package com.company;
import java.io.FileNotFoundException;
import java.util.*;
import java.io.File;


public class Main {

    public static void main(String[] args) {
        String fileName = "Property_Assessment_data_2019.csv";
        // We are going to read from a .csv file, Comma Separated Value File
        Integer[] assessedValues = getAssessedValues(fileName);
        //Now we sort the array
        Arrays.sort(assessedValues);
        System.out.println("Descriptive statistics of " + fileName);
        System.out.println("n = "+ getN(assessedValues));
        System.out.println("min = " + getMin(assessedValues));
        System.out.println("max = " + getMax(assessedValues));
        System.out.println("range = " + getRange(assessedValues));
        System.out.println("mean = " + getMean(assessedValues));
        System.out.println("sd = " + getsd(assessedValues));
        System.out.println("Median = " + getMedian(assessedValues));



    }
    private static double getMedian(Integer[] args){
        double Median = 0;
        int totalElements= args.length;
        if (totalElements % 2 == 0){
            int sumMiddle = args[totalElements/2] + args[totalElements/2 -1];
            //now get average of the middle elements
            Median = (double) sumMiddle /2;
        }
        else{
            Median = (double) args[totalElements/2];
        }
        return  Median;
    }
    private static double getsd(Integer[] args){
        double sd = 0;
        double average = getMean(args);
        for (int i=0; i<args.length;i++){
            sd = sd + Math.pow(args[i] - average, 2);

        }
        return sd;
    }
    private static double getMean(Integer[] args){
        double sum = 0;
        double sd = 0;
        for (int i = 0; i< args.length; i++){
            sum += args[i];
        }
        return sum / args.length;
    }
    private static Integer getRange(Integer[] args){
        int max = getMax(args);
        int min = getMin(args);
        return max-min;
    }
    private static Integer getMax(Integer[] args){
        int last = args.length -1;
        return args[last];
    }
    private static Integer getMin(Integer[] args){
        return args[0];
    }
    private static Integer getN(Integer[] args){
        int length = args.length;
        return length;
    }
    //This method opens the file, and gets all the assessed values from the csv file, then stores them inside of an Integer array.
    public static Integer[] getAssessedValues(String args){
        ArrayList<Integer> assessedValues = new ArrayList<Integer>();
        String fileName = "Property_Assessment_Data_2019.csv";
        File file = new File(fileName);
        try{
            Scanner inputStream = new Scanner(file);
            inputStream.nextLine(); //We ignore first line.
            while (inputStream.hasNext()){
                String data = inputStream.nextLine();
                String[] values = data.split(",");
                //Here we need to parse int, as it is a string, so we store each asssessed value as an int.
                int parsed = Integer.parseInt(values[4]);
                //Here we add the parsed integer to our array list
                assessedValues.add(parsed);
            }
            //Here we convert the array list to an object array.
            inputStream.close();

        } catch (FileNotFoundException e){
            e.printStackTrace();
        }
        //Here we return the assessedValues with toArray, converting it into a new Integer array.(IDE did this)
        return assessedValues.toArray(new Integer[0]);
    }