/* jslint node: true */
'use strict';

//  ENiGMA½
const Config = require('./config.js').get;
const getServer = require('./listening_server.js').getServer;
const webServerPackageName = require('./servers/content/web.js').moduleInfo.packageName;
const {
    createToken,
    deleteToken,
    getTokenInfo,
    WellKnownTokenTypes,
} = require('./user_temp_token.js');
const { prepareOTP, createBackupCodes, otpFromType } = require('./user_2fa_otp.js');
const { sendMail } = require('./email.js');
const UserProps = require('./user_property.js');
const Log = require('./logger.js').log;
const { getConnectionByUserId } = require('./client_connections.js');

//  deps
const async = require('async');
const fs = require('fs-extra');
const _ = require('lodash');
const url = require('url');
const querystring = require('querystring');

function getWebServer() {
    return getServer(webServerPackageName);
}

const DefaultEmailTextTemplate = `%USERNAME%:
You have requested to enable 2-Factor Authentication via One-Time-Password
for your account on %BOARDNAME%.

    * If this was not you, please ignore this email and change your password.
    * Otherwise, please follow the link below:

    %REGISTER_URL%
`;

module.exports = class User2FA_OTPWebRegister {
    static startup(cb) {
        return User2FA_OTPWebRegister.registerRoutes(cb);
    }

    static sendRegisterEmail(user, otpType, cb) {
        async.waterfall(
            [
                callback => {
                    return createToken(
                        user.userId,
                        WellKnownTokenTypes.AuthFactor2OTPRegister,
                        { bits: 128 },
                        callback
                    );
                },
                (token, callback) => {
                    const config = Config();
                    const txtTemplateFile = _.get(
                        config,
                        'users.twoFactorAuth.otp.registerEmailText'
                    );
                    const htmlTemplateFile = _.get(
                        config,
                        'users.twoFactorAuth.otp.registerEmailHtml'
                    );

                    fs.readFile(txtTemplateFile, 'utf8', (err, textTemplate) => {
                        textTemplate = textTemplate || DefaultEmailTextTemplate;
                        fs.readFile(htmlTemplateFile, 'utf8', (err, htmlTemplate) => {
                            htmlTemplate = htmlTemplate || null; //  be explicit for waterfall
                            return callback(null, token, textTemplate, htmlTemplate);
                        });
                    });
                },
                (token, textTemplate, htmlTemplate, callback) => {
                    const webServer = getWebServer();
                    const registerUrl = webServer.instance.buildUrl(
                        `/_internal/enable_2fa_otp?token=${token}&otpType=${otpType}`
                    );

                    const replaceTokens = s => {
                        return s
                            .replace(/%BOARDNAME%/g, Config().general.boardName)
                            .replace(/%USERNAME%/g, user.username)
                            .replace(/%TOKEN%/g, token)
                            .replace(/%REGISTER_URL%/g, registerUrl);
                    };

                    textTemplate = replaceTokens(textTemplate);
                    if (htmlTemplate) {
                        htmlTemplate = replaceTokens(htmlTemplate);
                    }

                    const message = {
                        to: `${
                            user.getProperty(UserProps.RealName) || user.username
                        } <${user.getProperty(UserProps.EmailAddress)}>`,
                        //  from will be filled in
                        subject: '2-Factor Authentication Registration',
                        text: textTemplate,
                        html: htmlTemplate,
                    };

                    sendMail(message, (err, info) => {
                        if (err) {
                            Log.warn(
                                { error: err.message },
                                'Failed sending 2FA/OTP register email'
                            );
                        } else {
                            Log.info(
                                { info },
                                'Successfully sent 2FA/OTP register email'
                            );
                        }
                        return callback(err);
                    });
                },
            ],
            err => {
                return cb(err);
            }
        );
    }

    static fileNotFound(webServer, resp) {
        return webServer.instance.fileNotFound(resp);
    }

    static accessDenied(webServer, resp) {
        return webServer.instance.accessDenied(resp);
    }

    static routeRegisterGet(req, resp) {
        const webServer = getWebServer(); //  must be valid, we just got a req!

