lab3_2

package com.company;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Set;
import java.util.regex.PatternSyntaxException;

public class Main {
    static final HashSet<Character> setOfDigitsAndOperations = new HashSet<>(Set.of('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '-', '*', '/', '^', '√'));


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


    public static void main(String[] args) {
        System.out.print("Welcome to the program that will sort an array using cocktail sort\nSelect the source for entering the sequence of numbers:\n1:Console\n2:File\nEnter 1 or 2: ");
        byte inputSource = takeSource();
        Set<Character> initialSet = takeSet(inputSource);
        Set<Character> answer = takeAnswer(initialSet);
        System.out.print("Select the source for output:\n1:Console\n2:File\nEnter 1 or 2: ");
        byte outputSource = takeSource();
        output(outputSource, answer);
        scan.close();
    }

    static int takeSize() {
        final int MIN_SIZE = 2;
        final int MAX_SIZE = 30;
        int number = 0;
        boolean isIncorrect;
        do {
            isIncorrect = false;
            try {
                number = Integer.parseInt(scan.nextLine());
            } catch (NumberFormatException e) {
                System.out.println("Incorrect input!!!");
                isIncorrect = true;
            }
            if (!isIncorrect && (number < MIN_SIZE || number > MAX_SIZE)) {
                System.out.println("Incorrect input!!!");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return number;
    }

    static char takeChar() {
        char inputChar = 0;
        boolean isIncorrect;
        String line;
        do {
            line = scan.nextLine();
            isIncorrect = false;
            if ((line.length() != 1)){
                System.out.println("Incorrect input!!! Must be char:");
                isIncorrect = true;
            } else {
                try {
                    inputChar = (line).charAt(0);
                } catch (NumberFormatException e) {
                    System.out.println("Incorrect input!!!");
                    isIncorrect = true;
                }
            }
        } while (isIncorrect);
        return inputChar;
    }

    static byte takeSource() {
        final byte CONSOLE = 1;
        final byte FILE = 2;
        boolean isIncorrect;
        byte choice = 0;
        do {
            isIncorrect = false;
            try {
                choice = Byte.parseByte(scan.nextLine());
            } catch (Exception e) {
                System.out.print("Incorrect input!!! Select the source:\n1:Console\n2:File\nEnter 1 or 2: ");
                isIncorrect = true;
            }
            if (!isIncorrect && (choice != CONSOLE) && (choice != FILE)) {
                System.out.print("Incorrect input!!! Select the source:\n1:Console\n2:File\nEnter 1 or 2: ");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return choice;
    }

    static String takeInPath() {
        String path;
        boolean isIncorrect;
        System.out.print("Enter file path: ");
        do {
            isIncorrect = false;
            path = scan.nextLine();
            if (Files.notExists(Path.of(path))) {
                System.out.print("File is not found\nEnter file path: ");
                isIncorrect = true;
            }
            if (!isIncorrect && (!path.endsWith(".txt"))) {
                System.out.print("File is found, but it is not \".txt\" type file\nEnter file path: ");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return path;
    }

    static String takeOutPath() {
        String path;
        boolean isIncorrect;
        System.out.print("Enter file path: ");
        do {
            isIncorrect = false;
            path = scan.nextLine();
            if (!path.endsWith(".txt")) {
                System.out.print("It should be a \".txt\" file\nEnter file path: ");
                isIncorrect = true;
            }
        } while (isIncorrect);
        return path;
    }

    static Set<Character> takeSetFromConsole() {
        System.out.print("Enter size: ");
        int size = takeSize();
        Set<Character> initialSet = new HashSet<>();
        for (int i = 0; i < size; i++) {
            System.out.print("Enter element " + (i + 1) + ": ");
            initialSet.add(takeChar());
        }
        return initialSet;
    }

    static Set<Character> takeSetFromFile(final String path) {
        final int SET_LINE_NUMBER = 1;
        int lineCounter = 0;
        String line;
        boolean isCorrect = true;
        String[] stringArray = null;
        try (BufferedReader reader = new BufferedReader(new FileReader(path))) {
            while ((isCorrect) && ((line = reader.readLine()) != null)) {
                lineCounter++;
                if (lineCounter == SET_LINE_NUMBER) {
                    try {
                        stringArray = line.split(" ");
                    } catch (PatternSyntaxException e) {
                        System.out.println("Incorrect file content!!! Incorrect information in the set line!!!");
                        isCorrect = false;
                    }
                }
            }
        } catch (IOException e) {
            System.out.println("Input/Output error!!!");
            isCorrect = false;
        }
        Set<Character> initialSet = new HashSet<>();
        if (stringArray != null) {
            if ((isCorrect) && (lineCounter > SET_LINE_NUMBER)) {
                System.out.println("Incorrect file content!!!");
                isCorrect = false;
            } else {
                for (int i = 0; i < stringArray.length; i++) {
                    try {
                        initialSet.add((stringArray[i]).charAt(0));
                    } catch (Exception e) {
                        System.out.println("Incorrect file content!!!");
                        isCorrect = false;
                    }
                }
            }
        }
        if (isCorrect) {
            return initialSet;
        } else {
            return null;
        }
    }

    static Set<Character> takeSet(final byte source) {
        String inPath;
        Set<Character> initialSet;
        if (source == 1) {
            initialSet = takeSetFromConsole();
        } else {
            inPath = takeInPath();
            initialSet = takeSetFromFile(inPath);
            while (initialSet == null) {
                inPath = takeInPath();
                initialSet = takeSetFromFile(inPath);
            }
        }
        return initialSet;
    }

    static Set<Character> takeAnswer(Set<Character> initialSet) {
        initialSet.retainAll(setOfDigitsAndOperations);
        return initialSet;
    }

    static void outputToConsole(Set<Character> answer) {
        System.out.print("Answer is:\n(");
        Iterator<Character> iterator = answer.iterator();
        while (iterator.hasNext()) {
            System.out.print( "'" + iterator.next());
            if(iterator.hasNext()){
                System.out.print("', ");
            } else {
                System.out.println("')");
            }
        }
        System.out.println();
    }

    static void outputToFile(final String path, final Set<Character> answer) {
        try (FileWriter fw = new FileWriter(path)) {
            fw.write("Answer is:\n(");
            Iterator<Character> iterator = answer.iterator();
            while (iterator.hasNext()) {
                fw.write("'" + iterator.next() + "', ");
            }
            fw.write(")");
            System.out.println("Done");
        } catch (Exception e) {
            System.out.println("File error!");
        }
    }

    static void output(final byte source, final Set<Character> answer) {
        String outPath;
        if (source == 1) {
            outputToConsole(answer);
        } else {
            outPath = takeOutPath();
            outputToFile(outPath, answer);
        }
    }
}