/*
   *  Making sure that the user input is in range
   *  @param1 Scanner object for input
   *  @param2 lowerbound integer
   *  @param3 upperbound integer
   *  @param4 String that specifies for which attribute/field input is for
   *  printing purposes
   *  @param5 ValType enum that specifies whether the primitive value is
   *  an int or double
   *  @param6 boolean that specifies whether the input is an Enum value
   *  @param7 boolean that specifies whether to return the value if out of
   *  range (false) or not (true)
   */
  public static Number makeSureValInRange(
      Scanner input,
      int lowerbound,
      int upperbound,
      String inputFor,
      ValType valType,
      boolean enumeration,
      boolean withinRange) {

    boolean valid = !withinRange;
    Number val = 0;

    while (!valid) {

      System.out.println(inputString(inputFor, null, StringOption.SELECT, enumeration));

      val = valType == ValType.INTEGER ? input.nextInt() : input.nextDouble();

      if (val.intValue() < lowerbound || val.intValue() > upperbound) {
        System.out.println(inputString(inputFor, null, StringOption.INCORRECT, enumeration));
      } else {
        valid = true;
      }
    }
    return val;
  }
  public static void main(String[] args) {
    //////////////////////////
    // The values in following 4 lines should be user input
    int startPos = 200;
    int endPos = 1000;
    int totalNumPixel = 1044;
    double threshhold = 0.0001;
    /////////////////////////
    int numPixel = endPos - startPos;
    double wavelength[] = new double[totalNumPixel];
    double photonCount[] = new double[totalNumPixel];
    double SpecNoBk[] = new double[numPixel];
    double ThisSpectrum[] = new double[numPixel];
    double ThisXaxis[] = new double[numPixel];
    double Po[] = new double[numPixel];
    double Re[] = new double[numPixel];
    double P[] = new double[6];
    double Re2[] = new double[numPixel - 1];
    double mySUM[] = new double[numPixel];
    int ind[];
    double DEV;
    double prevDEV;
    Connection connection = null;
    Statement stmt = null;
    String pattern = "##.##";

    try {
      Scanner in = new Scanner(new FileReader(args[0]));
      int i = 0;
      while (in.hasNextDouble()) {
        wavelength[i] = in.nextDouble();
        photonCount[i] = in.nextDouble();
        ++i;
      }
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    }

    ThisSpectrum = Arrays.copyOfRange(photonCount, startPos, endPos);
    ThisXaxis = Arrays.copyOfRange(wavelength, startPos, endPos);
    final WeightedObservedPoints obs = new WeightedObservedPoints();

    for (int i = 0; i < numPixel; i++) {
      obs.add(ThisXaxis[i], ThisSpectrum[i]);
    }

    final PolynomialCurveFitter fitter = PolynomialCurveFitter.create(5);
    P = fitter.fit(obs.toList());
    Polyval pVal = new Polyval(P, ThisXaxis, numPixel);
    Po = pVal.evl();

    for (int i = 0; i < numPixel; i++) {
      Re[i] = ThisSpectrum[i] - Po[i];
    }

    for (int i = 0; i < numPixel - 1; i++) {
      Re2[i] = Re[i + 1] - Re[i];
    }

    DEV = Math.sqrt(StatUtils.populationVariance(Re2, 0, Re2.length));
    for (int i = 0; i < numPixel; i++) {
      mySUM[i] = Po[i] + DEV;
    }

    int jj = 0; // jj is the length of points to be removed
    for (int i = 0; i < numPixel; i++) {
      if (ThisSpectrum[i] > mySUM[i]) {
        jj++;
        ;
      }
    }
    ind = new int[jj];

    int jjj = 0;
    for (int i = 0; i < numPixel; i++) {
      if (ThisSpectrum[i] > mySUM[i]) {
        ind[jjj] = i;
        jjj++;
      }
    }

    int indKeepLength = numPixel - ind.length;
    int indKeep[] = new int[indKeepLength];
    int k = 0;
    for (int i = 0; i < numPixel; i++) {
      if (!ArrayUtils.contains(ind, i)) {
        indKeep[k] = i;
        k++;
      }
    }
    double ThisSpectrumKeep[] = new double[indKeepLength];
    double ThisXaxisKeep[] = new double[indKeepLength];
    double PoKeep[] = new double[indKeepLength];
    double ReKeep[] = new double[indKeepLength];
    double Re2Keep[] = new double[indKeepLength - 1];
    double mySUMKeep[] = new double[indKeepLength];

    for (int i = 0; i < indKeepLength; i++) {
      ThisSpectrumKeep[i] = ThisSpectrum[indKeep[i]];
      ThisXaxisKeep[i] = ThisXaxis[indKeep[i]];
    }

    prevDEV = DEV;

    // at the point, ThisSpectrum and ThisXaxis should have reduced size
    final WeightedObservedPoints obs1 = new WeightedObservedPoints();

    for (int i = 0; i < indKeepLength; i++) {
      obs1.add(ThisXaxisKeep[i], ThisSpectrumKeep[i]);
    }

    while (true) {
      final PolynomialCurveFitter fitter1 = PolynomialCurveFitter.create(5);
      P = fitter1.fit(obs1.toList());
      Polyval pVal1 = new Polyval(P, ThisXaxisKeep, indKeepLength);
      PoKeep = pVal1.evl();

      for (int i = 0; i < indKeepLength; i++) {
        ReKeep[i] = ThisSpectrumKeep[i] - PoKeep[i];
      }

      for (int i = 0; i < indKeepLength - 1; i++) {
        Re2Keep[i] = ReKeep[i + 1] - ReKeep[i];
      }

      DEV = Math.sqrt(StatUtils.populationVariance(Re2Keep, 0, Re2Keep.length));

      for (int i = 0; i < indKeepLength; i++) {
        mySUMKeep[i] = PoKeep[i] + DEV;
      }

      for (int i = 0; i < indKeepLength; i++) {
        if (ThisSpectrumKeep[i] > mySUMKeep[i]) ThisSpectrumKeep[i] = mySUMKeep[i];
      }
      if ((Math.abs(DEV - prevDEV) / DEV) < threshhold) break;
      prevDEV = DEV;

      obs1.clear();
      for (int i = 0; i < indKeepLength; i++) {
        obs1.add(ThisXaxisKeep[i], ThisSpectrumKeep[i]);
      }
    }
    Polyval pVal2 = new Polyval(P, ThisXaxis, numPixel);
    double FLbk[] = pVal2.evl();
    for (int i = 0; i < ThisXaxis.length; i++) {
      SpecNoBk[i] = ThisSpectrum[i] - FLbk[i];
    }

    // the write-to-file part is only for testing purpose, ThisXaxis and SpecNoBk are two outputs
    try {
      FileWriter fr = new FileWriter(args[1]);
      BufferedWriter br = new BufferedWriter(fr);
      PrintWriter out = new PrintWriter(br);
      DecimalFormat df = new DecimalFormat(pattern);
      for (int j = 0; j < ThisXaxis.length; j++) {
        if (Double.toString(wavelength[j]) != null) out.write(ThisXaxis[j] + "\t" + SpecNoBk[j]);
        out.write("\r\n");
      }
      out.close();
    } catch (IOException e) {
      System.out.println(e);
    }
  }