i18n: add template override mechanism

src/mail.rs

@@ -1,4 +1,4 @@
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
 use failure;
 use handlebars::Handlebars;
@@ -10,10 +10,9 @@ use uuid::Uuid;
 use crate::counters;
 
 use rocket_i18n::I18n;
-use gettext_macros::include_i18n;
 use gettext_macros::i18n;
 
-use crate::i18n::I18NHelper;
+use crate::template_helpers;
 
 use crate::database::types::Email;
 use crate::Result;
@@ -73,7 +72,7 @@ impl Service {
 
     fn new(from: String, base_uri: String, template_dir: PathBuf, transport: Transport)
            -> Result<Self> {
-        let templates = load_handlebars(template_dir)?;
+        let templates = template_helpers::load_handlebars(template_dir)?;
         let domain =
             url::Url::parse(&base_uri)
             ?.host_str().ok_or_else(|| failure::err_msg("No host in base-URI"))
@@ -167,7 +166,7 @@ impl Service {
         &self,
         template: &str,
         locale: &str,
-        ctx: impl Serialize + Clone
+        ctx: impl Serialize
     ) -> Result<(String, String)> {
         let html = self.templates.render(&format!("{}/{}.htm", locale, template), &ctx)
             .or_else(|_| self.templates.render(&format!("{}.htm", template), &ctx))
@@ -185,7 +184,7 @@ impl Service {
         subject: &str,
         template: &str,
         locale: &str,
-        ctx: impl Serialize + Clone
+        ctx: impl Serialize
     ) -> Result<()> {
         let (html, txt) = self.render_template(template, locale, ctx)?;
 
@@ -221,35 +220,3 @@ impl Service {
     }
 }
 
-fn load_handlebars(template_dir: PathBuf) -> Result<Handlebars> {
-    let mut handlebars = Handlebars::new();
-
-    let i18ns = include_i18n!();
-    let i18n_helper = I18NHelper::new(i18ns);
-    handlebars.register_helper("text", Box::new(i18n_helper));
-
-    let mut glob_path = template_dir.join("**").join("*");
-    glob_path.set_extension("hbs");
-    let glob_path = glob_path.to_str().expect("valid glob path string");
-
-    for path in glob::glob(glob_path).unwrap().flatten() {
-        let template_name = remove_extension(path.strip_prefix(&template_dir)?);
-        handlebars.register_template_file(&template_name.to_string_lossy(), &path)?;
-    }
-
-    Ok(handlebars)
-}
-
-fn remove_extension<P: AsRef<Path>>(path: P) -> PathBuf {
-    let path = path.as_ref();
-    let stem = match path.file_stem() {
-        Some(stem) => stem,
-        None => return path.to_path_buf()
-    };
-
-    match path.parent() {
-        Some(parent) => parent.join(stem),
-        None => PathBuf::from(stem)
-    }
-}
-

src/main.rs

@@ -52,6 +52,7 @@ mod rate_limiter;
 mod dump;
 mod counters;
 mod i18n;
+mod template_helpers;
 mod gettext_strings;
 mod web;
 

