lab2_5

import java.io.*;
import java.util.Scanner;

public class lab2_5 {

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

    private static PrintWriter getOutputFileLocation() {
        boolean isIncorrect;
        String location;
        PrintWriter file = null;
        do {
            isIncorrect = false;
            System.out.println("Enter file location:");
            location = scConsole.nextLine();
            try {
                file = new PrintWriter(location);
            } catch (FileNotFoundException e) {
                isIncorrect = true;
                System.out.println("File with this location is not found");
            }
        } while (isIncorrect);
        if (file != null)
            System.out.println("File opened successfully");
        return file;
    }

    private static Scanner getInputFileLocation() {
        boolean isIncorrect;
        String location;
        Scanner file = null;
        do {
            isIncorrect = false;
            System.out.println("Enter file location:");
            location = scConsole.nextLine();
            try {
                file = new Scanner(new File(location));
            } catch (FileNotFoundException e) {
                isIncorrect = true;
                System.out.println("File with this location is not found");
            }
        } while (isIncorrect);
        if (file != null)
            System.out.println("File opened successfully");
        return file;
    }

    private static void createTriangle(int size, int[][] triangle) {
        for (int n = 0; n <= size; n++) {
            triangle[n][0] = triangle[n][n] = 1;
            for (int k = 1; k < n; k++) {
                triangle[n][k] = triangle[n - 1][k - 1] + triangle[n - 1][k];
            }
        }
    }

    private static void resultPrint(int[][] triangle, int size) {
        for (int i = 0; i <= size; i++) {
            for (int j = 0; j <= i; j++) {
                System.out.print(triangle[i][j] + " ");
            }
            System.out.println();
        }
    }

    private static int getSizeFromConsole() {
        final int MIN_VALUE = 1;
        final int MAX_VALUE = 30;
        int size = 0;
        boolean isIncorrect;
        do {
            isIncorrect = false;
            try {
                size = Integer.parseInt(scConsole.nextLine());
            } catch (Exception e) {
                System.out.println("Enter the number");
                isIncorrect = true;
            }
            if ((!isIncorrect) && ((size < MIN_VALUE) || (size > MAX_VALUE))) {
                System.out.println("Please enter a natural value less than 30");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return size;
    }

    private static int getSizeFromFile() {
        final int MIN_VALUE = 1;
        final int MAX_VALUE = 30;
        boolean isIncorrect = false;
        int size = 0;
        Scanner file = getInputFileLocation();
        do {
            try {
                size = file.nextInt();
            } catch (Exception e) {
                isIncorrect = true;
                System.out.println("Enter natural number");
            }
            if ((!isIncorrect) && ((size < MIN_VALUE) || (size > MAX_VALUE))) {
                System.out.println("Please enter a natural value less than 30");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return size;
    }

    private static int chooseInput() {
        boolean isIncorrect;
        String line;
        do {
            isIncorrect = false;
            System.out.println("Do you want to input from file? (y/n)");
            line = scConsole.nextLine().toLowerCase();
            if (!line.equals("y") && !line.equals("n") && !line.equals("")) {
                isIncorrect = true;
                System.out.println("Enter valid answer");
            }
        } while (isIncorrect);
        if (line.equals("y") || line.equals("")) {
            return 0;
        } else {
            return 1;
        }
    }

    private static void outputToFile(int[][] triangle, int size) {
        PrintWriter out = getOutputFileLocation();
        for (int i = 0; i <= size; i++) {
            for (int j = 0; j <= i; j++) {
                out.print(triangle[i][j] + " ");
            }
            out.println();
        }
        out.close();
    }

    public static void main(String[] args) {
        int[][] triangle;
        int size;
        System.out.println("Данная программа строит треугольник Паскаля заданного размера.");
        int chosenInput = chooseInput();
        System.out.println("Enter the size of Pascal`s triangle");
        if (chosenInput == 0) {
            size = getSizeFromFile();
        } else {
            size = getSizeFromConsole();
        }
        triangle = new int[size + 1][size + 1];
        createTriangle(size, triangle);
        System.out.println("Triangle:");
        resultPrint(triangle, size);
        outputToFile(triangle, size);
    }
}