package launchserver.response.auth;

import java.util.Arrays;
import java.util.UUID;
import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;

import launcher.helper.IOHelper;
import launcher.helper.LogHelper;
import launcher.helper.SecurityHelper;
import launcher.helper.VerifyHelper;
import launcher.serialize.HInput;
import launcher.serialize.HOutput;
import launchserver.LaunchServer;
import launchserver.auth.AuthException;
import launchserver.auth.provider.AuthProvider;
import launchserver.response.Response;
import launchserver.response.profile.ProfileByUUIDResponse;

public final class AuthResponse extends Response {
    public AuthResponse(LaunchServer server, long id, HInput input, HOutput output) {
        super(server, id, input, output);
    }

    @Override
    public void reply() throws Exception {
        String login = input.readString(255);
        byte[] encryptedPassword = input.readByteArray(SecurityHelper.CRYPTO_MAX_LENGTH);

        // Decrypt password
        String password;
        try {
            password = IOHelper.decode(SecurityHelper.newRSADecryptCipher(server.privateKey).
                doFinal(encryptedPassword));
        } catch (IllegalBlockSizeException | BadPaddingException ignored) {
            requestError("Password decryption error");
            return;
        }

        // Authenticate
        debug("Login: '%s', Password: '%s'", login, echo(password.length()));
        String username;
        try {
            username = server.config.authProvider.auth(login, password);
            if (!VerifyHelper.isValidUsername(username)) {
                AuthProvider.authError(String.format("Illegal username: '%s'", username));
                return;
            }
        } catch (AuthException e) {
            requestError(e.getMessage());
            return;
        } catch (Exception e) {
            LogHelper.error(e);
            requestError("Internal auth provider error");
            return;
        }
        debug("Auth: '%s' -> '%s'", login, username);

        // Authenticate on server (and get UUID)
        String accessToken = SecurityHelper.randomStringToken();
        UUID uuid;
        try {
            uuid = server.config.authHandler.auth(username, accessToken);
        } catch (AuthException e) {
            requestError(e.getMessage());
            return;
        } catch (Exception e) {
            LogHelper.error(e);
            requestError("Internal auth handler error");
            return;
        }
        writeNoError(output);

        // Write profile and UUID
        ProfileByUUIDResponse.getProfile(server, uuid, username).write(output);
        output.writeASCII(accessToken, -SecurityHelper.TOKEN_STRING_LENGTH);
    }

    private static String echo(int length) {
        char[] chars = new char[length];
        Arrays.fill(chars, '*');
        return new String(chars);
    }
}