/* Filepath utilities */
const path = require('path');
/* Promise library */
const bluebird = require('bluebird');
const hbs = require('handlebars');
/*  Creates promise-returning async functions
    from callback-passed async functions      */
const fs = bluebird.promisifyAll(require('fs'));
const { updateHTML } = require('./populate');
const { getConfig, outDir } = require('./utils');

const assetDir = path.resolve(`${__dirname}/assets/`);
const config = path.join(outDir, 'config.json');

/**
 * Creates the stylesheet used by the site from a template stylesheet.
 * 
 * Theme styles are added to the new stylesheet depending on command line 
 * arguments.
 */
async function populateCSS({
    theme = 'light',
    background = 'https://images.unsplash.com/photo-1553748024-d1b27fb3f960?w=500&h=1000&q=80&fit=crop',
} = {}) {
    /* Get the theme the user requests. Defaults to 'light' */
    theme = `${theme}.css`;
    let template = path.resolve(assetDir, 'index.css');
    let stylesheet = path.join(outDir, 'index.css');

    let serviceWorker = path.resolve(assetDir, 'service-worker.js');

    try {
        await fs.accessAsync(outDir, fs.constants.F_OK);
    } catch (err) {
        await fs.mkdirAsync(outDir);
    }
    /* Copy over the template CSS stylesheet */
    await fs.copyFileAsync(template, stylesheet);

    /* Add Service Worker */
    await fs.copyFileSync(serviceWorker, `${outDir}/service-worker.js`);

    /* Get an array of every available theme */
    let themes = await fs.readdirAsync(path.join(assetDir, 'themes'));

    if (!themes.includes(theme)) {
        console.error('Error: Requested theme not found. Defaulting to "light".');
        theme = 'light';
    }
    /* Read in the theme stylesheet */
    let themeSource = await fs.readFileSync(path.join(assetDir, 'themes', theme));
    themeSource = themeSource.toString('utf-8');
    let themeTemplate = hbs.compile(themeSource);
    let styles = themeTemplate({
        'background': `${background}`
    })
    /* Add the user-specified styles to the new stylesheet */
    await fs.appendFileAsync(stylesheet, styles);

    /* Update the config file with the user's theme choice */
    const data = await getConfig();
    data[0].theme = theme;
    await fs.writeFileAsync(config, JSON.stringify(data, null, ' '));
}

async function populateConfig(sort, order, includeFork, twitter, linkedin, medium) {
    const data = await getConfig();
    data[0].sort = sort;
    data[0].order = order;
    data[0].includeFork = includeFork;
    data[0].twitter = twitter; // added twitter
    data[0].linkedin = linkedin; // added linkedin
    data[0].medium = medium; // added medium
    await fs.writeFileAsync(config, JSON.stringify(data, null, ' '));
}

async function buildCommand(username, program) {
    await populateCSS(program);
    let sort = program.sort ? program.sort : 'created';
    let order = program.order ? program.order : "asc";
    let includeFork = program.fork ? true : false;
    let twitter = program.twitter ? program.twitter : null;
    let linkedin = program.linkedin ? program.linkedin : null;
    let medium = program.medium ? program.medium : null;
    await populateConfig(sort, order, includeFork, twitter, linkedin, medium);
    updateHTML(('%s', username), sort, order, includeFork, twitter, linkedin, medium);
}

module.exports = {
    buildCommand
};