'use strict';

exports = module.exports = {
    checkForUpdates,

    getUpdateInfo,

    _checkAppUpdates: checkAppUpdates
};

var apps = require('./apps.js'),
    appstore = require('./appstore.js'),
    assert = require('assert'),
    async = require('async'),
    constants = require('./constants.js'),
    debug = require('debug')('box:updatechecker'),
    mailer = require('./mailer.js'),
    notifications = require('./notifications.js'),
    paths = require('./paths.js'),
    safe = require('safetydance'),
    settings = require('./settings.js'),
    users = require('./users.js');

function setUpdateInfo(state) {
    console.dir(state);
    // appid -> update info { creationDate, manifest }
    // box -> { version, changelog, upgrade, sourceTarballUrl }
    safe.fs.writeFileSync(paths.UPDATE_CHECKER_FILE, JSON.stringify(state, null, 4), 'utf8');
}

function getUpdateInfo() {
    const state = safe.JSON.parse(safe.fs.readFileSync(paths.UPDATE_CHECKER_FILE, 'utf8'));
    return state || {};
}

function checkAppUpdates(options, callback) {
    assert.strictEqual(typeof options, 'object');
    assert.strictEqual(typeof callback, 'function');

    debug('Checking App Updates');

    let state = getUpdateInfo();
    let newState = { };  // create new state so that old app ids are removed

    settings.getAutoupdatePattern(function (error, result) {
        if (error) return callback(error);
        const autoupdatesEnabled = (result !== constants.AUTOUPDATE_PATTERN_NEVER);

        var notificationPending = [];

        apps.getAll(function (error, result) {
            if (error) return callback(error);

            async.eachSeries(result, function (app, iteratorDone) {
                if (app.appStoreId === '') return iteratorDone(); // appStoreId can be '' for dev apps

                appstore.getAppUpdate(app, options, function (error, updateInfo) {
                    if (error) {
                        debug('Error getting app update info for %s', app.id, error);
                        return iteratorDone();  // continue to next
                    }

                    if (!updateInfo) return iteratorDone(); // skip if no next version is found

                    newState[app.id] = updateInfo;

                    if (safe.query(state[app.id], 'manifest.version') === updateInfo.manifest.version) {
                        debug(`Skipping app update notification of ${app.id} since user was already notified of ${updateInfo.manifest.version}`);
                        return iteratorDone();
                    }

                    const canAutoupdateApp = apps.canAutoupdateApp(app, updateInfo);
                    if (autoupdatesEnabled && canAutoupdateApp) return iteratorDone();

                    debug(`Notifying of app update for ${app.id} from ${app.manifest.version} to ${updateInfo.manifest.version}`);
                    notificationPending.push({ app, updateInfo });
                    iteratorDone();
                });
            }, function () {
                if ('box' in state) newState.box = state.box; // preserve the latest box state information
                setUpdateInfo(newState);

                if (notificationPending.length === 0) return callback();

                users.getAdmins(function (error, admins) {
                    if (error) {
                        debug('checkAppUpdates: failed to get admins', error);
                        return callback();
                    }

                    async.eachSeries(admins, (admin, done) => mailer.appUpdatesAvailable(admin.email, notificationPending, true /* subscription */, done), callback);
                });
            });
        });
    });
}

function checkBoxUpdates(options, callback) {
    assert.strictEqual(typeof options, 'object');
    assert.strictEqual(typeof callback, 'function');

    debug('Checking Box Updates');

    appstore.getBoxUpdate(options, function (error, updateInfo) {
        if (error || !updateInfo) return callback(error);

        let state = getUpdateInfo();

        if (state.box && state.box.version === updateInfo.version) {
            debug('Skipping notification of box update as user was already notified');
            return callback();
        }

        const changelog = updateInfo.changelog.map((m) => `* ${m}\n`).join('');

        const message = `Changelog:\n${changelog}\n\nGo to the settings view to update.\n\n`;

        notifications.alert(notifications.ALERT_BOX_UPDATE, `Cloudron v${updateInfo.version} is available`, message, function (error) {
            if (error) return callback(error);

            state.box = updateInfo;
            setUpdateInfo(state);

            callback();
        });
    });
}

function checkForUpdates(options, callback) {
    assert.strictEqual(typeof options, 'object');
    assert.strictEqual(typeof callback, 'function');

    checkBoxUpdates(options, function (boxError) {
        if (boxError) debug('checkForUpdates: error checking for box updates:', boxError);

        checkAppUpdates(options, function (appError) {
            if (appError) debug('checkForUpdates: error checking for app updates:', appError);

            callback(boxError || appError || null);
        });
    });

}