/*
 * Copyright 2024-2025 NVIDIA CORPORATION & AFFILIATES
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

use super::*;
use crate::Error;

impl<Resp: PipelineIO> Default for SinkEdge<Resp> {
    fn default() -> Self {
        Self {
            edge: OnceLock::new(),
        }
    }
}

#[async_trait]
impl<Resp: PipelineIO> Source<Resp> for SinkEdge<Resp> {
    async fn on_next(&self, data: Resp, _: Token) -> Result<(), Error> {
        self.edge
            .get()
            .ok_or(PipelineError::NoEdge)?
            .write(data)
            .await
    }

    fn set_edge(&self, edge: Edge<Resp>, _: Token) -> Result<(), PipelineError> {
        self.edge
            .set(edge)
            .map_err(|_| PipelineError::EdgeAlreadySet)?;
        Ok(())
    }
}