/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.ode.utils.cli;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.appender.ConsoleAppender;
import org.apache.logging.log4j.core.appender.FileAppender;
import org.apache.logging.log4j.core.config.AppenderRef;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.LoggerConfig;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.ode.utils.Version;
import org.apache.ode.utils.fs.TempFileManager;
import org.apache.ode.utils.msg.MessageBundle;
import org.slf4j.Logger;

import java.io.IOException;
import java.io.PrintWriter;
import java.nio.charset.Charset;

public abstract class BaseCommandlineTool {

	public static final int TERSE = 0;

	public static final int VERBOSE = 1;

	public static final int EFFUSIVE = 2;

	private static boolean _tempFileManagerRegistered = false;

	private static Class CLAZZ = BaseCommandlineTool.class;

	private static final String LOGGING_PATTERN = "%p - %d{ISO8601} - <%c> %m%n";

	protected static final Flag HELP_FLAG = new Flag("h", "print usage and help to the console and exit.", false);

	protected static final Fragments HELP = new Fragments(new CommandlineFragment[] { HELP_FLAG });

	protected static final Flag QUIET_F = new Flag("q", "only produce error output in the event of an error.", false);
	protected static final Flag VERBOSE_F = new Flag("v", "produce verbose (INFO-level) logging output.", false);
	protected static final Flag VERYVERBOSE_F = new Flag("vv", "product effusive (DEBUG-level) logging output", false);

	protected static final XorGroup LOGGING = new XorGroup(
			"set logging output verbosity from quiet (-q), to verbose (-v), to effusive (-vv).", true);

	static {
		LOGGING.addFragment(QUIET_F);
		LOGGING.addFragment(VERBOSE_F);
		LOGGING.addFragment(VERYVERBOSE_F);
	}

	private static final CommandLineMessages __msgs = MessageBundle.getMessages(CommandLineMessages.class);

	/**
	 * Print program banner.
	 */
	public static void outputHeader() {
		if (QUIET_F.isSet()) {
			return;
		}
		System.out.println(__msgs.msgCliHeader(getProgramName(), Version.getVersionName(), Version.getBuildDate()));
	}

	/**
	 * Initialize logging appropriate for command-line utilities. The logging
	 * will be limited to error messages on standard error, unless
	 * user-specified logging options are present. Among other things, this
	 * method looks for the <code>-v</code> option and configures logging
	 * verbosity appropriately
	 *
	 * @param level
	 */
	protected static void initLogging(int level) {
	      final LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
	      final Configuration config = ctx.getConfiguration();
	      LoggerConfig loggerConfig = config.getLoggerConfig(LogManager.ROOT_LOGGER_NAME);
	      Layout layout = PatternLayout.createLayout(LOGGING_PATTERN,config,null,Charset.forName("UTF-8"),true,false,null,null);
	      Appender appender = ConsoleAppender.createAppender(layout, null, "SYSTEM_OUT", "stderr appender", "false", "true");
	      AppenderRef ref = initialize("stderr appender", level);
	      AppenderRef[] refs = new AppenderRef[] {ref};
	      loggerConfig.addAppender(appender, ref.getLevel(), null);
	      loggerConfig.setLevel(ref.getLevel());
	      ctx.updateLoggers();
	}

	protected static void initLogFile() throws IOException {
		initLogFile(getLevel());
	}

	protected static void initLogFile(int level) throws IOException {
	      final LoggerContext ctx = (LoggerContext) LogManager.getContext(false);
	      final Configuration config = ctx.getConfiguration();
	      LoggerConfig loggerConfig = config.getLoggerConfig(LogManager.ROOT_LOGGER_NAME);
	      Layout layout = PatternLayout.createLayout(LOGGING_PATTERN,config,null,Charset.forName("UTF-8"),true,false,null,null);
	      Appender appender = FileAppender.createAppender(System.getProperty("ode.home") + "/logs/ode.log", "false", "false", "File", "false",
	          "true", "true", "8192", layout, null, "false", null, config);
	      AppenderRef ref = initialize("File", level);
	      AppenderRef[] refs = new AppenderRef[] {ref};
	      loggerConfig.addAppender(appender, ref.getLevel(), null);
	      loggerConfig.setLevel(ref.getLevel());
	      ctx.updateLoggers();
	}

	  private static AppenderRef initialize(String name, int level) {
	      Level appenderLevel = null;
	      switch (level) {
	          case EFFUSIVE :
	              appenderLevel = Level.DEBUG;
	          break;
	          case VERBOSE :
	              appenderLevel = Level.INFO;
	          break;
	          default :
	              appenderLevel = Level.WARN;
	          break;
	    }
	    return AppenderRef.createAppenderRef(name, appenderLevel, null);
	  }

	protected static void setClazz(Class c) {
		CLAZZ = c;
	}

	protected static String getProgramName() {
		return "java " + CLAZZ.getName();
	}

	protected static void initLogging() {
		initLogging(getLevel());
	}

	private static int getLevel() {
		if (QUIET_F.isSet()) {
			return TERSE;
		} else if (VERBOSE_F.isSet()) {
			return VERBOSE;
		} else if (VERYVERBOSE_F.isSet()) {
			return EFFUSIVE;
		} else {
			// none of the above.
			return -1;
		}
	}

	protected synchronized static final void registerTempFileManager() {
		if (!_tempFileManagerRegistered) {
			Runtime.getRuntime().addShutdownHook(new Thread() {

				public void run() {
					TempFileManager.cleanup();
				}
			});
		}
	}

	protected static void consoleErr(String errMsg) {
		String progName = getProgramName();
		System.err.println(progName + ": " + errMsg);
	}
}