<?php
// Shared Sales/Purchases data loading extracted from index.php to reduce risk when editing this module.
        $type = ($page === 'sales') ? 'sale' : 'purchase';
        $table = ($type === 'purchase') ? 'purchases' : 'invoices';
        $cust_supplier_col = ($type === 'purchase') ? 'supplier_id' : 'customer_id';
        $cust_supplier_table = ($type === 'purchase') ? 'suppliers' : 'customers';
        
        $where = ["1=1"];
        $params = [];
        
        $referenceSearchColumn = db_column_exists($table, 'transaction_no') ? 'transaction_no' : null;
        if (!empty($_GET['search'])) {
            $s = trim((string)$_GET['search']);
            $clean_id = preg_replace('/[^0-9]/', '', $s);
            $searchClauses = ["CAST(v.id AS CHAR) LIKE ?", "c.name LIKE ?"];
            $searchParams = ["%$s%", "%$s%"];

            if ($referenceSearchColumn !== null) {
                $searchClauses[] = "v.$referenceSearchColumn LIKE ?";
                $searchParams[] = "%$s%";
            }

            if ($clean_id !== '') {
                $searchClauses[] = "v.id = ?";
                $searchParams[] = $clean_id;
            }

            $where[] = '(' . implode(' OR ', $searchClauses) . ')';
            $params = array_merge($params, $searchParams);
        }
        
        if (!empty($_GET['customer_id'])) {
            $where[] = "v.$cust_supplier_col = ?";
            $params[] = $_GET['customer_id'];
        }
        
        if (!empty($_GET['start_date'])) {
            $where[] = "v.invoice_date >= ?";
            $params[] = $_GET['start_date'];
        }
        
        if (!empty($_GET['end_date'])) {
            $where[] = "v.invoice_date <= ?";
            $params[] = $_GET['end_date'];
        }
        
        $tableHasOutlet = db_column_exists($table, 'outlet_id');
        $oid = current_outlet_id();
        if ($tableHasOutlet && $oid !== -1) {
            $where[] = "(v.outlet_id = ? OR v.outlet_id IS NULL)";
            $params[] = $oid;
        }
        
        $whereSql = implode(" AND ", $where);
        
        $countStmt = db()->prepare("SELECT COUNT(*) FROM $table v LEFT JOIN $cust_supplier_table c ON v.$cust_supplier_col = c.id WHERE $whereSql");
        $countStmt->execute($params);
        $total_records = (int)$countStmt->fetchColumn();
        $data['total_pages'] = ceil($total_records / $limit);
        $data['current_page'] = $page_num;

        $customerTaxColumn = entity_tax_column($cust_supplier_table);
        $customerTaxSelect = $customerTaxColumn !== null ? "c.$customerTaxColumn" : "''";
        $outletSelectSql = "'' AS outlet_name";
        $outletJoinSql = '';
        if ($tableHasOutlet && db_table_exists('outlets')) {
            $outletSelectSql = "o.name AS outlet_name";
            $outletJoinSql = "LEFT JOIN outlets o ON v.outlet_id = o.id";
        }
        $stmt = db()->prepare("SELECT v.*, c.name as customer_name, $customerTaxSelect as customer_tax_id, c.phone as customer_phone, $outletSelectSql 
                               FROM $table v 
                               LEFT JOIN $cust_supplier_table c ON v.$cust_supplier_col = c.id 
                               $outletJoinSql
                               WHERE $whereSql 
                               ORDER BY v.id DESC LIMIT $limit OFFSET $offset");
        $stmt->execute($params);
        $data['invoices'] = $stmt->fetchAll();
        $documentPrefix = ($type === 'purchase') ? 'PUR' : 'INV';
        foreach ($data['invoices'] as &$inv) {
            $inv['due_date'] = $inv['due_date'] ?? null;
            $transactionNo = trim((string)($inv['transaction_no'] ?? ''));
            $partyFallback = ($type === 'sale' && !empty($inv['is_pos'])) ? 'Walk-in Customer' : '---';
            $normalizedPaymentType = strtolower(str_replace([' ', '-'], '_', (string)($inv['payment_type'] ?? 'cash')));
            $paymentTypeLabel = 'Cash';

            if ($normalizedPaymentType === 'bank_transfer') {
                $paymentTypeLabel = 'Bank Transfer';
            } elseif (in_array($normalizedPaymentType, ['card', 'credit_card'], true)) {
                $paymentTypeLabel = 'Card';
            } elseif ($normalizedPaymentType === 'credit') {
                $paymentTypeLabel = 'Credit';
            }

            $inv['party_name'] = trim((string)($inv['customer_name'] ?? '')) !== '' ? (string)$inv['customer_name'] : $partyFallback;
            $inv['document_no'] = ($type === 'sale' && $transactionNo !== '') ? $transactionNo : $documentPrefix . '-' . str_pad((string)$inv['id'], 5, '0', STR_PAD_LEFT);
            $inv['type'] = $type;
            $inv['payment_type'] = $normalizedPaymentType;
            $inv['payment_type_label'] = $paymentTypeLabel;
            $inv['total_with_vat'] = (float)($inv['total_with_vat'] ?? (($inv['total_amount'] ?? 0) + ($inv['vat_amount'] ?? 0)));
            $inv['paid_amount'] = (float)($inv['paid_amount'] ?? 0);
            $inv['balance_amount'] = max($inv['total_with_vat'] - $inv['paid_amount'], 0);
            $inv['total_in_words'] = numberToWordsOMR($inv['total_with_vat']);

            if ($type === 'sale') {
                $item_stmt = db()->prepare("SELECT ii.*, i.name_en, i.name_ar, i.vat_rate FROM invoice_items ii LEFT JOIN stock_items i ON ii.item_id = i.id WHERE ii.invoice_id = ?");
                $item_stmt->execute([$inv['id']]);
                $inv['items'] = $item_stmt->fetchAll(PDO::FETCH_ASSOC);
            } else {
                $item_stmt = db()->prepare("SELECT pi.*, i.name_en, i.name_ar, i.vat_rate FROM purchase_items pi LEFT JOIN stock_items i ON pi.item_id = i.id WHERE pi.purchase_id = ?");
                $item_stmt->execute([$inv['id']]);
                $inv['items'] = $item_stmt->fetchAll(PDO::FETCH_ASSOC);
            }
        }
        unset($inv);
        
        $oid = current_outlet_id(); $items_list_raw = db()->query("SELECT i.id, i.name_en, i.name_ar, i.sale_price, i.purchase_price, i.stock_quantity, i.vat_rate, i.is_promotion, i.promotion_start, i.promotion_end, i.promotion_percent FROM stock_items i  ORDER BY i.name_en ASC")->fetchAll(PDO::FETCH_ASSOC);
        foreach ($items_list_raw as &$item) {
            $item['sale_price'] = getPromotionalPrice($item);
        }
        $data['items_list'] = $items_list_raw;
        $data['customers_list'] = db()->query("SELECT id, name FROM $cust_supplier_table ORDER BY name ASC")->fetchAll();
        
        $oid = current_outlet_id();
        $outlet_sql = ($oid !== -1) ? "WHERE outlet_id = $oid" : "";

        if ($type === 'sale') {
            $data['sales_invoices'] = db()->query("SELECT id, invoice_date, total_with_vat FROM invoices $outlet_sql ORDER BY id DESC")->fetchAll();
        } else {
            $data['purchase_invoices'] = db()->query("SELECT id, invoice_date, total_with_vat FROM purchases $outlet_sql ORDER BY id DESC")->fetchAll();
        }