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Diffstat (limited to 'src/download-playlist.js')
-rw-r--r-- | src/download-playlist.js | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/download-playlist.js b/src/download-playlist.js new file mode 100644 index 0000000..bb6b86c --- /dev/null +++ b/src/download-playlist.js @@ -0,0 +1,155 @@ +'use strict' + +const fs = require('fs') +const downloaders = require('./downloaders') +const path = require('path') +const processArgv = require('./process-argv') +const sanitize = require('sanitize-filename') + +const { + isGroup, isTrack +} = require('./playlist-utils') + +const { promisify } = require('util') + +const access = promisify(fs.access) +const mkdir = promisify(fs.mkdir) +const readFile = promisify(fs.readFile) +const readdir = promisify(fs.readdir) +const stat = promisify(fs.stat) +const writeFile = promisify(fs.writeFile) +const ncp = promisify(require('ncp').ncp) + +// It's typically bad to attempt to download or copy a million files at once, +// so we create a "promise delayer" that forces only several promises to run at +// at one time. +let delayPromise +{ + const INTERVAL = 50 + const MAX = 5 + + let active = 0 + + let queue = [] + + delayPromise = function(promiseMaker) { + return new Promise((resolve, reject) => { + queue.push([promiseMaker, resolve, reject]) + }) + } + + setInterval(async () => { + if (active >= MAX) { + return + } + + const top = queue.pop() + + if (top) { + const [ promiseMaker, resolve, reject ] = top + + active++ + + console.log('Going - queue: ' + queue.length) + + try { + resolve(await promiseMaker()) + } catch(err) { + reject(err) + } + + active-- + } + }, INTERVAL) +} + +async function downloadCrawl(playlist, downloader, outPath = './out/') { + // If the output folder doesn't exist, we should create it. + let doesExist = true + try { + doesExist = (await stat(outPath)).isDirectory() + } catch(err) { + doesExist = false + } + + if (!doesExist) { + await mkdir(outPath) + } + + return Promise.all(playlist.map(async (item) => { + if (isGroup(item)) { + // TODO: Not sure if this is the best way to pick the next out dir. + const out = outPath + sanitize(item[0]) + '/' + + return [item[0], await downloadCrawl(item[1], downloader, out)] + } else if (isTrack(item)) { + // TODO: How should we deal with songs that don't have an extension? + const ext = path.extname(item[1]) + const base = path.basename(item[1], ext) + const out = outPath + base + ext + + // If we've already downloaded a file at some point in previous time, + // there's no need to download it again! + // + // Since we can't guarantee the extension name of the file, we only + // compare bases. + // + // TODO: This probably doesn't work well with things like the YouTube + // downloader. + const items = await readdir(outPath) + const match = items.find(x => path.basename(x, path.extname(x)) === base) + if (match) { + console.log(`\x1b[32;2mAlready downloaded: ${out}\x1b[0m`) + return [item[0], outPath + match] + } + + console.log(`\x1b[2mDownloading: ${item[0]} - ${item[1]}\x1b[0m`) + + const downloadFile = await delayPromise(() => downloader(item[1])) + // console.log(downloadFile, path.resolve(out)) + + try { + await delayPromise(() => ncp(downloadFile, path.resolve(out))) + console.log(`\x1b[32;1mDownloaded: ${out}\x1b[0m`) + return [item[0], out] + } catch(err) { + console.error(`\x1b[31mFailed: ${out}\x1b[0m`) + console.error(err) + return false + } + } + })).then(p => p.filter(Boolean)) +} + +async function main() { + // TODO: Implement command line stuff here + + if (process.argv.length === 2) { + console.error('Usage: download-playlist <playlistFile> [opts]') + return + } + + const playlist = JSON.parse(await readFile(process.argv[2])) + + let downloaderType = 'http' + + processArgv(process.argv.slice(3), { + '-downloader': util => { + downloaderType = util.nextArg() + } + }) + + const dl = downloaders.makePowerfulDownloader( + downloaders.getDownloader(downloaderType) + ) + + const outPlaylist = await downloadCrawl(playlist, dl) + + await writeFile('out/playlist.json', JSON.stringify(outPlaylist, null, 2)) + + console.log('Done - saved playlist to out/playlist.json.') + process.exit(0) +} + +main() + .catch(err => console.error(err)) |