package servlet;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.nio.charset.StandardCharsets;
import java.security.PublicKey;
import java.util.UUID;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import util.RSASignature;

@WebServlet(name = "Login", urlPatterns = "/login")
public class Login extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String token = request.getParameter("token");
        PrintWriter out = response.getWriter();

        if (token == null) {
            out.println("fail - no token");
            out.flush();
            return;
        }

        InputStream publicKeyInputStream = getClass().getClassLoader().getResourceAsStream("key_rsa.pub");
        if (publicKeyInputStream == null) {
            out.println("fail - no public key");
            out.flush();
            return;
        }
        String publicKeyString = new String(publicKeyInputStream.readAllBytes(), StandardCharsets.UTF_8);

        try {
            PublicKey publicKey = util.RSAKeyGenerator.getPublicKey(publicKeyString);
            boolean isVerified = RSASignature.verify(request.getRemoteAddr(), token, publicKey);

            if(isVerified) {
                UUID uuid = UUID.randomUUID();
                String plainUUID = uuid.toString();

                Cookie cookie = new Cookie("uuid", plainUUID);
                cookie.setHttpOnly(true);
                cookie.setSecure(true);
                cookie.setPath("/");
                response.addCookie(cookie);

                request.getSession().setAttribute("uuid", uuid);
                out.println("");
                out.flush();
                return;
            } else {
                out.println("fail - invalid token");
                out.flush();
                return;
            }
        } catch (Exception e) {
            e.printStackTrace();
            out.println("fail - " + e.getLocalizedMessage());
            out.flush();
        }
    }
}