From 7e4da5f0de16c35ce304620bd37b08d57ff46858 Mon Sep 17 00:00:00 2001
From: alyx <alyx@aleteoryx.me>
Date: Fri, 12 Jan 2024 01:28:22 -0500
Subject: [PATCH] Custom font support complete

---
 TODO.md              | 62 ++++++++++++++++++++-------------
 src/config.rs        | 83 ++++++++++++++++++++++++++++++++------------
 src/ctx.rs           | 35 ++++++++++++++-----
 src/font.rs          |  1 +
 src/main.rs          |  3 +-
 src/themes/plain.hbs |  8 ++---
 6 files changed, 131 insertions(+), 61 deletions(-)

diff --git a/TODO.md b/TODO.md
index e6cfb75..d55c742 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,32 +1,10 @@
 # Future plans for this project:
 
 
-## Custom Fonts
-
-For ease-of-inclusion this should probably be handled by internal code, and provided as a set of properties on `lfm_embed::ctx::model::Data`.
-
-There are 3 main kinds of fonts we should support.
-- User-hosted fonts. These would be loaded directly from a link to a TTF,WOFF2,etc font file.
-- Google fonts fonts. In theory, we'd proxy these, but that's not 100% necessary.
-- Named fonts. e.x. 'serif', 'sans-serif', 'monospace'. Browser will handle these.
-
-There is no good way to expose a typed enum with the current wizard UI, and the resulting UI from this could allow added user flexibility.
-
-### Query Parameters
-
-- `?font=foo` corresponds directly with `* { font-family: 'foo' }` in the CSS.
-- `?font=foo&include-font=https://example.com/font.otf` will additionally append `@font-face { font-family: 'foo' src: url('https://example.com/font.otf') }`.
-- `?include-stylesheet` allows for general stylesheet inclusion. It may be specified N times.
-
-### Context Members
-
-- `font: object` null if no font params specified.
-- `font.name: string` contains `?font`
-- `font.additional_css` will contain the `?include-font` css, as well as the proxied contents of `?include-stylesheet`.
-
-
 ## Move more things internal
 
+Untouched.
+
 Of the crates currently relied on, the following appear too feature-packed should be replaced with simpler internal code, to reduce binary size.
 
 - duration-str
@@ -35,6 +13,8 @@ Of the crates currently relied on, the following appear too feature-packed shoul
 
 ## Watermarking
 
+Untouched.
+
 Support for a limited form of (optional) watermaking. It would be up to the themes to include it.
 
 ### Query Parameters
@@ -64,12 +44,16 @@ A warning should be output on startup.
 
 ## Additional Helpers
 
+Untouched.
+
 - `(range Number start: Number = 0): Number` Generates values from start to the main argument, exclusive.
 - `(random): Number` Generates a random float.
 
 
 ## Additional Services to Support
 
+Untouched.
+
 This should be as transparent as possible to the theme and end-user.
 
 ### Services
@@ -94,3 +78,33 @@ This should be as transparent as possible to the theme and end-user.
 - `user.service` never not null
 - `user.service.type` `(audioscrobbler|listenbrainz|gnukebox)`
 - `user.service.domain` the string for the service's domain.
+
+
+## Error Cache
+
+Untouched.
+
+Add support to `lfm_embed::cache::AsyncCache` for caching `Err` values with a different lifetime from `Ok` values.
+
+
+# Completed Features
+
+
+## Custom Fonts
+
+Implemented!
+
+### Query Parameters
+
+Each of these are mutually exclusive, and take priority over eachother in the order listed below.
+The highest one detected will be handled and others, if present, will be silently ignored.
+
+- `?google_font=` the name of a google font to try loading. If it exists, the `fonts.googleapis.com` stylesheet will end up in `font.css`. The font name will end up in `font.name`.
+- `?include_font=` the URL to a font to include. `font.css` will be a generated `@font-family` declaration. A provided name will be in `font.name`.
+- `?font=` the name of a browser-native or system font. This will only set `font.name`.
+
+### Context Members
+
+- `font: object` null if no font overrides are present.
+- `font.name: string` All text elements should have their font set to this.
+- `font.css` If present, it should be placed inside a `<style>` tag somewhere. For legibility of generated HTML, preferably its own tag.
diff --git a/src/config.rs b/src/config.rs
index 4c5d4b7..8492f8b 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -20,18 +20,18 @@ pub static STATE: LazyLock<Arc<State>> = LazyLock::new(|| {
     State::new()
 });
 
