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open_chess_server/http/
mod.rs

1//! HTTP handlers, grouped as Lichess's API docs group them.
2
3pub mod account;
4pub mod app_files;
5pub mod challenges;
6pub mod fairplay;
7pub mod feed;
8pub mod games;
9pub mod lab;
10pub mod oauth;
11pub mod play;
12pub mod streams;
13pub mod web;
14
15use std::convert::Infallible;
16
17use axum::Json;
18use axum::body::Body;
19use axum::extract::State;
20use axum::http::{HeaderValue, header};
21use axum::response::{IntoResponse, Response};
22use bytes::Bytes;
23use serde::Serialize;
24use serde_json::json;
25use tokio::sync::mpsc;
26
27use crate::app::Ctx;
28
29/// The open-chess logo (the Chess lab's icon, `web/chess/icon.svg`).
30pub const LOGO_SVG: &str = include_str!("logo.svg");
31
32/// The logo at `size` pixels, inline in a page.
33pub fn logo(size: u32) -> String {
34    LOGO_SVG.replacen("<svg ", &format!("<svg width=\"{size}\" height=\"{size}\" aria-hidden=\"true\" "), 1)
35}
36
37/// `GET /favicon.svg` and `/favicon.ico`: the logo (browsers take an SVG
38/// whatever the name).
39pub async fn favicon() -> Response {
40    (
41        [
42            (header::CONTENT_TYPE, HeaderValue::from_static("image/svg+xml")),
43            (header::CACHE_CONTROL, HeaderValue::from_static("public, max-age=86400")),
44        ],
45        LOGO_SVG,
46    )
47        .into_response()
48}
49
50/// `GET /docs` and `/docs/{guide}`: the guides, shown in the Chess lab
51/// (`/app/#docs/…`) when it's installed, otherwise on GitHub.
52pub async fn docs(State(ctx): State<Ctx>, guide: Option<axum::extract::Path<String>>) -> Response {
53    let name = guide
54        .map(|g| g.0.trim_end_matches(".md").to_owned())
55        .filter(|n| !n.is_empty() && n.bytes().all(|b| b.is_ascii_alphanumeric() || b == b'-'));
56    let to = if ctx.cfg.app_dir.as_deref().is_some_and(|d| !d.is_empty()) {
57        let base = ctx.cfg.base_path().unwrap_or_default();
58        match name {
59            Some(n) => format!("{base}/app/#docs/{n}"),
60            None => format!("{base}/app/#docs"),
61        }
62    } else {
63        let repo = "https://github.com/OffeneDatenmodellierung/open-chess/blob/main/docs";
64        match name {
65            Some(n) => format!("{repo}/{n}.md"),
66            None => repo.to_owned(),
67        }
68    };
69    axum::response::Redirect::to(&to).into_response()
70}
71
72/// `GET /`: what this is. Browsers go to the training app when it's
73/// installed.
74pub async fn index(State(ctx): State<Ctx>, headers: axum::http::HeaderMap) -> Response {
75    if app_files::wants_html(&headers) && ctx.cfg.app_dir.as_deref().is_some_and(|d| !d.is_empty()) {
76        let base = ctx.cfg.base_path().unwrap_or_default();
77        return axum::response::Redirect::to(&format!("{base}/app/")).into_response();
78    }
79    Json(json!({
80        "name": "open-chess",
81        "site": ctx.cfg.site_name,
82        "api": "Lichess-compatible: Board, Bot, Challenge, OAuth (PKCE), event and game streams, game export",
83        "url": ctx.cfg.public_url(),
84        "version": env!("CARGO_PKG_VERSION"),
85        // Browser sign-in (the OAuth page, the Account page): always, with
86        // this server's own accounts; "signup" whether anyone may make one;
87        // "esports" whether the host site's players sign in with it.
88        "login": true,
89        "signup": ctx.cfg.signup,
90        "esports": ctx.cfg.esports().is_some(),
91        "app": ctx.cfg.app_dir.as_deref().is_some_and(|d| !d.is_empty()).then(|| format!("{}/app/", ctx.cfg.public_url())),
92        "docs": format!("{}/docs", ctx.cfg.public_url()),
93    }))
94    .into_response()
95}
96
97pub fn ok() -> Response {
98    Json(chess_proto::OK).into_response()
99}
100
101/// One NDJSON line.
102pub fn line<T: Serialize>(v: &T) -> Bytes {
103    let mut b = serde_json::to_vec(v).unwrap_or_default();
104    b.push(b'\n');
105    Bytes::from(b)
106}
107
108/// The response half of an NDJSON stream; a task writes lines into the
109/// sender and stops when sending fails (the client went away).
110pub fn ndjson(rx: mpsc::Receiver<Bytes>) -> Response {
111    let stream = futures_util::stream::unfold(rx, |mut rx| async move {
112        rx.recv().await.map(|b| (Ok::<Bytes, Infallible>(b), rx))
113    });
114    let mut r = Body::from_stream(stream).into_response();
115    let h = r.headers_mut();
116    h.insert(header::CONTENT_TYPE, HeaderValue::from_static("application/x-ndjson"));
117    h.insert(header::CACHE_CONTROL, HeaderValue::from_static("no-cache"));
118    // Ask proxies (nginx ingress) not to buffer the stream.
119    h.insert("x-accel-buffering", HeaderValue::from_static("no"));
120    r
121}
122
123/// A urlencoded body (missing or empty is fine: no fields).
124pub fn form(body: &[u8]) -> std::collections::HashMap<String, String> {
125    url::form_urlencoded::parse(body).into_owned().collect()
126}
127
128pub fn html_escape(s: &str) -> String {
129    s.replace('&', "&amp;")
130        .replace('<', "&lt;")
131        .replace('>', "&gt;")
132        .replace('"', "&quot;")
133        .replace('\'', "&#39;")
134}
135
136#[cfg(test)]
137mod tests {
138    use super::*;
139
140    #[test]
141    fn escapes() {
142        assert_eq!(html_escape("<a href=\"x\">&'"), "&lt;a href=&quot;x&quot;&gt;&amp;&#39;");
143    }
144
145    #[test]
146    fn logo_is_the_apps_icon() {
147        // In the repository (not in a published crate) the copy here must
148        // match the Chess lab's icon.
149        let app = concat!(env!("CARGO_MANIFEST_DIR"), "/../../web/chess/icon.svg");
150        if let Ok(icon) = std::fs::read_to_string(app) {
151            assert_eq!(icon, LOGO_SVG, "copy web/chess/icon.svg to crates/chess-server/src/http/logo.svg");
152        }
153        assert!(logo(36).starts_with("<svg width=\"36\" height=\"36\""));
154    }
155
156    #[test]
157    fn lines_end_in_newline() {
158        assert_eq!(&line(&json!({"a": 1}))[..], b"{\"a\":1}\n");
159    }
160}