package org.openslx.dozmod;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.apache.log4j.Logger;
import org.openslx.util.QuickTimer;
import org.openslx.util.QuickTimer.Task;
import org.openslx.util.Util;

/**
 * Represents the configuration of the client
 * 
 * @author Jonathan Bauer
 */

public class Config {

	/**
	 * Logger for this class
	 */
	private final static Logger LOGGER = Logger.getLogger(Config.class);

	public static final int TRANSFER_TIMEOUT = 20 * 1000; // 20s timeout for hung transfers

	public static interface ErrorCallback {
		void writeError(Throwable t);
	}

	/**
	 * Out property holder with all the setting keys
	 */
	private static final Properties prop = new Properties();

	private static ErrorCallback errorCb = null;

	private static File configFile = null;

	private static boolean writePending = false;

	/**
	 * Initializes the class by determining the path
	 * to the config.ini on the system and setting the
	 * private creating the ini member from that file.
	 * 
	 * This function will make a distinction between
	 * Linux and Windows OS's, as the standard paths
	 * for configuration files obviously differ.
	 * 
	 * @throws IOException
	 */
	public static void init() throws IOException {

		// Variables only needed locally
		String configPath = null;

		// Determine OS
		String osName = System.getProperty("os.name").toLowerCase();
		LOGGER.info("Machine's OS: " + osName);
		if (osName.contains("windows")) {
			// Windows machine. Use the environment variable 'APPDATA' which
			// should point to a path similar to:
			//		C:\Users\<user>\AppData\Roaming
			String appDataPath = System.getenv("APPDATA");
			if (!appDataPath.isEmpty()) {
				configPath = appDataPath;
			} else {
				// APPDATA was empty, let's guess
				LOGGER.warn("APPDATA is empty.");
				configPath = System.getProperty("user.home") + "\\AppData\\Roaming";
			}
		} else if (osName.contains("linux")) {
			configPath = System.getProperty("user.home") + "/.config";
		}
		if (configPath == null || configPath.isEmpty()) {
			// Not Windows nor Linux, try fallback to relative path
			// TODO MacOS Support?
			configPath = ".";
		}

		// Check if we got a path
		configFile = new File(configPath + File.separatorChar + "bwSuite" + File.separatorChar
				+ "config.properties");

		// Check if the directory exists.
		if (!configFile.getParentFile().exists()) {
			LOGGER.info("Folder " + configFile.getParentFile() + " does not exist, creating it.");
			// Does not, create it
			if (!configFile.getParentFile().mkdirs()) {
				throw new IOException("Could not create '" + configFile.getParentFile() + "'.");
			}
		}

		if (!configFile.exists()) {
			forceSaveInternal();
		}

		// Make sure all settings are saved when we exit
		Runtime.getRuntime().addShutdownHook(new Thread() {
			@Override
			public void run() {
				Config.forceSave();
			}
		});

		// Load configuration from java properties file
		InputStream in = new FileInputStream(configFile);
		try {
			prop.load(in);
		} finally {
			in.close();
		}
	}

	private static void forceSaveInternal() throws FileNotFoundException, IOException {
		synchronized (prop) {
			prop.store(new FileOutputStream(configFile), "bwLehrpool Dozentenmodul Client Config");
		}
	}

	public static boolean forceSave() {
		synchronized (prop) {
			if (!writePending)
				return true;
			writePending = false;
			if (configFile == null)
				return false;
			try {
				forceSaveInternal();
				return true;
			} catch (Exception e) {
				if (errorCb != null)
					errorCb.writeError(e);
			}
			return false;
		}
	}

	/**
	 * Called internally by all set[TYPE]() methods. This triggers
	 * a save-task in one second, if one isn't pending yet. This is so
	 * we don't write the file many times, possibly concurrently, if lots
	 * of settings are changed.
	 */
	private static void queueSave() {
		synchronized (prop) {
			if (writePending)
				return;
			writePending = true;
			QuickTimer.scheduleOnce(new Task() {
				@Override
				public void fire() {
					forceSave();
				}
			}, 1000);
		}
	}

	public static void setErrorCallback(ErrorCallback cb) {
		errorCb = cb;
	}

	/**
	 * Query the path of the configuration file
	 * 
	 * @return path to the configuration file
	 */
	public static String getPath() {
		return configFile.getParent();
	}

	/*
	 * Getters and setters for the various config options
	 */

	/**
	 * Query the value of 'BillOfRights' from the configuration file.
	 * 
	 * @return true if the user already accepted bill of rights, false
	 *         otherwise.
	 */
	public static int getDisclaimerAgreement() {
		return getInteger("disclaimer.accepted_version", 0);
	}

	/**
	 * Sets the value of 'BillOfRights' in the configuration file to 'value'
	 * 
	 * @return true if it succeeded, false otherwise
	 */
	public static void setDisclaimerAgreement(int value) {
		setInteger("disclaimer.accepted_version", value);
	}

	public static boolean getVirtualizerRead() {
		return getBoolean("notice.virtualizer", false);
	}

	public static void setVirtualizerRead(boolean selection) {
		setBoolean("notice.virtualizer", selection);
	}

