Add OTC sales UI with direct sales support

- Create OTC UI form at public/otc/index.php
- Add API endpoint public/api/otc-order.php
- Extract shared DB connection to includes/db.php
- Add migration for OTC products (0006_phase1_otc_products.sql)
- Support order_source='direct' with automatic DIR- reference generation
- Include billing address capture with default values
- Add payment methods cash and paypal for direct sales
- Implement stock allocation and inventory management

db/migrations/0006_phase1_otc_products.sql

@@ -0,0 +1,107 @@
+BEGIN;
+
+-- OTC products for direct sales
+INSERT INTO product (sku, name, status, uom) VALUES
+  ('SHIITAKE-50ML', 'PURE Shiitake Extrakt Tinktur 50ml', 'active', 'unit'),
+  ('REISHI-50ML', 'PURE Reishi Extrakt Tinktur 50ml', 'active', 'unit'),
+  ('LIONSMANE-50ML', 'PURE Lion''s Mane Extrakt Tinktur 50ml', 'active', 'unit'),
+  ('CHAGA-50ML', 'PURE Chaga Aroma Extrakt Tinktur 50ml', 'active', 'unit')
+ON CONFLICT (sku) DO UPDATE SET
+  name = EXCLUDED.name,
+  status = EXCLUDED.status,
+  uom = EXCLUDED.uom,
+  updated_at = NOW();
+
+-- Create sellable items for OTC products
+INSERT INTO sellable_item (item_code, display_name, status)
+SELECT 
+  'OTC-' || p.id,
+  p.name,
+  'active'
+FROM product p
+WHERE p.sku IN ('SHIITAKE-50ML', 'REISHI-50ML', 'LIONSMANE-50ML', 'CHAGA-50ML')
+ON CONFLICT (item_code) DO UPDATE SET
+  display_name = EXCLUDED.display_name,
+  status = EXCLUDED.status,
+  updated_at = NOW();
+
+-- Link sellable items to products
+INSERT INTO sellable_item_component (sellable_item_id, product_id, qty_per_item)
+SELECT 
+  si.id,
+  p.id,
+  1.0
+FROM sellable_item si
+JOIN product p ON p.name = si.display_name
+WHERE p.sku IN ('SHIITAKE-50ML', 'REISHI-50ML', 'LIONSMANE-50ML', 'CHAGA-50ML')
+ON CONFLICT (sellable_item_id, product_id) DO UPDATE SET
+  qty_per_item = EXCLUDED.qty_per_item,
+  updated_at = NOW();
+
+-- Ensure we have current lots for OTC products
+DO $$
+DECLARE
+  prod_record RECORD;
+  current_lot_id BIGINT;
+  open_lot_id BIGINT;
+BEGIN
+  FOR prod_record IN 
+    SELECT id FROM product 
+    WHERE sku IN ('SHIITAKE-50ML', 'REISHI-50ML', 'LIONSMANE-50ML', 'CHAGA-50ML')
+  LOOP
+    -- Check if current lot exists
+    SELECT id INTO current_lot_id
+    FROM stock_lot 
+    WHERE product_id = prod_record.id 
+      AND status = 'current'
+    LIMIT 1;
+    
+    IF current_lot_id IS NULL THEN
+      -- Check for open lot to promote
+      SELECT id INTO open_lot_id
+      FROM stock_lot 
+      WHERE product_id = prod_record.id 
+        AND status = 'open'
+      ORDER BY id
+      LIMIT 1;
+      
+      IF open_lot_id IS NULL THEN
+        -- Create both current and open lots
+        INSERT INTO stock_lot (product_id, lot_number, status)
+        VALUES (prod_record.id, 'OTC-INIT-' || prod_record.id, 'current')
+        RETURNING id INTO current_lot_id;
+        
+        INSERT INTO stock_lot (product_id, status)
+        VALUES (prod_record.id, 'open');
+        
+        -- Add initial stock
+        INSERT INTO stock_move (product_id, lot_id, from_location_id, to_location_id, qty, move_type, note)
+        SELECT 
+          prod_record.id,
+          current_lot_id,
+          NULL,
+          l.id,
+          100.0,
+          'in',
+          'Initial OTC stock'
+        FROM location l 
+        WHERE l.type = 'storage'
+        ORDER BY l.id
+        LIMIT 1;
+      ELSE
+        -- Promote open lot to current
+        UPDATE stock_lot 
+        SET status = 'current',
+            lot_number = COALESCE(lot_number, 'OTC-' || prod_record.id || '-' || open_lot_id),
+            updated_at = NOW()
+        WHERE id = open_lot_id;
+        
+        -- Create new open lot
+        INSERT INTO stock_lot (product_id, status)
+        VALUES (prod_record.id, 'open');
+      END IF;
+    END IF;
+  END LOOP;
+END $$;
+
+COMMIT;

includes/db.php

@@ -0,0 +1,151 @@
+<?php
+declare(strict_types=1);
+
+function parse_env_file(string $path): array
+{
+    if (!is_file($path)) {
+        return [];
+    }
+
+    $result = [];
+    $lines = file($path, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
+    if ($lines === false) {
+        return [];
+    }
+
+    foreach ($lines as $line) {
+        $trimmed = trim($line);
+        if ($trimmed === '' || str_starts_with($trimmed, '#')) {
+            continue;
+        }
+
+        $pos = strpos($trimmed, '=');
+        if ($pos === false) {
+            continue;
+        }
+
+        $key = trim(substr($trimmed, 0, $pos));
+        $value = trim(substr($trimmed, $pos + 1));
+        if ($key === '') {
+            continue;
+        }
+
+        if (strlen($value) >= 2) {
+            $first = $value[0];
