// Edit Invoice Logic
    const parseInvoiceButtonPayload = (btn) => {
        if (!btn || !btn.dataset || !btn.dataset.json) return {};
        try {
            return JSON.parse(btn.dataset.json);
        } catch (error) {
            console.warn('Failed to parse invoice payload from button data.', error);
            return {};
        }
    };

    const syncSelect2Value = (select) => {
        if (!select) return;
        if (select.classList.contains('select2') && window.jQuery && jQuery.fn && jQuery.fn.select2) {
            jQuery(select).trigger('change');
        }
    };

    const ensureSelectOption = (selectId, value, label = '') => {
        const select = document.getElementById(selectId);
        if (!select || value === null || value === undefined || String(value) === '') return;

        const alreadyExists = Array.from(select.options || []).some(option => option.value == String(value));
        if (!alreadyExists) {
            const option = document.createElement('option');
            option.value = String(value);
            option.textContent = label || String(value);
            select.appendChild(option);
        }
    };

    const setBlankSelectOptionLabel = (select, label = '---') => {
        if (!select) return;
        const emptyOption = Array.from(select.options || []).find(option => option.value === '');
        if (emptyOption) {
            emptyOption.textContent = label;
        }
    };

    const normalizeEditPaymentType = (paymentType) => {
        let normalized = String(paymentType || 'cash').toLowerCase().replace(/[\s-]+/g, '_');
        if (normalized === 'pos') normalized = 'cash';
        if (!['cash', 'card', 'bank_transfer', 'credit'].includes(normalized)) {
            normalized = 'cash';
        }
        return normalized;
    };

    const renderEditInvoiceItems = (items) => {
        const tableBody = document.getElementById('editInvoiceItemsTableBody');
        const grandTotalEl = document.getElementById('edit_grandTotal');
        const subtotalEl = document.getElementById('edit_subtotal');
        const totalVatEl = document.getElementById('edit_totalVat');

        if (!tableBody) return;
        tableBody.innerHTML = '';

        if (!Array.isArray(items) || items.length === 0) {
            if (typeof recalculate === 'function') {
                recalculate(tableBody, grandTotalEl, subtotalEl, totalVatEl);
            }
            return;
        }

        items.forEach(item => {
            addItemToTable({
                id: item.item_id || item.id,
                name_en: item.name_en || item.item_name_en || 'Item',
                name_ar: item.name_ar || item.item_name_ar || '',
                sku: item.sku || '',
                vat_rate: item.vat_rate || 0,
                stock_quantity: item.stock_quantity || 0
            }, tableBody, null, null, grandTotalEl, subtotalEl, totalVatEl, {
                quantity: item.quantity,
                unit_price: item.unit_price
            });
        });
    };

    const populateEditInvoiceModal = (data) => {
        if (!data) return;

        const invoiceIdInput = document.getElementById('edit_invoice_id');
        const partySelect = document.getElementById('edit_customer_id');
        const invoiceDateInput = document.getElementById('edit_invoice_date');
        const dueDateInput = document.getElementById('edit_due_date');
        const paymentTypeSelect = document.getElementById('edit_payment_type');
        const statusSelect = document.getElementById('edit_status');
        const paidAmountInput = document.getElementById('edit_paid_amount');
        const paidAmountContainer = document.getElementById('editPaidAmountContainer');

        const partyId = data.customer_id ?? data.supplier_id ?? '';
        const partyLabel = data.party_name || data.customer_name || data.supplier_name || '';

        ensureSelectOption('edit_customer_id', partyId, partyLabel);

        if (invoiceIdInput) invoiceIdInput.value = data.id || '';
        if (partySelect) {
            setBlankSelectOptionLabel(partySelect, (partyId === '' && partyLabel) ? partyLabel : '---');
            partySelect.value = partyId;
            syncSelect2Value(partySelect);
        }
        if (invoiceDateInput) invoiceDateInput.value = data.invoice_date || '';
        if (dueDateInput) dueDateInput.value = data.due_date || '';
        if (paymentTypeSelect) paymentTypeSelect.value = normalizeEditPaymentType(data.payment_type);
        if (statusSelect) statusSelect.value = data.status || 'unpaid';
        if (paidAmountInput) paidAmountInput.value = parseFloat(data.paid_amount || 0).toFixed(3);
        if (paidAmountContainer) {
            paidAmountContainer.style.display = data.status === 'partially_paid' ? 'block' : 'none';
        }

        renderEditInvoiceItems(data.items || []);
    };

    document.querySelectorAll('.edit-invoice-btn').forEach(btn => {
        btn.addEventListener('click', async function() {
            const fallbackData = parseInvoiceButtonPayload(this);
            const invoiceId = this.dataset.id || fallbackData.id || '';
            const type = this.dataset.type || fallbackData.type || invoiceType || 'sale';
            const tableBody = document.getElementById('editInvoiceItemsTableBody');

            if (Object.keys(fallbackData).length > 0) {
                populateEditInvoiceModal(fallbackData);
            } else if (tableBody) {
                tableBody.innerHTML = '<tr><td colspan="6" class="text-center"><div class="spinner-border spinner-border-sm text-primary"></div> <span data-en="Loading invoice..." data-ar="جاري تحميل الفاتورة...">Loading invoice...</span></td></tr>';
            }

            if (!invoiceId) return;

            try {
                const resp = await fetch(`index.php?action=get_invoice_details&invoice_id=${encodeURIComponent(invoiceId)}&type=${encodeURIComponent(type)}`);
                const data = await resp.json();

                if (data && data.id) {
                    populateEditInvoiceModal(data);
                } else if (data && data.error) {
                    throw new Error(data.error);
                }
            } catch (error) {
                console.error('Failed to load invoice details for edit modal.', error);
                if (window.Swal) {
                    Swal.fire('Error', 'Failed to load invoice details', 'error');
                }
            }
        });
    });

    // View and Print Invoice Logic