/*
Copyright 2024 New Vector Ltd.
Copyright 2015-2021 The Matrix.org Foundation C.I.C.

SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
Please see LICENSE files in the repository root for full details.
*/

import {
    AuthType,
    createClient,
    IAuthData,
    AuthDict,
    IInputs,
    MatrixError,
    IRegisterRequestParams,
    IRequestTokenResponse,
    MatrixClient,
    SSOFlow,
    SSOAction,
    RegisterResponse,
} from "matrix-js-sdk/src/matrix";
import React, { Fragment, ReactNode } from "react";
import classNames from "classnames";
import { logger } from "matrix-js-sdk/src/logger";

import { _t } from "../../../languageHandler";
import { adminContactStrings, messageForResourceLimitError, resourceLimitStrings } from "../../../utils/ErrorUtils";
import AutoDiscoveryUtils from "../../../utils/AutoDiscoveryUtils";
import * as Lifecycle from "../../../Lifecycle";
import { IMatrixClientCreds, MatrixClientPeg } from "../../../MatrixClientPeg";
import AuthPage from "../../views/auth/AuthPage";
import Login, { OidcNativeFlow } from "../../../Login";
import dis from "../../../dispatcher/dispatcher";
import SSOButtons from "../../views/elements/SSOButtons";
import ServerPicker from "../../views/elements/ServerPicker";
import RegistrationForm from "../../views/auth/RegistrationForm";
import AccessibleButton, { ButtonEvent } from "../../views/elements/AccessibleButton";
import AuthBody from "../../views/auth/AuthBody";
import AuthHeader from "../../views/auth/AuthHeader";
import InteractiveAuth, { InteractiveAuthCallback } from "../InteractiveAuth";
import Spinner from "../../views/elements/Spinner";
import { AuthHeaderDisplay } from "./header/AuthHeaderDisplay";
import { AuthHeaderProvider } from "./header/AuthHeaderProvider";
import SettingsStore from "../../../settings/SettingsStore";
import { ValidatedServerConfig } from "../../../utils/ValidatedServerConfig";
import { Features } from "../../../settings/Settings";
import { startOidcLogin } from "../../../utils/oidc/authorize";

const debuglog = (...args: any[]): void => {
    if (SettingsStore.getValue("debug_registration")) {
        logger.log.call(console, "Registration debuglog:", ...args);
    }
};

export interface MobileRegistrationResponse {
    user_id: string;
    home_server: string;
    access_token: string;
    device_id: string;
}

interface IProps {
    serverConfig: ValidatedServerConfig;
    defaultDeviceDisplayName?: string;
    email?: string;
    brand?: string;
    clientSecret?: string;
    sessionId?: string;
    idSid?: string;
    fragmentAfterLogin?: string;
    mobileRegister?: boolean;
    // Called when the user has logged in. Params:
    // - object with userId, deviceId, homeserverUrl, identityServerUrl, accessToken
    // - The user's password, if available and applicable (may be cached in memory
    //   for a short time so the user is not required to re-enter their password
    //   for operations like uploading cross-signing keys).
    onLoggedIn(params: IMatrixClientCreds, password: string): Promise<void>;
    // registration shouldn't know or care how login is done.
    onLoginClick(): void;
    onServerConfigChange(config: ValidatedServerConfig): void;
}

interface IState {
    // true if we're waiting for the user to complete
    busy: boolean;
    errorText?: ReactNode;
    // We remember the values entered by the user because
    // the registration form will be unmounted during the
    // course of registration, but if there's an error we
    // want to bring back the registration form with the
    // values the user entered still in it. We can keep
    // them in this component's state since this component
    // persist for the duration of the registration process.
    formVals: Record<string, string | undefined>;
    // user-interactive auth
    // If we've been given a session ID, we're resuming
    // straight back into UI auth
    doingUIAuth: boolean;
    // If set, we've registered but are not going to log
    // the user in to their new account automatically.
    completedNoSignin: boolean;
    flows:
        | {
              stages: string[];
          }[]
        | null;
    // We perform liveliness checks later, but for now suppress the errors.
    // We also track the server dead errors independently of the regular errors so
    // that we can render it differently, and override any other error the user may
    // be seeing.
    serverIsAlive: boolean;
    serverErrorIsFatal: boolean;
    serverDeadError?: ReactNode;