-fn getter(username: &String) -> Pin<Box<(dyn Future<Output = Result<Arc<(User, Track)>, (StatusCode, &'static str)>> + Send + Sync)>> {
+fn user_getter(username: &String) -> Pin<Box<(dyn Future<Output = Result<Arc<(User, Track)>, (StatusCode, &'static str)>> + Send + Sync)>> {
     let username = urlencoding::encode(username.as_ref()).to_string();
     Box::pin(async move {
-        let userreq = STATE.http.get(format!("https://ws.audioscrobbler.com/2.0/?method=user.getInfo&format=json&user={username}&api_key={}", STATE.api_key))
+        let userreq = STATE.http.get(format!("https://ws.audioscrobbler.com/2.0/?method=user.getInfo&format=json&user={username}&api_key={}", STATE.lastfm_api_key))
             .send().await
             .map_err(|e| {log::error!("Failed to get info for user `{username}`: {e}"); (StatusCode::SERVICE_UNAVAILABLE, "Couldn't connect to last.fm!")})?;
         if userreq.status() == StatusCode::NOT_FOUND { return Err((StatusCode::NOT_FOUND, "User does not exist!")); }
 
         let userinfo = userreq.json::<GetUserInfo>().await
             .map_err(|e| {log::error!("Couldn't parse user.getInfo for `{username}`: {e}"); (StatusCode::INTERNAL_SERVER_ERROR, "Couldn't parse user.getInfo!")})?.user;
-        
-        let tracksreq = STATE.http.get(format!("https://ws.audioscrobbler.com/2.0/?method=user.getRecentTracks&format=json&extended=1&limit=1&user={username}&api_key={}", STATE.api_key))
+
+        let tracksreq = STATE.http.get(format!("https://ws.audioscrobbler.com/2.0/?method=user.getRecentTracks&format=json&extended=1&limit=1&user={username}&api_key={}", STATE.lastfm_api_key))
             .send().await
             .map_err(|e| {log::error!("Failed to get tracks for user `{username}`: {e}"); (StatusCode::SERVICE_UNAVAILABLE, "Couldn't connect to last.fm!")})?;
         if tracksreq.status() == StatusCode::NOT_FOUND { return Err((StatusCode::NOT_FOUND, "User does not exist!")); }
@@ -44,23 +44,55 @@ fn getter(username: &String) -> Pin<Box<(dyn Future<Output = Result<Arc<(User, T
         Ok(Arc::new((userinfo, tracksinfo)))
     })
 }
-type Getter = fn(&String) -> Pin<Box<(dyn Future<Output = Result<Arc<(User, Track)>, (StatusCode, &'static str)>> + Send + Sync)>>;
-type Cache = Arc<RwLock<AsyncCache<String, Arc<(User, Track)>, Getter>>>;
+
+fn font_getter(fontname: &String) -> Pin<Box<(dyn Future<Output = Result<Arc<str>, (StatusCode, &'static str)>> + Send + Sync)>> {
+  let fontname = urlencoding::encode(fontname.as_ref()).to_string();
+  Box::pin(async move {
+    let Some(google_api_key) = STATE.google_api_key.clone()
+    else {
+      unreachable!();
+    };
+
+    let fontreq = STATE.http.get(format!("https://www.googleapis.com/webfonts/v1/webfonts?key={}&family={fontname}", google_api_key))
+      .send().await
+      .map_err(|e| {log::error!("Failed to get info for font `{fontname}`: {e}"); (StatusCode::SERVICE_UNAVAILABLE, "Couldn't connect to Google Fonts!")})?;
+    if fontreq.status() == StatusCode::NOT_FOUND { return Err((StatusCode::NOT_FOUND, "Font does not exist!")); }
+    if fontreq.status() == StatusCode::FORBIDDEN {
+      log::error!("Invalid Google API key in config!");
+      return Err((StatusCode::SERVICE_UNAVAILABLE, "This instance is not configured to support Google Fonts properly, please use a different font."));
+    }
+
+    let cssreq = STATE.http.get(format!("https://fonts.googleapis.com/css2?family={fontname}"))
+      .send().await
+      .map_err(|e| {log::error!("Failed to get CSS for font `{fontname}`: {e}"); (StatusCode::SERVICE_UNAVAILABLE, "Couldn't download font CSS!")})?;
+
+    Ok(cssreq.text().await.unwrap().into())
+  })
+}
+
+type UserGetter = fn(&String) -> Pin<Box<(dyn Future<Output = Result<Arc<(User, Track)>, (StatusCode, &'static str)>> + Send + Sync)>>;
+type UserCache = Arc<RwLock<AsyncCache<String, Arc<(User, Track)>, UserGetter>>>;
+type FontGetter = fn(&String) -> Pin<Box<(dyn Future<Output = Result<Arc<str>, (StatusCode, &'static str)>> + Send + Sync)>>;
+type FontCache = Arc<RwLock<AsyncCache<String, Arc<str>, FontGetter>>>;
 #[derive(Debug)]
 enum Whitelist {
-    Exclusive{cache: Cache, whitelist: HashSet<String>},
-    Open{default_cache: Cache, whitelist_cache: Cache, whitelist: HashSet<String>}
+    Exclusive{cache: UserCache, whitelist: HashSet<String>},
+    Open{default_cache: UserCache, whitelist_cache: UserCache, whitelist: HashSet<String>}
 }
 #[derive(Debug)]
 pub struct State {
-    api_key: Arc<str>,
+    lastfm_api_key: Arc<str>,
+    google_api_key: Option<Arc<str>>,
     whitelist: Whitelist,
     port: u16,
+
     handlebars: Handlebars<'static>,
     default_theme: Arc<str>,
     send_refresh_header: bool,
     http: Client,
 
