Improve downloading of discographies with the addition of an item count and total size.
// ==UserScript==
// @name Bandcamp Helper
// @namespace V.L
// @version 1.2.4
// @description Improve downloading of discographies with the addition of an item count and total size.
// @author Valerio Lyndon
// @match https://bandcamp.com/download*
// @match https://*.bandcamp.com/*
// @grant none
// @license AGPL-3.0-or-later
// ==/UserScript==
const debug = false;
const url = new URL(window.location);
function style( css ){
const element = document.createElement('style');
element.textContent = css;
document.documentElement.append(element);
}
class MassDownload {
constructor( ){
this.wrapper = document.createElement('li');
this.paragraph = document.createElement('p');
this.wrapper.append(this.paragraph);
document.querySelector('.download_list').prepend(this.wrapper);
this.dropdowns = document.querySelectorAll('select#format-type');
for( let dropdown of this.dropdowns ){
dropdown.addEventListener('change', ()=>{
this.calculateBytes();
});
}
this.calculateBytes();
}
calculateBytes( ){
let totalBytes = 0;
let totalItems = this.dropdowns.length;
for( let dropdown of this.dropdowns ){
dropdown.addEventListener('change', this.calculateBytes);
let selected = false;
for( let opt of dropdown.getElementsByTagName('option') ){
if( opt && opt.selected ){
selected = opt;
}
}
if( !selected ){
console.log('skipping 1 entry due to unknown format');
continue;
}
let match = selected.textContent.match(/([\d\.]+)([A-Za-z][bB])/);
let bytes = Number(match[1]);
let byteFormat = match[2];
switch( byteFormat.toUpperCase() ){
case 'TB':
bytes *= 1024;
case 'GB':
bytes *= 1024;
case 'MB':
bytes *= 1024;
case 'KB':
bytes *= 1024;
}
totalBytes += bytes;
}
function formatBytes( bytes ){
let format = 'B';
if( bytes / 1024 >= 1 ){
bytes /= 1024;
format = 'KiB';
}
if( bytes / 1024 >= 1 ){
bytes /= 1024;
format = 'MiB';
}
if( bytes / 1024 >= 1 ){
bytes /= 1024;
format = 'GiB';
}
if( bytes / 1024 >= 1 ){
bytes /= 1024;
format = 'TiB';
}
// round to two decimal places
bytes = Math.round(bytes*100) / 100;
return `${bytes}${format}`;
}
this.paragraph.textContent = `Total download size for ${totalItems} items of selected quality is ${formatBytes(totalBytes)}`;
}
}
class Discography {
constructor( ){
this.items = Array.from(document.getElementsByClassName('music-grid-item'));
style(`
.vl-price-tag {
position: absolute;
bottom: 4px;
right: 4px;
padding: 2px;
background: rgba(0,0,0,0.7);
border-radius: 2px;
color: #fff;
font-weight: bold;
text-shadow: 0 0 5px rgb(0,0,0,0.7);
}
`);
for( let item of this.items ){
const cached = window.sessionStorage.getItem(`price-${item.dataset.itemId}`);
let tag = document.createElement('span');
tag.className = `vl-price-tag`;
tag.textContent = cached !== null ? cached : '...';
item.getElementsByClassName('art')[0].append(tag);
if( cached === null ){
item.addEventListener('mouseenter', ()=>{ this.assignPrice(item) });
}
}
const grid = document.getElementById('music-grid');
grid.style.marginTop = '15px';
const loadAllBtn = document.createElement('a');
loadAllBtn.href = "#";
loadAllBtn.textContent = 'Load all prices.';
loadAllBtn.addEventListener('click', ()=>{ this.lazyLoadItems(0); });
grid.insertAdjacentElement('beforebegin', loadAllBtn);
const clearCacheBtn = document.createElement('a');
clearCacheBtn.href = "#";
clearCacheBtn.textContent = 'Clear price cache.';
clearCacheBtn.addEventListener('click', ()=>{ this.clearCache(); });
if( debug ){
grid.insertAdjacentElement('beforebegin', clearCacheBtn);
}
}
async lazyLoadItems( index ){
const item = this.items[index];
let wait = await this.assignPrice(item);
if( wait ){
const delay = 50*(1+(index*0.15));
setTimeout(()=>{
this.lazyLoadItems(index+1);
}, delay);
}
else {
this.lazyLoadItems(index+1);
}
}
async assignPrice( item ){
if( item.dataset.priced ){
return false;
}
const url = item.getElementsByTagName('a')[0].href;
const price = await this.getPrice(url);
let tag = item.querySelector('.vl-price-tag');
tag.textContent = price;
window.sessionStorage.setItem(`price-${item.dataset.itemId}`, price);
item.dataset.priced = true;
return true;
}
async getPrice( url ){
let price = 'unknown price';
let previousQuantity = 99999;
try {
const page = await fetch(url);
const text = await page.text();
const parser = new DOMParser();
const dom = parser.parseFromString(text, 'text/html');
const buyOptions = dom.querySelectorAll('.buyItem:not(.buyFullDiscography):not(.subscribeLink)');
if( buyOptions.length === 0 ){
price = 'not for sale';
}
for( let option of buyOptions ){
const link = option.querySelector('h4 .buy-link');
const detail = link ? link.nextElementSibling : null;
if( option.textContent.includes('Free') ){
price = 'free';
break;
}
else if( detail === null && dom.querySelector('.buyItem:not(.buyFullDiscography):not(.subscribeLink) .you-own-this') ){
price = 'owned';
break;
}
else if( detail && detail.childElementCount > 0 ){
const quantity = detail.querySelector('.base-text-color').textContent;
const rawQuantity = parseInt(quantity.replaceAll(/\D+/g,''));
if( rawQuantity < previousQuantity ){
previousQuantity = rawQuantity;
const currency = detail.querySelector('.secondaryText').textContent;
price = `${quantity} ${currency}`;
}
}
else if( detail && detail.className.includes('buyItemExtra') ){
price = 'name your price';
break;
}
}
}
catch {
false;
}
return price;
}
clearCache( ){
for( var i = 0; i < sessionStorage.length; i++ ){
const key = sessionStorage.key(i);
if( key.startsWith('price-') ){
sessionStorage.removeItem(key);
i--;
}
}
}
}
// Download pages
if( url.pathname.startsWith('/download') ){
document.querySelector('.bfd-download-dropdown').addEventListener('click', ()=>{ new MassDownload(); });
}
// Discographies
if( (url.hostname.match(/\./g) || []).length === 2 && /^\/$|^\/music\/?$/.test(url.pathname) ){
new Discography();
}