feat: filter pings

apps/api/src/routes/monitors.ts

@@ -149,10 +149,40 @@ export const monitors = new Elysia({ prefix: "/monitors" })
       SELECT id FROM monitors WHERE id = ${params.id} AND account_id = ${accountId}
     `;
     if (!monitor) { set.status = 404; return { error: "Not found" }; }
+
     const limit = Math.min(Number(query.limit) || 100, 1000);
+    const filter = query.filter; // "up", "down", "events", or undefined/all
+    const before = query.before; // cursor: ISO timestamp for pagination
+
+    const cursorClause = before ? sql`AND checked_at < ${new Date(before)}` : sql``;
+
+    if (filter === "up") {
+      return sql`
+        SELECT * FROM pings WHERE monitor_id = ${params.id} AND up = true ${cursorClause}
+        ORDER BY checked_at DESC LIMIT ${limit}
+      `;
+    }
+    if (filter === "down") {
+      return sql`
+        SELECT * FROM pings WHERE monitor_id = ${params.id} AND up = false ${cursorClause}
+        ORDER BY checked_at DESC LIMIT ${limit}
+      `;
+    }
+    if (filter === "events") {
+      // State changes: pings where `up` differs from the previous ping's `up` for this monitor
+      return sql`
+        SELECT * FROM (
+          SELECT *, LAG(up) OVER (ORDER BY checked_at) AS prev_up
+          FROM pings WHERE monitor_id = ${params.id}
+        ) t
+        WHERE prev_up IS NULL OR up != prev_up
+        ${before ? sql`AND checked_at < ${new Date(before)}` : sql``}
+        ORDER BY checked_at DESC LIMIT ${limit}
+      `;
+    }
+
     return sql`
-      SELECT * FROM pings
-      WHERE monitor_id = ${params.id}
+      SELECT * FROM pings WHERE monitor_id = ${params.id} ${cursorClause}
       ORDER BY checked_at DESC LIMIT ${limit}
     `;
   }, { detail: { summary: "Get ping history", tags: ["monitors"] } });