bandcamp-purchases-export.js

// @name Bandcamp Purchase Export
// @description  Allows to export Bandcamp purchases as a CSV file.

const main = async () => {
  const currentRates = rates("CHF");
  await loadAllPurchases();

  const allPurchases = purchases(await currentRates);
  if (allPurchases.length == 0) {
    alert(
      "No purchase has been found on the current page!\nEnsure you're on Bandcamp's purchases page, before running this bookmarklet.",
    );
    return;
  }

  download("bandcamp-purchases.csv", convertToCSV(allPurchases));
};

const loadAllPurchases = async (timeoutMS = 1000) => {
  const allButton = document.querySelector(".view-all-button");
  if (allButton != null) {
    allButton.click();
    await sleep(timeoutMS);
  }

  // scroll to bottom of page to trigger loading of additional purchases
  while (window.innerHeight + window.scrollY < document.body.offsetHeight - 2) {
    window.scrollTo(0, document.body.scrollHeight, { behavior: "smooth" });
    await sleep(timeoutMS);
  }
};

const purchases = (rates) =>
  [...document.querySelectorAll(".purchases-item")].map((e) => {
    const s = e
      .querySelector(".purchases-item-total strong:last-child")
      .innerText.split(" ");
    const purchaseDate = new Date(
      e.querySelector(".purchases-item-date").innerText.trim(),
    );

    const currency = s[1].trim();
    const amount = parseFloat(s[0].replace(/[^\d.-]/g, ""));

    return {
      date: purchaseDate.toLocaleDateString("de-CH"),
      currency: rates.base,
      amount:
        currency == rates.base
          ? amount
          : (amount * rates.rates[currency]).toFixed(2),
      originalCurrency: currency,
      originalAmount: amount,
      title: e.querySelector(".purchases-item-title").innerText.trim(),
    };
  });

const convertToCSV = (elements, separator = ",") =>
  [Object.keys(elements[0]), ...elements.map((line) => Object.values(line))]
    .map((line) =>
      line
        .map((element) => {
          if (typeof element !== "string") return element;
          return `"` + element.replaceAll(`"`, `""`) + `"`;
        })
        .join(separator),
    )
    .join("\n");

const download = (filename, text) => {
  const element = document.createElement("a");
  element.setAttribute(
    "href",
    "data:text/csv;charset=utf-8," + encodeURIComponent(text),
  );
  element.setAttribute("download", filename);

  element.style.display = "none";
  document.body.appendChild(element);

  element.click();

  document.body.removeChild(element);
};

const rates = async (base) => {
  const resp = await fetch(`https://api.frankfurter.app/latest?from=${base}`);
  return await resp.json();
};

const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

main();