use cached::proc_macro::cached;
use futures_lite::future::block_on;
use futures_lite::{future::Boxed, FutureExt};
use hyper::client::HttpConnector;
use hyper::{body, body::Buf, client, header, Body, Client, Method, Request, Response, Uri};
use hyper_rustls::HttpsConnector;
use libflate::gzip;
use log::error;
use once_cell::sync::Lazy;
use percent_encoding::{percent_encode, CONTROLS};
use serde_json::Value;
use std::{io, result::Result};
use tokio::sync::RwLock;
use crate::dbg_msg;
use crate::oauth::{force_refresh_token, token_daemon, Oauth};
use crate::server::RequestExt;
use crate::utils::format_url;
const REDDIT_URL_BASE: &str = "https://oauth.reddit.com";
pub static CLIENT: Lazy<Client<HttpsConnector<HttpConnector>>> = Lazy::new(|| {
let https = hyper_rustls::HttpsConnectorBuilder::new()
.with_native_roots()
.expect("No native root certificates found")
.https_only()
.enable_http1()
.build();
client::Client::builder().build(https)
});
pub static OAUTH_CLIENT: Lazy<RwLock<Oauth>> = Lazy::new(|| {
let client = block_on(Oauth::new());
tokio::spawn(token_daemon());
RwLock::new(client)
});
/// Gets the canonical path for a resource on Reddit. This is accomplished by
/// making a `HEAD` request to Reddit at the path given in `path`.
///
/// This function returns `Ok(Some(path))`, where `path`'s value is identical
/// to that of the value of the argument `path`, if Reddit responds to our
/// `HEAD` request with a 2xx-family HTTP code. It will also return an
/// `Ok(Some(String))` if Reddit responds to our `HEAD` request with a
/// `Location` header in the response, and the HTTP code is in the 3xx-family;
/// the `String` will contain the path as reported in `Location`. The return
/// value is `Ok(None)` if Reddit responded with a 3xx, but did not provide a
/// `Location` header. An `Err(String)` is returned if Reddit responds with a
/// 429, or if we were unable to decode the value in the `Location` header.
#[cached(size = 1024, time = 600, result = true)]
pub async fn canonical_path(path: String) -> Result<Option<String>, String> {
let res = reddit_head(path.clone(), true).await?;
let status = res.status().as_u16();
match status {
429 => Err("Too many requests.".to_string()),
// If Reddit responds with a 2xx, then the path is already canonical.
200..=299 => Ok(Some(path)),
// If Reddit responds with a 301, then the path is redirected.
301 => match res.headers().get(header::LOCATION) {
Some(val) => {
let Ok(original) = val.to_str() else {
return Err("Unable to decode Location header.".to_string());
};
// We need to strip the .json suffix from the original path.
// In addition, we want to remove share parameters.
// Cut it off here instead of letting it propagate all the way
// to main.rs
let stripped_uri = original.strip_suffix(".json").unwrap_or(original).split('?').next().unwrap_or_default();
// The reason why we now have to format_url, is because the new OAuth
// endpoints seem to return full paths, instead of relative paths.
// So we need to strip the .json suffix from the original path, and
// also remove all Reddit domain parts with format_url.
// Otherwise, it will literally redirect to Reddit.com.
let uri = format_url(stripped_uri);
Ok(Some(uri))
}
None => Ok(None),
},
// If Reddit responds with anything other than 3xx (except for the 2xx and 301
// as above), return a None.
300..=399 => Ok(None),
_ => Ok(
res
.headers()
.get(header::LOCATION)
.map(|val| percent_encode(val.as_bytes(), CONTROLS).to_string().trim_start_matches(REDDIT_URL_BASE).to_string()),
),
}
}
pub async fn proxy(req: Request<Body>, format: &str) -> Result<Response<Body>, String> {
let mut url = format!("{format}?{}", req.uri().query().unwrap_or_default());
// For each parameter in request
for (name, value) in &req.params() {
// Fill the parameter value in the url
url = url.replace(&format!("{{{name}}}"), value);
}
stream(&url, &req).await
}
async fn stream(url: &str, req: &Request<Body>) -> Result<Response<Body>, String> {
// First parameter is target URL (mandatory).
let parsed_uri = url.parse::<Uri>().map_err(|_| "Couldn't parse URL".to_string())?;
// Build the hyper client from the HTTPS connector.
