package org.apache.poi.hssf.record.formula;
import org.apache.poi.util.LittleEndian;

/**
 *
 * @author Jason Height (jheight at chariot dot net dot au)
 */
public class FuncVarPtg extends AbstractFunctionPtg{
    
    public final static byte sid  = 0x22;
    private final static int  SIZE = 4;  
    
    private FuncVarPtg() {
      //Required for clone methods
    }

 /**Creates new function pointer from a byte array 
     * usually called while reading an excel file. 
     */
    public FuncVarPtg(byte[] data, int offset) {
        offset++;
        field_1_num_args = data[ offset + 0 ];
        field_2_fnc_index  = LittleEndian.getShort(data,offset + 1 );
    }
    
    /**
     * Create a function ptg from a string tokenised by the parser
     */
    public FuncVarPtg(String pName, byte pNumOperands) {
        field_1_num_args = pNumOperands;
        field_2_fnc_index = lookupIndex(pName);
        try{
            returnClass = ( (Byte) functionData[field_2_fnc_index][0]).byteValue();
            paramClass = (byte[]) functionData[field_2_fnc_index][1];
        } catch (NullPointerException npe ) {
            returnClass = Ptg.CLASS_VALUE;
            paramClass = new byte[] {Ptg.CLASS_VALUE};
        }
    }
    
     public void writeBytes(byte[] array, int offset) {
        array[offset+0]=(byte) (sid + ptgClass);
        array[offset+1]=field_1_num_args;
        LittleEndian.putShort(array,offset+2,field_2_fnc_index);
    }
    
     public int getNumberOfOperands() {
        return field_1_num_args;
    }
    
    public Object clone() {
      FuncVarPtg ptg = new FuncVarPtg();
      ptg.field_1_num_args = field_1_num_args;
      ptg.field_2_fnc_index = field_2_fnc_index;
      ptg.setClass(ptgClass);
      return ptg;
    }
    
    public int getSize() {
        return SIZE;
    }
    
    public String toString() {
        StringBuffer buffer = new StringBuffer();
        buffer
        .append("<FunctionVarPtg>").append("\n")
        .append("   field_1_num_args=").append(field_1_num_args).append("\n")
        .append("      name         =").append(lookupName(field_2_fnc_index)).append("\n")
        .append("   field_2_fnc_index=").append(field_2_fnc_index).append("\n")
        .append("</FunctionPtg>");
        return buffer.toString();
    }

    
}