package be.nikiroo.fanfix;

import java.io.File;
import java.io.IOException;
import java.util.Date;

import be.nikiroo.fanfix.bundles.Config;
import be.nikiroo.fanfix.bundles.ConfigBundle;
import be.nikiroo.fanfix.bundles.StringIdBundle;
import be.nikiroo.fanfix.bundles.UiConfig;
import be.nikiroo.fanfix.bundles.UiConfigBundle;
import be.nikiroo.fanfix.output.BasicOutput.OutputType;
import be.nikiroo.utils.IOUtils;
import be.nikiroo.utils.resources.Bundles;

/**
 * Global state for the program (services and singletons).
 * 
 * @author niki
 */
public class Instance {
	private static ConfigBundle config;
	private static UiConfigBundle uiconfig;
	private static StringIdBundle trans;
	private static Cache cache;
	private static Library lib;
	private static boolean debug;
	private static File coverDir;
	private static File readerTmp;
	private static String configDir;

	static {
		// Most of the rest is dependent upon this:
		config = new ConfigBundle();

		configDir = System.getProperty("CONFIG_DIR");
		if (configDir == null) {
			configDir = System.getenv("CONFIG_DIR");
		}

		if (configDir == null) {
			configDir = new File(System.getProperty("user.home"), ".fanfix")
					.getPath();
		}

		if (!new File(configDir).exists()) {
			new File(configDir).mkdirs();
		} else {
			Bundles.setDirectory(configDir);
		}

		try {
			config = new ConfigBundle();
			config.updateFile(configDir);
		} catch (IOException e) {
			syserr(e);
		}
		try {
			uiconfig = new UiConfigBundle();
			uiconfig.updateFile(configDir);
		} catch (IOException e) {
			syserr(e);
		}
		try {
			trans = new StringIdBundle(getLang());
			trans.updateFile(configDir);
		} catch (IOException e) {
			syserr(e);
		}

		Bundles.setDirectory(configDir);

		uiconfig = new UiConfigBundle();
		trans = new StringIdBundle(getLang());
		try {
			lib = new Library(getFile(Config.LIBRARY_DIR),
					OutputType.INFO_TEXT, OutputType.CBZ);
		} catch (Exception e) {
			syserr(new IOException("Cannot create library for directory: "
					+ getFile(Config.LIBRARY_DIR), e));
		}

		debug = Instance.getConfig().getBoolean(Config.DEBUG_ERR, false);
		coverDir = getFile(Config.DEFAULT_COVERS_DIR);
		File tmp = getFile(Config.CACHE_DIR);
		readerTmp = getFile(UiConfig.CACHE_DIR_LOCAL_READER);

		if (checkEnv("NOUTF")) {
			trans.setUnicode(false);
		}

		if (checkEnv("DEBUG")) {
			debug = true;
		}

		// Could have used: System.getProperty("java.io.tmpdir")
		if (tmp == null) {
			tmp = new File(configDir, "tmp");
		}
		if (readerTmp == null) {
			readerTmp = new File(configDir, "tmp-reader");
		}
		//

		if (coverDir != null && !coverDir.exists()) {
			syserr(new IOException(
					"The 'default covers' directory does not exists: "
							+ coverDir));
			coverDir = null;
		}

		try {
			String ua = config.getString(Config.USER_AGENT);
			int hours = config.getInteger(Config.CACHE_MAX_TIME_CHANGING, -1);
			int hoursLarge = config
					.getInteger(Config.CACHE_MAX_TIME_STABLE, -1);

			cache = new Cache(tmp, ua, hours, hoursLarge);
		} catch (IOException e) {
			syserr(new IOException(
					"Cannot create cache (will continue without cache)", e));
		}
	}

	/**
	 * Get the (unique) configuration service for the program.
	 * 
	 * @return the configuration service
	 */
	public static ConfigBundle getConfig() {
		return config;
	}

	/**
	 * Get the (unique) UI configuration service for the program.
	 * 
	 * @return the configuration service
	 */
	public static UiConfigBundle getUiConfig() {
		return uiconfig;
	}

