Riven/riven/examples/proxy/main.rs
2024-02-24 21:42:06 -08:00

196 lines
6.2 KiB
Rust

use std::convert::Infallible;
use std::sync::OnceLock;
use http::{Method, Request, Response, StatusCode};
use hyper::header::HeaderValue;
use hyper::service::{make_service_fn, service_fn};
use hyper::{http, Body, Server};
use riven::consts::Route;
use riven::{RiotApi, RiotApiConfig};
use tracing as log;
static RIOT_API: OnceLock<RiotApi> = OnceLock::new();
pub fn riot_api() -> &'static RiotApi {
RIOT_API.get_or_init(|| {
let api_key = std::env::var("RGAPI_KEY")
.ok()
.or_else(|| {
use std::iter::FromIterator;
let path =
std::path::PathBuf::from_iter([env!("CARGO_MANIFEST_DIR"), "../apikey.txt"]);
std::fs::read_to_string(path).ok()
})
.expect("Failed to find RGAPI_KEY env var or apikey.txt.");
RiotApi::new(RiotApiConfig::with_key(api_key.trim()).preconfig_burst())
})
}
/// Helper to create JSON error responses.
fn create_json_response(body: &'static str, status: StatusCode) -> Response<Body> {
let mut resp = Response::new(Body::from(body));
*resp.status_mut() = status;
resp.headers_mut().insert(
hyper::header::CONTENT_TYPE,
HeaderValue::from_static("application/json"),
);
resp
}
/// Main request handler service.
async fn handle_request(req: Request<Body>) -> Result<Response<Body>, Infallible> {
let (parts, body) = req.into_parts();
let http::request::Parts { method, uri, .. } = parts;
// Handle path.
let path_data_opt = parse_path(&method, uri.path());
let (route, method_id, req_path) = match path_data_opt {
None => {
return Ok(create_json_response(
r#"{"error":"Riot API endpoint method not found."}"#,
StatusCode::NOT_FOUND,
))
}
Some(path_data) => path_data,
};
log::debug!(
"Request to route {:?}, method ID {:?}: {} {:?}.",
route,
method_id,
method,
req_path
);
// Convert http:request::Parts from hyper to reqwest's RequestBuilder.
let body = match hyper::body::to_bytes(body).await {
Err(err) => {
log::info!("Error handling request body: {:#?}", err);
return Ok(create_json_response(
r#"{"error":"Failed to handle request body."}"#,
StatusCode::BAD_REQUEST,
));
}
Ok(bytes) => bytes,
};
let req_builder = riot_api()
.request(method, route.into(), req_path)
.body(body);
// Send request to Riot API.
let resp_result = riot_api()
.execute_raw(method_id, route.into(), req_builder)
.await;
let resp_info = match resp_result {
Err(err) => {
log::info!("Riot API error: {:#?}", err.source_reqwest_error());
return Ok(create_json_response(
r#"{"error":"Riot API request failed."}"#,
StatusCode::INTERNAL_SERVER_ERROR,
));
}
Ok(resp_info) => resp_info,
};
// Write output.
let api_response = resp_info.response;
let mut out_response = Response::default();
*out_response.headers_mut() = api_response.headers().clone();
// If None, write "null" to body to be extra nice.
if resp_info.status_none {
*out_response.body_mut() = Body::from("null");
}
// Otherwise copy body.
else {
*out_response.status_mut() = api_response.status();
// Using streams would be faster.
let bytes_result = api_response.bytes().await;
let bytes = match bytes_result {
Err(_err) => {
return Ok(create_json_response(
r#"{"error":"Failed to get body from Riot API response."}"#,
StatusCode::INTERNAL_SERVER_ERROR,
))
}
Ok(bytes) => bytes,
};
*out_response.body_mut() = Body::from(bytes);
}
Ok(out_response)
}
/// Gets the region, method_id, and Riot API path based on the given http method and path.
fn parse_path<'a>(
http_method: &Method,
req_path: &'a str,
) -> Option<(Route, &'static str, &'a str)> {
// Split URI into region and rest of path.
let req_path = req_path.trim_start_matches('/');
let (route, req_path) = req_path.split_at(req_path.find('/')?);
let route: Route = route.to_uppercase().parse().ok()?;
// Find method_id for given path.
let method_id = find_matching_method_id(http_method, req_path)?;
Some((route, method_id, req_path))
}
/// Finds the method_id given the request path.
fn find_matching_method_id(http_method: &Method, req_path: &str) -> Option<&'static str> {
for (endpoint_http_method, ref_path, method_id) in &riven::meta::ALL_ENDPOINTS {
if http_method == endpoint_http_method && paths_match(ref_path, req_path) {
return Some(method_id);
}
}
None
}
/// Checks if the request path (req_path) matches the reference path (ref_path).
fn paths_match(ref_path: &str, req_path: &str) -> bool {
let mut ref_iter = ref_path.split('/');
let mut req_iter = req_path.split('/');
loop {
match (ref_iter.next(), req_iter.next()) {
(None, None) => return true,
(Some(ref_seg), Some(req_seg)) => {
if ref_seg.starts_with('{') || ref_seg == req_seg {
continue;
}
return false;
}
_ => return false,
}
}
}
#[tokio::main]
pub async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
// Setup loggers.
// env_logger::init();
tracing_subscriber::fmt::init();
// Trigger initialization.
let _ = riot_api();
// For every connection, we must make a `Service` to handle all
// incoming HTTP requests on said connection.
let make_svc = make_service_fn(|_conn| {
// This is the `Service` that will handle the connection.
// `service_fn` is a helper to convert a function that
// returns a Response into a `Service`.
async { Ok::<_, Infallible>(service_fn(handle_request)) }
});
let addr = ([127, 0, 0, 1], 3000).into();
let server = Server::bind(&addr).serve(make_svc);
log::info!("Listening on http://{}", addr);
server.await?;
Ok(())
}