let client: Client<_, Body> = CLIENT.clone();
let mut builder = Request::get(parsed_uri);
// Copy useful headers from original request
for &key in &["Range", "If-Modified-Since", "Cache-Control"] {
if let Some(value) = req.headers().get(key) {
builder = builder.header(key, value);
}
}
let stream_request = builder.body(Body::empty()).map_err(|_| "Couldn't build empty body in stream".to_string())?;
client
.request(stream_request)
.await
.map(|mut res| {
let mut rm = |key: &str| res.headers_mut().remove(key);
rm("access-control-expose-headers");
rm("server");
rm("vary");
rm("etag");
rm("x-cdn");
rm("x-cdn-client-region");
rm("x-cdn-name");
rm("x-cdn-server-region");
rm("x-reddit-cdn");
rm("x-reddit-video-features");
rm("Nel");
rm("Report-To");
res
})
.map_err(|e| e.to_string())
}
/// Makes a GET request to Reddit at `path`. By default, this will honor HTTP
/// 3xx codes Reddit returns and will automatically redirect.
fn reddit_get(path: String, quarantine: bool) -> Boxed<Result<Response<Body>, String>> {
request(&Method::GET, path, true, quarantine)
}
/// Makes a HEAD request to Reddit at `path`. This will not follow redirects.
fn reddit_head(path: String, quarantine: bool) -> Boxed<Result<Response<Body>, String>> {
request(&Method::HEAD, path, false, quarantine)
}
/// Makes a request to Reddit. If `redirect` is `true`, `request_with_redirect`
/// will recurse on the URL that Reddit provides in the Location HTTP header
/// in its response.
fn request(method: &'static Method, path: String, redirect: bool, quarantine: bool) -> Boxed<Result<Response<Body>, String>> {
// Build Reddit URL from path.
let url = format!("{REDDIT_URL_BASE}{path}");
// Construct the hyper client from the HTTPS connector.
let client: Client<_, Body> = CLIENT.clone();
let (token, vendor_id, device_id, mut user_agent, loid) = {
let client = block_on(OAUTH_CLIENT.read());
(
client.token.clone(),
client.headers_map.get("Client-Vendor-Id").cloned().unwrap_or_default(),
client.headers_map.get("X-Reddit-Device-Id").cloned().unwrap_or_default(),
client.headers_map.get("User-Agent").cloned().unwrap_or_default(),
client.headers_map.get("x-reddit-loid").cloned().unwrap_or_default(),
)
};
// Check if multi sub requested. If so, replace "Android" with a tricky word.
if path.contains("+") {
user_agent = user_agent.replace("Android", "Andr​oid");
}
// Build request to Reddit. When making a GET, request gzip compression.
// (Reddit doesn't do brotli yet.)
let builder = Request::builder()
.method(method)
.uri(&url)
.header("User-Agent", user_agent)
.header("Client-Vendor-Id", vendor_id)
.header("X-Reddit-Device-Id", device_id)
.header("x-reddit-loid", loid)
.header("Host", "oauth.reddit.com")
.header("Authorization", &format!("Bearer {token}"))
.header("Accept-Encoding", if method == Method::GET { "gzip" } else { "identity" })
.header("Accept-Language", "en-US,en;q=0.5")
.header("Connection", "keep-alive")
.header(
"Cookie",
if quarantine {
"_options=%7B%22pref_quarantine_optin%22%3A%20true%2C%20%22pref_gated_sr_optin%22%3A%20true%7D"
} else {
""
},
)
.body(Body::empty());
async move {
match builder {
Ok(req) => match client.request(req).await {
Ok(mut response) => {
// Reddit may respond with a 3xx. Decide whether or not to
// redirect based on caller params.
if response.status().is_redirection() {
if !redirect {
return Ok(response);
};
return request(
method,
response
.headers()
.get(header::LOCATION)
.map(|val| {
// We need to make adjustments to the URI
// we get back from Reddit. Namely, we
// must:
//
// 1. Remove the authority (e.g.
// https://www.reddit.com) that may be
// present, so that we recurse on the
// path (and query parameters) as
// required.
//
// 2. Percent-encode the path.
let new_path = percent_encode(val.as_bytes(), CONTROLS).to_string().trim_start_matches(REDDIT_URL_BASE).to_string();
format!("{new_path}{}raw_json=1", if new_path.contains('?') { "&" } else { "?" })
})
.unwrap_or_default()
.to_string(),
true,
quarantine,
)
.await;
};
match response.headers().get(header::CONTENT_ENCODING) {
// Content not compressed.
