package com.nilhcem.fakesmtp.core;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.InputStream;

 import java.util.Properties;

 import org.apache.commons.io.IOUtils;

 import org.slf4j.LoggerFactory;

 /**

  * Contains and returns some project-specific configuration variables.

  *

  * @author Nilhcem

  * @since 1.0

  */

 public enum Configuration {

         INSTANCE;

         private static final String CONFIG_FILE = "/configuration.properties";

         private static final String USER_CONFIG_FILE = ".fakeSMTP.properties";

         private final Properties config = new Properties();

         /**

          * Opens the "{@code configuration.properties}" file and maps data.

          */

         Configuration() {

                 InputStream in = getClass().getResourceAsStream(CONFIG_FILE);

                 try {

                         // Load defaults settings

                         config.load(in);

                         in.close();

                         // and override them from user settings

                         loadFromUserProfile();

                 } catch (IOException e) {

                         LoggerFactory.getLogger(Configuration.class).error("", e);

                 }

         }

         /**

          * Returns the value of a specific entry from the "{@code configuration.properties}" file.

          *

          * @param key a string representing the key from a key/value couple.

          * @return the value of the key, or an empty string if the key was not found.

          */

         public String get(String key) {

                 if (config.containsKey(key)) {

                         return config.getProperty(key);

                 }

                 return "";

         }

         /**

          * Sets the value of a specific entry.

          *

          * @param key a string representing the key from a key/value couple.

          * @param value the value of the key.

          */

         public void set(String key, String value) {

                 config.setProperty(key, value);

         }

         /**

          * Saves configuration to file.

          *

          * @param file file to save configuration.

          * @throws IOException

          */

         public void saveToFile(File file) throws IOException {

                 FileOutputStream fos = new FileOutputStream(file);

                 try {

                         config.store(fos, "Last user settings");

                 } finally {

                         IOUtils.closeQuietly(fos);

                 }

         }

         /**

          * Saves configuration to the {@code .fakesmtp.properties} file in user profile directory.

          * Calls {@link Configuration#saveToFile(java.io.File)}.

          *

          * @throws IOException

          */

         public void saveToUserProfile() throws IOException {

                 saveToFile(new File(System.getProperty("user.home"), USER_CONFIG_FILE));

         }

         /**

          * Loads configuration from file.

          *

          * @param file file to load configuration.

          * @return INSTANCE.

          * @throws IOException

          */

         public Configuration loadFromFile(File file) throws IOException {

                 if (file.exists() && file.canRead()) {

                         FileInputStream fis = new FileInputStream(file);

                         try {

                                 config.load(fis);

                         } finally {

                                 IOUtils.closeQuietly(fis);

                         }

                 }

                 return INSTANCE;

         }

         /**

          * Loads configuration from the .fakesmtp.properties file in user profile directory.

          * Calls {@link Configuration#loadFromFile(java.io.File)}.

          *

          * @return INSTANCE.

          * @throws IOException

          */

         public Configuration loadFromUserProfile() throws IOException {

                 return loadFromFile(new File(System.getProperty("user.home"), USER_CONFIG_FILE));

         }

 }