Does a tally of amount spent, orders and items ordered on amazon. To be executed on any amazon order history page.

amazon_total_tally.js

function fetchPage(link, callback) {
  var xhr = new XMLHttpRequest();

  xhr.open('get', link);
  xhr.onreadystatechange = function () {
    if (xhr.readyState == 4 && xhr.status == 200)
      callback.call(xhr, xhr);
  };

  xhr.send();
}

function makeDoc(docString) {
  var doc = document.implementation.createHTMLDocument();

  doc.documentElement.innerHTML = docString;

  return doc;
}

function walkYears(years, callback, result) {
  if (typeof result == 'undefined')
    result = {
      'years': {},
      'items': 0,
      'orders': 0,
      'total': 0
    };

  if (years.length > 0) {
    var year = years.pop(0);
    var link = '/gp/your-account/order-history?opt=ab&digitalOrders=1&unifiedOrders=1&orderFilter=year-' + year;

    console.log("Now fetching year " + year + "...");
    fetchPage(link, function (xhr) {
      var page = makeDoc(xhr.response);
      var pages = [];

      [].forEach.call(
        page.querySelectorAll('.a-pagination .a-normal a'),
        function (a) {
          pages.push(a.getAttribute('href'));
        }
      );

      walkPages(pages, function (total, items, orders) {
        result.years[year] = this;
        result.total += total;
        result.items += items;
        result.orders += orders;

        walkYears(years, callback, result);
      }, getPageTotal(page), getPageItems(page), getTotalOrders(page));
    });
  } else {
    callback.call(result, result);
  }
}

function walkPages(pages, callback, total = 0, items = 0, orders = undefined) {
  if (pages.length > 0) {
    var page = pages.pop(0);

    fetchPage(page, function (xhr) {
      var doc = makeDoc(xhr.response);

      total += getPageTotal(doc);
      items += getPageItems(doc);
      if (typeof orders === 'undefined') orders = getTotalOrders(doc);

      walkPages(pages, callback, total, items, orders);
    });
  } else {
    callback.call({'total': total, 'items': items, 'orders': orders}, total, items, orders);
  }
}

function getPageTotal(page) {
  var total = 0;

  [].forEach.call(
    page.querySelectorAll('.a-color-price'),
    function (a) {
      total += +(a.textContent.replace(',', '.').replace(/^[^\d]+/, ''));
    }
  );

  return total;
}

function getPageItems(page) {
  return page.querySelectorAll('.a-color-price').length;
}

function getTotalOrders(page) {
  return +(page.querySelector('span.num-orders').textContent.replace(/^(\d+).*/, '$1'));
}

var years = [];
[].forEach.call(
  document.querySelectorAll('[id^=\'orderFilterEntry-year\']'),
  function (a) {
    years.push(a.getAttribute('value').match(/year-(\d{4})/)[1]);
  }
);

walkYears(years, function (result) {
  window.prices = result;
  console.log(result);
});