+            $last = $value[strlen($value) - 1];
+            if (($first === '"' && $last === '"') || ($first === "'" && $last === "'")) {
+                $value = substr($value, 1, -1);
+            }
+        }
+
+        $result[$key] = $value;
+    }
+
+    return $result;
+}
+
+function expand_env_values(array $env): array
+{
+    $expanded = $env;
+    $pattern = '/\$\{([A-Za-z_][A-Za-z0-9_]*)\}/';
+
+    foreach ($expanded as $key => $value) {
+        $expanded[$key] = preg_replace_callback(
+            $pattern,
+            static function (array $matches) use (&$expanded): string {
+                $lookup = $matches[1];
+                return (string) ($expanded[$lookup] ?? getenv($lookup) ?: '');
+            },
+            (string) $value
+        ) ?? (string) $value;
+    }
+
+    return $expanded;
+}
+
+function env_value(string $key, array $localEnv, string $default = ''): string
+{
+    $runtime = getenv($key);
+    if ($runtime !== false && $runtime !== '') {
+        return $runtime;
+    }
+
+    if (isset($localEnv[$key]) && $localEnv[$key] !== '') {
+        return (string) $localEnv[$key];
+    }
+
+    return $default;
+}
+
+function connect_database(): PDO
+{
+    $env = parse_env_file(__DIR__ . '/../.env');
+    $env = expand_env_values($env);
+
+    $databaseUrl = env_value('DATABASE_URL', $env);
+    if ($databaseUrl !== '') {
+        $parts = parse_url($databaseUrl);
+        if ($parts !== false && ($parts['scheme'] ?? '') === 'postgresql') {
+            $host = (string) ($parts['host'] ?? '');
+            $port = (string) ($parts['port'] ?? '5432');
+            $dbName = ltrim((string) ($parts['path'] ?? ''), '/');
+            $user = (string) ($parts['user'] ?? '');
+            $pass = (string) ($parts['pass'] ?? '');
+            if ($host !== '' && $dbName !== '' && $user !== '') {
+                $dsn = "pgsql:host={$host};port={$port};dbname={$dbName}";
+                return new PDO($dsn, $user, $pass, [
+                    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+                    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+                ]);
+            }
+        }
+    }
+
+    $host = env_value('DB_HOST', $env);
+    $port = env_value('DB_PORT', $env, '5432');
+    $dbName = env_value('DB_NAME', $env);
+    $user = env_value('DB_USER', $env);
+    $pass = env_value('DB_PASSWORD', $env);
+
+    if ($host === '' || $dbName === '' || $user === '') {
+        throw new RuntimeException('Missing DB configuration');
+    }
+
+    $dsn = "pgsql:host={$host};port={$port};dbname={$dbName}";
+    return new PDO($dsn, $user, $pass, [
+        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+        PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
+    ]);
+}
+
+function parse_number(mixed $value): ?float
+{
+    if ($value === null || $value === '') {
+        return null;
+    }
+
+    if (is_int($value) || is_float($value)) {
+        return (float) $value;
+    }
+
+    if (!is_string($value)) {
+        return null;
+    }
+
+    $normalized = str_replace(["\u{00A0}", ' '], '', trim($value));
+    $normalized = str_replace(',', '.', $normalized);
+
+    if (!is_numeric($normalized)) {
+        return null;
+    }
+
+    return (float) $normalized;
+}
+
+function json_response(int $status, array $payload): void
+{
+    http_response_code($status);
+    header('Content-Type: application/json; charset=utf-8');
+    echo json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+    exit;
+}

public/api/otc-order.php

@@ -0,0 +1,338 @@
+<?php
+declare(strict_types=1);
+
+require_once __DIR__ . '/../../includes/db.php';
+
+header('Content-Type: application/json; charset=utf-8');
+
+if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
+    json_response(405, ['ok' => false, 'error' => 'Method Not Allowed']);
+}
+
+$jsonInput = file_get_contents('php://input');
+if ($jsonInput === false || trim($jsonInput) === '') {
+    json_response(400, ['ok' => false, 'error' => 'Empty payload']);
+}
+
+try {
+    $data = json_decode($jsonInput, true, 512, JSON_THROW_ON_ERROR);
+} catch (JsonException $e) {
+    json_response(400, ['ok' => false, 'error' => 'Invalid JSON payload']);
+}
+
+if (!is_array($data)) {
+    json_response(400, ['ok' => false, 'error' => 'JSON object expected']);
+}
+
+$required = ['products', 'totalPrice', 'paymentMethod', 'billing'];
+foreach ($required as $field) {
+    if (!isset($data[$field])) {
+        json_response(422, ['ok' => false, 'error' => "Missing field: {$field}"]);
+    }
+}
+
+$products = $data['products'];
+$totalPrice = parse_number($data['totalPrice']);
+$paymentMethodCode = trim((string) $data['paymentMethod']);
