Update RDB.DeleteTask with task state

internal/rdb/inspect.go

@@ -743,77 +743,79 @@ func (r *RDB) archiveAll(src, dst, qname string) (int64, error) {
 	return n, nil
 }
 
-// DeleteArchivedTask deletes an archived task that matches the given id and score from the given queue.
-// If a task that matches the id and score does not exist, it returns ErrTaskNotFound.
-func (r *RDB) DeleteArchivedTask(qname string, id uuid.UUID) error {
-	return r.deleteTask(base.ArchivedKey(qname), qname, id.String())
-}
-
-// DeleteRetryTask deletes a retry task that matches the given id and score from the given queue.
-// If a task that matches the id and score does not exist, it returns ErrTaskNotFound.
-func (r *RDB) DeleteRetryTask(qname string, id uuid.UUID) error {
-	return r.deleteTask(base.RetryKey(qname), qname, id.String())
-}
-
-// DeleteScheduledTask deletes a scheduled task that matches the given id and score from the given queue.
-// If a task that matches the id and score does not exist, it returns ErrTaskNotFound.
-func (r *RDB) DeleteScheduledTask(qname string, id uuid.UUID) error {
-	return r.deleteTask(base.ScheduledKey(qname), qname, id.String())
-}
-
-// KEYS[1] -> asynq:{<qname>}:pending
-// KEYS[2] -> asynq:{<qname>}:t:<task_id>
-// ARGV[1] -> task ID
-var deletePendingTaskCmd = redis.NewScript(`
-if redis.call("LREM", KEYS[1], 0, ARGV[1]) == 0 then
-	return 0
-end
-return redis.call("DEL", KEYS[2])
-`)
-
-// DeletePendingTask deletes a pending tasks that matches the given id from the given queue.
-// If there's no match, it returns ErrTaskNotFound.
-func (r *RDB) DeletePendingTask(qname string, id uuid.UUID) error {
-	keys := []string{base.PendingKey(qname), base.TaskKey(qname, id.String())}
-	res, err := deletePendingTaskCmd.Run(r.client, keys, id.String()).Result()
-	if err != nil {
-		return err
-	}
-	n, ok := res.(int64)
-	if !ok {
-		return fmt.Errorf("command error: unexpected return value %v", res)
-	}
-	if n == 0 {
-		return ErrTaskNotFound
-	}
-	return nil
-}
-
-// KEYS[1] -> ZSET key to remove the task from (e.g. asynq:{<qname>}:retry)
-// KEYS[2] -> asynq:{<qname>}:t:<task_id>
+// Input:
+// KEYS[1] -> asynq:{<qname>}:t:<task_id>
+// KEYS[2] -> all queues key
 // ARGV[1] -> task ID
+// ARGV[2] -> queue key prefix
+// ARGV[3] -> queue name
+//
+// Output:
+// Numeric code indicating the status:
+// Returns 1 if task is successfully deleted.
+// Returns 0 if task is not found.
+// Returns -1 if queue doesn't exist.
+// Returns -2 if task is in active state.
 var deleteTaskCmd = redis.NewScript(`
-if redis.call("ZREM", KEYS[1], ARGV[1]) == 0 then
+if redis.call("SISMEMBER", KEYS[2], ARGV[3]) == 0 then
+	return -1
+end
+if redis.call("EXISTS", KEYS[1]) == 0 then
 	return 0
 end
-return redis.call("DEL", KEYS[2])
+local state = redis.call("HGET", KEYS[1], "state")
+if state == "active" then
+	return -2
+end
+if state == "pending" then
+	if redis.call("LREM", ARGV[2] .. state, 0, ARGV[1]) == 0 then
+		return redis.error_reply("task is not found in list: " .. tostring(state))
+	end
+else
+	if redis.call("ZREM", ARGV[2] .. state, ARGV[1]) == 0 then
+		return redis.error_reply("task is not found in zset: " .. tostring(state))
+	end
+end
+return redis.call("DEL", KEYS[1])
 `)
 
-func (r *RDB) deleteTask(key, qname, id string) error {
-	keys := []string{key, base.TaskKey(qname, id)}
-	argv := []interface{}{id}
+// DeleteTask finds a task that matches the id from the given queue and deletes it.
+// It returns nil if it successfully archived the task.
+//
+// If a queue with the given name doesn't exist, it returns QueueNotFoundError.
+// If a task with the given id doesn't exist in the queue, it returns TaskNotFoundError
+// If a task is in active state it returns non-nil error with Code FailedPrecondition.
+func (r *RDB) DeleteTask(qname string, id uuid.UUID) error {
+	var op errors.Op = "rdb.DeleteTask"
+	keys := []string{
+		base.TaskKey(qname, id.String()),
+		base.AllQueues,
+	}
+	argv := []interface{}{
+		id.String(),
+		base.QueueKeyPrefix(qname),
+		qname,
+	}
 	res, err := deleteTaskCmd.Run(r.client, keys, argv...).Result()
 	if err != nil {
-		return err
+		return errors.E(op, errors.Unknown, err)
 	}
 	n, ok := res.(int64)
 	if !ok {
-		return fmt.Errorf("command error: unexpected return value %v", res)
+		return errors.E(op, errors.Internal, fmt.Sprintf("cast error: deleteTaskCmd script returned unexported value %v", res))
 	}
-	if n == 0 {
-		return ErrTaskNotFound
+	switch n {
+	case 1:
+		return nil
+	case 0:
+		return errors.E(op, errors.NotFound, &errors.TaskNotFoundError{Queue: qname, ID: id.String()})
+	case -1:
+		return errors.E(op, errors.NotFound, &errors.QueueNotFoundError{Queue: qname})
+	case -2:
+		return errors.E(op, errors.FailedPrecondition, "cannot delete task in active state. use CancelTask instead.")
+	default:
+		return errors.E(op, errors.Internal, fmt.Sprintf("unexpected return value from deleteTaskCmd script: %d", n))
 	}
-	return nil
 }
 
 // KEYS[1] -> queue to delete