use crate::api_types::{EndpointVersion, ForkVersionedResponse};
use eth2::CONSENSUS_VERSION_HEADER;
use serde::Serialize;
use types::{ForkName, InconsistentFork};
use warp::reply::{self, Reply, WithHeader};

pub const V1: EndpointVersion = EndpointVersion(1);
pub const V2: EndpointVersion = EndpointVersion(2);

pub fn fork_versioned_response<T: Serialize>(
    endpoint_version: EndpointVersion,
    fork_name: ForkName,
    data: T,
) -> Result<ForkVersionedResponse<T>, warp::reject::Rejection> {
    let fork_name = if endpoint_version == V1 {
        None
    } else if endpoint_version == V2 {
        Some(fork_name)
    } else {
        return Err(unsupported_version_rejection(endpoint_version));
    };
    Ok(ForkVersionedResponse {
        version: fork_name,
        data,
    })
}

/// Add the `Eth-Consensus-Version` header to a response.
pub fn add_consensus_version_header<T: Reply>(reply: T, fork_name: ForkName) -> WithHeader<T> {
    reply::with_header(reply, CONSENSUS_VERSION_HEADER, fork_name.to_string())
}

pub fn inconsistent_fork_rejection(error: InconsistentFork) -> warp::reject::Rejection {
    warp_utils::reject::custom_server_error(format!("wrong fork: {:?}", error))
}

pub fn unsupported_version_rejection(version: EndpointVersion) -> warp::reject::Rejection {
    warp_utils::reject::custom_bad_request(format!("Unsupported endpoint version: {}", version))
}