/*
 * JELBaseModelFunction.java
 *
 * Created on September 16, 2002, 3:27 PM
 */

package hep.aida.ref.function;
import java.util.*;
import hep.aida.*;
import hep.aida.ref.*;

/**
 *
 * @author  serbo
 */
public class JELBaseModelFunction extends BaseModelFunction {

    private JELBaseModelFunction() {}
    public JELBaseModelFunction(String treeName, int dim, String valexpr, String parameters, String description, String gradexpr) {
	//System.out.println("JELBaseModelFunction:: valexpr="+valexpr+",  parameters="+parameters+
	//		   ",   description="+description+",  gradexpr="+gradexpr);
	setName(treeName);
        FunctionCore f = createJELFunctionCore(dim, valexpr, parameters, gradexpr);
	init(description, f , f);
    }


    public JELFunctionCore createJELFunctionCore(int dim, String valexpr, String parameters, String gradexpr) {
	JELFunctionCore core = null;

	// Reformat parameters String into String[]
	String[] parNames = null;
	int nPar = 0;
	if (parameters != null && !parameters.equals("")) {
	    StringTokenizer st = new StringTokenizer(parameters, ",;");
	    nPar = st.countTokens();
	    if (nPar >0 ) parNames = new String[nPar];
	    int i =0;
	    while (st.hasMoreTokens()) {
		String token = st.nextToken().trim();
                checkParameterName(token);
		parNames[i] = token;
		//System.out.println(i+"\t"+parNames[i]);
		i++;
	    }
	}

	// Reformat gradient expression String into String[]
	String[] gr = null;
	int nGr = 0;
	if (gradexpr != null && !gradexpr.equals("") && !gradexpr.trim().toLowerCase().equals("null")) {
	    StringTokenizer st = new StringTokenizer(gradexpr, ",;");
	    nGr = st.countTokens();
	    if (nGr != dim ) 
		throw new IllegalArgumentException("Dimension of the gradient ("+nGr+") is not equal to the dimension of the function ("+dim+")");
	    gr = new String[dim];
	    int i =0;
	    while (st.hasMoreTokens()) {
		String token = st.nextToken().trim();
		gr[i] = token;
		//System.out.println(i+"\t"+gr[i]);
		i++;
	    }
	}
	core = new JELFunctionCore(dim, nPar, valexpr, parNames, gr );

	return core;
    }

    private void checkParameterName(String token) {
        if (token.startsWith("x") || token.startsWith("X")) {
            String tmp = token.substring(1);
            try {
                int i = Integer.parseInt(tmp);
            } catch (NumberFormatException e) {
                return;
            }
            String mess = "Illegal parameter name: \""+token+"\".\nNames like x0, x1, x2, ..., are reserved. Please rename this parameter..";
            throw new IllegalArgumentException(mess);
        }
        return;
    }
    
    
    public static void main(String[] args) {
        IAnalysisFactory af = IAnalysisFactory.create();
        ITree tree = af.createTreeFactory().create();
        IHistogramFactory hf = af.createHistogramFactory( tree );
        IFunctionFactory  ff = af.createFunctionFactory( tree );
        IPlotterFactory   pf = af.createPlotterFactory( );
	IPlotter plotter = pf.create("Function Plotter");
        
        hep.aida.IHistogram1D hist1 = hf.createHistogram1D("hist1","hist1",100,-5,5);

      	IModelFunction f1 = (IModelFunction) ff.createFunctionFromScript("My Test Function", 1, "a*x[0]+b", "a, b", "linear");
      	//IModelFunction f2 = (IModelFunction) ff.createFunctionFromScript("My Test Function", 1, "X2*x[0]+b", "X2, b", "linear");

	plotter.createRegions(1, 1);
        plotter.region(0).plot(hist1);
        plotter.region(0).plot(f1);
        plotter.show();
    }
}