/*
 * FunctionCreator.java
 *
 * Created on September 26, 2002, 11:57 AM
 */

package hep.aida.ref.function;
import hep.aida.IFunction;
import hep.aida.IManagedObject;
import hep.aida.ext.IManagedFunction;
import hep.aida.ref.ManagedObject;

import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.StringTokenizer;

/**
 * Singleton class that is used by FunctionFactory and FunctionCatalog
 * to create functions from codelet strings. Use static method 
 * getFunctionCreator() to get an instance of this class.
 *
 * @author  serbo
 */
public class FunctionCreator {

    public FunctionCreator() {
    }
    

    public IFunction createFromCodelet(String codeletString) {
	return createFromCodelet(null, codeletString);
    }

    
    public IFunction createFromCodelet(String nameInTree, String codeletString) {
	IFunction f = null;
	if (!codeletString.toLowerCase().startsWith(FunctionCatalog.prefix))
	    throw new IllegalArgumentException("\""+ codeletString + "\" is not a codelet string (must start with \""+FunctionCatalog.prefix+"\")");
	
	String name = CodeletUtils.modelFromCodelet(codeletString);
	String location = CodeletUtils.locationFromCodelet(codeletString);
	//System.out.println("Catalog:  index="+index+",  name="+name+",  location="+location);


	// Catalog entries for Build-in functions
	if (CodeletUtils.isCodeletFromCatalog(codeletString)) {
	    if (name.toLowerCase().equals("e")) { 
		f = new BaseModelFunction(name, name, new ExponentialCoreNotNorm(name), new ExponentialCoreNorm(name));
	    } else if (name.toLowerCase().startsWith("p")) {
		f = new BaseModelFunction(name, name, new PolynomialCoreNotNorm(name), new PolynomialCoreNorm(name));
	    } else if (name.toLowerCase().startsWith("g2")) {
		f = new BaseModelFunction(name, name, new GaussianCore2DNotNorm(name), new GaussianCore2DNorm(name));
	    } else if (name.toLowerCase().startsWith("g")) {
		f = new BaseModelFunction(name, name, new GaussianCoreNotNorm(name), new GaussianCoreNorm(name));
	    } else if (name.toLowerCase().startsWith("moyal")) {
		f = new BaseModelFunction(name, name, new MoyalCoreNotNorm(name), null);
	    } else if (name.toLowerCase().startsWith("lorentzian")) {
		f = new BaseModelFunction(name, name, new LorentzianCoreNotNorm(name), null);
	    } else {
		throw new UnsupportedOperationException("Can not create function: "+name);
	    }
	    ((BaseModelFunction) f).setCodeletString(codeletString);	 
            if ( nameInTree == null ) nameInTree = name;
	    ((ManagedObject) f).setName(nameInTree);
	}

	// Create JEL-based scripted function. The codeletString explession after
	// "codelet:verbatim:jel:" MUST contain a full description of scripted function.
	// Currently use ":" as deliminators. Example:
	// codelet:Script_Function:verbatim:jel :1 : a*(1+c*sin(x[0]-d)) : a,c,d : a*c*cos(x[0]-d) 
        else if (CodeletUtils.isCodeletFromScript(codeletString)) {
            //System.out.println("CODELETSTRING :: "+codeletString);
            StringTokenizer st = new StringTokenizer(codeletString, ":");
            String[] args = new String[st.countTokens()];
            int i = 0;
            while (st.hasMoreTokens()) {
                args[i] = st.nextToken().trim();
                //System.out.println(i+" "+args[i]);
                i++;
            }
            
	    int dim = Integer.parseInt(args[4]);
            String valexpr = args[5];
            String parameters = args[6];
	    String gradexpr = "";
            if (args.length > 7) {
                gradexpr = args[7];
            }
	    if (gradexpr.trim().toLowerCase().equals("null") || gradexpr.trim().equals("") ) gradexpr = null;
	    //System.out.println("dim="+dim+",  valexpr="+valexpr+",  parameters="+parameters+",  gradexpr="+gradexpr);

	    f = new JELBaseModelFunction(name, dim, valexpr, parameters, name, gradexpr);
	    ((JELBaseModelFunction) f).setCodeletString(codeletString);
	    ((ManagedObject) f).setName(nameInTree);
	}

	// Create function, given its full class name: 
        //     codelet:my.functions.MyFunction:classPath
        // No-argument constructor is used in such case: new MyFunction()
        // If optional list of variable names and parameter names is provided:
        //     codelet:my.functions.MyFunction:classPath:x0, x1: a, b, c
        // MyFunction(String[] varNames, String[] parNames) constructor is used
        else if (CodeletUtils.isCodeletFromClass(codeletString)) {
            StringTokenizer st = new StringTokenizer(codeletString, ":");
            String[] args = new String[st.countTokens()];
            int i = 0;
            while (st.hasMoreTokens()) {
                args[i] = st.nextToken().trim();
                i++;
            }
            String[] varList = CodeletUtils.stringToArray(args[3]);
            String[] parList = CodeletUtils.stringToArray(args[4]);
            
            try {
                if (varList != null && parList != null) {
                    Class[] types = new Class[] {String[].class, String[].class};
		    Class cl = Class.forName(name);                    
		    f = (IFunction) cl.getConstructor(types).newInstance(new Object[] {varList, parList});                    
                } else {
		    Class cl = Class.forName(name);
		    f = (IFunction) cl.newInstance();
                }
		if (f instanceof ManagedObject) ((ManagedObject) f).setName(nameInTree);
		if (f instanceof IManagedFunction) ((IManagedFunction) f).setName(nameInTree);
                if (f != null) f.setTitle(nameInTree);
            } catch (Exception ec) {
                throw new RuntimeException("Can not create user CLASS function:"+name, ec);
            }
        }
        
	// Load function from file. "name" MUST be just FULL name of the class
	// (e.g. "fitProject.functions.MyFunction"
        else if (CodeletUtils.isCodeletFromFile(codeletString)) {
	    try {
		String urlString = location.substring(5).trim();
		if (urlString == null || urlString.equals("")) {
		    Class cl = Class.forName(name);
		    f = (IFunction) cl.newInstance();
		} else {
		    URL[] urlList = new URL[] { new File(urlString.substring(1)).toURL() };
		    URLClassLoader loader = new URLClassLoader(urlList);
		    
		    System.out.println("Name: "+name+"\nFile Name: "+urlString);
		    System.out.println("URL: "+urlList[0].getFile());
		    Class cl = loader.loadClass(name);
		    f = (IFunction) cl.newInstance();
		}
		if (f instanceof ManagedObject) ((ManagedObject) f).setName(nameInTree);
		if (f instanceof IManagedFunction) ((IManagedFunction) f).setName(nameInTree);
	    } catch (Exception ec) { 
		throw new RuntimeException("Can not create user FILE function:"+name, ec);
	    }
	}

	return f;
    }

    public static String toString(IFunction f) {
	
	String out = "Codelet: "+f.codeletString()+"\n";
	if (f instanceof IManagedObject) out += "   name: "+((IManagedObject) f).name()+"\n";
	out += "\tDimensions: "+f.dimension()+"\n";
	for (int i =0; i