package ffx.utilities;
   
   import jakarta.xml.bind.annotation.adapters.XmlAdapter;
   
   import java.util.logging.Logger;
   
   import static java.lang.Double.parseDouble;
   import static java.lang.String.format;
   
  /**
   * Write/read Histogram data to/from a String.
   * The String is an array of lines separated by System dependent line separators.
   * Each line (row) corresponds to a fixed lambda.
   * The columns are a space-separated list of weights for the dUdL bins.
   *
   * @author Michael J. Schnieders
   * @see jakarta.xml.bind.annotation.adapters.XmlAdapter
   * @since 1.0
   */
  public class HistogramXmlAdapter extends XmlAdapter<String, double[][]> {
  
    /**
     * The logger for this class.
     */
    public static final Logger logger = Logger.getLogger(HistogramXmlAdapter.class.getName());
  
    /**
     * Convert the histogram data string to a 2D double array.
     *
     * @param value String containing the Histogram data.
     * @return The data.
     */
    @Override
    public double[][] unmarshal(String value) {
      double[][] data;
      try {
        String[] lines = value.split(System.lineSeparator());
        int lambdaBins = lines.length;
        data = new double[lambdaBins][];
        for (int i = 0; i < lambdaBins; i++) {
          String[] countToks = lines[i].split(" +");
          int dUdLBins = countToks.length;
          data[i] = new double[dUdLBins];
          double[] row = data[i];
          for (int j = 0; j < dUdLBins; j++) {
            row[j] = parseDouble(countToks[j]);
          }
        }
      } catch (Exception e) {
        logger.warning(" Returning a null histogram due to an XML parsing exception:\n " + e);
        data = null;
      }
      return data;
    }
  
    /**
     * Convert the 2D histogram double array into a String.
     *
     * @param data The histogram data.
     * @return A String representation of the data.
     */
    @Override
    public String marshal(double[][] data) {
      StringBuilder sb = new StringBuilder();
      for (double[] row : data) {
        sb.append(format("%.16e", row[0]));
        int dUdLBins = row.length;
        for (int j = 1; j < dUdLBins; j++) {
          sb.append(" ").append(format("%.16e", row[j]));
        }
        sb.append(System.lineSeparator());
      }
      return sb.toString();
    }
  }