/*
Copyright 2019-2022 The Matrix.org Foundation C.I.C.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

import React, { ChangeEvent, SyntheticEvent } from "react";
import { logger } from "matrix-js-sdk/src/logger";
import { Optional } from "matrix-events-sdk";
import { LoginFlow, MatrixError, SSOAction, SSOFlow } from "matrix-js-sdk/src/matrix";

import { _t } from "../../../languageHandler";
import dis from "../../../dispatcher/dispatcher";
import * as Lifecycle from "../../../Lifecycle";
import Modal from "../../../Modal";
import { IMatrixClientCreds, MatrixClientPeg } from "../../../MatrixClientPeg";
import { sendLoginRequest } from "../../../Login";
import AuthPage from "../../views/auth/AuthPage";
import { SSO_HOMESERVER_URL_KEY, SSO_ID_SERVER_URL_KEY } from "../../../BasePlatform";
import SSOButtons from "../../views/elements/SSOButtons";
import ConfirmWipeDeviceDialog from "../../views/dialogs/ConfirmWipeDeviceDialog";
import Field from "../../views/elements/Field";
import AccessibleButton from "../../views/elements/AccessibleButton";
import Spinner from "../../views/elements/Spinner";
import AuthHeader from "../../views/auth/AuthHeader";
import AuthBody from "../../views/auth/AuthBody";

enum LoginView {
    Loading,
    Password,
    CAS, // SSO, but old
    SSO,
    PasswordWithSocialSignOn,
    Unsupported,
}

const STATIC_FLOWS_TO_VIEWS: Record<string, LoginView> = {
    "m.login.password": LoginView.Password,
    "m.login.cas": LoginView.CAS,
    "m.login.sso": LoginView.SSO,
};

interface IProps {
    // Query parameters from MatrixChat
    realQueryParams: {
        loginToken?: string;
    };
    fragmentAfterLogin?: string;

    // Called when the SSO login completes
    onTokenLoginCompleted: () => void;
}

interface IState {
    loginView: LoginView;
    busy: boolean;
    password: string;
    errorText: string;
    flows: LoginFlow[];
}

export default class SoftLogout extends React.Component<IProps, IState> {
    public constructor(props: IProps) {
        super(props);

        this.state = {
            loginView: LoginView.Loading,
            busy: false,
            password: "",
            errorText: "",
            flows: [],
        };
    }

    public componentDidMount(): void {
        // We've ended up here when we don't need to - navigate to login
        if (!Lifecycle.isSoftLogout()) {
            dis.dispatch({ action: "start_login" });
            return;
        }

        this.initLogin();
    }

    private onClearAll = (): void => {
        Modal.createDialog(ConfirmWipeDeviceDialog, {
            onFinished: (wipeData) => {
                if (!wipeData) return;

                logger.log("Clearing data from soft-logged-out session");
                Lifecycle.logout();
            },
        });
    };

    private async initLogin(): Promise<void> {
        const queryParams = this.props.realQueryParams;
        const hasAllParams = queryParams?.["loginToken"];
        if (hasAllParams) {
            this.setState({ loginView: LoginView.Loading });
            this.trySsoLogin();
            return;
        }

        // Note: we don't use the existing Login class because it is heavily flow-based. We don't
        // care about login flows here, unless it is the single flow we support.
        const client = MatrixClientPeg.safeGet();
        const flows = (await client.loginFlows()).flows;
        const loginViews = flows.map((f) => STATIC_FLOWS_TO_VIEWS[f.type]);

        const isSocialSignOn = loginViews.includes(LoginView.Password) && loginViews.includes(LoginView.SSO);
        const firstView = loginViews.filter((f) => !!f)[0] || LoginView.Unsupported;
        const chosenView = isSocialSignOn ? LoginView.PasswordWithSocialSignOn : firstView;
        this.setState({ flows, loginView: chosenView });
    }

    private onPasswordChange = (ev: ChangeEvent<HTMLInputElement>): void => {
        this.setState({ password: ev.target.value });
    };

    private onForgotPassword = (): void => {
        dis.dispatch({ action: "start_password_recovery" });
    };

    private onPasswordLogin = async (ev: SyntheticEvent): Promise<void> => {
        ev.preventDefault();
        ev.stopPropagation();

        this.setState({ busy: true });

        const cli = MatrixClientPeg.safeGet();
        const hsUrl = cli.getHomeserverUrl();
        const isUrl = cli.getIdentityServerUrl();
        const loginType = "m.login.password";
        const loginParams = {
            identifier: {
                type: "m.id.user",
                user: cli.getUserId(),
            },
            password: this.state.password,
            device_id: cli.getDeviceId() ?? undefined,
        };

        let credentials: IMatrixClientCreds;
        try {
            credentials = await sendLoginRequest(hsUrl, isUrl, loginType, loginParams);
        } catch (e) {
            let errorText = _t("Failed to re-authenticate due to a homeserver problem");
            if (
                e instanceof MatrixError &&
                e.errcode === "M_FORBIDDEN" &&
                (e.httpStatus === 401 || e.httpStatus === 403)
            ) {
                errorText = _t("Incorrect password");
            }

