use std::convert::Infallible;
use std::ops::FromResidual;

use seed::fetch::{FetchError, Request};

pub mod public;

#[derive(Debug)]
pub enum NetRes<S> {
    Success(S),
    Error(model::api::Failure),
    Http(FetchError),
}

impl<S> FromResidual<Result<Infallible, NetRes<S>>> for NetRes<S> {
    fn from_residual(residual: Result<Infallible, NetRes<S>>) -> Self {
        match residual {
            Ok(_s) => unreachable!(),
            Err(s) => s,
        }
    }
}

async fn perform<S: serde::de::DeserializeOwned + 'static>(req: Request<'_>) -> NetRes<S> {
    let res = match req.fetch().await {
        Ok(res) => res,
        Err(err) => return NetRes::Http(err),
    };
    if res.status().is_error() {
        NetRes::Error(match res.json().await {
            Ok(json) => json,
            Err(_err) => match res.text().await {
                Ok(text) => model::api::Failure { errors: vec![text] },
                Err(_err) => model::api::Failure {
                    errors: vec!["There was internal server error. Please try later".into()],
                },
            },
        })
    } else {
        match res.json().await {
            Ok(json) => NetRes::Success(json),
            Err(err) => NetRes::Http(err),
        }
    }
}