(function() {
    'use strict';

    // Ensure EbayParser is loaded
    if (typeof EbayParser === 'undefined') {
        console.error("Ebay Cost/TB: CRITICAL - ebay_core.js was not loaded. @require path might be incorrect.");
        return;
    }

    const DEBUG_MODE = true; // Set to true to run unit tests on load

    // --- Global Variables (UI/State specific) ---
    let originalOrderMap = new Map();
    let isSorted = false;
    let mainListParentElement = null;
    let observer = null;
    let observerTargetNode = null;
    const observerConfig = { childList: true, subtree: true };
    let processTimer = null;

    // --- UI & DOM Functions ---
    function addStyles() { /* ... (Keep existing addStyles function) ... */
        const css = `
            li.s-item, li.srp-results__item {
                position: relative !important; overflow: visible !important; padding-bottom: 5px !important;
            }
            .cost-per-tb-info {
                position: absolute; right: 10px; top: 40px;
                background-color: rgba(0, 100, 0, 0.85); color: white;
                padding: 4px 8px; border-radius: 5px; z-index: 1000;
                font-size: 0.9em; font-weight: bold; text-align: center;
                box-shadow: 1px 1px 3px rgba(0,0,0,0.5); transition: transform 0.2s ease;
            }
            .cost-per-tb-info:hover { transform: scale(1.05); }
            .cost-per-tb-info small.check-desc-note { color: #FFD700; font-weight: bold; }
            #costPerTbSortControl {
                display: inline-block; margin-left: 20px; padding: 8px 12px;
                border: 1px solid #ccc; border-radius: 4px; background-color: #f0f0f0;
                vertical-align: middle; color: #333; cursor: pointer; font-size: 14px;
            }
            #costPerTbSortControl:hover { background-color: #e9e9e9; }
            #costPerTbSortControl input[type="checkbox"] { margin-right: 8px; vertical-align: middle; }
            #costPerTbSortControl label { cursor: pointer; vertical-align: middle; color: #333; }
        `;
        try {
            const styleSheet = document.createElement("style");
            styleSheet.type = "text/css"; styleSheet.innerText = css;
            document.head.appendChild(styleSheet);
        } catch (e) { console.error("Ebay Cost/TB: Failed to add styles:", e); }
    }
    function getItemSelector() { /* ... (Keep existing getItemSelector function) ... */
        if (document.querySelector('li.s-item')) return 'li.s-item';
        if (document.querySelector('li.srp-results__item')) return 'li.srp-results__item';
        if (document.querySelector('div.s-item')) return 'div.s-item';
        return 'li[class*="s-item"], div[class*="s-item"]';
    }
    function getMainListParent() { /* ... (Keep existing getMainListParent function) ... */
        if (mainListParentElement && document.body.contains(mainListParentElement)) {
            return mainListParentElement;
        }
        mainListParentElement = document.querySelector('ul.srp-results, div#srp-river-results ul.srp-results');
        if (!mainListParentElement) {
            mainListParentElement = document.querySelector('div#srp-river-results ul');
        }
        if (!mainListParentElement) {
            const itemSelector = getItemSelector();
            const containers = document.querySelectorAll('ul, div');
            for (const container of containers) {
                if (container.querySelector(itemSelector)) {
                    const directChildren = Array.from(container.children).filter(child => child.matches(itemSelector));
                    if (directChildren.length > 1) {
                         mainListParentElement = container;
                         break;
                    }
                }
            }
        }
        return mainListParentElement;
    }
    function storeOriginalOrder(itemsNodeList) { /* ... (Keep existing storeOriginalOrder function) ... */
         if (originalOrderMap.size > 0 && itemsNodeList.length === originalOrderMap.size) {
            return;
        }
        originalOrderMap.clear();
        itemsNodeList.forEach((itemElement, index) => {
            let itemId = itemElement.id;
            if (!itemId) {
                const linkWithItemId = itemElement.querySelector('a[href*="/itm/"]');
                if (linkWithItemId && linkWithItemId.href) {
                    const match = linkWithItemId.href.match(/\/itm\/(\d+)/);
                    if (match && match[1]) {
                        itemId = "ebayitem_" + match[1]; itemElement.id = itemId;
                    }
                }
            }
            if (itemId && !originalOrderMap.has(itemId)) originalOrderMap.set(itemId, index);
        });
    }

    function processResults() {
        const parent = getMainListParent();
        if (!parent) return;

