import java.io.FileInputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;

import regexjdk8.*;

/**
 * Loads a file and a regex and matches the regex to the file.
 *
 * @author Rody Kersten.
 */
public class RegexConcrete {

    static String regex = null;
    static String text = null;

    private static void readRegex(String file) {

        try (FileInputStream fis = new FileInputStream(file)) {

            List<Character> charList = new ArrayList<>();
            byte[] bytes = new byte[Character.BYTES];
            while (((fis.read(bytes)) != -1)) {
                charList.add(ByteBuffer.wrap(bytes).getChar());
            }
            char[] str = new char[charList.size()];
            for (int i = 0; i < charList.size(); i++) {
                str[i] = charList.get(i);
            }
            regex = new String(str);

            // regex = new String(Files.readAllBytes(Paths.get(file)));

            /* Remove whitespace at beginning and end */
            regex = regex.trim();

            /* Limit to 10 characters */
            if (!file.startsWith("resources") && regex.length() > 10)
                regex = regex.substring(0, 10);

        } catch (IOException e) {
            System.err.println("Error reading regex file: " + file);
        }
    }

    private static void readText(String file) {
        try (FileInputStream fis = new FileInputStream(file)) {

            List<Character> charList = new ArrayList<>();
            byte[] bytes = new byte[Character.BYTES];
            while (((fis.read(bytes)) != -1)) {
                charList.add(ByteBuffer.wrap(bytes).getChar());
            }
            char[] str = new char[charList.size()];
            for (int i = 0; i < charList.size(); i++) {
                str[i] = charList.get(i);
            }
            text = new String(str);
            // text = new String(Files.readAllBytes(Paths.get(file)));

            /* Limit to 100 characters */
            if (!file.startsWith("resources") && text.length() > 100)
                text = text.substring(0, 100);
        } catch (IOException e) {
            System.err.println("Error reading text file: " + file);
        }
    }

    public static void main(String[] args) {
        if (args.length != 2) {
            System.out.println("Usage: Regex <regexfile> <textfile>");
            return;
        }

        readRegex(args[0]);
        readText(args[1]);
        if (regex == null || text == null)
            return;

        // System.out.println("Read text file: " + text);
        System.out.println("Read regex: " + regex);

        /* now perform the matching */
        try {
            boolean match = Pattern.matches(regex, text);
            System.out.println("Matches: " + match);
        } catch (PatternSyntaxException e) {
            System.err.println("Invalid pattern: " + regex);
        }
    }
}
