/**
 * Copyright (c) 2014, the Railo Company Ltd.
 * Copyright (c) 2015, Lucee Assosication Switzerland
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */
package lucee.runtime.engine;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import lucee.commons.io.SystemUtil;
import lucee.commons.lang.StringUtil;
import lucee.runtime.PageContext;
import lucee.runtime.op.Caster;

public abstract class ExecutionLogSupport implements ExecutionLog {
	
	protected static final short UNIT_NANO=1;
	protected static final short UNIT_MICRO=2;
	protected static final short UNIT_MILLI=4;
	protected static final short UNIT_UNDEFINED=0;
	
	private Map<String,Pair> map=Collections.synchronizedMap(new HashMap<String,Pair>());
	protected long min=Long.MIN_VALUE;
	protected short unit=UNIT_UNDEFINED;
	
	@Override
	public void init(PageContext pc,Map<String,String> arguments) {
		// min
		if(min==Long.MIN_VALUE) {
			min=toNanos(arguments.get("min-time"),0);
		}
		// unit
		if(UNIT_UNDEFINED==unit){
			unit=UNIT_NANO;
			// unit
			String _unit=arguments.get("unit");
			if(_unit!=null) {
				_unit=_unit.trim();
				if(_unit.equalsIgnoreCase("micro"))		unit=UNIT_MICRO;
				else if(_unit.equalsIgnoreCase(SystemUtil.SYMBOL_MICRO+"s"))	unit=UNIT_MICRO;
				else if(_unit.equalsIgnoreCase("milli"))unit=UNIT_MILLI;
				else if(_unit.equalsIgnoreCase("ms"))	unit=UNIT_MILLI;
			}
		}
		_init(pc,arguments);
	}

	private static long toNanos(String str, int defaultValue) {
		if(StringUtil.isEmpty(str)) return defaultValue;
		str=str.trim().toLowerCase();
		long l = Caster.toLongValue(str,Long.MIN_VALUE);
		if(l!=Long.MIN_VALUE) return l;
		
		if(str.endsWith("ns")) {
			String sub=str.substring(0,str.length()-2);
			l = Caster.toLongValue(sub.trim(),Long.MIN_VALUE);
			if(l!=Long.MIN_VALUE) return l;
		}
		else if(str.endsWith(SystemUtil.SYMBOL_MICRO+"s")) {
			String sub=str.substring(0,str.length()-2);
			double d = Caster.toDoubleValue(sub.trim(),Double.NaN);
			if(!Double.isNaN(d)) return (long)(d*1000);
		}
		else if(str.endsWith("ms")) {
			String sub=str.substring(0,str.length()-2);
			double d = Caster.toDoubleValue(sub.trim(),Double.NaN);
			if(!Double.isNaN(d)) return (long)(d*1000*1000);
		}
		else if(str.endsWith("s")) {
			String sub=str.substring(0,str.length()-1);
			double d = Caster.toDoubleValue(sub.trim(),Double.NaN);
			if(!Double.isNaN(d)) return (long)(d*1000*1000);
		}
		
		return defaultValue;
	}
	

	@Override
	public final void release() {
		map.clear();
		_release();
	}
	
	@Override
	public final void start(int pos,String id) {
		long current = System.nanoTime();
		map.put(id,new Pair(current,pos));
	}

	@Override
	public final void end(int pos,String id) {
		long current = System.nanoTime();
		Pair pair=map.remove(id);
		if(pair!=null) {
			if((current-pair.time)>=min)
				_log(pair.pos,pos,pair.time,current);
		}
	}
	protected abstract void _init(PageContext pc, Map<String, String> arguments);
	protected abstract void _log(int startPos, int endPos, long startTime, long endTime);
	protected abstract void _release();


	protected String timeLongToString(long current) {
		if(unit==UNIT_MICRO) return (current/1000L)+" "+SystemUtil.SYMBOL_MICRO+"s";
		if(unit==UNIT_MILLI) return (current/1000000L)+" ms";
		return current+" ns";
	}
	protected static String unitShortToString(short unit) {
		if(unit==UNIT_MICRO) return SystemUtil.SYMBOL_MICRO+"s";
		if(unit==UNIT_MILLI) return "ms";
		return "ns";
	}
	
	private final static class Pair {
		private final long time;
		private final int pos;
		public Pair(long time, int pos) {
			this.time=time;
			this.pos=pos;
		}
	}
}