        const urlParts = url.parse(req.url, true);
        const token = urlParts.query && urlParts.query.token;
        const otpType = urlParts.query && urlParts.query.otpType;

        if (!token || !otpType) {
            return User2FA_OTPWebRegister.accessDenied(webServer, resp);
        }

        getTokenInfo(token, (err, tokenInfo) => {
            if (err) {
                //  assume expired
                return webServer.instance.respondWithError(
                    resp,
                    410,
                    'Invalid or expired registration link.',
                    'Expired Link'
                );
            }

            if (tokenInfo.tokenType !== WellKnownTokenTypes.AuthFactor2OTPRegister) {
                return User2FA_OTPWebRegister.accessDenied(webServer, resp);
            }

            const prepareOptions = {
                qrType: 'data',
                cellSize: 8,
                username: tokenInfo.user.username,
            };

            prepareOTP(otpType, prepareOptions, (err, otpInfo) => {
                if (err) {
                    Log.error({ error: err.message }, 'Failed to prepare OTP');
                    return User2FA_OTPWebRegister.accessDenied(webServer, resp);
                }

                const postUrl = webServer.instance.buildUrl('/_internal/enable_2fa_otp');
                const config = Config();
                return webServer.instance.routeTemplateFilePage(
                    _.get(config, 'users.twoFactorAuth.otp.registerPageTemplate'),
                    (templateData, next) => {
                        const finalPage = templateData
                            .replace(/%BOARDNAME%/g, config.general.boardName)
                            .replace(/%USERNAME%/g, tokenInfo.user.username)
                            .replace(/%TOKEN%/g, token)
                            .replace(/%OTP_TYPE%/g, otpType)
                            .replace(/%POST_URL%/g, postUrl)
                            .replace(/%QR_IMG_DATA%/g, otpInfo.qr || '')
                            .replace(/%SECRET%/g, otpInfo.secret);
                        return next(null, finalPage);
                    },
                    resp
                );
            });
        });
    }

    static routeRegisterPost(req, resp) {
        const webServer = getWebServer(); //  must be valid, we just got a req!

        const badRequest = () => {
            return webServer.instance.respondWithError(
                resp,
                400,
                'Bad Request.',
                'Bad Request'
            );
        };

        let bodyData = '';
        req.on('data', data => {
            bodyData += data;
        });

        req.on('end', () => {
            const formData = querystring.parse(bodyData);

            if (
                !formData.token ||
                !formData.otpType ||
                !formData.otp ||
                !formData.secret
            ) {
                return badRequest();
            }

            const otp = otpFromType(formData.otpType);
            if (!otp) {
                return badRequest();
            }

            const valid = otp.verify({ token: formData.otp, secret: formData.secret });
            if (!valid) {
                return User2FA_OTPWebRegister.accessDenied(webServer, resp);
            }

            getTokenInfo(formData.token, (err, tokenInfo) => {
                if (err) {
                    return User2FA_OTPWebRegister.accessDenied(webServer, resp);
                }

                const backupCodes = createBackupCodes();

                const props = {
                    [UserProps.AuthFactor2OTP]: formData.otpType,
                    [UserProps.AuthFactor2OTPSecret]: formData.secret,
                    [UserProps.AuthFactor2OTPBackupCodes]: JSON.stringify(backupCodes),
                };

                tokenInfo.user.persistProperties(props, err => {
                    if (err) {
                        return webServer.instance.respondWithError(
                            resp,
                            500,
                            'Internal Server Error',
                            'Internal Server Error'
                        );
                    }

                    //
                    //  User may be online still - find account & update it if so
                    //
                    const clientConn = getConnectionByUserId(tokenInfo.user.userId);
                    if (clientConn && clientConn.user) {
                        //  just update live props, we've already persisted them.
                        _.each(props, (v, n) => {
                            clientConn.user.setProperty(n, v);
                        });
                    }

                    //  we can now remove the token - no need to wait
                    deleteToken(formData.token, err => {
                        if (err) {
                            Log.error(
                                { error: err.message, token: formData.token },
                                'Failed to delete temporary token'
                            );
                        }
                    });

                    //  :TODO: use a html template here too, if provided
                    resp.writeHead(200);
                    return resp.end(
                        `2-Factor Authentication via One-Time-Password has been enabled for this account. Please write down your backup codes and store them in safe place:

${backupCodes}
                        `
                    );
                });
            });
        });
    }

    static registerRoutes(cb) {
        const webServer = getWebServer();
        if (!webServer || !webServer.instance.isEnabled()) {
            return cb(null); //  no webserver enabled
        }

        [
            {
                method: 'GET',
                path: /^\/_internal\/enable_2fa_otp\?token=[a-f0-9]+&otpType=[a-zA-Z0-9_]+$/,
                handler: User2FA_OTPWebRegister.routeRegisterGet,
            },
            {
                method: 'POST',
                path: /^\/_internal\/enable_2fa_otp$/,
                handler: User2FA_OTPWebRegister.routeRegisterPost,
            },
        ].forEach(r => {
            webServer.instance.addRoute(r);
        });

        return cb(null);
    }
};