/*
 * $Id$
 *
 * This file is part of the Cloud Services Integration Platform (CSIP),
 * a Model-as-a-Service framework, API, and application suite.
 *
 * 2012-2020, OMSLab, Colorado State University.
 *
 * OMSLab licenses this file to you under the MIT license.
 * See the LICENSE file in the project root for more information.
 */
package rhem.utils;

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;

/**
 *
 * @author rumpal
 */
public class RHEMUtils {

  private static final String DEFAULT_DOUBLE_PRECISION_FORMAT = "%.14f";
  private static final String DEFAULT_DOUBLE_FORMAT = "%.6f";

  public static final String[] MONTH_NAMES_LIST = {"January", "February", "March", "April", "May",
    "June", "July", "August", "September", "October", "November", "December"};

  //Round the value of a float or double

  public static double roundValues(double value, int places) {
    double power = Math.pow(10, places);
    return (Math.round(value * power) / power);
  }


  public static double interpolate(double pointToEvaluate, double[] functionValuesX, double[] functionValuesY) {
    double result = 0;
    int index = findIntervalLeftBorderIndex(pointToEvaluate, functionValuesX);
    if (index == functionValuesX.length - 1) {
      index--;
    }
    result = linearInterpolation(pointToEvaluate, functionValuesX[index], functionValuesY[index],
        functionValuesX[index + 1], functionValuesY[index + 1]);
    return result;
  }


  public static int findIntervalLeftBorderIndex(double point, double[] intervals) {

    if (point < intervals[0]) {
      return 0;
    }
    if (point > intervals[intervals.length - 1]) {
      return intervals.length - 1;
    }

    int leftBorderIndex = 0;
    int indexOfNumberToCompare;
    int rightBorderIndex = intervals.length - 1;

    while ((rightBorderIndex - leftBorderIndex) != 1) {
      indexOfNumberToCompare = leftBorderIndex
          + (int) Math.floor(((rightBorderIndex - leftBorderIndex) / 2));
      if (point >= intervals[indexOfNumberToCompare]) {
        leftBorderIndex = indexOfNumberToCompare;
      } else {
        rightBorderIndex = indexOfNumberToCompare;
      }
    }
    return leftBorderIndex;
  }


  public static double linearInterpolation(double x, double x0, double y0, double x1, double y1) {
    double a = (y1 - y0) / (x1 - x0);
    double b = -a * x0 + y0;
    return a * x + b;
  }


  public String formatPrecisionDouble(double value) {
    return formatDoubleString(value, DEFAULT_DOUBLE_PRECISION_FORMAT);
  }


  public static String formatDouble(double value) {
    return formatDoubleString(value, DEFAULT_DOUBLE_FORMAT);
  }


  private static String formatDoubleString(double value, String format) {
    return String.format(format, value);
  }


  public static String fmt(double d) {
    DecimalFormat df = new DecimalFormat("0", DecimalFormatSymbols.getInstance(Locale.ENGLISH));
    df.setMaximumFractionDigits(340);
    return df.format(d);
  }

}