src/template_helpers.rs

@@ -0,0 +1,82 @@
+use std::path::{Path, PathBuf};
+use std::collections::HashSet;
+
+use handlebars::Handlebars;
+
+use gettext_macros::include_i18n;
+
+use crate::Result;
+use crate::i18n::I18NHelper;
+
+#[derive(Debug)]
+pub struct TemplateOverrides(String, HashSet<(String)>);
+
+impl TemplateOverrides {
+    pub fn load(template_path: &Path, localized_dir: &str) -> Result<Self> {
+        load_localized_template_names(template_path, localized_dir)
+            .map(|vec| Self(localized_dir.to_owned(), vec))
+    }
+
+     pub fn get_template_override(&self, lang: &str, tmpl: &str) -> Option<String> {
+        let template_name = format!("{}/{}/{}", self.0, lang, tmpl);
+        if self.1.contains(&template_name) {
+            println!("{}", &template_name);
+            Some(template_name)
+        } else {
+            None
+        }
+    }
+}
+
+fn load_localized_template_names(template_path: &Path, localized_dir: &str) -> Result<HashSet<(String)>> {
+    let language_glob = template_path.join(localized_dir).join("*");
+    glob::glob(language_glob.to_str().expect("valid glob path string"))
+        .unwrap()
+        .flatten()
+        .flat_map(|language_path| {
+            let mut template_glob = language_path.join("**").join("*");
+            template_glob.set_extension("hbs");
+            glob::glob(template_glob.to_str().expect("valid glob path string"))
+                .unwrap()
+                .flatten()
+                .map(move |path| {
+                    // TODO this is a hack
+                    let template_name = remove_extension(remove_extension(path.strip_prefix(&template_path)?));
+                    Ok(template_name.to_string_lossy().into_owned())
+                })
+            })
+    .collect()
+}
+
+pub fn load_handlebars(template_dir: PathBuf) -> Result<Handlebars> {
+    let mut handlebars = Handlebars::new();
+
+    let i18ns = include_i18n!();
+    let i18n_helper = I18NHelper::new(i18ns);
+    handlebars.register_helper("text", Box::new(i18n_helper));
+
+    let mut glob_path = template_dir.join("**").join("*");
+    glob_path.set_extension("hbs");
+    let glob_path = glob_path.to_str().expect("valid glob path string");
+
+    for path in glob::glob(glob_path).unwrap().flatten() {
+        let template_name = remove_extension(path.strip_prefix(&template_dir)?);
+        handlebars.register_template_file(&template_name.to_string_lossy(), &path)?;
+    }
+
+    Ok(handlebars)
+}
+
+fn remove_extension<P: AsRef<Path>>(path: P) -> PathBuf {
+    let path = path.as_ref();
+    let stem = match path.file_stem() {
+        Some(stem) => stem,
+        None => return path.to_path_buf()
+    };
+
+    match path.parent() {
+        Some(parent) => parent.join(stem),
+        None => PathBuf::from(stem)
+    }
+}
+

src/web/mod.rs

@@ -21,6 +21,7 @@ use std::path::PathBuf;
 use crate::mail;
 use crate::tokens;
 use crate::counters;
+use crate::template_helpers::TemplateOverrides;
 use crate::i18n::I18NHelper;
 use crate::rate_limiter::RateLimiter;
 
@@ -48,9 +49,16 @@ impl Responder<'static> for HagridTemplate {
     fn respond_to(self, req: &rocket::Request) -> std::result::Result<Response<'static>, Status> {
         let HagridTemplate(tmpl, ctx) = self;
         let i18n: I18n = req.guard().expect("Error parsing language");
+        let template_overrides: rocket::State<TemplateOverrides> = req.guard().expect("TemplateOverrides must be in managed state");
+        let template_override = template_overrides.get_template_override(i18n.lang, tmpl);
         let origin: RequestOrigin = req.guard().expect("Error determining request origin");
         let layout_context = templates::HagridLayout::new(ctx, i18n, origin);
-        Template::render(tmpl, layout_context).respond_to(req)
+
+        if let Some(template_override) = template_override {
+            Template::render(template_override, layout_context)
+        } else {
+            Template::render(tmpl, layout_context)
+        }.respond_to(req)
     }
 }
 
@@ -410,6 +418,8 @@ fn rocket_factory(mut rocket: rocket::Rocket) -> Result<rocket::Rocket> {
     let mail_service = configure_mail_service(rocket.config())?;
     let rate_limiter = configure_rate_limiter(rocket.config())?;
     let maintenance_mode = configure_maintenance_mode(rocket.config())?;
+    let localized_template_list = configure_localized_template_list(rocket.config())?;
+    println!("{:?}", localized_template_list);
 
     let prometheus = configure_prometheus(rocket.config());
 
@@ -427,6 +437,7 @@ fn rocket_factory(mut rocket: rocket::Rocket) -> Result<rocket::Rocket> {
        .manage(mail_service)
        .manage(db_service)
        .manage(rate_limiter)
+       .manage(localized_template_list)
        .mount("/", routes);
 
     if let Some(prometheus) = prometheus {
@@ -514,6 +525,11 @@ fn configure_rate_limiter(config: &Config) -> Result<RateLimiter> {
     Ok(RateLimiter::new(timeout_secs))
 }
 
+fn configure_localized_template_list(config: &Config) -> Result<TemplateOverrides> {
+    let template_dir: PathBuf = config.get_str("template_dir")?.into();
+    TemplateOverrides::load(&template_dir, "localized")
+}
+
 fn configure_maintenance_mode(config: &Config) -> Result<MaintenanceMode> {
     let maintenance_file: PathBuf = config.get_str("maintenance_file")
         .unwrap_or("maintenance").into();