	/**
	 * Get the (unique) {@link Cache} for the program.
	 * 
	 * @return the {@link Cache}
	 */
	public static Cache getCache() {
		return cache;
	}

	/**
	 * Get the (unique) {link StringIdBundle} for the program.
	 * 
	 * @return the {link StringIdBundle}
	 */
	public static StringIdBundle getTrans() {
		return trans;
	}

	/**
	 * Get the (unique) {@link Library} for the program.
	 * 
	 * @return the {@link Library}
	 */
	public static Library getLibrary() {
		return lib;
	}

	/**
	 * Return the directory where to look for default cover pages.
	 * 
	 * @return the default covers directory
	 */
	public static File getCoverDir() {
		return coverDir;
	}

	/**
	 * Return the directory where to store temporary files for the local reader.
	 * 
	 * @return the directory
	 */
	public static File getReaderDir() {
		return readerTmp;
	}

	/**
	 * Check if we need to check that a new version of Fanfix is available.
	 * 
	 * @return TRUE if we need to
	 */
	public static boolean isVersionCheckNeeded() {
		try {
			long wait = config.getInteger(Config.UPDATE_INTERVAL, 1) * 24 * 60
					* 60 * 1000;
			if (wait >= 0) {
				String lastUpString = IOUtils.readSmallFile(new File(configDir,
						"LAST_UPDATE"));
				long delay = new Date().getTime()
						- Long.parseLong(lastUpString);
				if (delay > wait) {
					return true;
				}
			} else {
				return false;
			}
		} catch (Exception e) {
			// No file or bad file:
			return true;
		}

		return false;
	}

	/**
	 * Notify that we checked for a new version of Fanfix.
	 */
	public static void setVersionChecked() {
		try {
			IOUtils.writeSmallFile(new File(configDir), "LAST_UPDATE",
					Long.toString(new Date().getTime()));
		} catch (IOException e) {
			syserr(e);
		}
	}

	/**
	 * Report an error to the user
	 * 
	 * @param e
	 *            the {@link Exception} to report
	 */
	public static void syserr(Exception e) {
		if (debug) {
			e.printStackTrace();
		} else {
			System.err.println(e.getMessage());
		}
	}

	/**
	 * Return a path, but support the special $HOME variable.
	 * 
	 * @return the path
	 */
	private static File getFile(Config id) {
		return getFile(config.getString(id));
	}

	/**
	 * Return a path, but support the special $HOME variable.
	 * 
	 * @return the path
	 */
	private static File getFile(UiConfig id) {
		return getFile(uiconfig.getString(id));
	}

	/**
	 * Return a path, but support the special $HOME variable.
	 * 
	 * @return the path
	 */
	private static File getFile(String path) {
		File file = null;
		if (path != null && !path.isEmpty()) {
			path = path.replace('/', File.separatorChar);
			if (path.contains("$HOME")) {
				path = path.replace("$HOME",
						"" + System.getProperty("user.home"));
			}

			file = new File(path);
		}

		return file;
	}

	/**
	 * The language to use for the application (NULL = default system language).
	 * 
	 * @return the language
	 */
	private static String getLang() {
		String lang = config.getString(Config.LANG);

		if (System.getenv("LANG") != null && !System.getenv("LANG").isEmpty()) {
			lang = System.getenv("LANG");
		}

		if (lang != null && lang.isEmpty()) {
			lang = null;
		}

		return lang;
	}

	/**
	 * Check that the given environment variable is "enabled".
	 * 
	 * @param key
	 *            the variable to check
	 * 
	 * @return TRUE if it is
	 */
	private static boolean checkEnv(String key) {
		String value = System.getenv(key);
		if (value != null) {
			value = value.trim().toLowerCase();
			if ("yes".equals(value) || "true".equals(value)
					|| "on".equals(value) || "1".equals(value)
					|| "y".equals(value)) {
				return true;
			}
		}

		return false;
	}
}