'use strict';

exports = module.exports = {
    get,
    update,
    list,
    del,

    onEvent,

    // these are notification types, keep in sync with client.js
    ALERT_CLOUDRON_INSTALLED: 'cloudronInstalled',
    ALERT_CLOUDRON_UPDATED: 'cloudronUpdated',
    ALERT_CLOUDRON_UPDATE_FAILED: 'cloudronUpdateFailed',
    ALERT_CERTIFICATE_RENEWAL_FAILED: 'certificateRenewalFailed',
    ALERT_BACKUP_CONFIG: 'backupConfig',
    ALERT_DISK_SPACE: 'diskSpace',
    ALERT_MAIL_STATUS: 'mailStatus',
    ALERT_REBOOT: 'reboot',
    ALERT_BOX_UPDATE: 'boxUpdate',
    ALERT_UPDATE_UBUNTU: 'ubuntuUpdate',
    ALERT_MANUAL_APP_UPDATE: 'manualAppUpdate',
    ALERT_APP_OOM: 'appOutOfMemory',
    ALERT_APP_UPDATED: 'appUpdated',
    ALERT_BACKUP_FAILED: 'backupFailed',

    alert,
    clearAlert,

    // exported for testing
    _add: add
};

const assert = require('assert'),
    AuditSource = require('./auditsource.js'),
    BoxError = require('./boxerror.js'),
    changelog = require('./changelog.js'),
    constants = require('./constants.js'),
    dashboard = require('./dashboard.js'),
    database = require('./database.js'),
    eventlog = require('./eventlog.js'),
    mailer = require('./mailer.js'),
    users = require('./users.js');

const NOTIFICATION_FIELDS = [ 'id', 'eventId', 'type', 'title', 'message', 'creationTime', 'acknowledged' ];

function postProcess(result) {
    assert.strictEqual(typeof result, 'object');
    result.id = String(result.id);
    result.acknowledged = !!result.acknowledged; // convert to boolean
    return result;
}

async function add(type, title, message, data) {
    assert.strictEqual(typeof type, 'string');
    assert.strictEqual(typeof title, 'string');
    assert.strictEqual(typeof message, 'string');
    assert.strictEqual(typeof data, 'object');

    const query = 'INSERT INTO notifications (type, title, message, acknowledged, eventId) VALUES (?, ?, ?, ?, ?)';
    const args = [ type, title, message, false, data?.eventId || null ];

    const result = await database.query(query, args);
    return String(result.insertId);
}

async function get(id) {
    assert.strictEqual(typeof id, 'string');

    const result = await database.query(`SELECT ${NOTIFICATION_FIELDS} FROM notifications WHERE id = ?`, [ id ]);
    if (result.length === 0) return null;

    return postProcess(result[0]);
}

async function getByTitle(title) {
    assert.strictEqual(typeof title, 'string');

    const results = await database.query(`SELECT ${NOTIFICATION_FIELDS} from notifications WHERE title = ? ORDER BY creationTime LIMIT 1`, [ title ]);
    if (results.length === 0) return null;

    return postProcess(results[0]);
}

async function update(notification, data) {
    assert.strictEqual(typeof notification, 'object');
    assert.strictEqual(typeof data, 'object');

    const args = [];
    const fields = [];
    for (const k in data) {
        fields.push(k + ' = ?');
        args.push(data[k]);
    }
    args.push(notification.id);

    const result = await database.query('UPDATE notifications SET ' + fields.join(', ') + ' WHERE id = ?', args);
    if (result.affectedRows !== 1) throw new BoxError(BoxError.NOT_FOUND, 'Notification not found');
}

async function del(id) {
    assert.strictEqual(typeof id, 'string');

    const result = await database.query('DELETE FROM notifications WHERE id = ?', [ id ]);
    if (result.affectedRows !== 1) throw new BoxError(BoxError.NOT_FOUND, 'Notification not found');
}

async function list(filters, page, perPage) {
    assert.strictEqual(typeof filters, 'object');
    assert.strictEqual(typeof page, 'number');
    assert.strictEqual(typeof perPage, 'number');