    // Our matrix client - part of state because we can't render the UI auth
    // component without it.
    matrixClient?: MatrixClient;
    // The user ID we've just registered
    registeredUsername?: string;
    // if a different user ID to the one we just registered is logged in,
    // this is the user ID that's logged in.
    differentLoggedInUserId?: string;
    // the SSO flow definition, this is fetched from /login as that's the only
    // place it is exposed.
    ssoFlow?: SSOFlow;
    // the OIDC native login flow, when supported and enabled
    // if present, must be used for registration
    oidcNativeFlow?: OidcNativeFlow;
}

export default class Registration extends React.Component<IProps, IState> {
    private readonly loginLogic: Login;
    // `replaceClient` tracks latest serverConfig to spot when it changes under the async method which fetches flows
    private latestServerConfig?: ValidatedServerConfig;
    // cache value from settings store
    private oidcNativeFlowEnabled = false;

    public constructor(props: IProps) {
        super(props);

        this.state = {
            busy: false,
            errorText: null,
            formVals: {
                email: this.props.email,
            },
            doingUIAuth: Boolean(this.props.sessionId),
            flows: null,
            completedNoSignin: false,
            serverIsAlive: true,
            serverErrorIsFatal: false,
            serverDeadError: "",
        };

        // only set on a config level, so we don't need to watch
        this.oidcNativeFlowEnabled = SettingsStore.getValue(Features.OidcNativeFlow);

        const { hsUrl, isUrl, delegatedAuthentication } = this.props.serverConfig;
        this.loginLogic = new Login(hsUrl, isUrl, null, {
            defaultDeviceDisplayName: "Element login check", // We shouldn't ever be used
            // if native OIDC is enabled in the client pass the server's delegated auth settings
            delegatedAuthentication: this.oidcNativeFlowEnabled ? delegatedAuthentication : undefined,
        });
    }

    public componentDidMount(): void {
        this.replaceClient(this.props.serverConfig);
        //triggers a confirmation dialog for data loss before page unloads/refreshes
        window.addEventListener("beforeunload", this.unloadCallback);
    }

    public componentWillUnmount(): void {
        window.removeEventListener("beforeunload", this.unloadCallback);
    }

    private unloadCallback = (event: BeforeUnloadEvent): string | undefined => {
        if (this.state.doingUIAuth) {
            event.preventDefault();
            event.returnValue = "";
            return "";
        }
    };

    public componentDidUpdate(prevProps: IProps): void {
        if (
            prevProps.serverConfig.hsUrl !== this.props.serverConfig.hsUrl ||
            prevProps.serverConfig.isUrl !== this.props.serverConfig.isUrl
        ) {
            this.replaceClient(this.props.serverConfig);
        }
    }

    private async replaceClient(serverConfig: ValidatedServerConfig): Promise<void> {
        this.latestServerConfig = serverConfig;
        const { hsUrl, isUrl } = serverConfig;

        this.setState({
            errorText: null,
            serverDeadError: null,
            serverErrorIsFatal: false,
            // busy while we do live-ness check (we need to avoid trying to render
            // the UI auth component while we don't have a matrix client)
            busy: true,
        });

