Add JSON-LD structured data for recipes

- Create recipeJsonLd.ts function with Schema.org compliant Recipe markup
- Add API endpoint at /api/rezepte/json-ld/[name] for on-demand generation
- Include proper ISO 8601 time parsing for German formats
- Add rel="alternate" link in recipe pages for discoverability
- Set author to Alexander Bocken with proper Person type
- Include caching headers for performance optimization

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/lib/js/recipeJsonLd.ts

@@ -0,0 +1,126 @@
+function parseTimeToISO8601(timeString: string): string | undefined {
+  if (!timeString) return undefined;
+  
+  // Handle common German time formats
+  const cleanTime = timeString.toLowerCase().trim();
+  
+  // Match patterns like "30 min", "2 h", "1.5 h", "90 min"
+  const minMatch = cleanTime.match(/(\d+(?:[.,]\d+)?)\s*(?:min|minuten?)/);
+  const hourMatch = cleanTime.match(/(\d+(?:[.,]\d+)?)\s*(?:h|stunden?|std)/);
+  
+  if (minMatch) {
+    const minutes = Math.round(parseFloat(minMatch[1].replace(',', '.')));
+    return `PT${minutes}M`;
+  }
+  
+  if (hourMatch) {
+    const hours = parseFloat(hourMatch[1].replace(',', '.'));
+    if (hours % 1 === 0) {
+      return `PT${Math.round(hours)}H`;
+    } else {
+      const totalMinutes = Math.round(hours * 60);
+      return `PT${totalMinutes}M`;
+    }
+  }
+  
+  return undefined;
+}
+
+export function generateRecipeJsonLd(data: any) {
+  const jsonLd: any = {
+    "@context": "https://schema.org",
+    "@type": "Recipe",
+    "name": data.name?.replace(/<[^>]*>/g, ''), // Strip HTML tags
+    "description": data.description,
+    "author": {
+      "@type": "Person",
+      "name": "Alexander Bocken"
+    },
+    "datePublished": data.dateCreated ? new Date(data.dateCreated).toISOString() : undefined,
+    "dateModified": data.dateModified || data.updatedAt ? new Date(data.dateModified || data.updatedAt).toISOString() : undefined,
+    "recipeCategory": data.category,
+    "keywords": data.tags?.join(', '),
+    "image": {
+      "@type": "ImageObject",
+      "url": `https://bocken.org/static/rezepte/full/${data.short_name}.webp`,
+      "width": 1200,
+      "height": 800
+    },
+    "recipeIngredient": [] as string[],
+    "recipeInstructions": [] as any[],
+    "url": `https://bocken.org/rezepte/${data.short_name}`
+  };
+
+  // Add optional fields if they exist
+  if (data.portions) {
+    jsonLd.recipeYield = data.portions;
+  }
+
+  // Parse times properly for ISO 8601
+  const prepTime = parseTimeToISO8601(data.preparation);
+  if (prepTime) jsonLd.prepTime = prepTime;
+
+  const cookTime = parseTimeToISO8601(data.cooking);
+  if (cookTime) jsonLd.cookTime = cookTime;
+
+  const totalTime = parseTimeToISO8601(data.total_time);
+  if (totalTime) jsonLd.totalTime = totalTime;
+
+  // Extract ingredients
+  if (data.ingredients) {
+    for (const ingredientGroup of data.ingredients) {
+      if (ingredientGroup.list) {
+        for (const ingredient of ingredientGroup.list) {
+          if (ingredient.name) {
+            let ingredientText = ingredient.name;
+            if (ingredient.amount) {
+              ingredientText = `${ingredient.amount} ${ingredient.unit || ''} ${ingredient.name}`.trim();
+            }
+            jsonLd.recipeIngredient.push(ingredientText);
+          }
+        }
+      }
+    }
+  }
+
+  // Extract instructions
+  if (data.instructions) {
+    for (const instructionGroup of data.instructions) {
+      if (instructionGroup.steps) {
+        for (let i = 0; i < instructionGroup.steps.length; i++) {
+          jsonLd.recipeInstructions.push({
+            "@type": "HowToStep",
+            "name": `Schritt ${i + 1}`,
+            "text": instructionGroup.steps[i]
+          });
+        }
+      }
+    }
+  }
+
+  // Add baking instructions if available
+  if (data.baking?.temperature || data.baking?.length) {
+    const bakingText = [
+      data.baking.temperature ? `bei ${data.baking.temperature}` : '',
+      data.baking.length ? `für ${data.baking.length}` : '',
+      data.baking.mode || ''
+    ].filter(Boolean).join(' ');
+    
+    if (bakingText) {
+      jsonLd.recipeInstructions.push({
+        "@type": "HowToStep",
+        "name": "Backen",
+        "text": `Backen ${bakingText}`
+      });
+    }
+  }
+
+  // Clean up undefined values
+  Object.keys(jsonLd).forEach(key => {
+    if (jsonLd[key] === undefined) {
+      delete jsonLd[key];
+    }
+  });
+
+  return jsonLd;
+}

src/routes/api/rezepte/json-ld/[name]/+server.ts

@@ -0,0 +1,32 @@
+import { json, type RequestHandler } from '@sveltejs/kit';
+import { Recipe } from '../../../../../models/Recipe';
+import { dbConnect, dbDisconnect } from '../../../../../utils/db';
+import { generateRecipeJsonLd } from '$lib/js/recipeJsonLd';
+import type { RecipeModelType } from '../../../../../types/types';
+import { error } from '@sveltejs/kit';
+
+export const GET: RequestHandler = async ({ params, setHeaders }) => {
+  await dbConnect();
+  let recipe = (await Recipe.findOne({ short_name: params.name }).lean()) as RecipeModelType;
+  await dbDisconnect();
+
+  recipe = JSON.parse(JSON.stringify(recipe));
+  if (recipe == null) {
+    throw error(404, "Recipe not found");
+  }
+
+  const jsonLd = generateRecipeJsonLd(recipe);
+
+  // Set appropriate headers for JSON-LD
+  setHeaders({
+    'Content-Type': 'application/ld+json',
+    'Cache-Control': 'public, max-age=3600' // Cache for 1 hour
+  });
+
+  return new Response(JSON.stringify(jsonLd, null, 2), {
+    headers: {
+      'Content-Type': 'application/ld+json',
+      'Cache-Control': 'public, max-age=3600'
+    }
+  });
+};

src/routes/rezepte/[name]/+page.svelte

@@ -13,6 +13,7 @@
 	import RecipeNote from '$lib/components/RecipeNote.svelte';
 	import {stripHtmlTags} from '$lib/js/stripHtmlTags';
 	import FavoriteButton from '$lib/components/FavoriteButton.svelte';
+	import { generateRecipeJsonLd } from '$lib/js/recipeJsonLd';
 
     	export let data: PageData;
 
@@ -277,6 +278,7 @@ h4{
 	<meta property="og:image:secure_url" content="https://bocken.org/static/rezepte/thumb/{data.short_name}.webp" />
 	<meta property="og:image:type" content="image/webp" />
 	<meta property="og:image:alt" content="{stripHtmlTags(data.name)}" />
+	<link rel="alternate" type="application/ld+json" href="/api/rezepte/json-ld/{data.short_name}" />
 </svelte:head>
 
 <TitleImgParallax src={hero_img_src} {placeholder_src}>