fix: harden queue retries and quota reservation

src/api/webhooks.rs

@@ -52,11 +52,23 @@ async fn stripe_webhook(
         AppError::new(ErrorCode::InvalidRequest, "Webhook JSON 解析失败").with_source(err)
     })?;
 
-    let inserted: Option<String> = sqlx::query_scalar(
+    let claimed: Option<String> = sqlx::query_scalar(
         r#"
-        INSERT INTO webhook_events (provider, provider_event_id, event_type, payload)
-        VALUES ('stripe', $1, $2, $3)
-        ON CONFLICT (provider, provider_event_id) DO NOTHING
+        INSERT INTO webhook_events (
+          provider, provider_event_id, event_type, payload, status
+        ) VALUES ('stripe', $1, $2, $3, 'processing')
+        ON CONFLICT (provider, provider_event_id) DO UPDATE
+        SET event_type = EXCLUDED.event_type,
+            payload = EXCLUDED.payload,
+            received_at = NOW(),
+            processed_at = NULL,
+            status = 'processing',
+            error_message = NULL
+        WHERE webhook_events.status IN ('received', 'failed')
+           OR (
+             webhook_events.status = 'processing'
+             AND webhook_events.received_at < NOW() - INTERVAL '5 minutes'
+           )
         RETURNING provider_event_id
         "#,
     )
@@ -67,16 +79,29 @@ async fn stripe_webhook(
     .await
     .map_err(|err| AppError::new(ErrorCode::Internal, "Webhook 入库失败").with_source(err))?;
 
-    if inserted.is_none() {
-        return Ok(Json(Envelope {
-            success: true,
-            data: serde_json::json!({ "status": "duplicate" }),
-        }));
+    if claimed.is_none() {
+        let status: Option<String> = sqlx::query_scalar(
+            "SELECT status FROM webhook_events WHERE provider = 'stripe' AND provider_event_id = $1",
+        )
+        .bind(&event.id)
+        .fetch_optional(&state.db)
+        .await
+        .map_err(|err| AppError::new(ErrorCode::Internal, "Webhook 状态查询失败").with_source(err))?;
+        if status.as_deref() == Some("processed") {
+            return Ok(Json(Envelope {
+                success: true,
+                data: serde_json::json!({ "status": "duplicate" }),
+            }));
+        }
+        return Err(AppError::new(
+            ErrorCode::StorageUnavailable,
+            "Webhook 事件正在处理，请稍后重试",
+        ));
     }
 
     if let Err(err) = process_stripe_event(&state, &event).await {
         let _ = sqlx::query(
-            "UPDATE webhook_events SET status = 'failed', error_message = $2, processed_at = NOW() WHERE provider = 'stripe' AND provider_event_id = $1",
+            "UPDATE webhook_events SET status = 'failed', error_message = $2, processed_at = NULL WHERE provider = 'stripe' AND provider_event_id = $1 AND status = 'processing'",
         )
         .bind(&event.id)
         .bind(err.to_string())
@@ -528,7 +553,11 @@ async fn upsert_invoice(state: &AppState, object: &serde_json::Value) -> Result<
 
 fn truncate(mut s: String, max: usize) -> String {
     if s.len() > max {
-        s.truncate(max);
+        let mut end = max;
+        while !s.is_char_boundary(end) {
+            end -= 1;
+        }
+        s.truncate(end);
     }
     s
 }
@@ -552,3 +581,15 @@ fn map_invoice_status(status: &str) -> &'static str {
         _ => "open",
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn truncate_preserves_utf8_boundaries() {
+        assert_eq!(truncate("中文测试".to_string(), 5), "中");
+        assert_eq!(truncate("abc中文".to_string(), 5), "abc");
+        assert_eq!(truncate("short".to_string(), 20), "short");
+    }
+}