chore: enhance error handling and optimize database queries in user credit functions

src/credits/credits.ts

@@ -13,13 +13,23 @@ import { CREDIT_TRANSACTION_TYPE } from './types';
  * @returns User's current credit balance
  */
 export async function getUserCredits(userId: string): Promise<number> {
+  try {
     const db = await getDb();
+
+    // Optimized query: only select the needed field
+    // This can benefit from covering index if we add one later
     const record = await db
-    .select()
+      .select({ currentCredits: userCredit.currentCredits })
       .from(userCredit)
       .where(eq(userCredit.userId, userId))
       .limit(1);
+
     return record[0]?.currentCredits || 0;
+  } catch (error) {
+    console.error('getUserCredits, error:', error);
+    // Return 0 on error to prevent UI from breaking
+    return 0;
+  }
 }
 
 /**
@@ -28,11 +38,15 @@ export async function getUserCredits(userId: string): Promise<number> {
  * @param credits - New credit balance
  */
 export async function updateUserCredits(userId: string, credits: number) {
+  try {
     const db = await getDb();
     await db
       .update(userCredit)
       .set({ currentCredits: credits, updatedAt: new Date() })
       .where(eq(userCredit.userId, userId));
+  } catch (error) {
+    console.error('updateUserCredits, error:', error);
+  }
 }
 
 /**
@@ -41,11 +55,15 @@ export async function updateUserCredits(userId: string, credits: number) {
  * @param date - Last refresh time
  */
 export async function updateUserLastRefreshAt(userId: string, date: Date) {
+  try {
     const db = await getDb();
     await db
       .update(userCredit)
       .set({ lastRefreshAt: date, updatedAt: new Date() })
       .where(eq(userCredit.userId, userId));
+  } catch (error) {
+    console.error('updateUserLastRefreshAt, error:', error);
+  }
 }
 
 /**