+$billing = $data['billing'];
+
+if (!is_array($products) || count($products) === 0) {
+    json_response(422, ['ok' => false, 'error' => 'No products specified']);
+}
+
+if ($totalPrice === null || $totalPrice <= 0) {
+    json_response(422, ['ok' => false, 'error' => 'Invalid total price']);
+}
+
+$totalQty = 0;
+foreach ($products as $product) {
+    if (!isset($product['qty']) || !isset($product['title'])) {
+        json_response(422, ['ok' => false, 'error' => 'Product missing title or qty']);
+    }
+    $qty = parse_number($product['qty']);
+    if ($qty === null || $qty <= 0) {
+        json_response(422, ['ok' => false, 'error' => 'Invalid product quantity']);
+    }
+    $totalQty += $qty;
+}
+
+try {
+    $pdo = connect_database();
+    $pdo->beginTransaction();
+
+    $partyName = trim($billing['firstName'] . ' ' . $billing['lastName']);
+    $partyName = $partyName === '' ? 'OTC Kunde' : $partyName;
+
+    $stmt = $pdo->prepare('
+        INSERT INTO party (type, name, status, created_at, updated_at)
+        VALUES (\'customer\', :name, \'active\', NOW(), NOW())
+        RETURNING id
+    ');
+    $stmt->execute([':name' => $partyName]);
+    $partyId = (int) $stmt->fetchColumn();
+
+    $stmt = $pdo->prepare('
+        INSERT INTO address (
+            party_id, type, first_name, last_name, street, house_number, zip, city,
+            country_name, created_at, updated_at
+        ) VALUES (
+            :party_id, \'billing\', :first_name, :last_name, :street, :house_number, :zip, :city,
+            \'Switzerland\', NOW(), NOW()
+        )
+    ');
+    $stmt->execute([
+        ':party_id' => $partyId,
+        ':first_name' => trim($billing['firstName'] ?? ''),
+        ':last_name' => trim($billing['lastName'] ?? ''),
+        ':street' => trim($billing['street'] ?? ''),
+        ':house_number' => trim($billing['houseNumber'] ?? ''),
+        ':zip' => trim($billing['zip'] ?? ''),
+        ':city' => trim($billing['city'] ?? ''),
+    ]);
+
+    $paymentMethodStmt = $pdo->prepare('SELECT id FROM payment_method WHERE code = :code LIMIT 1');
+    $paymentMethodStmt->execute([':code' => $paymentMethodCode]);
+    $paymentMethodId = $paymentMethodStmt->fetchColumn();
+    if ($paymentMethodId === false) {
+        throw new RuntimeException('Invalid payment method');
+    }
+    $paymentMethodId = (int) $paymentMethodId;
+
+    $orderStmt = $pdo->prepare('
+        INSERT INTO sales_order (
+            external_ref, party_id, order_source, order_status, payment_status, payment_method_id,
+            total_amount, currency, imported_at, created_at, updated_at
+        ) VALUES (
+            :external_ref, :party_id, \'direct\', \'imported\', \'paid\', :payment_method_id,
+            :total_amount, \'CHF\', NOW(), NOW(), NOW()
+        )
+        RETURNING id, external_ref
+    ');
+    $orderStmt->execute([
+        ':external_ref' => '', 
+        ':party_id' => $partyId,
+        ':payment_method_id' => $paymentMethodId,
+        ':total_amount' => $totalPrice,
+    ]);
+    $order = $orderStmt->fetch();
+    if ($order === false) {
+        throw new RuntimeException('Could not create order');
+    }
+    $orderId = (int) $order['id'];
+    $externalRef = $order['external_ref'];
+
+    $unitPrice = $totalPrice / $totalQty;
+
+    $lineInsert = $pdo->prepare('
+        INSERT INTO sales_order_line (
+            sales_order_id, line_no, raw_external_title, qty, unit_price, line_total,
+            created_at, updated_at
+        ) VALUES (
+            :sales_order_id, :line_no, :title, :qty, :unit_price, :line_total,
+            NOW(), NOW()
+        )
+        RETURNING id
+    ');
+
+    $locationsStmt = $pdo->query('
+        SELECT
+            (SELECT id FROM location WHERE type = \'storage\' ORDER BY id LIMIT 1) AS storage_id,
+            (SELECT id FROM location WHERE type = \'dispatch\' ORDER BY id LIMIT 1) AS dispatch_id
+    ');
+    $locations = $locationsStmt->fetch();
+    $storageId = (int) $locations['storage_id'];
+    $dispatchId = (int) $locations['dispatch_id'];
+
+    foreach ($products as $index => $product) {
+        $qty = parse_number($product['qty']);
+        $title = trim($product['title']);
+        $lineTotal = round($qty * $unitPrice, 2);
+
+        $lineInsert->execute([
+            ':sales_order_id' => $orderId,
+            ':line_no' => $index + 1,
+            ':title' => $title,
+            ':qty' => $qty,
+            ':unit_price' => $unitPrice,
+            ':line_total' => $lineTotal,
+        ]);
+        $lineId = (int) $lineInsert->fetchColumn();
+
+        $resolveProductStmt = $pdo->prepare('
+            SELECT id FROM product WHERE name ILIKE :pattern ORDER BY id LIMIT 1
