/*******************************************************************************
 * ============LICENSE_START====================================================
 * * org.onap.aaf
 * * ===========================================================================
 * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
 * * ===========================================================================
 * * Licensed 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.
 * * ============LICENSE_END====================================================
 * *
 * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 * *
 ******************************************************************************/
package org.onap.aaf.inno.env;

import java.io.PrintStream;
import java.util.Date;

import org.onap.aaf.inno.env.util.Chrono;

/**
 * LogTarget is the interface with which to assign any kind of Logging Implementations.
 * 
 * Implement for any Logging Library of your choice, and for any logging string Format desired.
 * 
 * Included are several Static Implementations for various uses:
 * 	 NULL: Does nothing with Logging Messages
 *   SYSOUT: Writes messages in general form to System Out
 *   SYSERR: Writes messages in general form to System Err
 *   
 *
 */
public interface LogTarget {
	public abstract void log(Object... msgs);
	public abstract void log(Throwable e, Object ... msgs);
	public abstract boolean isLoggable();
	public abstract void printf(String fmt, Object ... vars);

	// A Convenient LogTarget to insert when a NO-OP is desired.
	public static final LogTarget NULL = new LogTarget() {
		public void log(Object ... msgs) {
		}

		public void log(Throwable t, Object ... msgs) {
		}

		public boolean isLoggable() {
			return false;
		}

		@Override
		public void printf(String fmt, Object ... vars) {
		}
	};

	// A Convenient LogTarget to write to the Console
	public static final LogTarget SYSOUT = new LogTarget() {
		public void log(Object ... msgs) {
			PrintStream out = System.out;
			out.print(org.onap.aaf.inno.env.util.Chrono.dateFmt.format(new Date()));
			out.print(": ");
			for(Object str : msgs) {
				if(str!=null) {
					out.print(str.toString());
					out.print(' ');
				} else {
					out.print("null ");
				}
			}
			out.println();
		}

		public void log(Throwable t, Object ... msgs) {
			PrintStream out = System.out;
			out.print(Chrono.dateFmt.format(new Date()));
			out.print(": ");
			for(Object str : msgs) {
				out.print(str.toString());
				out.print(' ');
			}
			out.println();
			t.printStackTrace(out);
			out.println();
		}

		public boolean isLoggable() {
			return true;
		}

		@Override
		public void printf(String fmt, Object ... vars) {
			log(String.format(fmt,vars));
		}
	};
	
	// A Convenient LogTarget to write to the Console
	public static final LogTarget SYSERR = new LogTarget() {
		public void log(Object ... msgs) {
			PrintStream out = System.err;
			out.print(Chrono.dateFmt.format(new Date()));
			out.print(": ");
			for(Object str : msgs) {
				out.print(str.toString());
				out.print(' ');
			}
			out.println();
			out.flush();
		}

		public void log(Throwable t, Object ... msgs) {
			PrintStream out = System.err;
			out.print(Chrono.dateFmt.format(new Date()));
			out.print(": ");
			for(Object str : msgs) {
				out.print(str.toString());
				out.print(' ');
			}
			out.println();
			t.printStackTrace(out);
		}

		public boolean isLoggable() {
			return true;
		}
		@Override
		public void printf(String fmt, Object ... vars) {
			log(String.format(fmt,vars));
		}

	};


};