package com.company;

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

public class Main {

    public static int Pntr = 0;

    public static void main(String[] args) throws Exception{
        System.out.println("This program will check the balance of the brackets in the lines");
        IsBracketCorrect();
    }

    public static char OpenBracket(final char Ch) {
        switch (Ch) {
            case (')'): return('(');
            case (']'): return('[');
            case ('}'): return ('{');
            default: return ('0');
        }
    }

    public static void Push(char[] MassStack, char Ch ) {
        MassStack[Pntr] = Ch;
        Pntr++;
    }

    public static char Pop(char[] MassStack) {
        Pntr--;
        if (Pntr > -1) {
            return (MassStack[Pntr]);
        }
        else {
            return ('0');
        }
    }

    public static boolean Proc(String StrSrc) {
        int i = 0;
        Pntr = 0;
        char [] MassStack = new char[100];
        boolean Balance = true;
        while ((i <  StrSrc.length()) && Balance) {
            if ((StrSrc.charAt(i) == '(') || (StrSrc.charAt(i) == '[') || (StrSrc.charAt(i) == '{')) {
                Push(MassStack, StrSrc.charAt(i));
            }
            else {
                if ((StrSrc.charAt(i) == ')') || (StrSrc.charAt(i) == ']') || (StrSrc.charAt(i) == '}')) {
                    if (Pop(MassStack) != OpenBracket(StrSrc.charAt(i))) {
                        Balance = false;
                    }
                }
            }
            i++;
        }
        return((Pntr == 0) && Balance);
    }

    public static boolean isStrCorrect(String StrSrc) {
        boolean isCorrect = false;
        for (int i = 0; i <  StrSrc.length(); i++) {
            if ((StrSrc.charAt(i) == '(') || (StrSrc.charAt(i) == '[') || (StrSrc.charAt(i) == '{') || (StrSrc.charAt(i) == ')') || (StrSrc.charAt(i) == ']') || (StrSrc.charAt(i) == '}')) {
                isCorrect = true;
            }
        }
        return (isCorrect);
    }

    public static String FileNameInputRead() throws Exception {
        boolean isCorrect = true;
        String FileName;
        do {
            System.out.println("Enter file name:");
            Scanner scan = new Scanner(System.in);
            FileName = scan.next();
            File FileIn = new File(FileName);
            if (FileIn.exists()) {
                isCorrect = false;
            }
            else {
                System.out.println("This file does not exist!");
            }
        }
        while (isCorrect);
        return (FileName);
    }

    public static void IsBracketCorrect() throws Exception {
        String FileName = FileNameInputRead();
        String StrSrc;
        BufferedReader buff = new BufferedReader(new FileReader(FileName));
        StrSrc = buff.readLine();
        do {
            System.out.println(StrSrc);
            if (isStrCorrect(StrSrc)) {
                if (Proc(StrSrc)) {
                    System.out.println("Brackets agreed.");
                }
                else {
                    System.out.println("Brackets are not agreed.");
                }
            }
            else {
                System.out.println("There are no brackets in the line!");
            }
            StrSrc = buff.readLine();
        }
        while (StrSrc != null);
        buff.close();
    }
}