'use strict';

exports = module.exports = {
    passwordReset,

    sendInvite,
    sendNewLoginLocation,

    backupFailed,

    certificateRenewalError,

    sendTestMail,

    _mailQueue: [] // accumulate mails in test mode
};

const assert = require('assert'),
    BoxError = require('./boxerror.js'),
    branding = require('./branding.js'),
    constants = require('./constants.js'),
    dashboard = require('./dashboard.js'),
    debug = require('debug')('box:mailer'),
    ejs = require('ejs'),
    mailServer = require('./mailserver.js'),
    nodemailer = require('nodemailer'),
    path = require('path'),
    safe = require('safetydance'),
    translation = require('./translation.js'),
    util = require('util');

const MAIL_TEMPLATES_DIR = path.join(__dirname, 'mail_templates');

// This will collect the most common details required for notification emails
async function getMailConfig() {
    const cloudronName = await branding.getCloudronName();
    const { domain:dashboardDomain } = await dashboard.getLocation();

    return {
        cloudronName,
        notificationFrom: `"${cloudronName}" <no-reply@${dashboardDomain}>`,
        supportEmail: 'support@cloudron.io'
    };
}

async function sendMail(mailOptions) {
    assert.strictEqual(typeof mailOptions, 'object');

    if (constants.TEST) {
        exports._mailQueue.push(mailOptions);
        return;
    }

    const { domain:dashboardDomain } = await dashboard.getLocation();
    const data = await mailServer.getMailAuth();

    const transport = nodemailer.createTransport({
        host: data.ip,
        port: data.port,
        auth: {
            user: mailOptions.authUser || `no-reply@${dashboardDomain}`,
            pass: data.relayToken
        }
    });

    const transportSendMail = util.promisify(transport.sendMail.bind(transport));
    const [error] = await safe(transportSendMail(mailOptions));
    if (error) throw new BoxError(BoxError.EXTERNAL_ERROR, error);
    debug(`Email "${mailOptions.subject}" sent to ${mailOptions.to}`);
}

function render(templateFile, params, translationAssets) {
    assert.strictEqual(typeof templateFile, 'string');
    assert.strictEqual(typeof params, 'object');

    let content = null;
    let raw = safe.fs.readFileSync(path.join(MAIL_TEMPLATES_DIR, templateFile), 'utf8');
    if (raw === null) {
        debug(`Error loading ${templateFile}`);
        return '';
    }

    if (typeof translationAssets === 'object') raw = translation.translate(raw, translationAssets.translations || {}, translationAssets.fallback || {});

    try {
        content = ejs.render(raw, params);
    } catch (e) {
        debug(`Error rendering ${templateFile}`, e);
    }

    return content;
}

async function sendInvite(user, invitor, email, inviteLink) {
    assert.strictEqual(typeof user, 'object');
    assert.strictEqual(typeof invitor, 'object');
    assert.strictEqual(typeof email, 'string');
    assert.strictEqual(typeof inviteLink, 'string');

    const mailConfig = await getMailConfig();
    const translationAssets = await translation.getTranslations();
    const { fqdn:dashboardFqdn } = await dashboard.getLocation();

    const templateData = {
        user: user.displayName || user.username || user.email,
        webadminUrl: `https://${dashboardFqdn}`,
        inviteLink: inviteLink,
        invitor: invitor ? invitor.email : null,
        cloudronName: mailConfig.cloudronName,
        cloudronAvatarUrl: `https://${dashboardFqdn}/api/v1/cloudron/avatar`
    };

    const mailOptions = {
        from: mailConfig.notificationFrom,
        to: email,
        subject: ejs.render(translation.translate('{{ welcomeEmail.subject }}', translationAssets.translations || {}, translationAssets.fallback || {}), { cloudron: mailConfig.cloudronName }),
        text: render('welcome_user-text.ejs', templateData, translationAssets),
        html: render('welcome_user-html.ejs', templateData, translationAssets)
    };

    await sendMail(mailOptions);
}

async function sendNewLoginLocation(user, loginLocation) {
    assert.strictEqual(typeof user, 'object');
    assert.strictEqual(typeof loginLocation, 'object');