	/**
	 * Get the remembered user, if set.
	 * 
	 * @return user name if saved, an empty string otherwise.
	 */
	public static String getUsername() {
		return getString("login.name", "");
	}

	/**
	 * Sets the name of the remembered user
	 * 
	 * @return true if it succeeded, false otherwise
	 */
	public static void setUsername(String value) {
		setString("login.name", value);
	}

	/**
	 * Query the value of 'Letzter Downloadpfad' from the configuration file.
	 * 
	 * @return last download path if saved, the path to the user's home
	 *         otherwise.
	 */
	public static String getDownloadPath() {
		return getString("download.path", System.getProperty("user.home"));
	}

	/**
	 * Sets the value of 'Letzter Downloadpfad' in the configuration file to
	 * 'value'
	 * 
	 * @return true if it succeeded, false otherwise
	 */
	public static void setDownloadPath(String value) {
		setString("download.path", value);
	}

	/**
	 * Query the value of 'Letzter Uploadpfad' from the configuration file.
	 * 
	 * @return last upload path if saved, the path to the user's home otherwise.
	 */
	public static String getUploadPath() {
		return getString("upload.path", System.getProperty("user.home"));
	}

	/**
	 * Sets the value of "Letzter Uploadpfad" in the configuration file to
	 * 'value'
	 * 
	 * @return true if it succeeded, false otherwise
	 */
	public static void setUploadPath(String value) {
		setString("upload.path", value);
	}

	/**
	 * Query the IdP of the configuration file
	 * 
	 * @return stored IdP
	 */
	public static String getIdentityProvider() {
		return getString("login.idp", "");
	}

	/**
	 * Sets the value of "IdP" in the configuration file to 'value'
	 * 
	 * @return true if it succeeded, false otherwise
	 */
	public static void setIdentityProvider(String value) {
		setString("login.idp", value);
	}

	/**
	 * Query the authentication method of the configuration file
	 * 
	 * @return stored IdP
	 */
	public static String getAuthenticationMethod() {
		return getString("login.method", "ECP");
	}

	/**
	 * Sets the value of the selected authentication method in the configuration
	 * file to 'value'
	 * 
	 * @return true if it succeeded, false otherwise
	 */
	public static void setAuthenticationMethod(String value) {
		setString("login.method", value);
	}

	/**
	 * Saves the current session, identified by the satellite server's address
	 * and token.
	 * 
	 * @param satAddress
	 * @param satToken
	 */
	public static void saveCurrentSession(String satAddress, String satToken, String masterToken) {
		setString("session.address", satAddress);
		setString("session.token", satToken);
		setString("session.mastertoken", masterToken);
	}

	/**
	 * Load a saved session.
	 * 
	 * @return Saved session, or <code>null</code> if no session was saved
	 */
	public static SavedSession getSavedSession() {
		SavedSession session = new SavedSession(getString("session.address", ""), getString("session.token",
				""), getString("session.mastertoken", ""));
		if (session.token.isEmpty() || session.address.isEmpty() || session.masterToken.isEmpty())
			return null;
		return session;
	}

	/*
	 * Generic helpers for different data types
	 */

	/**
	 * Gets the boolean from the given key.
	 * If nothing is found, return the given default value
	 * 
	 * @param key key to query in that section
	 * @param defaultValue default value to be returned, if none is found.
	 * @return
	 */
	private static boolean getBoolean(String key, boolean defaultValue) {
		return Boolean.parseBoolean(prop.getProperty(key, Boolean.toString(defaultValue)));
	}

	/**
	 * Sets the given key to value.
	 * 
	 * @param key key to set
	 * @param value value to assign to key
	 */
	private static void setBoolean(String key, boolean value) {
		prop.setProperty(key, Boolean.toString(value));
		queueSave();
	}

	/**
	 * Gets the integer from the given key.
	 * If nothing is found, return the given default value
	 * 
	 * @param key key to query in that section
	 * @param defaultValue default value to be returned, if none is found.
	 * @return
	 */
	private static int getInteger(String key, int defaultValue) {
		return Util.parseInt(prop.getProperty(key), defaultValue);
	}

	/**
	 * Sets the given key to value.
	 * 
	 * @param key key to set
	 * @param value value to assign to key
	 */
	private static void setInteger(String key, int value) {
		prop.setProperty(key, Integer.toString(value));
		queueSave();
	}

	/**
	 * Gets the string from the given key.
	 * If nothing is found, return the given default value
	 * 
	 * @param key key to lookup in the section
	 * @param defaultValue default value to return if none is found in the file
	 * @return
	 */
	private static String getString(String key, String defaultValue) {
		return prop.getProperty(key, defaultValue);
	}

	/**
	 * Sets the given 'key' in the given 'section' to 'value'.
	 * Restricted to string.
	 * 
	 * @param key key to set
	 * @param value value to assign to key
	 */
	private static void setString(String key, String value) {
		prop.setProperty(key, value);
		queueSave();
	}

	public static class SavedSession {
		public final String address;
		public final String token;
		public final String masterToken;

		public SavedSession(String address, String token, String masterToken) {
			this.address = address;
			this.token = token;
			this.masterToken = masterToken;
		}
	}

}