+    google_fonts_cache: FontCache,
+
     default_refresh: Duration,
     whitelist_refresh: Duration,
 }
@@ -68,33 +100,33 @@ pub struct State {
 impl State {
     fn new() -> Arc<Self> {
         let duration_from_var = |v: &str, d: u64| -> Duration {var(v).map(|r| ds::parse(&r).expect("bad duration string")).unwrap_or_else(|_| Duration::from_secs(d))};
-        let cache_from_duration = |d: Duration| -> Cache {
-            Arc::new(RwLock::new(AsyncCache::new(d, getter as Getter)))
+        let user_cache_from_duration = |d: Duration| -> UserCache {
+            Arc::new(RwLock::new(AsyncCache::new(d, user_getter as UserGetter)))
         };
         let default_refresh = duration_from_var("LFME_DEFAULT_REFRESH", 300);
         let whitelist_refresh = duration_from_var("LFME_WHITELIST_REFRESH", 60);
-        let default_cache = cache_from_duration(default_refresh);
-        let whitelist_cache = cache_from_duration(whitelist_refresh);
+        let default_cache = user_cache_from_duration(default_refresh);
+        let whitelist_cache = user_cache_from_duration(whitelist_refresh);
 
         Arc::new(State {
-            api_key: var("LFME_API_KEY").expect("API key must be set").into(),
+            lastfm_api_key: var("LFME_LASTFM_API_KEY").expect("last.fm API key must be set").into(),
             port: var("LFME_PORT").map(|p| p.parse().expect("cannot parse as a port number")).unwrap_or(9999),
             send_refresh_header: !var("LFME_NO_REFRESH").map(|h| &h == "1").unwrap_or(false),
             http: Client::builder().https_only(true).user_agent(concat!(env!("CARGO_PKG_NAME"), "/", env!("CARGO_PKG_VERSION"))).build().unwrap(),
-            
+
             handlebars: {
                 let mut hb = Handlebars::new();
-                
+
                 handlebars_helper!(url_encode: |s: String| urlencoding::encode(&s));
 