        const itemSelector = getItemSelector();
        const itemsOnPage = parent.querySelectorAll(itemSelector + ':not(.cost-per-tb-processed-flag)');

        itemsOnPage.forEach(item => {
            const titleElement = item.querySelector('.s-item__title, .srp-results__title');
            const priceElement = item.querySelector('.s-item__price, .srp-results__price');

            if (titleElement && priceElement) {
                const title = titleElement.innerText;
                const priceText = priceElement.innerText;
                // --- Use Core Parser ---
                const price = EbayParser.parsePrice(priceText);
                const parsedInfo = EbayParser.parseSizeAndQuantity(title);
                // -----------------------
                const totalTB = parsedInfo.totalTB;
                const needed_description_check = parsedInfo.needed_description_check;

                item.dataset.neededDescriptionCheck = String(needed_description_check);

                let displayElement = item.querySelector('.cost-per-tb-info');
                if (!displayElement) {
                    displayElement = document.createElement('div');
                    displayElement.className = 'cost-per-tb-info';
                    const imageContainer = item.querySelector('.s-item__image-section, .s-item__image');
                    if (imageContainer && imageContainer.parentNode) {
                        imageContainer.parentNode.style.position = 'relative';
                        imageContainer.parentNode.appendChild(displayElement);
                    } else { item.appendChild(displayElement); }
                }

                if (price !== null && totalTB > 0) {
                    const costPerTB = price / totalTB;
                    if (needed_description_check) {
                        item.dataset.costPerTb = '9999999';
                        displayElement.innerHTML = `$${costPerTB.toFixed(2)}*<span> / TB</span><br><small class="check-desc-note">(${totalTB.toFixed(2)} TB, Check Desc.)</small>`;
                    } else {
                        item.dataset.costPerTb = costPerTB;
                        displayElement.innerHTML = `$${costPerTB.toFixed(2)}<span> / TB</span><br><small>(${totalTB.toFixed(2)} TB)</small>`;
                    }
                } else {
                    item.dataset.costPerTb = '9999999';
                    let ambiguousNote = needed_description_check || (parsedInfo.quantity > 1 && totalTB === 0) ? "(Check Desc.)" : "(Details N/A)";
                    let tbDisplay = totalTB > 0 ? `(${totalTB.toFixed(2)} TB, Price N/A)` : ambiguousNote;
                    if (totalTB === 0) tbDisplay = ambiguousNote;
                    displayElement.innerHTML = `<i>Details unclear</i><br><small class="check-desc-note">${tbDisplay}</small>`;
                }

                if(displayElement.querySelector('span')) displayElement.querySelector('span').style.fontSize = '0.8em';
                if(displayElement.querySelector('small')) displayElement.querySelector('small').style.fontSize = '0.7em';

            } else { item.dataset.costPerTb = '9999999'; }
            item.classList.add('cost-per-tb-processed-flag');
            item.dataset.costPerTbProcessed = 'true';
        });

        const allItems = parent.querySelectorAll(itemSelector);
        if (originalOrderMap.size === 0 || Math.abs(originalOrderMap.size - allItems.length) > 5) {
            if (allItems.length > 0) storeOriginalOrder(allItems);
        }
        if (isSorted) sortResults();
    }

