feat: auto-pin entries with ≥10 votes and ≥80% approval

lib/api/auto-pin.ts

@@ -0,0 +1,51 @@
+import { db } from "@/lib/db/index"
+import { performanceEntries } from "@/lib/db/schema"
+import { eq, and } from "drizzle-orm"
+
+/**
+ * Auto-pin check: an entry is eligible for auto-pinning when:
+ * 1. NOT already pinned (isPinned = false)
+ * 2. NOT removed (isRemoved = false)
+ * 3. Total votes >= 10 (upvotes + downvotes)
+ * 4. Approval ratio >= 0.80 (upvotes / total_votes)
+ * 5. Absolute upvotes >= 8
+ */
+const AUTO_PIN_MIN_TOTAL_VOTES = 10
+const AUTO_PIN_MIN_APPROVAL_RATIO = 0.80
+const AUTO_PIN_MIN_UPVOTES = 8
+
+export async function checkAndAutoPin(entryId: string): Promise<boolean> {
+  const [entry] = await db
+    .select({
+      id: performanceEntries.id,
+      isPinned: performanceEntries.isPinned,
+      isRemoved: performanceEntries.isRemoved,
+      upvotes: performanceEntries.upvotes,
+      downvotes: performanceEntries.downvotes,
+    })
+    .from(performanceEntries)
+    .where(eq(performanceEntries.id, entryId))
+    .limit(1)
+
+  if (!entry) return false
+  if (entry.isPinned) return false
+  if (entry.isRemoved) return false
+
+  const totalVotes = entry.upvotes + entry.downvotes
+  if (totalVotes < AUTO_PIN_MIN_TOTAL_VOTES) return false
+  if (entry.upvotes < AUTO_PIN_MIN_UPVOTES) return false
+
+  const approvalRatio = entry.upvotes / totalVotes
+  if (approvalRatio < AUTO_PIN_MIN_APPROVAL_RATIO) return false
+
+  // Conditions met — auto-pin
+  await db
+    .update(performanceEntries)
+    .set({
+      isPinned: true,
+      pinnedAt: new Date(),
+    })
+    .where(eq(performanceEntries.id, entryId))
+
+  return true
+}