+        ');
+        
+        $pattern = '';
+        if (strpos($title, 'Shiitake') !== false) {
+            $pattern = '%Shiitake%';
+        } elseif (strpos($title, 'Reishi') !== false) {
+            $pattern = '%Reishi%';
+        } elseif (strpos($title, 'Lion') !== false) {
+            $pattern = '%Lion%';
+        } elseif (strpos($title, 'Chaga') !== false) {
+            $pattern = '%Chaga%';
+        }
+        
+        $productId = null;
+        if ($pattern !== '') {
+            $resolveProductStmt->execute([':pattern' => $pattern]);
+            $productId = $resolveProductStmt->fetchColumn();
+        }
+        if ($productId === false) {
+            $productStmt = $pdo->prepare('
+                INSERT INTO product (sku, name, status, uom, created_at, updated_at)
+                VALUES (:sku, :name, \'active\', \'unit\', NOW(), NOW())
+                RETURNING id
+            ');
+            $productStmt->execute([
+                ':sku' => 'OTC-' . preg_replace('/[^A-Za-z0-9]/', '', substr($title, 0, 20)),
+                ':name' => $title,
+            ]);
+            $productId = (int) $productStmt->fetchColumn();
+        } else {
+            $productId = (int) $productId;
+        }
+
+        $sellableItemStmt = $pdo->prepare('
+            SELECT id FROM sellable_item WHERE item_code = :item_code ORDER BY id LIMIT 1
+        ');
+        $sellableItemStmt->execute([':item_code' => 'OTC-' . $productId]);
+        $sellableItemId = $sellableItemStmt->fetchColumn();
+        if ($sellableItemId === false) {
+            $sellableInsert = $pdo->prepare('
+                INSERT INTO sellable_item (item_code, display_name, status, created_at, updated_at)
+                VALUES (:item_code, :display_name, \'active\', NOW(), NOW())
+                RETURNING id
+            ');
+            $sellableInsert->execute([
+                ':item_code' => 'OTC-' . $productId,
+                ':display_name' => $title,
+            ]);
+            $sellableItemId = (int) $sellableInsert->fetchColumn();
+        } else {
+            $sellableItemId = (int) $sellableItemId;
+        }
+
+        $updateLineStmt = $pdo->prepare('
+            UPDATE sales_order_line
+            SET sellable_item_id = :sellable_item_id
+            WHERE id = :id
+        ');
+        $updateLineStmt->execute([
+            ':sellable_item_id' => $sellableItemId,
+            ':id' => $lineId,
+        ]);
+
+        $currentLotStmt = $pdo->prepare('
+            SELECT sl.id, COALESCE(v.qty_net, 0) AS qty_net
+            FROM stock_lot sl
+            LEFT JOIN v_stock_lot_balance v ON v.stock_lot_id = sl.id
+            WHERE sl.product_id = :product_id
+                AND sl.status = \'current\'
+            LIMIT 1
+            FOR UPDATE
+        ');
+        $currentLotStmt->execute([':product_id' => $productId]);
+        $lot = $currentLotStmt->fetch();
+        if ($lot === false || (float) $lot['qty_net'] < $qty) {
+            $closeLotStmt = $pdo->prepare('
+                UPDATE stock_lot
+                SET status = \'closed\', updated_at = NOW()
+                WHERE id = :id
+            ');
+            $closeLotStmt->execute([':id' => (int) $lot['id']]);
+
+            $openLotStmt = $pdo->prepare('
+                SELECT id FROM stock_lot
+                WHERE product_id = :product_id
+                    AND status = \'open\'
+                ORDER BY id LIMIT 1
+                FOR UPDATE
+            ');
+            $openLotStmt->execute([':product_id' => $productId]);
+            $openLotId = $openLotStmt->fetchColumn();
+            if ($openLotId === false) {
+                $createOpenLotStmt = $pdo->prepare('
+                    INSERT INTO stock_lot (product_id, status, created_at, updated_at)
+                    VALUES (:product_id, \'open\', NOW(), NOW())
+                    RETURNING id
+                ');
+                $createOpenLotStmt->execute([':product_id' => $productId]);
+                $openLotId = (int) $createOpenLotStmt->fetchColumn();
+            } else {
+                $openLotId = (int) $openLotId;
+            }
+
+            $promoteLotStmt = $pdo->prepare('
+                UPDATE stock_lot
+                SET status = \'current\',
+                    lot_number = COALESCE(lot_number, \'OTC-\' || :product_id || \'-\' || :lot_id),
+                    updated_at = NOW()
+                WHERE id = :lot_id
+            ');
+            $promoteLotStmt->execute([
+                ':product_id' => $productId,
+                ':lot_id' => $openLotId,
+            ]);
+
+            $lotId = $openLotId;
+        } else {
+            $lotId = (int) $lot['id'];