None => Ok(response),
// Content encoded (hopefully with gzip).
Some(hdr) => {
match hdr.to_str() {
Ok(val) => match val {
"gzip" => {}
"identity" => return Ok(response),
_ => return Err("Reddit response was encoded with an unsupported compressor".to_string()),
},
Err(_) => return Err("Reddit response was invalid".to_string()),
}
// We get here if the body is gzip-compressed.
// The body must be something that implements
// std::io::Read, hence the conversion to
// bytes::buf::Buf and then transformation into a
// Reader.
let mut decompressed: Vec<u8>;
{
let mut aggregated_body = match body::aggregate(response.body_mut()).await {
Ok(b) => b.reader(),
Err(e) => return Err(e.to_string()),
};
let mut decoder = match gzip::Decoder::new(&mut aggregated_body) {
Ok(decoder) => decoder,
Err(e) => return Err(e.to_string()),
};
decompressed = Vec::<u8>::new();
if let Err(e) = io::copy(&mut decoder, &mut decompressed) {
return Err(e.to_string());
};
}
response.headers_mut().remove(header::CONTENT_ENCODING);
response.headers_mut().insert(header::CONTENT_LENGTH, decompressed.len().into());
*(response.body_mut()) = Body::from(decompressed);
Ok(response)
}
}
}
Err(e) => {
dbg_msg!("{} {}: {}", method, path, e);
Err(e.to_string())
}
},
Err(_) => Err("Post url contains non-ASCII characters".to_string()),
}
}
.boxed()
}
// Make a request to a Reddit API and parse the JSON response
#[cached(size = 100, time = 30, result = true)]
pub async fn json(path: String, quarantine: bool) -> Result<Value, String> {
// Closure to quickly build errors
let err = |msg: &str, e: String| -> Result<Value, String> {
// eprintln!("{} - {}: {}", url, msg, e);
Err(format!("{msg}: {e}"))
};
// Fetch the url...
match reddit_get(path.clone(), quarantine).await {
Ok(response) => {
let status = response.status();
// asynchronously aggregate the chunks of the body
match hyper::body::aggregate(response).await {
Ok(body) => {
// Parse the response from Reddit as JSON
match serde_json::from_reader(body.reader()) {
Ok(value) => {
let json: Value = value;
// If Reddit returned an error
if json["error"].is_i64() {
// OAuth token has expired; http status 401
if json["message"] == "Unauthorized" {
error!("Forcing a token refresh");
let () = force_refresh_token().await;
return Err("OAuth token has expired. Please refresh the page!".to_string());
}
Err(format!("Reddit error {} \"{}\": {}", json["error"], json["reason"], json["message"]))
} else {
Ok(json)
}
}
Err(e) => {
error!("Got an invalid response from reddit {e}. Status code: {status}");
if status.is_server_error() {
Err("Reddit is having issues, check if there's an outage".to_string())
} else {
err("Failed to parse page JSON data", e.to_string())
}
}
}
}
Err(e) => err("Failed receiving body from Reddit", e.to_string()),
}
}
Err(e) => err("Couldn't send request to Reddit", e),
}
}
#[tokio::test(flavor = "multi_thread")]
async fn test_localization_popular() {
let val = json("/r/popular/hot.json?&raw_json=1&geo_filter=GLOBAL".to_string(), false).await.unwrap();
assert_eq!("GLOBAL", val["data"]["geo_filter"].as_str().unwrap());
}
#[tokio::test(flavor = "multi_thread")]
async fn test_obfuscated_share_link() {
let share_link = "/r/rust/s/kPgq8WNHRK".into();
// Correct link without share parameters
let canonical_link = "/r/rust/comments/18t5968/why_use_tuple_struct_over_standard_struct/kfbqlbc".into();
assert_eq!(canonical_path(share_link).await, Ok(Some(canonical_link)));
}
#[tokio::test(flavor = "multi_thread")]
async fn test_share_link_strip_json() {
let link = "/17krzvz".into();
let canonical_link = "/r/nfl/comments/17krzvz/rapoport_sources_former_no_2_overall_pick/".into();
assert_eq!(canonical_path(link).await, Ok(Some(canonical_link)));
}