDOMAINS_SEPARATOR = ",";

         private static final String OPT_MEMORYMODE_SHORT = "m";

         private static final String OPT_MEMORYMODE_LONG = "memory-mode";

         private static final String OPT_MEMORYMODE_DESC = "Disable the persistence in order to avoid the overhead that it adds";

         private static final String OPT_BINDADDRESS_SHORT = "a";

         private static final String OPT_BINDADDRESS_LONG = "bind-address";

         private static final String OPT_BINDADDRESS_DESC = "IP address or hostname to bind to. Binds to all local IP addresses if not specified. Only works together with the -" + OPT_BACKGROUNDSTART_SHORT + " (--" +  OPT_BACKGROUNDSTART_LONG + ") argument.";

         private static final String OPT_EMLVIEWER_SHORT = "e";

         private static final String OPT_EMLVIEWER_LONG = "eml-viewer";

         private static final String OPT_EMLVIEWER_DESC = "Executable of program used for viewing emails";

         private final Options options;

         private String port;

         private String bindAddress;

         private String outputDirectory;

         private String emlViewer;

         private boolean backgroundStart;

         private boolean startServerAtLaunch;

         private boolean memoryModeEnabled;

         /**

          * Handles command line arguments.

          */

         ArgsHandler() {

                 options = new Options();

                 options.addOption(OPT_EMAILS_DIR_SHORT, OPT_EMAILS_DIR_LONG, true, OPT_EMAILS_DESC);

                 options.addOption(OPT_AUTOSTART_SHORT, OPT_AUTOSTART_LONG, false, OPT_AUTOSTART_DESC);

                 options.addOption(OPT_PORT_SHORT, OPT_PORT_LONG, true, OPT_PORT_DESC);

                 options.addOption(OPT_BINDADDRESS_SHORT, OPT_BINDADDRESS_LONG, true, OPT_BINDADDRESS_DESC);

                 options.addOption(OPT_BACKGROUNDSTART_SHORT, OPT_BACKGROUNDSTART_LONG, false, OPT_BACKGROUNDSTART_DESC);

                 options.addOption(OPT_RELAYDOMAINS_SHORT, OPT_RELAYDOMAINS_LONG, true, OPT_RELAYDOMAINS_DESC);

                 options.addOption(OPT_MEMORYMODE_SHORT, OPT_MEMORYMODE_LONG, false, OPT_MEMORYMODE_DESC);

                 options.addOption(OPT_EMLVIEWER_SHORT, OPT_EMLVIEWER_LONG, true, OPT_EMLVIEWER_DESC);

         }

         /**

          * Interprets command line arguments.

          *

          * @param args program's arguments.

          * @throws ParseException when arguments are invalid.

          */

         public void handleArgs(String[] args) throws ParseException {

                 CommandLineParser parser = new GnuParser();

                 CommandLine cmd = parser.parse(options, args);

                 outputDirectory = cmd.getOptionValue(OPT_EMAILS_DIR_SHORT);

                 if (outputDirectory != null) {

                         UIModel.INSTANCE.setSavePath(outputDirectory);

                 }

                 port = cmd.getOptionValue(OPT_PORT_SHORT);

                 bindAddress = cmd.getOptionValue(OPT_BINDADDRESS_SHORT);

                 startServerAtLaunch = cmd.hasOption(OPT_AUTOSTART_SHORT);

                 backgroundStart = cmd.hasOption(OPT_BACKGROUNDSTART_SHORT);

                 memoryModeEnabled = cmd.hasOption(OPT_MEMORYMODE_SHORT);

                 emlViewer = cmd.getOptionValue(OPT_EMLVIEWER_SHORT);

                 // Change SMTP server log level to info if memory mode was enabled to improve performance

                 if (memoryModeEnabled) {

                         ((Logger) LoggerFactory.getLogger(org.subethamail.smtp.server.Session.class)).setLevel(Level.INFO);

                 }

                 String relaydomains = cmd.getOptionValue(OPT_RELAYDOMAINS_SHORT);

                 if (relaydomains != null) {

                         List<String> domains = new ArrayList<String>();

                         for (String domain : Arrays.asList(relaydomains.split(OPT_RELAYDOMAINS_SEPARATOR))) {

                                 domains.add(domain.trim());

                         }

                         UIModel.INSTANCE.setRelayDomains(domains);

                 }

         }

         /**

          * Displays the app's usage in the standard output.

          */

         public void displayUsage() {

                 HelpFormatter formatter = new HelpFormatter();

                 formatter.printHelp(String.format(Locale.US, "java -jar %s [OPTION]...", getJarName()), options);

         }

         /**

          * @return whether or not the SMTP server must be started automatically at launch.

          */

         public boolean shouldStartServerAtLaunch() {

                 return startServerAtLaunch;

         }

         /**

          * @return whether or not the SMTP server must be running without a GUI, only if started at launch (if {@code shouldStartServerAtLaunch()} returns true}).

          * @see #shouldStartServerAtLaunch

          */

         public boolean shouldStartInBackground() {

                 return startServerAtLaunch && backgroundStart;

         }

         /**

          * @return the port, as specified by the user, or a {@code null} string if unspecified.

          */

         public String getPort() {

                 return port;

         }

         /**

          * @return the bind address, as specified by the user, or a {@code null} string if unspecified.

          */

         public String getBindAddress() {

                 return bindAddress;

         }

         /**

          * @return the output directory, as specified by the user, or a {@code null} string if unspecified.

          */

         public String getOutputDirectory() {

                 return outputDirectory;

         }

         /**

          * @return whether or not the SMTP server should disable the persistence in order to avoid the overhead that it adds.

          * This is particularly useful when we launch performance tests that massively send emails.

          */

         public boolean memoryModeEnabled() {

                 return memoryModeEnabled;

         }

         /**

          * @return the name of executable used for viewing eml files, as specified by the user, or a {@code null} string if unspecified.

          */

         public String getEmlViewer() {

                 return emlViewer;

         }

         /**

          * @return the file name of the program.

          */

         private String getJarName() {

                 return new java.io.File(

                                 ArgsHandler.class.getProtectionDomain()

                                 .getCodeSource()

                                 .getLocation()

                                 .getPath())

                 .getName();

         }

 }