        // Do a liveliness check on the URLs
        try {
            await AutoDiscoveryUtils.validateServerConfigWithStaticUrls(hsUrl, isUrl);
            if (serverConfig !== this.latestServerConfig) return; // discard, serverConfig changed from under us
            this.setState({
                serverIsAlive: true,
                serverErrorIsFatal: false,
            });
        } catch (e) {
            if (serverConfig !== this.latestServerConfig) return; // discard, serverConfig changed from under us
            this.setState({
                busy: false,
                ...AutoDiscoveryUtils.authComponentStateForError(e, "register"),
            });
            if (this.state.serverErrorIsFatal) {
                return; // Server is dead - do not continue.
            }
        }

        const cli = createClient({
            baseUrl: hsUrl,
            idBaseUrl: isUrl,
        });

        this.loginLogic.setHomeserverUrl(hsUrl);
        this.loginLogic.setIdentityServerUrl(isUrl);
        // if native OIDC is enabled in the client pass the server's delegated auth settings
        const delegatedAuthentication = this.oidcNativeFlowEnabled ? serverConfig.delegatedAuthentication : undefined;

        this.loginLogic.setDelegatedAuthentication(delegatedAuthentication);

        let ssoFlow: SSOFlow | undefined;
        let oidcNativeFlow: OidcNativeFlow | undefined;
        try {
            const loginFlows = await this.loginLogic.getFlows(true);
            if (serverConfig !== this.latestServerConfig) return; // discard, serverConfig changed from under us
            ssoFlow = loginFlows.find((f) => f.type === "m.login.sso" || f.type === "m.login.cas") as SSOFlow;
            oidcNativeFlow = loginFlows.find((f) => f.type === "oidcNativeFlow") as OidcNativeFlow;
        } catch (e) {
            if (serverConfig !== this.latestServerConfig) return; // discard, serverConfig changed from under us
            logger.error("Failed to get login flows to check for SSO support", e);
        }

        await new Promise<void>((resolve) => {
            this.setState(
                ({ flows }) => ({
                    matrixClient: cli,
                    ssoFlow,
                    oidcNativeFlow,
                    // if we are using oidc native we won't continue with flow discovery on HS
                    // so set an empty array to indicate flows are no longer loading
                    flows: oidcNativeFlow ? [] : flows,
                    busy: false,
                }),
                resolve,
            );
        });

        // don't need to check with homeserver for login flows
        // since we are going to use OIDC native flow
        if (oidcNativeFlow) {
            return;
        }

        try {
            // We do the first registration request ourselves to discover whether we need to
            // do SSO instead. If we've already started the UI Auth process though, we don't
            // need to.
            if (!this.state.doingUIAuth) {
                await this.makeRegisterRequest(null);
                if (serverConfig !== this.latestServerConfig) return; // discard, serverConfig changed from under us
                // This should never succeed since we specified no auth object.
                logger.log("Expecting 401 from register request but got success!");
            }
        } catch (e) {
            if (serverConfig !== this.latestServerConfig) return; // discard, serverConfig changed from under us
            if (e instanceof MatrixError && e.httpStatus === 401) {
                this.setState({
                    flows: e.data.flows,
                });
            } else if (e instanceof MatrixError && (e.httpStatus === 403 || e.errcode === "M_FORBIDDEN")) {
                // Check for 403 or M_FORBIDDEN, Synapse used to send 403 M_UNKNOWN but now sends 403 M_FORBIDDEN.
                // At this point registration is pretty much disabled, but before we do that let's
                // quickly check to see if the server supports SSO instead. If it does, we'll send
                // the user off to the login page to figure their account out.
                if (ssoFlow) {
                    // Redirect to login page - server probably expects SSO only
                    dis.dispatch({ action: "start_login" });
                } else {
                    this.setState({
                        serverErrorIsFatal: true, // fatal because user cannot continue on this server
                        errorText: _t("auth|registration_disabled"),
                        // add empty flows array to get rid of spinner
                        flows: [],
                    });
                }
            } else {
                logger.log("Unable to query for supported registration methods.", e);
                this.setState({
                    errorText: _t("auth|failed_query_registration_methods"),
                    // add empty flows array to get rid of spinner
                    flows: [],
                });
            }
        }
    }

    private onFormSubmit = async (formVals: Record<string, string>): Promise<void> => {
        this.setState({
            errorText: "",
            busy: true,
            formVals,
            doingUIAuth: true,
        });
    };

