Grasscutter/src/main/java/emu/grasscutter/auth/DefaultAuthenticators.java

package emu.grasscutter.auth;

import emu.grasscutter.Grasscutter;
import emu.grasscutter.auth.AuthenticationSystem.AuthenticationRequest;
import emu.grasscutter.database.DatabaseHelper;
import emu.grasscutter.game.Account;
import emu.grasscutter.server.http.objects.*;

import static emu.grasscutter.Configuration.*;
import static emu.grasscutter.utils.Language.translate;

/**
 * A class containing default authenticators.
 */
public final class DefaultAuthenticators {
    
    /**
     * Handles the authentication request from the username and password form.
     */
    public static class PasswordAuthenticator implements Authenticator<LoginResultJson> {
        @Override public LoginResultJson authenticate(AuthenticationRequest request) {
            var response = new LoginResultJson();
            
            var requestData = request.getPasswordRequest();
            assert requestData != null; // This should never be null.
            int playerCount = Grasscutter.getGameServer().getPlayers().size();

            boolean successfulLogin = false; 
            String address = request.getRequest().ip();
            String responseMessage = translate("messages.dispatch.account.username_error");
            String loggerMessage = "";

            // Get account from database.
            Account account = DatabaseHelper.getAccountByName(requestData.account);
            if (ACCOUNT.maxPlayer <= -1 || playerCount < ACCOUNT.maxPlayer) {
                // Check if account exists.
                if(account == null && ACCOUNT.autoCreate) {
                    // This account has been created AUTOMATICALLY. There will be no permissions added.
                    account = DatabaseHelper.createAccountWithUid(requestData.account, 0);

                    // Check if the account was created successfully.
                    if(account == null) {
                        responseMessage = translate("messages.dispatch.account.username_create_error");
                        Grasscutter.getLogger().info(translate("messages.dispatch.account.account_login_create_error", address));
                    } else {
                        // Continue with login.
                        successfulLogin = true;

                        // Log the creation.
                        Grasscutter.getLogger().info(translate("messages.dispatch.account.account_login_create_success", address, response.data.account.uid));
                    }
                } else if(account != null)
                    successfulLogin = true;
                 else
                    loggerMessage = translate("messages.dispatch.account.account_login_exist_error", address);

            } else {
                responseMessage = translate("messages.dispatch.account.server_max_player_limit");
                loggerMessage = translate("messages.dispatch.account.login_max_player_limit", address);
            }

            
            // Set response data.
            if(successfulLogin) {
                response.message = "OK";
                response.data.account.uid = account.getId();
                response.data.account.token = account.generateSessionKey();
                response.data.account.email = account.getEmail();

                loggerMessage = translate("messages.dispatch.account.login_success", address, account.getId());
            } else {
                response.retcode = -201;
                response.message = responseMessage;

            }
            Grasscutter.getLogger().info(loggerMessage);

            return response;
        }
    }

    /**
     * Handles the authentication request from the game when using a registry token.
     */
    public static class TokenAuthenticator implements Authenticator<LoginResultJson> {
        @Override public LoginResultJson authenticate(AuthenticationRequest request) {
            var response = new LoginResultJson();
            
            var requestData = request.getTokenRequest();
            assert requestData != null;

            boolean successfulLogin;
            String address = request.getRequest().ip();
            String loggerMessage;
            int playerCount = Grasscutter.getGameServer().getPlayers().size();

            // Log the attempt.
            Grasscutter.getLogger().info(translate("messages.dispatch.account.login_token_attempt", address));

            if (ACCOUNT.maxPlayer <= -1 || playerCount < ACCOUNT.maxPlayer) {

                // Get account from database.
                Account account = DatabaseHelper.getAccountById(requestData.uid);

                // Check if account exists/token is valid.
                successfulLogin = account != null && account.getSessionKey().equals(requestData.token);

