/**
 * Assignment 8 // Problem 1
 * For UPEI Computer Science 1910 Fall 2018
 *
 * @author Josh Theriault
 * @version 11/25/2018
 */

import java.util.Scanner;
import java.util.ArrayList;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.PrintWriter;

public class Problem1
{
    /**
     * Opens the specified file by fileName for reading and returns a Scanner for it
     * @param fileName the file name
     * @return Scanner object handling the opened file
     */
    private static Scanner openFile(String fileName) throws FileNotFoundException
    {
        return new Scanner(new File(fileName));
    }

    /**
     * Opens the specified file by fileName for writing and returns a PrintWriter for it
     * @param fileName the file name
     * @return PrintWriter object handling the opened file
     */
    private static PrintWriter writeFile(String fileName) throws FileNotFoundException
    {
        return new PrintWriter(fileName);
    }

    /**
     * Returns an ArrayList<String> of all the words found in the Scanner object
     * @param input Scanner object that handles the input to scan
     * @return an ArrayList<String> of all the words
     */
    private static ArrayList<String> findWords(Scanner input)
    {
        ArrayList<String> words = new ArrayList<String>();

        input.useDelimiter("[\\s,;:]+");
        while (input.hasNext())
        {
            String word = input.next();
            words.add(word.replaceAll("[^a-zA-Z0-9]", ""));
        }

        return words;
    }

    /**
     * Returns an ArrayList<String> of all the palindromes found in the words array
     * @param words an ArrayList<String> of words
     * @return an ArrayList<String> of palindrome words
     */
    private static ArrayList<String> findPalindromes(ArrayList<String> words)
    {
        ArrayList<String> palindromes = new ArrayList<String>();

        for (int i = 0; i < words.size(); i++)
        {
            String word = words.get(i);
            String wordBackwards = "";
            if (word.length() > 1)
            {
                for (int j = word.length() - 1; j >= 0; j--)
                {
                    wordBackwards += word.charAt(j);
                }
                if (word.equalsIgnoreCase(wordBackwards))
                {
                    palindromes.add(word);
                }
            }
        }

        return palindromes;
    }

    /**
     * Returns an ArrayList<String> of all the long words found in the words array
     * @param words an ArrayList<String> of words
     * @return an ArrayList<String> of long words
     */
    private static ArrayList<String> findLongWords(ArrayList<String> words)
    {
        ArrayList<String> longWords = new ArrayList<String>();

        for (int i = 0; i < words.size(); i++)
        {
            String word = words.get(i);
            if (word.length() >= 9)
            {
                longWords.add(word);
            }
        }

        return longWords;
    }

    /**
     * Main entry point
     */
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);

        System.out.print("Input file name: ");
        String inputFileName = in.nextLine();

        System.out.print("Output file name: ");
        String outputFileName = in.nextLine();

        Scanner inFile;
        PrintWriter outFile;

        //Attempt to open input file
        try
        {
            inFile = openFile(inputFileName);
        }
        catch (FileNotFoundException e)
        {
            System.out.println("ERROR: Could not open file \""+inputFileName+"\" for reading");
            return;
        }

        //Attempt to open output file
        try
        {
            outFile = writeFile(outputFileName);
        }
        catch (FileNotFoundException e)
        {
            System.out.println("ERROR: Could not open file \""+inputFileName+"\" for writing");
            return;
        }

        //Find words, palindromes, and long words
        ArrayList<String> words = findWords(inFile);
        ArrayList<String> palindromes = findPalindromes(words);
        ArrayList<String> longWords = findLongWords(words);

        //Output results
        outFile.printf("Palindromes: %s%n", palindromes.toString().replaceAll("[,\\[\\]]+", ""));
        outFile.printf("Long words: %s%n", longWords.toString().replaceAll("[,\\[\\]]+", ""));

        System.out.println("File " + outputFileName + " has been created.");

        inFile.close();
        outFile.close();
    }
}