const fs = require('fs');

const path = require('path');

const fetch = require('node-fetch');

const async = require('async');

const createGitHubHeaders = require('./createGitHubHeaders');

const { createMarkdownParser } = require('./apiDocsTransformUtils');

const { apiReleaseContents } = require('../apiUrls');

const { apiPath } = require('../pathPrefixes');

const ignoredFiles = ['index.md', 'README.md'];

const getFileName = file => file.name.replace('.md', '');

const filterOutInvalidFiles = file =>

!ignoredFiles.includes(file.name) && file.name.endsWith('.md');

async function getApiDocsData(releaseVersions, callback) {

// This creates an asynchronous queue that fetches the directory listing of the

// /doc/api/ directory on the Node.js repository with the contents of a specific version (Git Tag)

// Then the worker creates a new queue that dispatches a list of files (their metadata and the release version)

const apiDownloadListQueue = async.queue((releaseData, cb) => {

const pushToDocsQueue = files => {

const markdownFiles = files.filter(filterOutInvalidFiles);

const navigationEntry = {

version: releaseData.version,

items: [],

};

const currentVersionPath = path.resolve(

__dirname,

`../content${apiPath}${releaseData.version}/`

);

// Creates the API version directory if it doesn't exist

if (!fs.existsSync(currentVersionPath)) {

fs.mkdirSync(currentVersionPath);

}

// Here we create a new queue to parse each one of the Markdown files

// We first iterate through the contents with mostly Regex and string interpolation instead of AST

// As we don't want to overcomplicate things. There are definitel drawbacks of using ReGeX

const apiDocsParser = async.queue((file, dCb) => {

// eslint-disable-next-line no-console

console.log(`Parsing: ${file.name}@${releaseData.version}`);

const parseMarkdownCallback = contents => {

// We create a Markdown Parser that will be responsible of parsing the file

// The parser includes utilities to create a Frontmatter, replace the YAML metadata

// with JSX Components, fix URL links, update the Headings levels and many other small improvements

const { parseMarkdown, getNavigationEntries } = createMarkdownParser(

contents,

{

name: getFileName(file),

version: releaseData.version,

fullVersion: releaseData.fullVersion,

downloadUrl: file.download_url,

}

);

const resultingContent = parseMarkdown();

// Our Navigation Sidebar is generated from within the Markdown Parser

// And it has a format that matches the <NavigationItem> type

navigationEntry.items.push(...getNavigationEntries());

const currentFilePath = path.resolve(

currentVersionPath,

// Creates the file path for English version of the file

`${getFileName(file)}.en.md`

);

// Creates the File within the File System

fs.writeFile(

currentFilePath,

resultingContent,

{ encoding: 'utf8' },

dCb

);

};

fetch(file.download_url)

.then(response => response.text())

.then(contents => parseMarkdownCallback(contents));

}, 8);

// Add files to be Downloaded and Parsed to Text

apiDocsParser.push([...markdownFiles]);

// We finished processing all files for this release

apiDocsParser.drain(() => {

const navigationDataPath = path.resolve(

currentVersionPath,

'navigation.json'

);

fs.writeFile(

navigationDataPath,

// Stringifies and Pretty-Prints the JSON

JSON.stringify(navigationEntry, null, 2),

cb

);

});

};

// This fetches a JSON containing the metadata of the files within the API Folder

// @see https://docs.github.com/en/rest/repos/contents#get-repository-content

fetch(apiReleaseContents(releaseData.fullVersion), createGitHubHeaders())

.then(response => response.json())

.then(files => pushToDocsQueue(files));

}, 2);

// Retrieves all the Lists of the Documentation files for that Node.js version

apiDownloadListQueue.push(...releaseVersions);

// After the whole queue ends we call the callback with our Navigation entries

apiDownloadListQueue.drain(() => callback());

}

module.exports = getApiDocsData;