+        }
+
+        $stockMoveStmt = $pdo->prepare('
+            INSERT INTO stock_move (
+                product_id, lot_id, from_location_id, to_location_id, qty, move_type,
+                move_date, note, created_at, updated_at
+            ) VALUES (
+                :product_id, :lot_id, :from_location_id, :to_location_id, :qty, \'out\',
+                NOW(), :note, NOW(), NOW()
+            )
+            RETURNING id
+        ');
+        $stockMoveStmt->execute([
+            ':product_id' => $productId,
+            ':lot_id' => $lotId,
+            ':from_location_id' => $storageId,
+            ':to_location_id' => $dispatchId,
+            ':qty' => $qty,
+            ':note' => 'OTC order ' . $orderId . ': ' . $title,
+        ]);
+        $stockMoveId = (int) $stockMoveStmt->fetchColumn();
+
+        $allocationStmt = $pdo->prepare('
+            INSERT INTO sales_order_line_lot_allocation (
+                sales_order_line_id, product_id, lot_id, qty, allocation_status,
+                stock_move_id, created_at, updated_at
+            ) VALUES (
+                :line_id, :product_id, :lot_id, :qty, \'allocated\',
+                :stock_move_id, NOW(), NOW()
+            )
+        ');
+        $allocationStmt->execute([
+            ':line_id' => $lineId,
+            ':product_id' => $productId,
+            ':lot_id' => $lotId,
+            ':qty' => $qty,
+            ':stock_move_id' => $stockMoveId,
+        ]);
+    }
+
+    $pdo->commit();
+
+    json_response(201, [
+        'ok' => true,
+        'orderId' => $orderId,
+        'externalRef' => $externalRef,
+        'partyId' => $partyId,
+        'message' => 'OTC order created successfully',
+    ]);
+} catch (Exception $e) {
+    if (isset($pdo) && $pdo->inTransaction()) {
+        $pdo->rollBack();
+    }
+    json_response(500, [
+        'ok' => false,
+        'error' => 'Internal server error: ' . $e->getMessage(),
+    ]);
+}

public/otc/index.php

@@ -0,0 +1,495 @@
+<!DOCTYPE html>
+<html lang="de">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>OTC-Verkauf</title>
+    <style>
+        * {
+            box-sizing: border-box;
+            margin: 0;
+            padding: 0;
+        }
+        
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+            background: #f5f5f5;
+            color: #333;
+            line-height: 1.6;
+            padding: 20px;
+        }
+        
+        .container {
+            max-width: 600px;
+            margin: 0 auto;
+            background: white;
+            border-radius: 8px;
+            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
+            padding: 30px;
+        }
+        
+        h1 {
+            font-size: 24px;
+            margin-bottom: 20px;
+            color: #2c3e50;
+            border-bottom: 2px solid #3498db;
+            padding-bottom: 10px;
+        }
+        
+        h2 {
+            font-size: 18px;
+            margin: 25px 0 15px 0;
+            color: #34495e;
+            padding-bottom: 5px;
+            border-bottom: 1px solid #eee;
+        }
+        
+        .section {
+            margin-bottom: 25px;
+        }
+        
+        .form-group {
+            margin-bottom: 20px;
+        }
+        
+        label {
+            display: block;
+            margin-bottom: 5px;
+            font-weight: 500;
+            color: #2c3e50;
+        }
+        
+        input[type="number"],
+        input[type="text"],
+        select {
+            width: 100%;
+            padding: 10px 12px;
+            border: 1px solid #ddd;
+            border-radius: 4px;
+            font-size: 16px;
+            transition: border-color 0.3s;
+        }
+        
+        input[type="number"]:focus,
+        input[type="text"]:focus,
+        select:focus {
+            outline: none;
+            border-color: #3498db;
+            box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
+        }
+        
+        .product-row {
+            margin-bottom: 15px;
+        }
+        
+        .product-row label {
+            font-size: 14px;
+            color: #555;
+        }
+        
+        .price-note {
+            font-size: 13px;
+            color: #666;
+            margin-top: 5px;
+            font-style: italic;
+        }
+        
+        .price-breakdown {
+            background: #f8f9fa;
+            border: 1px solid #eee;
+            border-radius: 4px;
+            padding: 10px;
+            margin-top: 10px;
+            font-size: 14px;
+        }
+        
+        .price-line {
+            display: flex;
+            justify-content: space-between;
+            margin-bottom: 5px;
+        }
+        
