import java.io.*;
import java.nio.charset.StandardCharsets;
import java.nio.file.NoSuchFileException;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.Map;
public class WordStatInput {
    private static boolean isLegalCharacter(char c) {
        return ((Character.isLetter(c)) || (Character.getType(c) == Character.DASH_PUNCTUATION) || (c == '\''));
    }

    public static void main(String[] args) {

        Map<String, Integer> wordsStats = new LinkedHashMap<String, Integer>();
        // :NOTE: why do you allocate extra memory for input output files?
        String inputFile = args[0];
        String outputFile = args[1];

        try (BufferedReader reader = new BufferedReader(new FileReader(inputFile, StandardCharsets.UTF_8))) {
            // :NOTE: use StringBuilder
            String line;
            // :NOTE: if the input is given a very large string, readLine() will break
            while ((line = reader.readLine()) != null) {
                int startIndex = 0;
                // :NOTE: crutch
                line += " ";
                for (int index = 0; index < line.length(); index++) {
                    char character = line.charAt(index);
                    if (!isLegalCharacter(character)) {
                        // :NOTE: same
                        String word = line.substring(startIndex, index).toLowerCase();
                        if (!word.isEmpty()) {
                            // :NOTE: use getOrDefault method instead of if else
                            if (!wordsStats.containsKey(word)) {
                                wordsStats.put(word, 1);
                            } else {
                                // :NOTE: extra memory
                                Integer wordOccurence = (Integer) wordsStats.get(word);
                                wordsStats.put(word, wordOccurence + 1);
                            }
                        }
                        startIndex = index + 1;
                    }
                }
            }
        } catch (FileNotFoundException e) {
            // :NOTE: user wants to read the detailed message of the throwable exception (use getMessage)
            System.out.println("Unable to access file");
        } catch (IllegalArgumentException e) {
            // :NOTE: same
            System.out.println("Passed an unsuitable argument");
        } catch (IOException e) {
            // :NOTE: same
            System.out.println("Unable to read file");
        }

        try (BufferedWriter out = new BufferedWriter(new FileWriter(outputFile, StandardCharsets.UTF_8))) {
            for (Map.Entry<String, Integer> entry : wordsStats.entrySet()) {
                out.write(entry.getKey() + " " + entry.getValue() + System.lineSeparator().toString());
            }
            // :NOTE: you can use general try to catch same exceptions
        } catch (IllegalArgumentException e) {
            // :NOTE: same
            System.out.println("Passed an unsuitable argument");
            // :NOTE: why do you use NoSuchFile? maybe it is better to use FileNotFound?
        } catch (NoSuchFileException e) {
            // :NOTE: same
            System.out.println("File does not exist");
        } catch (IOException e) {
            // :NOTE: same
            System.out.println("Unable to write file");
        }
    }
}