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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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package org.openoffice.xmerge.converter.xml.sxc.pexcel.records;

import java.io.OutputStream;
import java.io.InputStream;
import java.io.IOException;

import org.openoffice.xmerge.util.Debug;
import org.openoffice.xmerge.util.EndianConverter;
import org.openoffice.xmerge.converter.xml.OfficeConstants;
import org.openoffice.xmerge.converter.xml.sxc.Format;
import org.openoffice.xmerge.converter.xml.sxc.pexcel.records.formula.FormulaHelper;
import org.openoffice.xmerge.converter.xml.sxc.pexcel.records.Workbook;
import org.openoffice.xmerge.converter.xml.sxc.pexcel.PocketExcelConstants;


/**
 * Represents a BIFF Record describing a formula  
 */
public class Formula extends CellValue implements OfficeConstants {

    private byte[] num		= new byte[8];
    private byte grbit;
    private byte[] cce		= new byte[2];
    private byte[] rgce;
	private FormulaHelper fh = new FormulaHelper();
   
	/**
 	 * Constructs a <code>Formula</code> using specified attributes
	 * 
	 * @param row row number
	 * @param col column number 
	 * @param cellContents contents of the cell 
	 * @param ixfe font index
	 * @param value the value of the cell
 	 */
    public Formula(int row, int column, String cellContents, int ixfe, Format fmt, Workbook wb)
	throws Exception {

		fh.setWorkbook(wb);

		setRow(row);
		setCol(column);
		setIxfe(ixfe);
		setFormula(cellContents);
		
		String category = fmt.getCategory();
		String value = fmt.getValue();
		
		if(category.equalsIgnoreCase(CELLTYPE_BOOLEAN)) {
			num[0]=(byte)0x01;
			num[1]=(byte)0x00;
			if(value.equalsIgnoreCase("true")) {
				num[2]=(byte)0x01;
			} else {
				num[2]=(byte)0x00;
			}
			num[3]=(byte)0x00;num[4]=(byte)0x00;num[5]=(byte)0x00;
			num[6]=(byte)0xFF;num[7]=(byte)0xFF;
		} else if(category.equalsIgnoreCase(CELLTYPE_DATE)) {
			Debug.log(Debug.TRACE,"Date Formula");
			num = EndianConverter.writeDouble(toExcelSerialDate(fmt.getValue()));
		} else if(category.equalsIgnoreCase(CELLTYPE_TIME)) {
			Debug.log(Debug.TRACE,"Time Formula");
			num = EndianConverter.writeDouble(toExcelSerialTime(fmt.getValue()));
		} else if(category.equalsIgnoreCase(CELLTYPE_PERCENT)) {
			Debug.log(Debug.TRACE,"Percent Formula");
			double percent = (double) Double.parseDouble(fmt.getValue());
			num = EndianConverter.writeDouble(percent);
		} else if(category.equalsIgnoreCase(CELLTYPE_CURRENCY)) {
			Debug.log(Debug.TRACE,"Currency Formula");
		} else if(category.equalsIgnoreCase(CELLTYPE_STRING)) {
			Debug.log(Debug.TRACE,"String Formula");
			num[0]=(byte)0x00;
			num[1]=(byte)0x00;
			num[2]=(byte)0x00;
			num[3]=(byte)0x00;
			num[4]=(byte)0x00;
			num[5]=(byte)0x00;
			num[6]=(byte)0xFF;
			num[7]=(byte)0xFF;
		} else {
			Debug.log(Debug.TRACE,"Float Formula");
			double cellLong = (double) Double.parseDouble(fmt.getValue());
			num = EndianConverter.writeDouble(cellLong);
		}
    }
  
	/**
 	 * Translates a <code>String</code> written in infix which represents a
	 * formula into a byte[] what can be written to pocket excel file.
 	 *
 	 * @param	formula string
 	 */
    public void setFormula(String inFormula) throws Exception {

		rgce = fh.convertCalcToPXL(inFormula);
		cce = EndianConverter.writeShort((short) rgce.length);
	}
  
