add filtering and sorting features; enhance events and articles pages with URL state persistence

src/routes/admin.js

@@ -224,7 +224,7 @@ async function adminRoutes(fastify) {
     return rows.map(r => r.source);
   });
 
-  // events
+  // events — supports keyword / date range / min-article-count / sort
   fastify.get('/admin/api/events', async (request, reply) => {
     if (!checkAuth(request, reply)) return;
 
@@ -232,17 +232,66 @@ async function adminRoutes(fastify) {
     const limit = Math.min(parseInt(q.limit, 10) || 50, 200);
     const offset = parseInt(q.offset, 10) || 0;
 
-    const total = db.prepare(`SELECT COUNT(*) as n FROM events`).get().n;
+    const where = [];
+    const whereParams = [];
+
+    if (q.keyword) {
+      where.push('e.title LIKE ?');
+      whereParams.push(`%${q.keyword}%`);
+    }
+    if (q.from) {
+      where.push('e.created_at >= ?');
+      whereParams.push(q.from);
+    }
+    if (q.to) {
+      where.push('e.created_at <= ?');
+      whereParams.push(q.to);
+    }
+
+    // having filters operate on the aggregate count
+    const having = [];
+    const havingParams = [];
+    if (q.min_articles) {
+      const n = parseInt(q.min_articles, 10);
+      if (!isNaN(n)) { having.push('article_count >= ?'); havingParams.push(n); }
+    }
+
+    // whitelist sort columns + direction so user input cant break the query
+    const sortMap = {
+      created_desc:   'e.created_at DESC',
+      created_asc:    'e.created_at ASC',
+      articles_desc:  'article_count DESC',
+      articles_asc:   'article_count ASC',
+    };
+    const orderBy = sortMap[q.sort] || sortMap.created_desc;
+
+    const whereClause  = where.length  ? `WHERE ${where.join(' AND ')}`    : '';
+    const havingClause = having.length ? `HAVING ${having.join(' AND ')}`  : '';
+
+    // total count has to respect the HAVING clause too, so wrap the grouped query
+    const totalRow = db.prepare(`
+      SELECT COUNT(*) as n FROM (
+        SELECT e.id, COUNT(a.id) as article_count
+        FROM events e
+        LEFT JOIN articles a ON a.event_id = e.id
+        ${whereClause}
+        GROUP BY e.id
+        ${havingClause}
+      )
+    `).get(...whereParams, ...havingParams);
+
     const rows = db.prepare(`
       SELECT e.id, e.title, e.created_at, COUNT(a.id) as article_count
       FROM events e
       LEFT JOIN articles a ON a.event_id = e.id
+      ${whereClause}
       GROUP BY e.id
-      ORDER BY e.created_at DESC
+      ${havingClause}
+      ORDER BY ${orderBy}
       LIMIT ? OFFSET ?
-    `).all(limit, offset);
+    `).all(...whereParams, ...havingParams, limit, offset);
 
-    return { total, rows };
+    return { total: totalRow.n, rows };
   });
 
   fastify.delete('/admin/api/events/:id', async (request, reply) => {