/**
 *
 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
 *
 * 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/>.
 * 
 **/
/**
 * Implements the CFML Function hash
 */
package lucee.runtime.functions.string;

import java.security.MessageDigest;

import lucee.commons.digest.HashUtil;
import lucee.commons.lang.ExceptionUtil;
import lucee.commons.lang.StringUtil;
import lucee.commons.lang.SystemOut;
import lucee.runtime.PageContext;
import lucee.runtime.config.Config;
import lucee.runtime.exp.PageException;
import lucee.runtime.ext.function.Function;
import lucee.runtime.op.Caster;

public final class Hash implements Function {

	private static final long serialVersionUID = 1161445102079248547L;

	// function for old code in ra files calling this function
	public static String call(PageContext pc, String input) throws PageException {
		return invoke( pc.getConfig(), input, null, null, 1 );
	}
    public static String call(PageContext pc , String input, String algorithm) throws PageException {
		return invoke( pc.getConfig(), input, algorithm, null, 1 );
	}
    public static String call(PageContext pc , String input, String algorithm, String encoding) throws PageException {
		return invoke( pc.getConfig(), input, algorithm, encoding, 1 );
	}
	//////
	
	
	public static String call(PageContext pc, Object input) throws PageException {
		return invoke( pc.getConfig(), input, null, null, 1 );
	}
	
    public static String call(PageContext pc , Object input, String algorithm) throws PageException {
		return invoke( pc.getConfig(), input, algorithm, null, 1 );
	}

    public static String call(PageContext pc , Object input, String algorithm, String encoding) throws PageException {
		return invoke( pc.getConfig(), input, algorithm, encoding, 1 );
	}
    
    public static String call(PageContext pc , Object input, String algorithm, String encoding, double numIterations) throws PageException {
		return invoke( pc.getConfig(), input, algorithm, encoding, (int)numIterations );
	}

    /*/	this method signature was called from ConfigWebAdmin.createUUID(), comment this comment to enable
    public synchronized static String invoke(Config config, Object input, String algorithm, String encoding) throws PageException {
    	
    	return invoke(config, input, algorithm, encoding, 1);
    }	//*/
    
    public static String invoke(Config config, Object input, String algorithm, String encoding, int numIterations) throws PageException {
		
    	if(StringUtil.isEmpty(algorithm))algorithm="md5";
		else algorithm=algorithm.trim().toLowerCase();
    	if("cfmx_compat".equals(algorithm)) algorithm="md5";
    	else if("quick".equals(algorithm)) {
    		if(numIterations>1) 
    			SystemOut.printDate("for algorithm [quick], argument numIterations makes no sense, because this algorithm has no security in mind");
    		return HashUtil.create64BitHashAsString(Caster.toString(input), 16);
    	}
    	
    	
		
    	if(StringUtil.isEmpty(encoding))encoding=config.getWebCharset().name();
		byte[] data = null;
		
		try {			
			if(input instanceof byte[]) data = (byte[])input;
			else data = Caster.toString(input).getBytes( encoding );
			
			MessageDigest md=MessageDigest.getInstance(algorithm);
		    md.reset();
		    for(int i=0; i<numIterations; i++) {
		    	data=md.digest(data);
			}
		    return lucee.commons.digest.Hash.toHexString(data,true);
		} 
		catch(Throwable t) {
			ExceptionUtil.rethrowIfNecessary(t);
			throw Caster.toPageException(t);
		}
	}

}