package net.curisit.securis.utils;

import java.io.IOException;
import java.io.InputStream;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

/**
 * Class that loads and serves global config parameters.
 * 
 * @author rsanchez
 */
public class Params {

	private static Logger log = LogManager.getLogger(Params.class);

	/**
	 * Key used to store config file resource location. In a web application, can be set as initial parameter in a servlet loaded on startup
	 */
	public static final String KEY_CONFIG_FILE = "/securis-client.properties";

	private static Properties params = null;

	static {
		try {
			loadParameters(KEY_CONFIG_FILE);
		} catch (IOException e) {
			log.error("Config file {} was not found in classpath", KEY_CONFIG_FILE);
			System.exit(-2);
		}
	}

	/**
	 * Loads application global parameters from a classpath resource
	 * 
	 * @param resource
	 *            : Resource location in classpath, i.e: "/resource/cp-securis.conf"
	 * @throws IOException
	 */
	public static void loadParameters(String resource) throws IOException {

		log.debug("Loading params from " + resource);
		InputStream fileis = Params.class.getResourceAsStream(resource);

		params = new Properties();
		try {

			params.load(fileis);
			log.debug("Params loaded OK from {}", resource);
		} catch (IOException e) {
			log.error("Error loading config file: " + e);
			params = null;
			throw e;
		}

	}

	public static String getByDomain(String domain, String paramname) {
		return getByDomain(domain, paramname, null);
	}

	public static String getByPrefix(String prefix, String paramname) {
		return get(prefix + "." + paramname, get(paramname));
	}

	public static String getByPrefix(String prefix, String paramname, String defaultVal) {
		return get(prefix + "." + paramname, get(paramname, defaultVal));
	}

	public static String getByDomain(String domain, String paramname, String defaultval) {
		return get(paramname + "." + domain, defaultval);
	}

	public static int getIntByDomain(String domain, String paramname) {
		return getInt(paramname + "." + domain, getInt(paramname));
	}

	public static int getIntByDomain(String domain, String paramname, int defaultval) {
		return getInt(paramname + "." + domain, defaultval);
	}

	/**
	 * Gets a List with all values of properties that begins with <code>prefix</code> It reads sequentially. For example:
	 * 
	 * <pre>
	 * 	securis.sort.comparator.0: net.cp.securis.comparators.ComparePttidVsPtn
	 * 	securis.sort.comparator.1: net.cp.securis.comparators.CompareFrequency
	 * 	securis.sort.comparator.2: net.cp.securis.comparators.CompareOutgoingVsIncomming
	 * 	securis.sort.comparator.3: net.cp.securis.comparators.CompareDuration 
	 * 	securis.sort.comparator.4: net.cp.securis.comparators.CompareCallVsSms
	 * </pre>
	 * 
	 * That config (for prefix: "securis.sort.comparator" ) will return a List<String> with values:
	 * 
	 * <pre>
	 * 	"net.cp.securis.comparators.ComparePttidVsPtn", 
	 * 	"net.cp.securis.comparators.CompareFrequency", 
	 * 	"net.cp.securis.comparators.CompareOutgoingVsIncomming", 
	 * 	"net.cp.securis.comparators.CompareDuration", 
	 * 	"net.cp.securis.comparators.CompareCallVsSms"
	 * </pre>
	 * 
	 * Note: If there is a gap between suffixes process will stop, that is, only will be returned properties found before gap.
	 * 
	 * @param prefix
	 * @return
	 */
	public static List<String> getListByPrefix(String prefix) {
		List<String> list = new ArrayList<String>();

		String tpl = prefix + ".{0}";

		int i = 0;
		String value = get(MessageFormat.format(tpl, i++));
		while (value != null) {
			list.add(value);
			value = get(MessageFormat.format(tpl, i++));
		}

		return list;
	}

	/**
	 * Gets param value in config file or environment variables
	 * 
	 * @param paramname
	 *            Global parameter's name
	 * @return Value of paramname or null if paramname is not found neither in config file nor in environment variables
	 */
	public static String get(String paramname) {

		assert (params != null) : "Parameters have not been loaded. Call method loadParameters(resource) before use Params.";

		String value = params.getProperty(paramname);
		if (value == null)
			value = System.getenv(paramname);
		return value;
	}

	/**
	 * Gets param value from config file or environment variables
	 * 
	 * @param paramname
	 *            Global parameter's name
	 * @param defaultval
	 * @return Value of paramname or defaultval if paramname is not found
	 */
	public static String get(String paramname, String defaultval) {
		String value = get(paramname);
		return (value == null ? defaultval : value);
	}

	/**
	 * Gets param value in config file or environment variables
	 * 
	 * @param paramname
	 *            Global parameter's name
	 * @return Integer value of paramname or -1 if paramname is not found neither in config file nor in environment variables
	 */
	public static int getInt(String paramname) {
		String value = get(paramname);
		return (value == null ? -1 : Integer.parseInt(value));
	}

	/**
	 * Gets param value from config file or environment variables
	 * 
	 * @param paramname
	 *            Global parameter's name
	 * @param defaultval
	 * @return Integer value of paramname or defaultval if paramname is not found
	 */
	public static int getInt(String paramname, int defaultval) {
		String value = get(paramname);
		return (value == null ? defaultval : Integer.parseInt(value));
	}

	public static class KEYS {

		/**
		 * Public key file, Usually in "PEM" format
		 */
		public static final String PUBLIC_KEY_FILE = "public.key.file";

		public static final String APPLICATION_CODE = "app.code";

		public static final String CUSTOMER_CODE = "customer.code";

		public static final String LICENSE_SERVER_URL = "license.server.url";
	}

}