    function sortResults() { /* ... (Keep existing sortResults function) ... */
        const parent = getMainListParent(); if (!parent) return;
        const itemSelector = getItemSelector(); let itemsArray = Array.from(parent.querySelectorAll(itemSelector));
        if (originalOrderMap.size === 0 && itemsArray.length > 0) storeOriginalOrder(itemsArray);
        itemsArray.sort((a, b) => parseFloat(a.dataset.costPerTb || '9999999') - parseFloat(b.dataset.costPerTb || '9999999'));
        if (observer) observer.disconnect(); itemsArray.forEach(item => parent.appendChild(item));
        if (observer && observerTargetNode) observer.observe(observerTargetNode, observerConfig);
    }
    function restoreOriginalOrder() { /* ... (Keep existing restoreOriginalOrder function) ... */
        const parent = getMainListParent(); if (!parent) return; if (originalOrderMap.size === 0) return;
        let itemsToReorder = [];
        originalOrderMap.forEach((originalIndex, itemId) => {
            const itemElement = document.getElementById(itemId) || parent.querySelector(`[id="${itemId}"]`);
            if (itemElement && parent.contains(itemElement)) itemsToReorder.push({ element: itemElement, originalIndex: originalIndex });
        });
        const itemSelector = getItemSelector(); const currentItemsInDOM = parent.querySelectorAll(itemSelector); let newItemsCount = 0;
        currentItemsInDOM.forEach(domItem => {
            if (domItem.id && !originalOrderMap.has(domItem.id)) itemsToReorder.push({ element: domItem, originalIndex: 900000 + newItemsCount++ });
        });
        itemsToReorder.sort((a, b) => a.originalIndex - b.originalIndex);
        if (observer) observer.disconnect(); itemsToReorder.forEach(entry => parent.appendChild(entry.element));
        if (observer && observerTargetNode) observer.observe(observerTargetNode, observerConfig);
    }
    function handleSortToggle(event) { /* ... (Keep existing handleSortToggle function) ... */
        isSorted = event.currentTarget.checked;
        if (isSorted) sortResults(); else restoreOriginalOrder();
    }
    function addSortControl() { /* ... (Keep existing addSortControl function) ... */
        let controlsContainer = document.querySelector('.srp-controls__sort- σήμερα') || document.querySelector('.srp-controls__sort') || document.querySelector('div[class*="srp-controls__sort"]');
        if (!controlsContainer) controlsContainer = document.querySelector('.srp-sort, .srp-controls');
        if (!controlsContainer || document.getElementById('costPerTbSortControlWrapper')) return;
        const controlWrapper = document.createElement('div'); controlWrapper.id = 'costPerTbSortControlWrapper'; controlWrapper.style.display = 'inline-block'; controlWrapper.style.marginLeft = '20px'; controlWrapper.style.verticalAlign = 'middle';
        const controlDiv = document.createElement('div'); controlDiv.id = 'costPerTbSortControl';
        const checkbox = document.createElement('input'); checkbox.type = 'checkbox'; checkbox.id = 'costPerTbSortCheckbox'; checkbox.checked = isSorted; checkbox.style.verticalAlign = 'middle';
        const label = document.createElement('label'); label.htmlFor = 'costPerTbSortCheckbox'; label.innerText = 'Sort by $/TB'; label.style.verticalAlign = 'middle'; label.style.marginLeft = '5px';
        controlDiv.appendChild(checkbox); controlDiv.appendChild(label); controlWrapper.appendChild(controlDiv);
        controlDiv.addEventListener('click', (e) => { if (e.target !== checkbox) { checkbox.checked = !checkbox.checked; checkbox.dispatchEvent(new Event('change', { bubbles: true })); } });
        checkbox.addEventListener('change', handleSortToggle);
        if (controlsContainer.nextSibling) controlsContainer.parentNode.insertBefore(controlWrapper, controlsContainer.nextSibling);
        else controlsContainer.parentNode.appendChild(controlWrapper);
    }
    function setupObserver() { /* ... (Keep existing setupObserver function but without needsProcessing/callback logic, just call process/addControl) ... */
        observerTargetNode = getMainListParent() || document.body; if (!observerTargetNode) return;
        const itemSelector = getItemSelector();
        const callback = function(mutationsList, obs) {
            let needsProcessing = false;
            for(const mutation of mutationsList) {
                if (mutation.type === 'childList') {
                     if (mutation.addedNodes.length > 0) {
                        mutation.addedNodes.forEach(node => {
                            if (node.nodeType === 1 && !node.classList.contains('cost-per-tb-info') && (node.matches && node.matches(itemSelector) || (node.querySelector && node.querySelector(itemSelector)))) {
                                needsProcessing = true;
                            }
                        });
                     }
                }
                if (!document.getElementById('costPerTbSortControlWrapper') && document.querySelector('.srp-controls__sort')) {
                    needsProcessing = true;
                }
            }
            if (needsProcessing) {
                 clearTimeout(processTimer);
                 processTimer = setTimeout(() => { processResults(); addSortControl(); }, 750);
            }
        };
        if (observer) observer.disconnect(); observer = new MutationObserver(callback);
        observer.observe(observerTargetNode, observerConfig);
    }

    // --- Main Execution ---
    function init() {
        console.log("Ebay Cost/TB V2.7 (Refactored) starting...");
        if (DEBUG_MODE) {
            // --- Use Core Unit Tests ---
            EbayParser.runUnitTests();
            // --------------------------
        }
        addStyles();
        setTimeout(() => {
            processResults();
            addSortControl();
            setupObserver();
        }, 2000);
    }

    init(); // Run-at document-idle handles load state

})();