    private requestEmailToken = (
        emailAddress: string,
        clientSecret: string,
        sendAttempt: number,
        sessionId: string,
    ): Promise<IRequestTokenResponse> => {
        if (!this.state.matrixClient) throw new Error("Matrix client has not yet been loaded");
        return this.state.matrixClient.requestRegisterEmailToken(emailAddress, clientSecret, sendAttempt);
    };

    private onUIAuthFinished: InteractiveAuthCallback<RegisterResponse> = async (success, response): Promise<void> => {
        if (!this.state.matrixClient) throw new Error("Matrix client has not yet been loaded");

        debuglog("Registration: ui authentication finished: ", { success, response });
        if (!success) {
            let errorText: ReactNode = (response as Error).message || (response as Error).toString();
            // can we give a better error message?
            if (response instanceof MatrixError && response.errcode === "M_RESOURCE_LIMIT_EXCEEDED") {
                const errorTop = messageForResourceLimitError(
                    response.data.limit_type,
                    response.data.admin_contact,
                    resourceLimitStrings,
                );
                const errorDetail = messageForResourceLimitError(
                    response.data.limit_type,
                    response.data.admin_contact,
                    adminContactStrings,
                );
                errorText = (
                    <div>
                        <p>{errorTop}</p>
                        <p>{errorDetail}</p>
                    </div>
                );
            } else if ((response as IAuthData).flows?.some((flow) => flow.stages.includes(AuthType.Msisdn))) {
                const flows = (response as IAuthData).flows ?? [];
                const msisdnAvailable = flows.some((flow) => flow.stages.includes(AuthType.Msisdn));
                if (!msisdnAvailable) {
                    errorText = _t("auth|unsupported_auth_msisdn");
                }
            } else if (response instanceof MatrixError && response.errcode === "M_USER_IN_USE") {
                errorText = _t("auth|username_in_use");
            } else if (response instanceof MatrixError && response.errcode === "M_THREEPID_IN_USE") {
                errorText = _t("auth|3pid_in_use");
            }

            this.setState({
                busy: false,
                doingUIAuth: false,
                errorText,
            });
            return;
        }

        const userId = (response as RegisterResponse).user_id;
        const accessToken = (response as RegisterResponse).access_token;
        if (!userId || !accessToken) throw new Error("Registration failed");

        MatrixClientPeg.setJustRegisteredUserId(userId);

        const newState: Partial<IState> = {
            doingUIAuth: false,
            registeredUsername: userId,
            differentLoggedInUserId: undefined,
            completedNoSignin: false,
            // we're still busy until we get unmounted: don't show the registration form again
            busy: true,
        };

        // The user came in through an email validation link. To avoid overwriting
        // their session, check to make sure the session isn't someone else, and
        // isn't a guest user since we'll usually have set a guest user session before
        // starting the registration process. This isn't perfect since it's possible
        // the user had a separate guest session they didn't actually mean to replace.
        const [sessionOwner, sessionIsGuest] = await Lifecycle.getStoredSessionOwner();
        if (sessionOwner && !sessionIsGuest && sessionOwner !== userId) {
            logger.log(`Found a session for ${sessionOwner} but ${userId} has just registered.`);
            newState.differentLoggedInUserId = sessionOwner;
        }

