const fs = require('fs');
const libpath = require('path');

const globDirectory = 'dist/public';

const STATIC_FILE_EXTENSIONS = ["css", "html", "png", "svg", "ico", "woff2"];
const JAVASCRIPT_AND_STATIC_FILE_EXTENSIONS = ["js", ...STATIC_FILE_EXTENSIONS];

function recurse(dir) {

    const files = fs.readdirSync(dir);

    const result  = [];

    for (const file of files) {

        const path = libpath.join(dir, file);

        const stat = fs.statSync(path);

        if (stat.isDirectory()) {
            result.push(...recurse(path));
        }

        if (stat.isFile()) {
            result.push(path);
        }

    }

    return result;

}

function toExtension(path) {

    if (! path) {
        return undefined;
    }

    const matches = path.match(/\.([a-z0-9]{1,15})$/);

    if (matches && matches.length === 2) {
        return matches[1];
    }

    return undefined;

}

/**
 * Return true if the path has one of the given extensions.
 */
function hasExtension(path, exts) {

    const ext = toExtension(path);

    if (! ext) {
        return false;
    }

    return exts.includes(ext);

}

function stripDirPrefix(path, prefix) {

    if (! prefix.endsWith(libpath.sep)) {
        prefix = prefix + libpath.sep
    }

    if (path.startsWith(prefix)) {
        return path.substring(prefix.length);
    }

    return path;

}

function createGlobsRecursively(path, exts) {

    if (! exts) {
        exts = STATIC_FILE_EXTENSIONS;
    }

    return recurse(libpath.join(globDirectory, path))
        .filter(current => hasExtension(current, exts))
        .map(current => stripDirPrefix(current, globDirectory));

}

const globPatterns = [

    ...createGlobsRecursively('apps', STATIC_FILE_EXTENSIONS),

    ...createGlobsRecursively('pdfviewer-custom', JAVASCRIPT_AND_STATIC_FILE_EXTENSIONS),
    ...createGlobsRecursively('web/dist', JAVASCRIPT_AND_STATIC_FILE_EXTENSIONS),
    ...createGlobsRecursively('web/assets', JAVASCRIPT_AND_STATIC_FILE_EXTENSIONS),
    'icon.ico',
    'icon.png',
    'icon.svg',
    'index.html',
    'manifest.json',
    'apps/init.js',
    'apps/service-worker-registration.js',

];

console.log("Using static file globs: \n ", globPatterns.join("\n  "));
console.log("====");

// https://stackoverflow.com/questions/49482680/workbox-the-danger-of-self-skipwaiting
// https://developers.google.com/web/tools/workbox/reference-docs/latest/module-workbox-build#.generateSW
module.exports = {
    globDirectory: 'dist/public',
    skipWaiting: true,
    globPatterns,
    globIgnores: [],
    globStrict: false,
    // stripPrefix: 'dist/public',
    maximumFileSizeToCacheInBytes: 150000000,
    swDest: 'dist/public/service-worker.js',
    runtimeCaching: [
        {
            // https://js.stripe.com/v3
            urlPattern: /https:\/\/js\.stripe\.com\/v3/,
            handler: 'staleWhileRevalidate'
        }
    ],
    //     {
    //         urlPattern: /.*/,
    //         handler: 'staleWhileRevalidate'
    //     },
    //     {
    //         // these URLs are immutable based on content hash as computed by
    //         // webpack so just use cacheFirst which only fetches them the
    //         // first time
    //         urlPattern: /https:\/\/storage.google.com\/stash/,
    //         handler: 'CacheFirst'
    //     }
    // ],
    // runtimeCaching: [
    //     {
    //         // these URLs are immutable based on content hash as computed by
    //         // webpack so just use cacheFirst which only fetches them the
    //         // first time
    //         urlPattern: /web\/dist\/images\/.*/,
    //         handler: 'CacheFirst'
    //     }
    // ],
    modifyURLPrefix: {
        // Remove a '/dist' prefix from the URLs:
        '/dist/public': ''
    }
};