package org.simantics.spreadsheet.graph.formula;

import org.simantics.spreadsheet.graph.CellFormulaFunction;
import org.simantics.spreadsheet.graph.CellValueVisitor;
import org.simantics.spreadsheet.graph.SpreadsheetGraphUtils;
import org.simantics.spreadsheet.graph.SpreadsheetMatrix;
import org.simantics.spreadsheet.graph.parser.ast.AstArgList;
import org.simantics.spreadsheet.graph.parser.ast.AstValue;

public class GeomeanFormulaFunction implements CellFormulaFunction<Object> {

    @Override
    public Object evaluate(CellValueVisitor visitor, AstArgList args) {
        if (args.values.size() == 0)
            throw new IllegalStateException();
        double result = 1.0;
        double count = 0.0;
        for (AstValue value : args.values){
        	Object r = value.accept(visitor);
        	if (r instanceof SpreadsheetMatrix) {
              Object v = ((SpreadsheetMatrix) r).productWithFormulaError();
              if(v instanceof String) return v;
              double dval = ((Number)v).doubleValue();
              if(dval!=0.0){
                  result = result*dval;
                  count += ((SpreadsheetMatrix) r).countOfActualDoubleValues();
              }
        	} else {
				FormulaError2 error = FormulaError2.forObject(r);
				if(error!=null) return error.getString();
        		
				Number vNum = SpreadsheetGraphUtils.asValidNumber(r);
				Double v = null;
				if(vNum!=null) v = vNum.doubleValue();
				
        		if(v!=null){
        			if(v<=0) return FormulaError2.NUM.getString();
        			result = result*v;
        			count++;
        		}
        	}
        }
        if(result==0.0 || count==0.0) return FormulaError2.NUM.getString();
        return Double.valueOf(Math.pow(result, (1.0/count)));
    }

}