                // Set response data.
                if(successfulLogin) {
                    response.message = "OK";
                    response.data.account.uid = account.getId();
                    response.data.account.token = account.getSessionKey();
                    response.data.account.email = account.getEmail();

                    // Log the login.
                    loggerMessage = translate("messages.dispatch.account.login_token_success", address, requestData.uid);
                } else {
                    response.retcode = -201;
                    response.message = translate("messages.dispatch.account.account_cache_error");

                    // Log the failure.
                    loggerMessage = translate("messages.dispatch.account.login_token_error", address);
                }

            } else {
                response.retcode = -201;
                response.message = translate("messages.dispatch.account.server_max_player_limit");

                loggerMessage = translate("messages.dispatch.account.login_max_player_limit", address);
            }

            Grasscutter.getLogger().info(loggerMessage);
            return response;
        }
    }

    /**
     * Handles the authentication request from the game when using a combo token/session key.
     */
    public static class SessionKeyAuthenticator implements Authenticator<ComboTokenResJson> {
        @Override public ComboTokenResJson authenticate(AuthenticationRequest request) {
            var response  = new ComboTokenResJson();
            
            var requestData = request.getSessionKeyRequest();
            var loginData = request.getSessionKeyData();
            assert requestData != null; assert loginData != null;
            
            boolean successfulLogin;
            String address = request.getRequest().ip();
            String loggerMessage;
            int playerCount = Grasscutter.getGameServer().getPlayers().size();

            if (ACCOUNT.maxPlayer <= -1 || playerCount < ACCOUNT.maxPlayer) {
                // Get account from database.
                Account account = DatabaseHelper.getAccountById(loginData.uid);

                // Check if account exists/token is valid.
                successfulLogin = account != null && account.getSessionKey().equals(loginData.token);

                // Set response data.
                if(successfulLogin) {
                    response.message = "OK";
                    response.data.open_id = account.getId();
                    response.data.combo_id = "157795300";
                    response.data.combo_token = account.generateLoginToken();

                    // Log the login.
                    loggerMessage = translate("messages.dispatch.account.combo_token_success", address);

                } else {
                    response.retcode = -201;
                    response.message = translate("messages.dispatch.account.session_key_error");

                    // Log the failure.
                    loggerMessage = translate("messages.dispatch.account.combo_token_error", address);
                }
            } else {
                response.retcode = -201;
                response.message = translate("messages.dispatch.account.server_max_player_limit");

                loggerMessage = translate("messages.dispatch.account.login_max_player_limit", address);
            }

            Grasscutter.getLogger().info(loggerMessage);
            return response;
        }
    }

    /**
     * Handles authentication requests from external sources.
     */
    public static class ExternalAuthentication implements ExternalAuthenticator {
        @Override public void handleLogin(AuthenticationRequest request) {
            assert request.getResponse() != null;
            request.getResponse().send("Authentication is not available with the default authentication method.");
        }

        @Override public void handleAccountCreation(AuthenticationRequest request) {
            assert request.getResponse() != null;
            request.getResponse().send("Authentication is not available with the default authentication method.");
        }

        @Override public void handlePasswordReset(AuthenticationRequest request) {
            assert request.getResponse() != null;
            request.getResponse().send("Authentication is not available with the default authentication method.");
        }
    }

    /**
     * Handles authentication requests from OAuth sources.
     */
    public static class OAuthAuthentication implements OAuthAuthenticator {
        @Override public void handleLogin(AuthenticationRequest request) {
            assert request.getResponse() != null;
            request.getResponse().send("Authentication is not available with the default authentication method.");
        }

        @Override public void handleRedirection(AuthenticationRequest request, ClientType type) {
            assert request.getResponse() != null;
            request.getResponse().send("Authentication is not available with the default authentication method.");
        }

        @Override public void handleTokenProcess(AuthenticationRequest request) {
            assert request.getResponse() != null;
            request.getResponse().send("Authentication is not available with the default authentication method.");
        }
    }
}