fix(voice): recover empty failed lessons

server/src/recording_routes.rs

@@ -38,6 +38,7 @@ pub fn router() -> OpenApiRouter<SharedState> {
         .routes(routes!(finish_lesson_session))
         .routes(routes!(mark_lesson_applied))
         .routes(routes!(retry_audio_segment))
+        .routes(routes!(discard_empty_failed_lesson))
         .routes(routes!(discard_audio_segment))
         .routes(routes!(create_feedback_summary_run))
         .routes(routes!(get_feedback_summary_run))
@@ -796,6 +797,67 @@ async fn retry_audio_segment(
     }))
 }
 
+#[utoipa::path(
+    delete,
+    path = "/api/v1/feedback-lessons/{lesson_id}",
+    tag = "语音反馈",
+    summary = "删除未保留音频的失败课堂",
+    description = "删除没有任何录音片段、因而无法重试转录的失败课堂记录。",
+    params(
+        ("Authorization" = String, Header, description = "Bearer 会话令牌", example = "Bearer <access-token>"),
+        ("lesson_id" = Uuid, Path, description = "失败课堂录音 ID")
+    ),
+    responses(
+        (status = 204, description = "空失败课堂已删除"),
+        (status = 404, description = "课堂不存在、不属于当前用户或仍包含录音片段", body = ErrorBody),
+        CommonApiErrors
+    )
+)]
+async fn discard_empty_failed_lesson(
+    State(state): State<SharedState>,
+    headers: HeaderMap,
+    Path(lesson_id): Path<Uuid>,
+) -> Result<StatusCode, ApiError> {
+    let owner_id = state
+        .auth
+        .authenticate(state.pool.as_ref(), &headers)
+        .await?
+        .user_id;
+    let mut transaction = pool(&state)?.begin().await?;
+    let session_id = sqlx::query_scalar::<_, Uuid>(
+        "SELECT f.id FROM lesson_sessions l \
+         JOIN feedback_sessions f ON f.id = l.feedback_session_id \
+         WHERE l.id = $1 AND f.owner_id = $2 AND f.status = 'active' \
+           AND l.status = 'failed' \
+           AND NOT EXISTS (SELECT 1 FROM audio_segments s WHERE s.lesson_session_id = l.id) \
+         FOR UPDATE OF l",
+    )
+    .bind(lesson_id)
+    .bind(owner_id)
+    .fetch_optional(&mut *transaction)
+    .await?
+    .ok_or(ApiError::NotFound)?;
+
+    sqlx::query("DELETE FROM lesson_sessions WHERE id = $1")
+        .bind(lesson_id)
+        .execute(&mut *transaction)
+        .await?;
+    sqlx::query("UPDATE feedback_sessions SET updated_at = now() WHERE id = $1")
+        .bind(session_id)
+        .execute(&mut *transaction)
+        .await?;
+    transaction.commit().await?;
+
+    tracing::info!(
+        event = "empty_failed_lesson_discarded",
+        feedback_session_id = %session_id,
+        lesson_id = %lesson_id,
+        status = "discarded",
+        "empty failed lesson discarded"
+    );
+    Ok(StatusCode::NO_CONTENT)
+}
+
 #[utoipa::path(
     delete,
     path = "/api/v1/audio-segments/{segment_id}",

server/src/routes.rs

@@ -924,7 +924,8 @@ mod tests {
             .filter(|operation| operation.get("responses").is_some())
             .collect::<Vec<_>>();
 
-        assert_eq!(operations.len(), 27);
+        assert_eq!(operations.len(), 28);
+        assert!(paths.contains_key("/api/v1/feedback-lessons/{lesson_id}"));
         assert!(paths.contains_key("/api/v1/feedback-sessions/{session_id}/summary-runs"));
         assert!(paths.contains_key("/api/v1/feedback-summary-runs/{run_id}"));
         assert!(paths.contains_key("/api/v1/feedback-summary-runs/{run_id}/apply"));