/**
 * Assignment 2, COMP268 Class: ReversedSentence.java
 *
 * @description Provides a class to manipulating strings.
 * @author: mo khan Student ID: 3431709
 * @date Jun 2, 2019
 * @version 1.0
 */
package Q1;

import java.util.Scanner;

public class ReversedSentence {
  /**
   * Replaces the every character that is in an index that is evenly divisible by 5 with the
   * character 'z', excluding 0.
   *
   * @param s The input string to substitue
   * @return The new string with the substitution.
   */
  public static String change5thPosition(String s) {
    char[] result = new char[s.length()];

    for (int i = 0; i < s.length(); i++) result[i] = (i > 0 && i % 5 == 0) ? 'z' : s.charAt(i);

    return new String(result);
  }

  /**
   * Combines the 2D array of character into a printable string.
   *
   * @param arr the two dimensional array of characters.
   * @return a String of the combined character arrays separated by a line separator.
   */
  public static String printChar2DArray(char[][] arr) {
    String[] strings = new String[arr.length];

    for (int i = 0; i < arr.length; i++) strings[i] = new String(arr[i]);
    return String.join(System.lineSeparator(), strings);
  }

  /**
   * Reverses a string.
   *
   * @param s the input String to reverse
   * @return the reversed String.
   */
  public static String reverseByCharacter(String s) {
    char[] result = new char[s.length()];
    int length = s.length();

    for (int i = 0; i < length; i++) result[length - i - 1] = s.charAt(i);

    return new String(result);
  }

  /**
   * Reverses the words in a string
   *
   * @param s the input string to reverse
   * @return a string with the words in reverse order
   */
  public static String reverseByWord(String s) {
    String[] words = s.split(" ");
    String[] result = new String[words.length];

    for (int i = 0; i < words.length; i++) {
      String word = words[i];
      result[words.length - i - 1] = word;
    }
    return String.join(" ", result);
  }

  /**
   * Truncates a tring to a maximum of 80 characters.
   *
   * @param s the input string to truncate
   * @return the truncated string
   */
  public static String truncateSentence(String s) {
    return s.substring(0, Math.min(s.length(), 80));
  }

  /**
   * The entry point for the console application.
   *
   * @param args the commandline arguments passed to the program
   */
  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    String[] sentences = new String[3];

    for (int i = 0; i < 3; i++) {
      System.out.println(String.format("Enter sentence %d: (max 80 characters)", i + 1));
      sentences[i] = ReversedSentence.truncateSentence(in.nextLine());
    }

    char[][] matrix = new char[3][80];
    matrix[0] = ReversedSentence.reverseByCharacter(sentences[0]).toCharArray();
    matrix[1] = ReversedSentence.reverseByWord(sentences[1]).toCharArray();
    matrix[2] = ReversedSentence.change5thPosition(sentences[2]).toCharArray();

    System.out.println();
    System.out.println("Result: ");
    System.out.println();
    System.out.print(ReversedSentence.printChar2DArray(matrix));

    System.out.println();
    System.out.println();
    System.out.println("Bye");
  }
}