Widerhall/src/main/java/de/srsoftware/widerhall/Util.java

package de.srsoftware.widerhall;

import de.srsoftware.tools.translations.Translation;
import de.srsoftware.widerhall.data.MailingList;
import de.srsoftware.widerhall.data.User;

import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.servlet.http.HttpServletRequest;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Map;
import java.util.stream.Collectors;

import static de.srsoftware.widerhall.Constants.*;

public class Util {

    private static final MessageDigest SHA256 = getSha256();
    private static final String EMAIL_PATTERN = "^[a-zA-Z0-9_!#$%&'*+/=?`{|}~^-]+(?:\\.[a-zA-Z0-9_!#$%&'*+/=?`{|}~^-]+)*@[a-zA-Z0-9-]+(?:\\.[a-zA-Z0-9-]+)*$";

    public static String urlEncode(Map<String, Object> data) {
        String params = data.entrySet()
                .stream()
                .map(entry -> encode(entry.getKey()) + "=" + encode(entry.getValue()))
                .collect(Collectors.joining("&"));
        return params;
    }

    private static String encode(Object value) {
        return URLEncoder.encode(value.toString(), StandardCharsets.UTF_8);
    }


    public static MessageDigest getSha256() {
        try {
            return MessageDigest.getInstance("SHA-256");
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
            return null;
        }
    }

    public static String sha256(String s) {
        byte[] bytes = SHA256.digest(s.getBytes(StandardCharsets.UTF_8));
        return hex(bytes);
    }

    private static String hex(byte[] bytes) {
        StringBuffer buf = new StringBuffer(bytes.length*2);
        for (var byt : bytes) buf.append(hex(byt));
        return buf.toString();
    }

    public static String hex(int b){
        int lower = b & 0x0F;
        int upper = (b & 0xF0) >> 4;
        return (char)(upper < 10 ? '0'+upper : 'A'+upper-10)+""+(char)(lower < 10 ? '0'+lower : 'A'+lower-10);
    }

    public static String t(String tx, Object ... fills){
        return Translation.get(Application.class,tx,fills);
    }

    public static boolean isEmail(String email) {
        return email.matches(EMAIL_PATTERN);
    }

    public static boolean simplePassword(String pass) {
        if (pass.length() < 6) return true;
        if (pass.length() < 8){
            for (int i=0; i<pass.length();i++){
                if (!Character.isLetterOrDigit(pass.charAt(i))) return false; // password contains special character
            }
            return true;
        }
        if (pass.length() < 10){
            var digit = false;
            var letter = false;
            for (int i=0; i<pass.length();i++){
                char c = pass.charAt(i);
                if (!Character.isLetterOrDigit(c)) return false; // password contains special character
                digit |= Character.isDigit(c);
                letter |= Character.isLetter(c);
                if (letter && digit) return false; // password contains letters and digits
            }
            return true;
        }
        return false;
    }

    public static int unset(int value, int...flags) {
        for (int flag : flags){
            if ((value & flag) > 0) value ^= flag;
        }
        return value;
    }

    public static User getUser(HttpServletRequest req) {
        var o = req.getSession().getAttribute(USER);
        return o instanceof User ? (User) o : null;
    }

    public static String getPath(HttpServletRequest req) {
        var path = req.getPathInfo();
        return path == null ? INDEX : path.substring(1);

    }

    public static MailingList getMailingList(HttpServletRequest req) {
        var listEmail = req.getParameter(LIST);
        if (listEmail == null || listEmail.isBlank()) return null;
        return MailingList.load(listEmail);
    }

    public static boolean getCheckbox(HttpServletRequest req, String key) {
        return "on".equals(req.getParameter(key));
    }
}