package net.messagevortex;

// ************************************************************************************
// * Copyright (c) 2018 Martin Gwerder (martin@gwerder.net)
// *
// * Permission is hereby granted, free of charge, to any person obtaining a copy
// * of this software and associated documentation files (the "Software"), to deal
// * in the Software without restriction, including without limitation the rights
// * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// * copies of the Software, and to permit persons to whom the Software is
// * furnished to do so, subject to the following conditions:
// *
// * The above copyright notice and this permission notice shall be included in all
// * copies or substantial portions of the Software.
// *
// * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// * SOFTWARE.
// ************************************************************************************

import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.ConsoleHandler;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.LogRecord;
import java.util.logging.Logger;

public class MessageVortexLogger extends Logger {

  static final String LINE_SEPARATOR = System.getProperty("line.separator");

  static final Handler consoleHandler = new ConsoleHandler();

  private static int init = 0;
  private static final Object lock = new Object();

  static {
    init();
  }

  private static void init() {
    synchronized (lock) {
      if (init == 0) {
        init = 1;

        // remove all existing console handler
        Handler[] handlers = getGlobalLogger().getParent().getHandlers();
        if (handlers != null) {
          for (Handler h : handlers) {
            getGlobalLogger().getParent().removeHandler(h);
          }
        }

        // set log formater
        consoleHandler.setFormatter(new MyLogFormatter());
        getGlobalLogger().getParent().addHandler(consoleHandler);
        getGlobalLogger().log(Level.INFO, "log level is set to " + getGlobalLogLevel());

        init = 2;

        getLogger("Logger").log(Level.INFO, "Logger initialized");
      }
    }
  }

  private MessageVortexLogger() {
    super(null, null);
    init();
  }

  /***
   * <p>Sets the provided log level globally.</p>
   * @param l the log level to be set
   */
  public static void setGlobalLogLevel(Level l) {
    init();
    consoleHandler.setLevel(l);
    getGlobalLogger().getParent().setLevel(l);
  }

  /***
   * <p>Gets the log level of the global logger.</p>
   * @return the previously set log level
   */
  public static Level getGlobalLogLevel() {
    init();
    return getGlobalLogger().getParent().getLevel();
  }

  /***
   * <p>gets the global logger.</p>
   * @return the requested logger
   */
  public static Logger getGlobalLogger() {
    init();
    return LogManager.getLogManager().getLogger(Logger.GLOBAL_LOGGER_NAME);
  }

  public static Logger getLogger(String name) {
    init();
    return getGlobalLogger().getLogger(Logger.GLOBAL_LOGGER_NAME);
  }

  static final class MyLogFormatter extends Formatter {

    private static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    @Override
    public String format(LogRecord record) {

      StringBuilder sb = new StringBuilder();
      try {
        synchronized (sdf) {
          String time = sdf.format(new Date());

          sb.append(time).append(' ').append(record.getLevel().getLocalizedName()).append(": ")
              .append('[').append(Thread.currentThread().getName()).append('/')
              .append(record.getLoggerName()).append("] ")
              .append(formatMessage(record)).append(LINE_SEPARATOR);
        }

        //noinspection ThrowableResultOfMethodCallIgnored
        if (record.getThrown() != null) {
          try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            //noinspection ThrowableResultOfMethodCallIgnored
            record.getThrown().printStackTrace(pw);
            pw.close();
            sb.append(sw);
          } catch (Exception ex) {
            assert true : "Never throw assertion" + ex;
          }
        }
      } catch (Exception e) {
        System.err.println("DESASTER: exception while logging");
        e.printStackTrace();
        System.exit(200);
      }

      return sb.toString();
    }
  }

  public static void flush() {
    init();
    consoleHandler.flush();
  }

}