    const args = [];

    const where = [];
    if ('acknowledged' in filters) {
        where.push('acknowledged=?');
        args.push(filters.acknowledged);
    }

    let query = `SELECT ${NOTIFICATION_FIELDS} FROM notifications`;
    if (where.length) query += ' WHERE ' + where.join(' AND ');
    query += ' ORDER BY creationTime DESC LIMIT ?,?';

    args.push((page-1)*perPage);
    args.push(perPage);

    const results = await database.query(query, args);
    results.forEach(postProcess);
    return results;
}

async function oomEvent(eventId, containerId, app, addonName /*, event*/) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof containerId, 'string');
    assert.strictEqual(typeof app, 'object');
    assert(addonName === null || typeof addonName === 'string');

    assert(app || addonName);

    const { fqdn:dashboardFqdn } = await dashboard.getLocation();
    let title, message;
    if (addonName) {
        if (app) {
            title = `The ${addonName} service of the app at ${app.fqdn} ran out of memory`;
        } else {
            title = `The ${addonName} service ran out of memory`;
        }
        message = `The service has been restarted automatically. If you see this notification often, consider increasing the [memory limit](https://${dashboardFqdn}/#/services)`;
    } else if (app) {
        title = `The app at ${app.fqdn} ran out of memory.`;
        message = `The app has been restarted automatically. If you see this notification often, consider increasing the [memory limit](https://${dashboardFqdn}/#/app/${app.id}/resources)`;
    }

    await add(exports.ALERT_APP_OOM, title, message, { eventId });
}

async function appUpdated(eventId, app, fromManifest, toManifest) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof app, 'object');
    assert.strictEqual(typeof fromManifest, 'object');
    assert.strictEqual(typeof toManifest, 'object');

    if (!app.appStoreId) return; // skip notification of dev apps

    const tmp = toManifest.description.match(/<upstream>(.*)<\/upstream>/i);
    const upstreamVersion = (tmp && tmp[1]) ? tmp[1] : '';
    const title = upstreamVersion ? `${toManifest.title} at ${app.fqdn} updated to ${upstreamVersion} (package version ${toManifest.version})`
        : `${toManifest.title} at ${app.fqdn} updated to package version ${toManifest.version}`;

    await add(exports.ALERT_APP_UPDATED, title, `The application installed at https://${app.fqdn} was updated.\n\nChangelog:\n${toManifest.changelog}\n`, { eventId });
}

async function boxInstalled(eventId, version) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof version, 'string');

    const changes = changelog.getChanges(version.replace(/\.([^.]*)$/, '.0')); // last .0 release
    const changelogMarkdown = changes.map((m) => `* ${m}\n`).join('');

    await add(exports.ALERT_CLOUDRON_INSTALLED, `Cloudron v${version} installed`, `Cloudron v${version} was installed.\n\nPlease join our community at ${constants.FORUM_URL} .\n\nChangelog:\n${changelogMarkdown}\n`, { eventId });
}

async function boxUpdated(eventId, oldVersion, newVersion) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof oldVersion, 'string');
    assert.strictEqual(typeof newVersion, 'string');

    const changes = changelog.getChanges(newVersion);
    const changelogMarkdown = changes.map((m) => `* ${m}\n`).join('');

    await add(exports.ALERT_CLOUDRON_UPDATED, `Cloudron updated to v${newVersion}`, `Cloudron was updated from v${oldVersion} to v${newVersion}.\n\nChangelog:\n${changelogMarkdown}\n`, { eventId });
}

async function boxUpdateError(eventId, errorMessage) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof errorMessage, 'string');

    await add(exports.ALERT_CLOUDRON_UPDATE_FAILED, 'Cloudron update failed', `Failed to update Cloudron: ${errorMessage}.`, { eventId });
}

async function certificateRenewalError(eventId, fqdn, errorMessage) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof fqdn, 'string');
    assert.strictEqual(typeof errorMessage, 'string');

    await add(exports.ALERT_CERTIFICATE_RENEWAL_FAILED, `Certificate renewal of ${fqdn} failed`, `Failed to renew certs of ${fqdn}: ${errorMessage}. Renewal will be retried in 12 hours.`, { eventId });

