/// Helper functions for writing adapters.

pub mod helper {

    use super::{MessageError, Request, Response, RunId, RunResult};

    /// Read a request from stdin.

    pub fn read_request() -> Result<Request, NativeMessageError> {

        let req =

            Request::from_reader(std::io::stdin()).map_err(NativeMessageError::ReadRequest)?;

        Ok(req)

    }

    // Write response to stdout.

    fn write_response(resp: &Response) -> Result<(), NativeMessageError> {

        resp.to_writer(std::io::stdout())

            .map_err(|e| NativeMessageError::WriteResponse(resp.clone(), Box::new(e)))?;

        Ok(())

    }

    /// Write a "triggered" response to stdout.

    pub fn write_triggered(

        run_id: &RunId,

        info_url: Option<&str>,

    ) -> Result<(), NativeMessageError> {

        let response = if let Some(url) = info_url {

            Response::triggered_with_url(run_id.clone(), url)

        } else {

            Response::triggered(run_id.clone())

        };

        write_response(&response)?;

        Ok(())

    }

    /// Write a message indicating failure to stdout.

    pub fn write_failed() -> Result<(), NativeMessageError> {

        write_response(&Response::Finished {

            result: RunResult::Failure,

        })?;

        Ok(())

    }

    /// Write a message indicating success to stdout.

    pub fn write_succeeded() -> Result<(), NativeMessageError> {

        write_response(&Response::Finished {

            result: RunResult::Success,

        })?;

        Ok(())

    }

    /// Possible errors from this module.

    #[derive(Debug, thiserror::Error)]

    pub enum NativeMessageError {

        /// Error reading request from stdin.

        #[error("failed to read request from stdin: {0:?}")]

        ReadRequest(#[source] MessageError),

        /// Error writing response to stdout.

        #[error("failed to write response to stdout: {0:?}")]

        WriteResponse(Response, #[source] Box<MessageError>),

    }

}