/*
 * Copyright (C) 2003-2007 eXo Platform SAS.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Affero General Public License
 * as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see<http://www.gnu.org/licenses/>.
 */
package org.exoplatform.services.document.impl;

import java.io.IOException;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.exoplatform.services.document.DocumentReadException;

/**
 * Created by The eXo Platform SAS A parser of Microsoft Excel files.
 * 
 * @author <a href="mailto:phunghainam@gmail.com">Phung Hai Nam</a>
 * @author Gennady Azarenkov
 * @version Oct 21, 2005
 */
public class MSExcelDocumentReader extends BaseDocumentReader {

  private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSZ");

  /**
   * Get the application/excel mime type.
   * 
   * @return The string with application/excel mime type.
   */
  public String[] getMimeTypes() {
    return new String[] { "application/excel", "application/xls" };
  }

  /**
   * Returns only a text from .xls file content.
   * 
   * @param is an input stream with .xls file content.
   * @return The string only with text from file content.
   */
  public String getContentAsText(InputStream is) throws IOException, DocumentReadException {
    if (is == null) {
      throw new NullPointerException("InputStream is null.");
    }

    String text = "";
   
    try {
      HSSFWorkbook wb;
      try{
        wb = new HSSFWorkbook(is);
      }catch(IOException e){
        return text;
      }
      for (int sheetNum = 0; sheetNum < wb.getNumberOfSheets(); sheetNum++) {
        HSSFSheet sheet = wb.getSheetAt(sheetNum);
        if (sheet != null) {
          for (int rowNum = sheet.getFirstRowNum(); rowNum <= sheet.getLastRowNum(); rowNum++) {
            HSSFRow row = sheet.getRow(rowNum);

            if (row != null) {
              int lastcell = row.getLastCellNum();
              for (int k = 0; k < lastcell; k++) {
                HSSFCell cell = row.getCell((short) k);
                if (cell != null) {
                  switch (cell.getCellType()) {
                  case HSSFCell.CELL_TYPE_NUMERIC: {
                    double d = cell.getNumericCellValue();
                    if (isCellDateFormatted(cell)) {
                      Date date = HSSFDateUtil.getJavaDate(d);
                      String cellText = this.DATE_FORMAT.format(date);
                      text = text + cellText + " ";
                    } else {
                      text = text + d + " ";
                    }
                    break;
                  }
                  case HSSFCell.CELL_TYPE_FORMULA:
                    text = text + cell.getCellFormula().toString() + " ";
                    break;
                  case HSSFCell.CELL_TYPE_BOOLEAN:
                    text = text + cell.getBooleanCellValue() + " ";
                    break;
                  case HSSFCell.CELL_TYPE_ERROR:
                    text = text + cell.getErrorCellValue() + " ";
                    break;
                  case HSSFCell.CELL_TYPE_STRING:
                    text = text + cell.getStringCellValue().toString() + " ";
                    break;
                  default:
                    break;
                  }
                }
              }
            }
          }
        }
      }
    } finally {
      if (is != null) {
        try {
          is.close();
        } catch (IOException e) {
        }
      }
    }
    return text;
  }

  public String getContentAsText(InputStream is, String encoding) throws IOException,
                                                                 DocumentReadException {
    // Ignore encoding
    return getContentAsText(is);
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.exoplatform.services.document.DocumentReader#getProperties(java.io.
   *      InputStream)
   */
  public Properties getProperties(InputStream is) throws IOException, DocumentReadException {
    POIPropertiesReader reader = new POIPropertiesReader();
    reader.readDCProperties(is);
    return reader.getProperties();
  }

  public static boolean isCellDateFormatted(HSSFCell cell) {
    boolean bDate = false;
    double d = cell.getNumericCellValue();
    if (HSSFDateUtil.isValidExcelDate(d)) {
      HSSFCellStyle style = cell.getCellStyle();
      int i = style.getDataFormat();
      switch (i) {
      case 0xe: // m/d/yy
      case 0xf: // d-mmm-yy
      case 0x10: // d-mmm
      case 0x11: // mmm-yy
      case 0x12: // h:mm AM/PM
      case 0x13: // h:mm:ss AM/PM
      case 0x14: // h:mm
      case 0x15: // h:mm:ss
      case 0x16: // m/d/yy h:mm
      case 0x2d: // mm:ss
      case 0x2e: // [h]:mm:ss
      case 0x2f: // mm:ss.0

      case 0xa5: // ??
      case 0xa7: // ??
      case 0xa9: // ??

      case 0xac: // mm:dd:yy not specified in javadoc
      case 0xad: // yyyy-mm-dd not specified in javadoc
      case 0xae: // mm:dd:yyyy not specified in javadoc
      case 0xaf: // m:d:yy not specified in javadoc
        bDate = true;
        break;
      default:
        bDate = false;
        break;
      }
    }
    return bDate;
  }
}