        // if we don't have an email at all, only one client can be involved in this flow, and we can directly log in.
        //
        // if we've got an email, it needs to be verified. in that case, two clients can be involved in this flow, the
        // original client starting the process and the client that submitted the verification token. After the token
        // has been submitted, it can not be used again.
        //
        // we can distinguish them based on whether the client has form values saved (if so, it's the one that started
        // the registration), or whether it doesn't have any form values saved (in which case it's the client that
        // verified the email address)
        //
        // as the client that started registration may be gone by the time we've verified the email, and only the client
        // that verified the email is guaranteed to exist, we'll always do the login in that client.
        const hasEmail = Boolean(this.state.formVals.email);
        const hasAccessToken = Boolean(accessToken);
        debuglog("Registration: ui auth finished:", { hasEmail, hasAccessToken });
        // don’t log in if we found a session for a different user
        if (hasAccessToken && !newState.differentLoggedInUserId) {
            if (this.props.mobileRegister) {
                const mobileResponse: MobileRegistrationResponse = {
                    user_id: userId,
                    home_server: this.state.matrixClient.getHomeserverUrl(),
                    access_token: accessToken,
                    device_id: (response as RegisterResponse).device_id!,
                };
                const event = new CustomEvent<MobileRegistrationResponse>("mobileregistrationresponse", {
                    detail: mobileResponse,
                });
                window.dispatchEvent(event);
                newState.busy = false;
                newState.completedNoSignin = true;
            } else {
                await this.props.onLoggedIn(
                    {
                        userId,
                        deviceId: (response as RegisterResponse).device_id!,
                        homeserverUrl: this.state.matrixClient.getHomeserverUrl(),
                        identityServerUrl: this.state.matrixClient.getIdentityServerUrl(),
                        accessToken,
                    },
                    this.state.formVals.password!,
                );

                this.setupPushers();
            }
        } else {
            newState.busy = false;
            newState.completedNoSignin = true;
        }

        this.setState(newState as IState);
    };

    private setupPushers(): Promise<void> {
        if (!this.props.brand) {
            return Promise.resolve();
        }
        const matrixClient = MatrixClientPeg.safeGet();
        return matrixClient.getPushers().then(
            (resp) => {
                const pushers = resp.pushers;
                for (let i = 0; i < pushers.length; ++i) {
                    if (pushers[i].kind === "email") {
                        const emailPusher = pushers[i];
                        emailPusher.data = { brand: this.props.brand };
                        matrixClient.setPusher(emailPusher).then(
                            () => {
                                logger.log("Set email branding to " + this.props.brand);
                            },
                            (error) => {
                                logger.error("Couldn't set email branding: " + error);
                            },
                        );
                    }
                }
            },
            (error) => {
                logger.error("Couldn't get pushers: " + error);
            },
        );
    }

    private onLoginClick = (ev: ButtonEvent): void => {
        ev.preventDefault();
        ev.stopPropagation();
        this.props.onLoginClick();
    };

    private onGoToFormClicked = (ev: ButtonEvent): void => {
        ev.preventDefault();
        ev.stopPropagation();
        this.replaceClient(this.props.serverConfig);
        this.setState({
            busy: false,
            doingUIAuth: false,
        });
    };

    private makeRegisterRequest = (auth: AuthDict | null): Promise<RegisterResponse> => {
        if (!this.state.matrixClient) throw new Error("Matrix client has not yet been loaded");

        const registerParams: IRegisterRequestParams = {
            username: this.state.formVals.username,
            password: this.state.formVals.password,
            initial_device_display_name: this.props.defaultDeviceDisplayName,
            auth: undefined,
            // we still want to avoid the race conditions involved with multiple clients handling registration, but
            // we'll handle these after we've received the access_token in onUIAuthFinished
            inhibit_login: undefined,
        };
        if (auth) registerParams.auth = auth;
        debuglog("Registration: sending registration request:", auth);
        return this.state.matrixClient.registerRequest(registerParams);
    };

    private getUIAuthInputs(): IInputs {
        return {
            emailAddress: this.state.formVals.email,
            phoneCountry: this.state.formVals.phoneCountry,
            phoneNumber: this.state.formVals.phoneNumber,
        };
    }

