feat(Wikidata API): implement endpoints for fetching property labels, properties, and suggestions

src/app/api/wikidata/labels/route.ts

@@ -0,0 +1,54 @@
+import { NextRequest, NextResponse } from 'next/server';
+
+export async function POST(request: NextRequest) {
+  try {
+    const { propertyIds } = await request.json();
+
+    if (!propertyIds || !Array.isArray(propertyIds)) {
+      return NextResponse.json({ error: 'propertyIds array is required' }, { status: 400 });
+    }
+
+    const cleanIds = propertyIds.map(id => id.replace('http://www.wikidata.org/prop/', ''));
+    const propertyIdsStr = cleanIds.join(' wd:');
+    
+    const sparqlQuery = `
+      SELECT ?prop ?propLabel WHERE {
+        VALUES ?prop { wd:${propertyIdsStr} }
+        SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+      }
+    `;
+
+    const url = `https://query.wikidata.org/sparql?query=${encodeURIComponent(sparqlQuery)}&format=json`;
+    
+    const response = await fetch(url, {
+      headers: { 
+        'Accept': 'application/json',
+        'User-Agent': 'WikidataApp/1.0 (https://example.com/contact)'
+      }
+    });
+    
+    if (!response.ok) {
+      throw new Error(`Wikidata SPARQL error: ${response.status}`);
+    }
+    
+    const data = await response.json();
+    const result: Record<string, string> = {};
+    
+    if (data.results?.bindings) {
+      for (const binding of data.results.bindings) {
+        const propUri = binding.prop?.value;
+        const label = binding.propLabel?.value || '';
+        
+        if (propUri) {
+          const propId = propUri.split('/').pop() || '';
+          result[propId] = label;
+        }
+      }
+    }
+    
+    return NextResponse.json(result);
+  } catch (error) {
+    console.error('Error fetching property labels:', error);
+    return NextResponse.json({});
+  }
+}

src/app/api/wikidata/properties/route.ts

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+import { NextRequest, NextResponse } from 'next/server';
+
+export async function GET(request: NextRequest) {
+  const { searchParams } = new URL(request.url);
+  const wikidataId = searchParams.get('wikidataId');
+
+  if (!wikidataId || typeof wikidataId !== 'string') {
+    return NextResponse.json({ error: 'wikidataId parameter is required' }, { status: 400 });
+  }
+
+  try {
+    const sparqlQuery = `
+      SELECT ?prop ?propLabel ?value ?valueLabel WHERE {
+        wd:${wikidataId} ?prop ?statement.
+        ?statement ?ps ?value.
+        ?property wikibase:claim ?prop.
+        ?property wikibase:statementProperty ?ps.
+        SERVICE wikibase:label { 
+          bd:serviceParam wikibase:language "en". 
+          ?prop rdfs:label ?propLabel.
+          ?value rdfs:label ?valueLabel.
+        }
+      }
+    `;
+
+    const url = `https://query.wikidata.org/sparql?query=${encodeURIComponent(sparqlQuery)}&format=json`;
+    
+    const response = await fetch(url, {
+      headers: { 
+        'Accept': 'application/json',
+        'User-Agent': 'WikidataApp/1.0 (https://example.com/contact)'
+      }
+    });
+    
+    if (!response.ok) {
+      throw new Error(`Wikidata SPARQL error: ${response.status}`);
+    }
+    
+    const data = await response.json();
+    const result: Record<string, string> = {};
+    
+    if (data.results?.bindings) {
+      for (const binding of data.results.bindings) {
+        const propUri = binding.prop?.value;
+        const value = binding.valueLabel?.value || binding.value?.value || '';
+        
+        if (propUri) {
+          const propId = propUri.split('/').pop() || '';
+          result[propId] = value;
+        }
+      }
+    }
+    
+    return NextResponse.json(result);
+  } catch (error) {
+    console.error('Error fetching Wikidata properties:', error);
+    return NextResponse.json({});
+  }
+}

src/app/api/wikidata/suggestions/route.ts

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+import { NextRequest, NextResponse } from 'next/server';
+
+// Define interfaces for Wikidata API response
+interface WikidataSearchItem {
+  id: string;
+  label?: string;
+  description?: string;
+  concepturi?: string;
+  url?: string;
+  title?: string;
+}
+
+interface WikidataSearchResponse {
+  search?: WikidataSearchItem[];
+  searchinfo?: {
+    search: string;
+  };
+  success?: number;
+}
+
+export async function GET(request: NextRequest) {
+  const { searchParams } = new URL(request.url);
+  const query = searchParams.get('query');
+
+  if (!query || typeof query !== 'string') {
+    return NextResponse.json({ error: 'Query parameter is required' }, { status: 400 });
+  }
+
+  try {
+    const wikidataUrl = `https://www.wikidata.org/w/api.php?action=wbsearchentities&search=${encodeURIComponent(query)}&language=en&limit=5&format=json&origin=*`;
+    
+    const response = await fetch(wikidataUrl, {
+      headers: {
+        'User-Agent': 'WikidataApp/1.0 (https://example.com/contact)'
+      }
+    });
+
+    if (!response.ok) {
+      throw new Error(`Wikidata API error: ${response.status}`);
+    }
+
+    const data: WikidataSearchResponse = await response.json();
+    
+    // Transform the response to match our WikidataSuggestion interface
+    const suggestions = (data.search || []).map((item: WikidataSearchItem) => ({
+      id: item.id,
+      label: item.label || '',
+      description: item.description || ''
+    }));
+
+    return NextResponse.json(suggestions);
+  } catch (error) {
+    console.error('Error fetching Wikidata suggestions:', error);
+    return NextResponse.json({ error: 'Failed to fetch suggestions' }, { status: 500 });
+  }
+}