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

        Lifecycle.hydrateSession(credentials).catch((e) => {
            logger.error(e);
            this.setState({ busy: false, errorText: _t("Failed to re-authenticate") });
        });
    };

    private async trySsoLogin(): Promise<void> {
        this.setState({ busy: true });

        const hsUrl = localStorage.getItem(SSO_HOMESERVER_URL_KEY);
        if (!hsUrl) {
            logger.error("Homeserver URL unknown for SSO login callback");
            this.setState({ busy: false, loginView: LoginView.Unsupported });
            return;
        }

        const isUrl = localStorage.getItem(SSO_ID_SERVER_URL_KEY) || MatrixClientPeg.safeGet().getIdentityServerUrl();
        const loginType = "m.login.token";
        const loginParams = {
            token: this.props.realQueryParams["loginToken"],
            device_id: MatrixClientPeg.safeGet().getDeviceId() ?? undefined,
        };

        let credentials: IMatrixClientCreds;
        try {
            credentials = await sendLoginRequest(hsUrl, isUrl, loginType, loginParams);
        } catch (e) {
            logger.error(e);
            this.setState({ busy: false, loginView: LoginView.Unsupported });
            return;
        }

        Lifecycle.hydrateSession(credentials)
            .then(() => {
                if (this.props.onTokenLoginCompleted) this.props.onTokenLoginCompleted();
            })
            .catch((e) => {
                logger.error(e);
                this.setState({ busy: false, loginView: LoginView.Unsupported });
            });
    }

    private renderPasswordForm(introText: Optional<string>): JSX.Element {
        let error: JSX.Element | undefined;
        if (this.state.errorText) {
            error = <span className="mx_Login_error">{this.state.errorText}</span>;
        }

        return (
            <form onSubmit={this.onPasswordLogin}>
                {introText ? <p>{introText}</p> : null}
                {error}
                <Field
                    type="password"
                    label={_t("common|password")}
                    onChange={this.onPasswordChange}
                    value={this.state.password}
                    disabled={this.state.busy}
                />
                <AccessibleButton
                    onClick={this.onPasswordLogin}
                    kind="primary"
                    type="submit"
                    disabled={this.state.busy}
                >
                    {_t("action|sign_in")}
                </AccessibleButton>
                <AccessibleButton onClick={this.onForgotPassword} kind="link">
                    {_t("Forgotten your password?")}
                </AccessibleButton>
            </form>
        );
    }

    private renderSsoForm(introText: Optional<string>): JSX.Element {
        const loginType = this.state.loginView === LoginView.CAS ? "cas" : "sso";
        const flow = this.state.flows.find((flow) => flow.type === "m.login." + loginType) as SSOFlow;

        return (
            <div>
                {introText ? <p>{introText}</p> : null}
                <SSOButtons
                    matrixClient={MatrixClientPeg.safeGet()}
                    flow={flow}
                    loginType={loginType}
                    fragmentAfterLogin={this.props.fragmentAfterLogin}
                    primary={!this.state.flows.find((flow) => flow.type === "m.login.password")}
                    action={SSOAction.LOGIN}
                />
            </div>
        );
    }

    private renderSignInSection(): JSX.Element {
        if (this.state.loginView === LoginView.Loading) {
            return <Spinner />;
        }

        if (this.state.loginView === LoginView.Password) {
            return this.renderPasswordForm(_t("Enter your password to sign in and regain access to your account."));
        }

        if (this.state.loginView === LoginView.SSO || this.state.loginView === LoginView.CAS) {
            return this.renderSsoForm(_t("Sign in and regain access to your account."));
        }

        if (this.state.loginView === LoginView.PasswordWithSocialSignOn) {
            // We render both forms with no intro/error to ensure the layout looks reasonably
            // okay enough.
            //
            // Note: "mx_AuthBody_centered" text taken from registration page.
            return (
                <>
                    <p>{_t("Sign in and regain access to your account.")}</p>
                    {this.renderSsoForm(null)}
                    <h2 className="mx_AuthBody_centered">
                        {_t("%(ssoButtons)s Or %(usernamePassword)s", {
                            ssoButtons: "",
                            usernamePassword: "",
                        }).trim()}
                    </h2>
                    {this.renderPasswordForm(null)}
                </>
            );
        }

        // Default: assume unsupported/error
        return (
            <p>
                {_t("You cannot sign in to your account. Please contact your homeserver admin for more information.")}
            </p>
        );
    }

    public render(): React.ReactNode {
        return (
            <AuthPage>
                <AuthHeader />
                <AuthBody>
                    <h1>{_t("You're signed out")}</h1>

                    <h2>{_t("action|sign_in")}</h2>
                    <div>{this.renderSignInSection()}</div>

                    <h2>{_t("Clear personal data")}</h2>
                    <p>
                        {_t(
                            "Warning: your personal data (including encryption keys) is still stored in this session. Clear it if you're finished using this session, or want to sign in to another account.",
                        )}
                    </p>
                    <div>
                        <AccessibleButton onClick={this.onClearAll} kind="danger">
                            {_t("Clear all data")}
                        </AccessibleButton>
                    </div>
                </AuthBody>
            </AuthPage>
        );
    }
}