+        .price-line.total {
+            font-weight: bold;
+            border-top: 1px solid #ddd;
+            padding-top: 5px;
+            margin-top: 5px;
+        }
+        
+        .billing-grid {
+            display: grid;
+            grid-template-columns: 1fr 1fr;
+            gap: 15px;
+        }
+        
+        .billing-grid .form-group:first-child,
+        .billing-grid .form-group:nth-child(2) {
+            grid-column: span 1;
+        }
+        
+        .billing-grid .form-group:nth-child(3) {
+            grid-column: span 2;
+        }
+        
+        .billing-grid .form-group:nth-child(4),
+        .billing-grid .form-group:nth-child(5),
+        .billing-grid .form-group:nth-child(6) {
+            grid-column: span 1;
+        }
+        
+        .billing-grid .form-group:nth-child(4) {
+            grid-column: span 1;
+        }
+        
+        .billing-grid .form-group:nth-child(5) {
+            grid-column: span 1;
+        }
+        
+        .billing-grid .form-group:nth-child(6) {
+            grid-column: span 2;
+        }
+        
+        button {
+            background: #3498db;
+            color: white;
+            border: none;
+            padding: 14px 20px;
+            font-size: 16px;
+            border-radius: 4px;
+            cursor: pointer;
+            width: 100%;
+            font-weight: 500;
+            transition: background 0.3s;
+            margin-top: 20px;
+        }
+        
+        button:hover {
+            background: #2980b9;
+        }
+        
+        button:disabled {
+            background: #95a5a6;
+            cursor: not-allowed;
+        }
+        
+        .error {
+            color: #e74c3c;
+            font-size: 14px;
+            margin-top: 5px;
+            display: none;
+        }
+        
+        .success {
+            background: #2ecc71;
+            color: white;
+            padding: 15px;
+            border-radius: 4px;
+            margin-top: 20px;
+            display: none;
+        }
+        
+        .hidden {
+            display: none;
+        }
+        
+        .loading {
+            display: inline-block;
+            width: 20px;
+            height: 20px;
+            border: 2px solid #fff;
+            border-radius: 50%;
+            border-top-color: transparent;
+            animation: spin 0.8s linear infinite;
+            margin-right: 10px;
+            vertical-align: middle;
+        }
+        
+        @keyframes spin {
+            to { transform: rotate(360deg); }
+        }
+        
+        @media (max-width: 600px) {
+            .container {
+                padding: 20px;
+            }
+            
+            .billing-grid {
+                grid-template-columns: 1fr;
+            }
+            
+            .billing-grid .form-group:nth-child(3),
+            .billing-grid .form-group:nth-child(6) {
+                grid-column: span 1;
+            }
+        }
+    </style>
+</head>
+<body>
+    <div class="container">
+        <h1>OTC-Verkauf</h1>
+        
+        <div class="section">
+            <h2>PRODUKTE</h2>
+            
+            <div class="product-row">
+                <label for="product1">PURE Shiitake Extrakt Tinktur 50ml</label>
+                <input type="number" id="product1" min="0" step="1" value="0" data-title="PURE Shiitake Extrakt Tinktur 50ml">
+            </div>
+            
+            <div class="product-row">
+                <label for="product2">PURE Reishi Extrakt Tinktur 50ml</label>
+                <input type="number" id="product2" min="0" step="1" value="0" data-title="PURE Reishi Extrakt Tinktur 50ml">
+            </div>
+            
+            <div class="product-row">
+                <label for="product3">PURE Lion's Mane Extrakt Tinktur 50ml</label>
+                <input type="number" id="product3" min="0" step="1" value="0" data-title="PURE Lion's Mane Extrakt Tinktur 50ml">
+            </div>
+            
+            <div class="product-row">
+                <label for="product4">PURE Chaga Aroma Extrakt Tinktur 50ml</label>
+                <input type="number" id="product4" min="0" step="1" value="0" data-title="PURE Chaga Aroma Extrakt Tinktur 50ml">
+            </div>
+        </div>
+        
+        <div class="section">
+            <div class="form-group">
+                <label for="totalPrice">Preis alle Flaschen brutto (CHF)</label>
+                <input type="number" id="totalPrice" min="0" step="0.01" value="0.00">
+                <div class="price-note">
+                    Der Preis wird durch die Anzahl aller Flaschen geteilt und das Ergebnis ist der Preis jeder einzelnen Flasche.
