use actix_web::body::{BoxBody, MessageBody};
use actix_web::dev::{ServiceRequest, ServiceResponse};
use actix_web::http::header::{HeaderName, HeaderValue};
use actix_web::middleware::Next;
use actix_web::{Error, HttpMessage};

pub use envelope::RequestId;
pub use envelope::context::{request_id, resolve_request_id, with_request_id};

pub const REQUEST_ID_HEADER: HeaderName = HeaderName::from_static(envelope::REQUEST_ID_HEADER);

pub async fn trace_request<B>(
    request: ServiceRequest,
    next: Next<B>,
) -> Result<ServiceResponse<BoxBody>, Error>
where
    B: MessageBody + 'static,
{
    let request_id = RequestId::from_header(header(&request));

    request.extensions_mut().insert(request_id.clone());

    let response =
        envelope::context::with_request_id(Some(request_id.as_str()), next.call(request)).await?;
    let mut response = response.map_into_boxed_body();
    if let Ok(value) = HeaderValue::try_from(request_id.as_str()) {
        response.headers_mut().insert(REQUEST_ID_HEADER, value);
    }
    Ok(response)
}

fn header(request: &ServiceRequest) -> Option<&str> {
    request
        .headers()
        .get(&REQUEST_ID_HEADER)
        .and_then(|value| value.to_str().ok())
}