    // Links to the login page shown after registration is completed are routed through this
    // which checks the user hasn't already logged in somewhere else (perhaps we should do
    // this more generally?)
    private onLoginClickWithCheck = async (ev: ButtonEvent): Promise<boolean> => {
        ev.preventDefault();

        const sessionLoaded = await Lifecycle.loadSession({ ignoreGuest: true });
        if (!sessionLoaded) {
            // ok fine, there's still no session: really go to the login page
            this.props.onLoginClick();
        }

        return sessionLoaded;
    };

    private renderRegisterComponent(): ReactNode {
        if (this.state.matrixClient && this.state.doingUIAuth) {
            return (
                <InteractiveAuth
                    matrixClient={this.state.matrixClient}
                    makeRequest={this.makeRegisterRequest}
                    onAuthFinished={this.onUIAuthFinished}
                    inputs={this.getUIAuthInputs()}
                    requestEmailToken={this.requestEmailToken}
                    sessionId={this.props.sessionId}
                    clientSecret={this.props.clientSecret}
                    emailSid={this.props.idSid}
                    poll={true}
                />
            );
        } else if (!this.state.matrixClient && !this.state.busy) {
            return null;
        } else if (this.state.busy || !this.state.flows) {
            return (
                <div className="mx_AuthBody_spinner">
                    <Spinner />
                </div>
            );
        } else if (this.state.matrixClient && this.state.oidcNativeFlow) {
            return (
                <AccessibleButton
                    className="mx_Login_fullWidthButton"
                    kind="primary"
                    onClick={async () => {
                        await startOidcLogin(
                            this.props.serverConfig.delegatedAuthentication!,
                            this.state.oidcNativeFlow!.clientId,
                            this.props.serverConfig.hsUrl,
                            this.props.serverConfig.isUrl,
                            true /* isRegistration */,
                        );
                    }}
                >
                    {_t("action|continue")}
                </AccessibleButton>
            );
        } else if (this.state.matrixClient && this.state.flows.length) {
            let ssoSection: JSX.Element | undefined;
            if (!this.props.mobileRegister && this.state.ssoFlow) {
                let continueWithSection;
                const providers = this.state.ssoFlow.identity_providers || [];
                // when there is only a single (or 0) providers we show a wide button with `Continue with X` text
                if (providers.length > 1) {
                    // i18n: ssoButtons is a placeholder to help translators understand context
                    continueWithSection = (
                        <h2 className="mx_AuthBody_centered">
                            {_t("auth|continue_with_sso", { ssoButtons: "" }).trim()}
                        </h2>
                    );
                }

                // i18n: ssoButtons & usernamePassword are placeholders to help translators understand context
                ssoSection = (
                    <React.Fragment>
                        {continueWithSection}
                        <SSOButtons
                            matrixClient={this.loginLogic.createTemporaryClient()}
                            flow={this.state.ssoFlow}
                            loginType={this.state.ssoFlow.type === "m.login.sso" ? "sso" : "cas"}
                            fragmentAfterLogin={this.props.fragmentAfterLogin}
                            action={SSOAction.REGISTER}
                        />
                        <h2 className="mx_AuthBody_centered">
                            {_t("auth|sso_or_username_password", {
                                ssoButtons: "",
                                usernamePassword: "",
                            }).trim()}
                        </h2>
                    </React.Fragment>
                );
            }
            return (
                <React.Fragment>
                    {ssoSection}
                    <RegistrationForm
                        defaultUsername={this.state.formVals.username}
                        defaultEmail={this.state.formVals.email}
                        defaultPhoneCountry={this.state.formVals.phoneCountry}
                        defaultPhoneNumber={this.state.formVals.phoneNumber}
                        defaultPassword={this.state.formVals.password}
                        onRegisterClick={this.onFormSubmit}
                        flows={this.state.flows}
                        serverConfig={this.props.serverConfig}
                        canSubmit={!this.state.serverErrorIsFatal}
                        matrixClient={this.state.matrixClient}
                    />
                </React.Fragment>
            );
        }

        return null;
    }

    public render(): React.ReactNode {
        let errorText;
        const err = this.state.errorText;
        if (err) {
            errorText = <div className="mx_Login_error">{err}</div>;
        }

        let serverDeadSection;
        if (!this.state.serverIsAlive) {
            const classes = classNames({
                mx_Login_error: true,
                mx_Login_serverError: true,
                mx_Login_serverErrorNonFatal: !this.state.serverErrorIsFatal,
            });
            serverDeadSection = <div className={classes}>{this.state.serverDeadError}</div>;
        }

        const signIn = (
            <span className="mx_AuthBody_changeFlow">
                {_t(
                    "auth|sign_in_instead_prompt",
                    {},
                    {
                        a: (sub) => (
                            <AccessibleButton kind="link_inline" onClick={this.onLoginClick}>
                                {sub}
                            </AccessibleButton>
                        ),
                    },
                )}
            </span>
        );