+                </div>
+            </div>
+            
+            <div id="priceBreakdown" class="price-breakdown hidden">
+                <div class="price-line">
+                    <span>Total Flaschen:</span>
+                    <span id="totalBottles">0</span>
+                </div>
+                <div class="price-line">
+                    <span>Preis pro Flasche:</span>
+                    <span id="pricePerBottle">CHF 0.00</span>
+                </div>
+                <div class="price-line total">
+                    <span>Gesamtpreis:</span>
+                    <span id="displayTotalPrice">CHF 0.00</span>
+                </div>
+            </div>
+        </div>
+        
+        <div class="section">
+            <div class="form-group">
+                <label for="paymentMethod">Bezahlung</label>
+                <select id="paymentMethod">
+                    <option value="twint">Twint</option>
+                    <option value="cash">Barzahlung</option>
+                    <option value="paypal">PayPal</option>
+                    <option value="bank_transfer">Überweisung</option>
+                </select>
+            </div>
+        </div>
+        
+        <div class="section">
+            <h2>RECHNUNGSADRESSE</h2>
+            <div class="billing-grid">
+                <div class="form-group">
+                    <label for="firstName">Vorname</label>
+                    <input type="text" id="firstName" value="Fabienne">
+                </div>
+                
+                <div class="form-group">
+                    <label for="lastName">Nachname</label>
+                    <input type="text" id="lastName" value="Föhn">
+                </div>
+                
+                <div class="form-group">
+                    <label for="street">Strasse</label>
+                    <input type="text" id="street" value="Im Hochrain">
+                </div>
+                
+                <div class="form-group">
+                    <label for="houseNumber">Hausnummer</label>
+                    <input type="text" id="houseNumber" value="2">
+                </div>
+                
+                <div class="form-group">
+                    <label for="zip">PLZ</label>
+                    <input type="text" id="zip" value="8102">
+                </div>
+                
+                <div class="form-group">
+                    <label for="city">Ort</label>
+                    <input type="text" id="city" value="Oberengstringen">
+                </div>
+            </div>
+        </div>
+        
+        <div id="error" class="error"></div>
+        
+        <button id="submitBtn" onclick="submitOrder()">
+            Verkaufen
+        </button>
+        
+        <div id="success" class="success">
+            Bestellung erfolgreich erfasst! Die Bestellnummer wird automatisch generiert.
