<?php
// Shared Sales/Purchases secondary handlers extracted from index.php.

if (!function_exists('sales_purchases_target_page')) {
    function sales_purchases_target_page(string $type): string {
        return $type === 'purchase' ? 'purchases' : 'sales';
    }
}

if (isset($_POST['delete_invoice'])) {
    $id = (int)($_POST['id'] ?? 0);
    $type = ($page === 'purchases') ? 'purchase' : 'sale';
    $table = ($type === 'purchase') ? 'purchases' : 'invoices';
    $item_table = ($type === 'purchase') ? 'purchase_items' : 'invoice_items';
    $fk_col = ($type === 'purchase') ? 'purchase_id' : 'invoice_id';

    db()->prepare("DELETE FROM $table WHERE id = ?")->execute([$id]);
    db()->prepare("DELETE FROM $item_table WHERE $fk_col = ?")->execute([$id]);
    redirectWithMessage(($type === 'purchase' ? 'Purchase' : 'Invoice') . ' deleted!', page_url(sales_purchases_target_page($type)));
}

if (isset($_POST['convert_to_invoice'])) {
    $db = db();
    try {
        $db->beginTransaction();
        $quot_id = (int)($_POST['quotation_id'] ?? 0);

        $stmt = $db->prepare("SELECT * FROM quotations WHERE id = ?");
        $stmt->execute([$quot_id]);
        $quot = $stmt->fetch();

        if (!$quot) {
            throw new Exception('Quotation not found.');
        }
        if (($quot['status'] ?? '') === 'converted') {
            throw new Exception('Quotation already converted.');
        }

        $stmtItems = $db->prepare("SELECT * FROM quotation_items WHERE quotation_id = ?");
        $stmtItems->execute([$quot_id]);
        $qItems = $stmtItems->fetchAll();

        $inv_date = date('Y-m-d');
        $stmtInv = $db->prepare("INSERT INTO invoices (customer_id, invoice_date, status, payment_type, total_amount, vat_amount, total_with_vat, paid_amount, outlet_id) VALUES (?, ?, 'unpaid', 'credit', ?, ?, ?, 0, ?)");
        $stmtInv->execute([$quot['customer_id'], $inv_date, $quot['total_amount'], $quot['vat_amount'], $quot['total_with_vat'], current_outlet_id()]);
        $inv_id = $db->lastInsertId();

        $items_for_journal = [];
        foreach ($qItems as $item) {
            $qty = normalize_quantity($item['quantity'] ?? 0);
            $lineVatAmount = line_item_vat_amount($db, $item);
            $db->prepare("INSERT INTO invoice_items (invoice_id, item_id, quantity, unit_price, vat_amount, total_price) VALUES (?, ?, ?, ?, ?, ?)")
               ->execute([$inv_id, $item['item_id'], $qty, $item['unit_price'], $lineVatAmount, $item['total_price']]);

            update_stock($item['item_id'], -$qty);
            $items_for_journal[] = ['id' => $item['item_id'], 'qty' => $qty];
        }

        $db->prepare("UPDATE quotations SET status = 'converted' WHERE id = ?")->execute([$quot_id]);
        recordSaleJournal($inv_id, $quot['total_with_vat'], $inv_date, $items_for_journal, $quot['vat_amount']);

        $db->commit();
        redirectWithMessage("Quotation converted to Invoice #$inv_id successfully!", page_url('sales'));
    } catch (Exception $e) {
        $db->rollBack();
        $message = 'Error: ' . $e->getMessage();
    }
}

if (isset($_POST['convert_lpo_to_purchase'])) {
    $db = db();
    try {
        $db->beginTransaction();
        $lpo_id = (int)($_POST['lpo_id'] ?? 0);

        $stmt = $db->prepare("SELECT * FROM lpos WHERE id = ?");
        $stmt->execute([$lpo_id]);
        $lpo = $stmt->fetch();

        if (!$lpo) {
            throw new Exception('LPO not found.');
        }
        if (($lpo['status'] ?? '') === 'converted') {
            throw new Exception('LPO already converted.');
        }

        $stmtItems = $db->prepare("SELECT * FROM lpo_items WHERE lpo_id = ?");
        $stmtItems->execute([$lpo_id]);
        $lItems = $stmtItems->fetchAll();

        $pur_date = date('Y-m-d');
        $stmtPur = $db->prepare("INSERT INTO purchases (supplier_id, invoice_date, status, payment_type, total_amount, vat_amount, total_with_vat, paid_amount, outlet_id) VALUES (?, ?, 'unpaid', 'credit', ?, ?, ?, 0, ?)");
        $stmtPur->execute([$lpo['supplier_id'], $pur_date, $lpo['total_amount'], $lpo['vat_amount'], $lpo['total_with_vat'], current_outlet_id()]);
        $pur_id = $db->lastInsertId();

        foreach ($lItems as $item) {
            $qty = normalize_quantity($item['quantity'] ?? 0);
            $db->prepare("INSERT INTO purchase_items (purchase_id, item_id, quantity, unit_price, vat_amount, total_price) VALUES (?, ?, ?, ?, ?, ?)")
               ->execute([$pur_id, $item['item_id'], $qty, $item['unit_price'], $item['vat_amount'], $item['total_amount']]);

            update_stock($item['item_id'], $qty);
        }

        $db->prepare("UPDATE lpos SET status = 'converted' WHERE id = ?")->execute([$lpo_id]);

        $db->commit();
        redirectWithMessage("LPO converted to Purchase Invoice #$pur_id successfully!", page_url('purchases'));
    } catch (Exception $e) {
        $db->rollBack();
        $message = 'Error: ' . $e->getMessage();
    }
}

if (isset($_POST['record_payment'])) {
    $id = (int)($_POST['invoice_id'] ?? 0);
    $amount = (float)($_POST['amount'] ?? 0);
    $date = !empty($_POST['payment_date']) ? (string)$_POST['payment_date'] : date('Y-m-d');
    $method = $_POST['payment_method'] ?? 'Cash';
    $type = ($page === 'purchases') ? 'purchase' : 'sale';
    $table = ($type === 'purchase') ? 'purchases' : 'invoices';
    $payment_table = ($type === 'purchase') ? 'purchase_payments' : 'payments';
    $fk_col = ($type === 'purchase') ? 'purchase_id' : 'invoice_id';

    $db = db();
    $db->prepare("INSERT INTO $payment_table ($fk_col, amount, payment_date, payment_method, notes) VALUES (?, ?, ?, ?, ?)")
       ->execute([$id, $amount, $date, $method, $_POST['notes'] ?? '']);
    $pay_id = $db->lastInsertId();
    $db->prepare("UPDATE $table SET paid_amount = paid_amount + ?, status = IF(paid_amount + ? >= total_with_vat, 'paid', 'partially_paid') WHERE id = ?")
       ->execute([$amount, $amount, $id]);

    if ($type === 'sale') {
        recordPaymentReceivedJournal((int)$pay_id, $amount, $date, $method);
    } else {
        recordPaymentMadeJournal((int)$pay_id, $amount, $date, $method);
    }

    $_SESSION['trigger_receipt_modal'] = true;
    $_SESSION['show_receipt_id'] = $pay_id;
    redirectWithMessage('Payment recorded!', page_url(sales_purchases_target_page($type)));
}