	/**
 	 * Constructs a pocket Excel formula from the
 	 * <code>InputStream</code> 
 	 *
 	 * @param	is InputStream containing a Pocket Excel Data file.
 	 */
    public Formula(InputStream is, Workbook wb) throws IOException {
    	read(is);
		fh.setWorkbook(wb);
	}

    /**
	 * Get the hex code for this particular <code>BIFFRecord</code> 
	 *
	 * @return the hex code for <code>Formula</code>
	 */
    public short getBiffType() {
        return PocketExcelConstants.FORMULA_CELL;
    }
    
    /**
	 * Reads the formula data members from the stream. Byte arrays for Strings
	 * are doubled as they are stored as  unicode
	 *
	 * @return total number of bytes read 
	 */
    public int read(InputStream input) throws IOException {

		int numOfBytesRead = super.read(input);

        numOfBytesRead += input.read(num);
        grbit				= (byte) input.read();        
        numOfBytesRead		++;
        numOfBytesRead		+= input.read(cce);
       
		int strLen = EndianConverter.readShort(cce);
        rgce = new byte[strLen];
        input.read(rgce, 0, strLen);        
        
        Debug.log(Debug.TRACE, " num : " + num +
                            "\n\tgrbit : " + grbit +        
                            " cce : " + EndianConverter.readShort(cce) +
                            " rgce : " + new String(rgce,"UTF-16LE") + 
							"\n" + numOfBytesRead + " Bytes Read");
        
        return numOfBytesRead;
    }

     /**
	 * Writes the Formula record to the <code>OutputStream</code> 
	 *
	 * @param the <code>OutputStream</code> being written to 
	 */   
    public void write(OutputStream output) throws IOException {

    	output.write(getBiffType());
		
		super.write(output);

	    output.write(num);
	    output.write(grbit);
	    output.write(cce);
	    output.write(rgce);

		Debug.log(Debug.TRACE,"Writing Formula record");
    }

   /**
	 * Gets the <code>String</code> representing the cell value
	 *
	 * @return the <code>String</code> representing the cell value
	 */
	public String getValue() throws IOException {

		double value = EndianConverter.readDouble(num);
		Double myDo = new Double(value);
		return myDo.toString();
	}

    /**
	 * Gets the <code>String</code> representing the cells contents 
	 *
	 * @return the <code>String</code> representing the cells contents
	 */
	public String getString() throws IOException {

		return fh.convertPXLToCalc(rgce);
	}
	
    /**
	 * Excel dates are the number of days since 1/1/1900. This method converts
	 * to this date.
	 *
	 * @param s String representing a date in the form YYYY-MM-DD 
	 * @return The excel serial date  
	 */
	public long toExcelSerialDate(String s) throws IOException {

		int year = Integer.parseInt(s.substring(0,4));
		int month = Integer.parseInt(s.substring(5,7));
		int day = Integer.parseInt(s.substring(8,10));

		long serialDate =	(1461 * (year + 4800 + (month - 14) / 12)) / 4 +
							(367 * (month - 2 - 12 * ((month - 14) / 12))) / 12 -
							(3 * ((year + 4900 + (month - 14) / 12)) / 100) / 4 +
							day - 2415019 - 32075;	

		return serialDate;
	}
	
    /**
	 * Excel times are a fraction of a 24 hour day expressed in seconds. This method converts
	 * to this time.
	 *
	 * @param s String representing a time in the form ??HH?MM?SS? 
	 * @return The excel serial time  
	 */
	public double toExcelSerialTime(String s) throws IOException {

		int hours = Integer.parseInt(s.substring(2,4));
		int mins = Integer.parseInt(s.substring(5,7));
		int secs = Integer.parseInt(s.substring(8,10));

		int timeSecs = (hours*3600) + (mins*60) + (secs);

		double d = (double) timeSecs / (24 * 3600);	

		return d;
	}

}