                 hb.register_helper("url-encode", Box::new(url_encode));
-                
+
                 for (key, fulltext) in INTERNAL_THEMES {
                     log::info!(target: "lfm::config::theme", "Registering internal theme `{key}`");
                     hb.register_template_string(key, fulltext).unwrap();
                 }
                 hb.set_dev_mode(var("LFME_THEME_DEV").map(|h| &h == "1").unwrap_or(false));
-                
+
                 if let Ok(themes_dir) = var("LFME_THEME_DIR") {
                     log::info!(target: "lfm::config::theme", "Registering theme dir `{themes_dir}`");
                     hb.register_templates_directory(&var("LFME_THEME_EXT").unwrap_or_else(|_| ".hbs".into()), themes_dir).unwrap();
@@ -103,14 +135,17 @@ impl State {
                 hb
             },
             default_theme: var("LFME_THEME_DEFAULT").map(Into::into).unwrap_or_else(|_| "plain".into()),
-            
+
+            google_api_key: var("LFME_GOOGLE_API_KEY").map(Into::into).ok(),
+            google_fonts_cache: Arc::new(RwLock::new(AsyncCache::new(Duration::from_secs(86400), font_getter as FontGetter))),
+
             whitelist: {
                 let load_whitelist = || -> Option<HashSet<String>> {
                     var("LFME_WHITELIST").ok().map(
-                        |w| w.split(",").map(|s| s.trim().to_string()).collect()                           
+                        |w| w.split(",").map(|s| s.trim().to_string()).collect()
                     )
                 };
-                
+
                 match var("LFME_WHITELIST_MODE").map(|m| m.to_ascii_lowercase()).unwrap_or_else(|_| "open".into()).as_str() {
                     "open" => {
                         Whitelist::Open{default_cache, whitelist_cache, whitelist: load_whitelist().unwrap_or_default()}
@@ -127,9 +162,13 @@ impl State {
             whitelist_refresh: whitelist_refresh + Duration::from_secs(1)
         })
     }
-    
+
     pub fn port(&self) -> u16 { self.port }
     pub fn send_refresh_header(&self) -> bool { self.send_refresh_header }
+    pub async fn get_fontinfo(&self, font: &String) -> Result<Arc<str>, (StatusCode, &'static str)> {
+      self.google_fonts_cache.write().await.get_owned(font).await
+    }
+    pub fn has_google_api_key(&self) -> bool { self.google_api_key.is_some() }
     pub async fn get_userinfo(&self, user: &String) -> (Result<Arc<(User, Track)>, (StatusCode, &'static str)>, Duration) {
         match &self.whitelist {
             Whitelist::Open{default_cache, whitelist_cache, whitelist} => {
diff --git a/src/ctx.rs b/src/ctx.rs
index 904667d..df910bd 100644
--- a/src/ctx.rs
+++ b/src/ctx.rs
@@ -3,6 +3,7 @@ use super::deserialize as de;
 use std::sync::Arc;
 use std::collections::BTreeMap;
 use super::font::FontQuery;
+use super::config::STATE;
 
 pub mod model {
     use std::sync::Arc;
@@ -70,7 +71,7 @@ pub mod model {
     #[derive(serde::Serialize, Debug)]
     #[serde(untagged)]
     pub enum Font {
-        Url { css: Arc<str> },
+        External { css: Arc<str>, name: Arc<str> },
         Name { name: Arc<str> },
     }
 
@@ -89,10 +90,9 @@ pub mod model {
 #[derive(Debug)]
 pub struct ResponseCtx(pub model::Data, pub StatusCode);
 
