johnpyeauctions.user.js

// ==UserScript==
// @name         John Pye Auctions Total Calculator
// @namespace    http://tampermonkey.net/
// @version      2026-06-18_12-06
// @description  Calculates the total to pay on John Pye Auctions site
// @author       Pedro Lamas
// @match        https://www.johnpyeauctions.co.uk/Event/LotDetails/*
// @match        https://www.johnpyeauctions.co.uk/Events/Details/*
// @match        https://www.johnpyeauctions.co.uk/Browse*
// @match        https://www.johnpyeauctions.co.uk/Account/Bidding/Watching
// @icon         https://www.google.com/s2/favicons?sz=64&domain=johnpyeauctions.co.uk
// @grant        GM_getValue
// @grant        GM_setValue
// ==/UserScript==

(function () {
    'use strict';

    const CACHE_KEY = 'jpa_shipping_cache';
    const CACHE_TTL_MS = 10 * 24 * 60 * 60 * 1000; // 10 days

    const now = Date.now();

    const getValue = (x) => +(x.replace(/,/g, ''))

    const getShippingValue = (x) => getValue(/[$€£]((\d+,)*\d+\.\d+)/.exec(x.innerText)[1]);

    const formatNumber = (x) => x.toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 })

    const getListingIdAndShippingCost = (listingElement) => {
        const listingId = listingElement.getAttribute('data-listingid');
        const shippingTableElement = listingElement.getElementsByClassName("shipping-table")[0];
        const vatOnlyOnBuyersPremium = /VAT +Only +Payable +on +(the +)?Buyer\'?s +Premium/i
            .test(document.title);

        if (shippingTableElement) {
            const shippingCost = getShippingValue(shippingTableElement);

            const cacheItem = cache[listingId] = {
                value: shippingCost,
                timestamp: now
            };

            if (vatOnlyOnBuyersPremium) {
                cacheItem.vatOnlyOnBuyersPremium = true;
            }

            return {
                listingId,
                shippingCost,
                vatOnlyOnBuyersPremium,
                shippingSource: 'table'
            };
        }

        const cacheItem = cache[listingId];

        if (cacheItem) {
            return {
                listingId,
                shippingCost: cacheItem.value,
                vatOnlyOnBuyersPremium: cacheItem.vatOnlyOnBuyersPremium,
                shippingSource: 'cache'
            }
        }

        return {
            listingId,
            shippingCost: 7.99,
            vatOnlyOnBuyersPremium: false,
            shippingSource: 'fallback'
        };
    }

    const updateObservedElementTotal = (element, calculateTotal, shippingSource) => {
        const indicator = shippingSource === 'fallback'
            ? '🔴'
            : shippingSource === 'cache'
                ? '🟡'
                : '🟢'
        element.nextElementSibling.innerText = `${indicator}${element.previousSibling.textContent.trim()}${calculateTotal(getValue(element.innerText))}`;
    };

    const rawCache = GM_getValue(CACHE_KEY, {});
    const cache = Object.fromEntries(
        Object.entries(rawCache).filter(([, entry]) => now - entry.timestamp <= CACHE_TTL_MS)
    )

    const listingElements = document.querySelectorAll('div[data-listingid]');

    for (const listingElement of listingElements) {
        const { listingId, shippingCost, shippingSource, vatOnlyOnBuyersPremium } = getListingIdAndShippingCost(listingElement);

        const calculateTotal = vatOnlyOnBuyersPremium
            ? (value) => formatNumber(value + (value * 0.25 + shippingCost) * 1.2)
            : (value) => formatNumber((value * 1.25 + shippingCost) * 1.2);

        const bidAmountElement = document.getElementById("BidAmount");

        if (bidAmountElement && bidAmountElement.type != "hidden") {
            const updateBidAmountTotal = () => {
                bidAmountElement.nextElementSibling.innerText = calculateTotal(getValue(bidAmountElement.value));
            }

            bidAmountElement.oninput = updateBidAmountTotal;

            updateBidAmountTotal();
        }

        const elementsToObserve = listingElement.querySelectorAll('span.NumberPart');

        const observer = new MutationObserver(() => {
            for (const element of elementsToObserve) {
                updateObservedElementTotal(element, calculateTotal, shippingSource);
            }
        });

        for (const element of elementsToObserve) {
            element.insertAdjacentHTML("afterEnd", "<span></span>");
            updateObservedElementTotal(element, calculateTotal, shippingSource);
            observer.observe(element, { childList: true });
        }
    }

    GM_setValue(CACHE_KEY, cache);
})();