package com.company;

import com.sun.org.apache.bcel.internal.generic.SWAP;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.Scanner;
import java.io.*;
import java.lang.NumberFormatException;

public class Main {


    static Scanner sc = new Scanner(System.in);

    static int[] shellSort(int[] arr) {
        int step = arr.length;
        while (step > 0) {
            for (int i = 0; i < arr.length - step; i++) {
                int j = i;
                while (j >= 0 && arr[j] > arr[j + step]) {
                    arr[j] += arr[j + step];
                    arr[j + step] = arr[j] - arr[j + step];
                    arr[j] -= arr[j + step];
                    j--;
                }
            }
            step /= 2;
        }
        return arr;
    }

    static void outputArray(int[] arr) {
        System.out.println("Resul array");
        for (int i = 0; i < arr.length; i++) {
            if (i != 0)
                System.out.print(", ");
            System.out.print(arr[i]);
        }
        System.out.println();
    }

    static void outputToFile(int[] arr) {
        boolean incorrect;
        sc.nextLine();
        do {
            incorrect = false;
            System.out.println("Enter new file location:");
            String line = sc.nextLine();
            try (PrintWriter writer = new PrintWriter(line, "UTF-8")) {
                for (int i = 0; i < arr.length; i++)
                    writer.write(arr[i] + "\n");
            } catch (FileNotFoundException e) {
                System.out.println("File not found, try again");
                incorrect = true;
            } catch (Exception e) {
                incorrect = true;
                e.printStackTrace();
            }
            System.out.println("Successfully recorded");
        } while (incorrect);
    }

    static int[] getArrayFromFile() {
        sc.nextLine();
        boolean incorrect;
        String line = "";
        int[] arr = {};
        do {
            incorrect = false;
            System.out.println("Enter file location: ");
            line = sc.nextLine();
            try (BufferedReader br = new BufferedReader(new FileReader(new File(line)))) {
                line = br.readLine();
                int size = Integer.parseInt(line);
                arr = new int[size];
                line = br.readLine();
                String[] arrFillings = line.split(" ");
                for (int i = 0; i < size; i++)
                    arr[i] = Integer.parseInt(arrFillings[i]);
            } catch (NumberFormatException e) {
                incorrect = true;
                System.out.println("Invalid data, try again");
            } catch (FileNotFoundException e) {
                incorrect = true;
                System.out.println("File with this location not found");
            } catch (Exception e) {
                incorrect = true;
                e.printStackTrace();
            }
        } while (incorrect);
        return arr;
    }

    static int[] getArrayFromConsole() {
        boolean incorrect;
        String line;
        sc.nextLine();
        do {
            incorrect = false;
            System.out.println("Enter the number of items greater than 2");
            line = sc.nextLine();
            try {
                if (Integer.parseInt(line) < 2) {
                    incorrect = true;
                    System.out.println("The number of elements must be greater than 2");
                }
            } catch (Exception e) {
                incorrect = true;
                System.out.println("Enter a natural numeric value");
            }
        } while (incorrect);
        int[] arr = new int[Integer.parseInt(line)];
        for (int i = 0; i < arr.length; i++) {
            do {
                incorrect = false;
                System.out.println("Enter " + (i + 1) + " element");
                line = sc.nextLine();
                try {
                    arr[i] = Integer.parseInt(line);
                } catch (Exception e) {
                    incorrect = true;
                    System.out.println("Enter an integer value");
                }
            } while (incorrect);
        }
        return arr;
    }

    static int[] chooseInput() {
        char inputType;
        int[] resArr = {};
        boolean incorrect;
        incorrect = true;
        do {
            System.out.println("Enter 'F' to choose input from file\nEnter 'C to choose input from console");
            inputType = sc.next().charAt(0);
            inputType = Character.toUpperCase(inputType);
            switch (inputType) {
                case 'F':
                    resArr = getArrayFromFile();
                    incorrect = false;
                    break;
                case 'C':
                    resArr = getArrayFromConsole();
                    incorrect = false;
                    break;
                default:
                    System.out.println("Your choose incorrect, try again");
                    break;
            }

        } while (incorrect);
        return resArr;
    }

    public static void main(String[] args) {
        System.out.println("Task: This program sorts numbers by the shell method");
        char output;
        boolean incorrect = true;
        int[] resArr;
        resArr = chooseInput();
        resArr = shellSort(resArr);
        outputArray(resArr);
        do {
            System.out.println("Do u want to save your array to file? (Y/N)");
            output = sc.next().charAt(0);
            output = Character.toUpperCase(output);
            switch (output) {
                case 'Y':
                    outputToFile(resArr);
                    incorrect = false;
                    break;
                case 'N':
                    incorrect = false;
                    System.out.println("End of program");
                    break;
                default:
                    System.out.println("Your choose incorrect, try again");
                    break;
            }
        } while (incorrect);
    }
}