+        </div>
+    </div>
+    
+    <script>
+        const productInputs = [
+            document.getElementById('product1'),
+            document.getElementById('product2'),
+            document.getElementById('product3'),
+            document.getElementById('product4')
+        ];
+        
+        const totalPriceInput = document.getElementById('totalPrice');
+        const priceBreakdown = document.getElementById('priceBreakdown');
+        const totalBottlesEl = document.getElementById('totalBottles');
+        const pricePerBottleEl = document.getElementById('pricePerBottle');
+        const displayTotalPriceEl = document.getElementById('displayTotalPrice');
+        const submitBtn = document.getElementById('submitBtn');
+        const errorEl = document.getElementById('error');
+        const successEl = document.getElementById('success');
+        
+        function updatePriceBreakdown() {
+            const totalQty = productInputs.reduce((sum, input) => sum + parseInt(input.value || 0), 0);
+            const totalPrice = parseFloat(totalPriceInput.value || 0);
+            
+            if (totalQty > 0 && totalPrice > 0) {
+                priceBreakdown.classList.remove('hidden');
+                totalBottlesEl.textContent = totalQty;
+                const pricePerBottle = totalPrice / totalQty;
+                pricePerBottleEl.textContent = 'CHF ' + pricePerBottle.toFixed(2);
+                displayTotalPriceEl.textContent = 'CHF ' + totalPrice.toFixed(2);
+            } else {
+                priceBreakdown.classList.add('hidden');
+            }
+            
+            validateForm();
+        }
+        
+        function validateForm() {
+            const totalQty = productInputs.reduce((sum, input) => sum + parseInt(input.value || 0), 0);
+            const totalPrice = parseFloat(totalPriceInput.value || 0);
+            const paymentMethod = document.getElementById('paymentMethod').value;
+            
+            const firstName = document.getElementById('firstName').value.trim();
+            const lastName = document.getElementById('lastName').value.trim();
+            const street = document.getElementById('street').value.trim();
+            const houseNumber = document.getElementById('houseNumber').value.trim();
+            const zip = document.getElementById('zip').value.trim();
+            const city = document.getElementById('city').value.trim();
+            
+            let isValid = true;
+            let errorMsg = '';
+            
+            if (totalQty === 0) {
+                isValid = false;
+                errorMsg = 'Mindestens ein Produkt mit Menge > 0 erforderlich.';
+            } else if (totalPrice <= 0) {
+                isValid = false;
+                errorMsg = 'Preis muss größer als 0 sein.';
+            } else if (!paymentMethod) {
+                isValid = false;
+                errorMsg = 'Zahlungsart auswählen.';
+            } else if (!firstName || !lastName || !street || !houseNumber || !zip || !city) {
+                isValid = false;
+                errorMsg = 'Alle Rechnungsadress-Felder ausfüllen.';
+            }
+            
+            if (!isValid) {
+                errorEl.textContent = errorMsg;
+                errorEl.style.display = 'block';
+                submitBtn.disabled = true;
+            } else {
+                errorEl.style.display = 'none';
+                submitBtn.disabled = false;
+            }
+            
+            return isValid;
+        }
+        
+        productInputs.forEach(input => {
+            input.addEventListener('input', updatePriceBreakdown);
+        });
+        
+        totalPriceInput.addEventListener('input', updatePriceBreakdown);
+        
+        document.getElementById('paymentMethod').addEventListener('change', validateForm);
+        document.getElementById('firstName').addEventListener('input', validateForm);
+        document.getElementById('lastName').addEventListener('input', validateForm);
+        document.getElementById('street').addEventListener('input', validateForm);
+        document.getElementById('houseNumber').addEventListener('input', validateForm);
+        document.getElementById('zip').addEventListener('input', validateForm);
+        document.getElementById('city').addEventListener('input', validateForm);
+        
+        async function submitOrder() {
+            if (!validateForm()) {
+                return;
+            }
+            
+            const products = productInputs
+                .filter(input => parseInt(input.value || 0) > 0)
+                .map(input => ({
+                    title: input.dataset.title,
+                    qty: parseInt(input.value)
+                }));
+            
+            const orderData = {
+                products: products,
+                totalPrice: parseFloat(totalPriceInput.value),
+                paymentMethod: document.getElementById('paymentMethod').value,
+                billing: {
+                    firstName: document.getElementById('firstName').value.trim(),
+                    lastName: document.getElementById('lastName').value.trim(),
+                    street: document.getElementById('street').value.trim(),
+                    houseNumber: document.getElementById('houseNumber').value.trim(),
+                    zip: document.getElementById('zip').value.trim(),
+                    city: document.getElementById('city').value.trim()
+                }
+            };
+            
+            const originalBtnText = submitBtn.innerHTML;
+            submitBtn.innerHTML = '<span class="loading"></span> Wird verarbeitet...';
+            submitBtn.disabled = true;
+            errorEl.style.display = 'none';
+            
+            try {
+                const response = await fetch('/api/otc-order.php', {
+                    method: 'POST',
+                    headers: {
+                        'Content-Type': 'application/json',
+                    },
+                    body: JSON.stringify(orderData)
+                });
+                
+                const result = await response.json();
+                
+                if (response.ok && result.ok) {
+                    successEl.style.display = 'block';
+                    productInputs.forEach(input => input.value = '0');
+                    totalPriceInput.value = '0.00';
+                    priceBreakdown.classList.add('hidden');
+                    
+                    setTimeout(() => {
+                        successEl.style.display = 'none';
+                    }, 5000);
+                } else {
+                    errorEl.textContent = result.error || 'Unbekannter Fehler';
+                    errorEl.style.display = 'block';
+                }
+            } catch (error) {
+                errorEl.textContent = 'Netzwerkfehler: ' + error.message;
+                errorEl.style.display = 'block';
+            } finally {
+                submitBtn.innerHTML = originalBtnText;
+                submitBtn.disabled = false;
+                validateForm();
+            }
+        }
+        
+        updatePriceBreakdown();
+    </script>
+</body>
+</html>