    const admins = await users.getAdmins();
    for (const admin of admins) {
        await mailer.certificateRenewalError(admin.email, fqdn, errorMessage);
    }
}

async function backupFailed(eventId, taskId, errorMessage) {
    assert.strictEqual(typeof eventId, 'string');
    assert.strictEqual(typeof taskId, 'string');
    assert.strictEqual(typeof errorMessage, 'string');

    await add(exports.ALERT_BACKUP_FAILED, 'Backup failed', `Backup failed: ${errorMessage}. Logs are available [here](/frontend/logs.html?taskId=${taskId}).`, { eventId });

    // only send mail if the past 3 automated backups failed
    const backupEvents = await eventlog.listPaged([eventlog.ACTION_BACKUP_FINISH], null /* search */, 1, 20);
    let count = 0;
    for (const event of backupEvents) {
        if (!event.data.errorMessage) return; // successful backup (manual or cron)
        if (event.source.username === AuditSource.CRON.username && ++count === 3) break; // last 3 consecutive crons have failed
    }
    if (count !== 3) return; // less than 3 failures

    const { fqdn:dashboardFqdn } = await dashboard.getLocation();
    const superadmins = await users.getSuperadmins();
    for (const superadmin of superadmins) {
        await mailer.backupFailed(superadmin.email, errorMessage, `https://${dashboardFqdn}/frontend/logs.html?taskId=${taskId}`);
    }
}

// type must be one of ALERT_*
async function alert(type, title, message, options) {
    assert.strictEqual(typeof type, 'string');
    assert.strictEqual(typeof title, 'string');
    assert.strictEqual(typeof message, 'string');
    assert.strictEqual(typeof options, 'object');

    const result = await getByTitle(title);

    if (!result) return await add(type, title, message, { eventId: null });
    if (!options.persist) return result.id;

    await update(result, {
        id: result.id,
        eventId: null,
        type: type,
        title,
        message,
        acknowledged: false,
        creationTime: new Date()
    });
    return result.id;
}

// id is unused but nice to search code
async function clearAlert(type) {
    assert.strictEqual(typeof type, 'string');

    await database.query('DELETE FROM notifications WHERE type = ?', [ type ]);
    return null;
}

async function onEvent(id, action, source, data) {
    assert.strictEqual(typeof id, 'string');
    assert.strictEqual(typeof action, 'string');
    assert.strictEqual(typeof source, 'object');
    assert.strictEqual(typeof data, 'object');

    switch (action) {
    case eventlog.ACTION_APP_OOM:
        return await oomEvent(id, data.containerId, data.app, data.addonName, data.event);

    case eventlog.ACTION_APP_UPDATE_FINISH:
        if (source.username !== AuditSource.CRON.username) return; // updated by user
        if (data.errorMessage) return; // the update indicator will still appear, so no need to notify user
        return await appUpdated(id, data.app, data.fromManifest, data.toManifest);

    case eventlog.ACTION_CERTIFICATE_RENEWAL:
    case eventlog.ACTION_CERTIFICATE_NEW:
        if (!data.errorMessage) return;
        if (!data.notAfter || (data.notAfter - new Date() >= (10 * 24 * 60 * 60 * 1000))) return; // more than 10 days left to expire
        return await certificateRenewalError(id, data.domain, data.errorMessage);

    case eventlog.ACTION_BACKUP_FINISH:
        if (!data.errorMessage) return;
        if (source.username !== AuditSource.CRON.username && !data.timedOut) return; // manual stop by user

        return await backupFailed(id, data.taskId, data.errorMessage); // only notify for automated backups or timedout

    case eventlog.ACTION_INSTALL_FINISH:
        return await boxInstalled(id, data.version);

    case eventlog.ACTION_UPDATE_FINISH:
        if (!data.errorMessage) return await boxUpdated(id, data.oldVersion, data.newVersion);
        if (data.timedOut) return await boxUpdateError(id, data.errorMessage);
        return;

    default:
        return;
    }
}