        // Only show the 'go back' button if you're not looking at the form
        let goBack;
        if (this.state.doingUIAuth) {
            goBack = (
                <AccessibleButton kind="link" className="mx_AuthBody_changeFlow" onClick={this.onGoToFormClicked}>
                    {_t("action|go_back")}
                </AccessibleButton>
            );
        }

        let body;
        if (this.state.completedNoSignin) {
            let regDoneText;
            if (this.props.mobileRegister) {
                regDoneText = undefined;
            } else if (this.state.differentLoggedInUserId) {
                regDoneText = (
                    <div>
                        <p>
                            {_t("auth|account_clash", {
                                newAccountId: this.state.registeredUsername,
                                loggedInUserId: this.state.differentLoggedInUserId,
                            })}
                        </p>
                        <p>
                            <AccessibleButton
                                kind="link_inline"
                                onClick={async (event: ButtonEvent): Promise<void> => {
                                    const sessionLoaded = await this.onLoginClickWithCheck(event);
                                    if (sessionLoaded) {
                                        dis.dispatch({ action: "view_welcome_page" });
                                    }
                                }}
                            >
                                {_t("auth|account_clash_previous_account")}
                            </AccessibleButton>
                        </p>
                    </div>
                );
            } else {
                // regardless of whether we're the client that started the registration or not, we should
                // try our credentials anyway
                regDoneText = (
                    <h2>
                        {_t(
                            "auth|log_in_new_account",
                            {},
                            {
                                a: (sub) => (
                                    <AccessibleButton
                                        kind="link_inline"
                                        onClick={async (event: ButtonEvent): Promise<void> => {
                                            const sessionLoaded = await this.onLoginClickWithCheck(event);
                                            if (sessionLoaded) {
                                                dis.dispatch({ action: "view_home_page" });
                                            }
                                        }}
                                    >
                                        {sub}
                                    </AccessibleButton>
                                ),
                            },
                        )}
                    </h2>
                );
            }
            body = (
                <div>
                    <h1>{_t("auth|registration_successful")}</h1>
                    {regDoneText}
                </div>
            );
        } else if (this.props.mobileRegister) {
            body = this.renderRegisterComponent();
        } else {
            body = (
                <Fragment>
                    <div className="mx_Register_mainContent">
                        <AuthHeaderDisplay
                            title={_t("auth|create_account_title")}
                            serverPicker={
                                <ServerPicker
                                    title={_t("auth|server_picker_title_registration")}
                                    dialogTitle={_t("auth|server_picker_dialog_title")}
                                    serverConfig={this.props.serverConfig}
                                    onServerConfigChange={
                                        this.state.doingUIAuth ? undefined : this.props.onServerConfigChange
                                    }
                                />
                            }
                        >
                            {errorText}
                            {serverDeadSection}
                        </AuthHeaderDisplay>
                        {this.renderRegisterComponent()}
                    </div>
                    <div className="mx_Register_footerActions">
                        {goBack}
                        {signIn}
                    </div>
                </Fragment>
            );
        }
        if (this.props.mobileRegister) {
            return (
                <Fragment>
                    <div className="mx_MobileRegister_body">{body}</div>
                </Fragment>
            );
        }
        return (
            <AuthPage>
                <AuthHeader />
                <AuthHeaderProvider>
                    <AuthBody flex>{body}</AuthBody>
                </AuthHeaderProvider>
            </AuthPage>
        );
    }
}