    const { ip, userAgent, country, city } = loginLocation;

    assert.strictEqual(typeof ip, 'string');
    assert.strictEqual(typeof userAgent, 'string');
    assert.strictEqual(typeof country, 'string');
    assert.strictEqual(typeof city, 'string');

    const mailConfig = await getMailConfig();
    const translationAssets = await translation.getTranslations();
    const { fqdn:dashboardFqdn } = await dashboard.getLocation();

    const templateData = {
        user: user.displayName || user.username || user.email,
        ip,
        userAgent: userAgent || 'unknown',
        country,
        city,
        cloudronName: mailConfig.cloudronName,
        cloudronAvatarUrl: `https://${dashboardFqdn}/api/v1/cloudron/avatar`
    };

    const mailOptions = {
        from: mailConfig.notificationFrom,
        to: user.email,
        subject: ejs.render(translation.translate('{{ newLoginEmail.subject }}', translationAssets.translations || {}, translationAssets.fallback || {}), { cloudron: mailConfig.cloudronName }),
        text: render('new_login_location-text.ejs', templateData, translationAssets),
        html: render('new_login_location-html.ejs', templateData, translationAssets)
    };

    await sendMail(mailOptions);
}

async function passwordReset(user, email, resetLink) {
    assert.strictEqual(typeof user, 'object');
    assert.strictEqual(typeof email, 'string');
    assert.strictEqual(typeof resetLink, 'string');

    const mailConfig = await getMailConfig();
    const translationAssets = await translation.getTranslations();
    const { fqdn:dashboardFqdn } = await dashboard.getLocation();

    const templateData = {
        user: user.displayName || user.username || user.email,
        resetLink: resetLink,
        cloudronName: mailConfig.cloudronName,
        cloudronAvatarUrl: `https://${dashboardFqdn}/api/v1/cloudron/avatar`
    };

    const mailOptions = {
        from: mailConfig.notificationFrom,
        to: email,
        subject: ejs.render(translation.translate('{{ passwordResetEmail.subject }}', translationAssets.translations || {}, translationAssets.fallback || {}), { cloudron: mailConfig.cloudronName }),
        text: render('password_reset-text.ejs', templateData, translationAssets),
        html: render('password_reset-html.ejs', templateData, translationAssets)
    };

    await sendMail(mailOptions);
}

async function backupFailed(mailTo, errorMessage, logUrl) {
    assert.strictEqual(typeof mailTo, 'string');
    assert.strictEqual(typeof errorMessage, 'string');
    assert.strictEqual(typeof logUrl, 'string');

    const mailConfig = await getMailConfig();

    const mailOptions = {
        from: mailConfig.notificationFrom,
        to: mailTo,
        subject: `[${mailConfig.cloudronName}] Failed to backup`,
        text: render('backup_failed.ejs', { cloudronName: mailConfig.cloudronName, message: errorMessage, logUrl, format: 'text' })
    };

    await sendMail(mailOptions);
}

async function certificateRenewalError(mailTo, domain, message) {
    assert.strictEqual(typeof mailTo, 'string');
    assert.strictEqual(typeof domain, 'string');
    assert.strictEqual(typeof message, 'string');

    const mailConfig = await getMailConfig();

    const mailOptions = {
        from: mailConfig.notificationFrom,
        to: mailTo,
        subject: `[${mailConfig.cloudronName}] Certificate renewal error`,
        text: render('certificate_renewal_error.ejs', { domain: domain, message: message, format: 'text' })
    };

    await sendMail(mailOptions);
}

async function sendTestMail(domain, email) {
    assert.strictEqual(typeof domain, 'string');
    assert.strictEqual(typeof email, 'string');

    const mailConfig = await getMailConfig();

    const mailOptions = {
        authUser: `no-reply@${domain}`,
        from: `"${mailConfig.cloudronName}" <no-reply@${domain}>`,
        to: email,
        subject: `[${mailConfig.cloudronName}] Test Email`,
        text: render('test.ejs', { cloudronName: mailConfig.cloudronName, format: 'text'})
    };

    await sendMail(mailOptions);
}