-impl From<(Result<Arc<(de::User, de::Track)>, (StatusCode, &'static str)>, Option<FontQuery>, BTreeMap<String, String>)> for ResponseCtx {
-    fn from(v: (Result<Arc<(de::User, de::Track)>, (StatusCode, &'static str)>, Option<FontQuery>, BTreeMap<String, String>)) -> ResponseCtx {
-        let (v, f, q) = v;
-        match v {
+impl ResponseCtx {
+    pub async fn create(api_result: Result<Arc<(de::User, de::Track)>, (StatusCode, &'static str)>, font_query: Option<FontQuery>, query: BTreeMap<String, String>) -> ResponseCtx {
+        match api_result {
             Ok(a) => {
                 let (user, track) = a.as_ref();
                 ResponseCtx(model::Data::Data {
@@ -123,12 +123,29 @@ impl From<(Result<Arc<(de::User, de::Track)>, (StatusCode, &'static str)>, Optio
                         url: track.url.clone(),
                         loved: track.loved.unwrap_or(false)
                     },
-                    font: match f {
-                        Some(FontQuery { font: Some(s), include_font: None }) => Some(model::Font::Name { name: s }),
-                        Some(FontQuery { include_font: Some(s), .. }) => Some(model::Font::Url { css: format!("@font-face {{ font-family: 'included_font'; src: url('{}'); }}", s.replace("\\", "\\\\").replace("'", "\\'")).into() }),
+                    font: match font_query {
+                        Some(FontQuery { google_font: Some(f), .. }) if STATE.has_google_api_key() => {
+                          let css = match STATE.get_fontinfo(&f.to_string()).await {
+                            Ok(css) => css,
+                            Err((status, error)) => { return ResponseCtx(model::Data::Error {error}, status); }
+                          };
+                          Some(model::Font::External {
+                              css,
+                              name: f
+                          })
+                        },
+                        Some(FontQuery { include_font: Some(f), .. }) => Some(
+                          model::Font::External {
+                            css: format!(
+                              "@font-face {{ font-family: 'included_font'; src: url('{}'); }}",
+                              f.replace("\\", "\\\\")
+                               .replace("'", "\\'")).into(),
+                            name: "included_font".into()
+                        }),
+                        Some(FontQuery { font: Some(s), .. }) => Some(model::Font::Name { name: s }),
                         _ => None,
                     },
-                    query: q
+                    query
                 }, StatusCode::OK)
             },
             Err((status, error)) => {
diff --git a/src/font.rs b/src/font.rs
index f9f4f4d..ba3bbd9 100644
--- a/src/font.rs
+++ b/src/font.rs
@@ -6,5 +6,6 @@ use std::sync::Arc;
 pub struct FontQuery {
   pub font: Option<Arc<str>>,
   pub include_font: Option<Arc<str>>,
+  pub google_font: Option<Arc<str>>,
 //  pub small_font: Option<()>
 }
diff --git a/src/main.rs b/src/main.rs
index f8b0e7b..648603b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -10,6 +10,7 @@ use lfm_embed::font::FontQuery;
 use warp::Filter;
 
 #[derive(serde::Deserialize, Debug)]
+#[serde(rename = "kebab-case")]
 struct UserQuery {
     #[serde(default)]
     theme: Option<Arc<str>>,
@@ -44,7 +45,7 @@ async fn main() {
         .then(|s, q: UserQuery| async move {
             log::debug!(target: "lfm::server::user", "Handling request for user `{s}` with {q:?}");
             let (ctx, dur) = STATE.get_userinfo(&s).await;
-            let ResponseCtx(mut data, status) = (ctx, q.font, q.rest).into();
+            let ResponseCtx(mut data, status) = ResponseCtx::create(ctx, q.font, q.rest).await;
             
             let theme = q.theme.filter(|a| STATE.handlebars().has_template(&a)).unwrap_or_else(|| STATE.default_theme());
             log::debug!(target: "lfm::server::user", "Using theme {theme}");
diff --git a/src/themes/plain.hbs b/src/themes/plain.hbs
index bbd0589..975d6c5 100644
--- a/src/themes/plain.hbs
+++ b/src/themes/plain.hbs
@@ -3,6 +3,7 @@
   <head>
     <meta charset="UTF-8"/>
     <title>{{#if error}}Error!{{else}}@{{user.name}}'s Last.fm Stats{{/if}}</title>
+    <style>{{#if font.css}}{{{font.css}}}{{/if}}</style>
     <style>
       {{#if (eq query.dark null)}}
         :root { --b: black; color: black; background-color: white; }
@@ -11,12 +12,9 @@
         a:visited { color: pink }
         a { color: cyan; }
       {{/if}}
-      * { font-size: {{#if font}}17px{{else}}20px{{/if}}; }
-      {{#if font.css}}
-        {{{font.css}}}
-      {{/if}}
+      * { font-size: {{#if font}}17px{{else}}{{#if font.scale}}calc(20px * {{font.scale}}){{else}}20px{{/if}}{{/if}}; }
       {{#if (or font.name font.css)}}
-        * { font-family: '{{#if font.name}}{{font.name}}{{/if}}{{#if font.url}}included_font{{/if}}' }
+        * { font-family: '{{#if font.name}}{{font.name}}{{/if}}' }
       {{/if}}
       p { margin: 0px; padding: 0px; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
     </style>
-- 
2.45.2