package laba7_2;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.Writer;
import java.util.Scanner;

public class Main {
    private static int[][] matrix;
    private static StringBuilder list;
    private static Scanner scanner = new Scanner(System.in);

    public static void main(String[] args) {
        displayMainMenu();
    }

    private static void displayMainMenu() {
        System.out.println("========");
        System.out.println("LABA 7 2");
        System.out.println("========");
        System.out.println("This program converts adjacent matrix to incident list");
        System.out.println("Choose option by picking a number.");
        System.out.println("1) Input matrix");
        System.out.println("2) Input matrix (file)");
        System.out.println("3) Show list");
        System.out.println("4) Save list");
        System.out.println("5) Exit");
        int picked = 0;
        try {
            picked = Integer.parseInt(scanner.nextLine());
        } catch (Exception e) {
            displayMainMenu();
            return;
        }
        if(picked < 1 || picked > 5) {
            displayMainMenu();
            return;
        }
        switch(picked) {
        case 1:
            inputMatrix();
            return;
        case 2:
            inputMatrixFile();
            return;
        case 3:
            showList();
            return;
        case 4:
            saveList();
            return;
        case 5:
            System.out.println("The program has now terminated.");
            return;
        }
    }

    private static void inputMatrix() {
        int amount = inputFunc("amount of vertices", 2, 6);
        matrix = new int[amount][amount];
        for(int i = 0; i < amount; i++) {
            for(int j = 0; j < amount; j++) {
                    int adjacent = inputFunc("adjacent value of vertices " + (i+1) + "-" + (j+1), 0, 10);
                    matrix[i][j] = adjacent;
                }
            }
        System.out.println("Matrix successfully added.");
        displayMainMenu();
    }

    private static void inputMatrixFile() {
        System.out.println("Input location of the file:");
        String line;
        try (BufferedReader br = new BufferedReader(new FileReader(new File(scanner.nextLine())))) {
            line = br.readLine();
            int amount = Integer.parseInt(line);
            matrix = new int[amount][amount];
            for(int i = 0; i < amount; i++) {
                line = br.readLine();
                for(int j = 0; j < amount; j++) {
                        int adjacent = line.charAt(j) - '0';
                        matrix[i][j] = adjacent;
                    }
            }
        } catch(Exception e) {
            System.out.println("File was not found.");
            displayMainMenu();
            return;
        }
        System.out.println("Matrix successfully added.");
        displayMainMenu();
    }

    private static void showList() {
        if(matrix == null) {
            System.out.println("Nothing to convert");
            displayMainMenu();
            return;
        }
        convertMatrix();
        System.out.println("\n======LIST======");
        System.out.println(list);
        displayMainMenu();
    }

    private static void saveList() {
        if(matrix == null) {
            System.out.println("Nothing to save");
            displayMainMenu();
            return;
        }
        if(list == null)
            convertMatrix();
        System.out.println("Input location of the file:");
        try (BufferedWriter bw = new BufferedWriter(new FileWriter(new File(scanner.nextLine()), false))) {
            bw.append(list);
        } catch(Exception e) {
            System.out.println("An error has occured");
            displayMainMenu();
            return;
        }
        System.out.println("File successfully saved");
        displayMainMenu();
    }

    private static void convertMatrix() {
        list = new StringBuilder("");
        for(int i = 0; i < matrix.length; i++) {
            list.append((i+1) + ": ");
            for(int j = 0; j < matrix.length; j++) {
                int amount = matrix[i][j];
                for(int k = 0; k < amount; k++) {
                    list.append((j+1) + " ");
                }
            }
            list.append("\n");
        }
    }

    private static int inputFunc(String name, int min, int max) {
        boolean incorrect;
        String line;
        int element = 0;
        do {
            incorrect = false;
            System.out.println("Input " + name + ":");
            line = scanner.nextLine();
            try {
                element = Integer.parseInt(line);
            } catch (Exception e) {
                incorrect = true;
                System.out.println("Element should be a numerical value");
            }
            if(element < min || element >= max) {
                incorrect = true;
                System.out.printf("Element should be between %d and %d\n", min, max - 1);
            }
        } while(incorrect);
        return element;
    }
}