'use strict';

exports = module.exports = {
    checkForUpdates,

    getUpdateInfo,

    _checkAppUpdates: checkAppUpdates
};

const apps = require('./apps.js'),
    appstore = require('./appstore.js'),
    assert = require('assert'),
    async = require('async'),
    debug = require('debug')('box:updatechecker'),
    notifications = require('./notifications.js'),
    paths = require('./paths.js'),
    safe = require('safetydance');

function setUpdateInfo(state) {
    // appid -> update info { creationDate, manifest }
    // box -> { version, changelog, upgrade, sourceTarballUrl }
    state.version = 2;
    if (!safe.fs.writeFileSync(paths.UPDATE_CHECKER_FILE, JSON.stringify(state, null, 4), 'utf8')) debug(`setUpdateInfo: Error writing to update checker file: ${safe.error.message}`);
}

function getUpdateInfo() {
    const state = safe.JSON.parse(safe.fs.readFileSync(paths.UPDATE_CHECKER_FILE, 'utf8'));
    if (!state || state.version !== 2) return {};
    delete state.version;
    return state;
}

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

    debug('checkAppUpdates: checking for updates');

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

    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('checkAppUpdates: 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;

                iteratorDone();
            });
        }, function () {
            if ('box' in state) newState.box = state.box; // preserve the latest box state information

            setUpdateInfo(newState);

            callback();
        });
    });
}

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

    debug('checkBoxUpdates: checking for updates');

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

        let state = getUpdateInfo();

        if (!updateInfo) { // no update
            if ('box' in state) {
                delete state.box;
                setUpdateInfo(state);
            }
            debug('checkBoxUpdates: no updates');
            return callback(null);
        }

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

        debug(`checkBoxUpdates: ${updateInfo.version} is available`);

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

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

        [error] = await safe(notifications.alert(notifications.ALERT_BOX_UPDATE, `Cloudron v${updateInfo.version} is available`, message));
        if (error) return callback(error);

        state.box = updateInfo;
        setUpdateInfo(state);

        callback(null);
    });
}

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);
        });
    });
}