Implement i18n backend

Cargo.lock

@@ -711,6 +711,70 @@ version = "1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7fcaabb2fef8c910e7f4c7ce9f67a1283a1715879a7c230ca9d6d1ae31f16d91"
 
+[[package]]
+name = "encoding"
+version = "0.2.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b0d943856b990d12d3b55b359144ff341533e516d94098b1d3fc1ac666d36ec"
+dependencies = [
+ "encoding-index-japanese",
+ "encoding-index-korean",
+ "encoding-index-simpchinese",
+ "encoding-index-singlebyte",
+ "encoding-index-tradchinese",
+]
+
+[[package]]
+name = "encoding-index-japanese"
+version = "1.20141219.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04e8b2ff42e9a05335dbf8b5c6f7567e5591d0d916ccef4e0b1710d32a0d0c91"
+dependencies = [
+ "encoding_index_tests",
+]
+
+[[package]]
+name = "encoding-index-korean"
+version = "1.20141219.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4dc33fb8e6bcba213fe2f14275f0963fd16f0a02c878e3095ecfdf5bee529d81"
+dependencies = [
+ "encoding_index_tests",
+]
+
+[[package]]
+name = "encoding-index-simpchinese"
+version = "1.20141219.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d87a7194909b9118fc707194baa434a4e3b0fb6a5a757c73c3adb07aa25031f7"
+dependencies = [
+ "encoding_index_tests",
+]
+
+[[package]]
+name = "encoding-index-singlebyte"
+version = "1.20141219.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3351d5acffb224af9ca265f435b859c7c01537c0849754d3db3fdf2bfe2ae84a"
+dependencies = [
+ "encoding_index_tests",
+]
+
+[[package]]
+name = "encoding-index-tradchinese"
+version = "1.20141219.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd0e20d5688ce3cab59eb3ef3a2083a5c77bf496cb798dc6fcdb75f323890c18"
+dependencies = [
+ "encoding_index_tests",
+]
+
+[[package]]
+name = "encoding_index_tests"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a246d82be1c9d791c5dfde9a2bd045fc3cbba3fa2b11ad558f27d01712f00569"
+
 [[package]]
 name = "encoding_rs"
 version = "0.8.32"
@@ -987,6 +1051,16 @@ dependencies = [
  "wasi 0.11.0+wasi-snapshot-preview1",
 ]
 
+[[package]]
+name = "gettext"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ebb594e753d5997e4be036e5a8cf048ab9414352870fb45c779557bbc9ba971"
+dependencies = [
+ "byteorder",
+ "encoding",
+]
+
 [[package]]
 name = "ghash"
 version = "0.5.0"
@@ -3034,6 +3108,7 @@ dependencies = [
  "comrak",
  "derive_more",
  "dotenv",
+ "gettext",
  "poise",
  "reqwest",
  "rocket 0.5.0-rc.3",

Cargo.toml

@@ -10,6 +10,7 @@ chrono = { version = "0.4.26", features = ["serde"] }
 comrak = "0.18.0"
 derive_more = "0.99.17"
 dotenv = "0.15.0"
+gettext = "0.4.0"
 poise = "0.5.5"
 reqwest = "0.11.18"
 rocket = { version = "=0.5.0-rc.3", features = ["secrets"] }

i18n/.gitignore

@@ -0,0 +1 @@
+*.mo

i18n/en.po

@@ -0,0 +1,2 @@
+msgid "title"
+msgstr "Tegaki Tuesday"

i18n/ja.po

@@ -0,0 +1,2 @@
+msgid "title"
+msgstr "手書きの火曜日"

shell.nix

@@ -17,5 +17,6 @@ pkgs.mkShell {
     bacon
     pkg-config
     openssl
+    gettext
   ];
 }

src/i18n.rs

@@ -0,0 +1,55 @@
+use std::{collections::HashMap, fs::{self, File}, io::BufReader, process::Command};
+use derive_more::From;
+use rocket_dyn_templates::tera::{self, Value};
+
+use gettext::Catalog;
+
+#[derive(From, Debug)]
+pub enum LoadCatalogsError {
+    Io(std::io::Error),
+    Parse(gettext::Error),
+    MissingDefaultLanguage,
+}
+
+const DEFAULT: &str = "ja";
+
+pub fn load_catalogs() -> Result<HashMap<String, Catalog>, LoadCatalogsError> {
+    let mut catalogs = HashMap::new();
+    for file in fs::read_dir("i18n")? {
+        let file = file?;
+        let path = file.path();
+        if !file.file_type()?.is_file() || !path.extension().map(|extension| extension.eq("po")).unwrap_or(false) {
+            continue;
+        }
+        let language_code = path
+            .file_stem()
+            .expect("Invalid translation file name")
+            .to_string_lossy()
+            .to_string();
+        let po_file_path = path;
+        let mo_file_path = format!("i18n/{}.mo", language_code);
+        Command::new("msgfmt")
+            .arg(&po_file_path)
+            .arg("-o")
+            .arg(&mo_file_path)
+            .output()?;
+        catalogs.insert(language_code, Catalog::parse(BufReader::new(File::open(mo_file_path)?))?);
+    }
+    if !catalogs.contains_key(DEFAULT) {
+        return Err(LoadCatalogsError::MissingDefaultLanguage);
+    }
+    Ok(catalogs)
+}
+
+pub fn i18n_filter(value: &Value, _args: &HashMap<String, Value>, catalogs: &HashMap<String, Catalog>) -> tera::Result<Value> {
+    let key = value.as_str().ok_or_else(|| {
+        tera::Error::msg("The translation key must be a string")
+    })?;
+
+    let translation = catalogs
+        .get(DEFAULT)
+        .expect("Missing catalog")
+        .gettext(key);
+
+    Ok(Value::String(translation.to_owned()))
+}

src/main.rs

@@ -3,9 +3,9 @@ extern crate rocket;
 
 use poise::serenity_prelude::Http;
 use rocket::fs::{relative, FileServer};
-use rocket_dyn_templates::Template;
+use rocket_dyn_templates::{Template, tera};
 use sass_rocket_fairing::SassFairing;
-use std::env;
+use std::{env, collections::HashMap};
 
 mod models;
 use models::Settings;
@@ -17,6 +17,9 @@ mod cookies;
 mod routes;
 use routes::*;
 
+mod i18n;
+use i18n::{load_catalogs, i18n_filter};
+
 mod prelude;
 
 #[launch]
@@ -40,6 +43,12 @@ async fn rocket() -> _ {
             routes![get_challenge, login, post_login, success, logout, testing],
         )
         .mount("/css", FileServer::from(relative!("styles/css")))
-        .attach(Template::fairing())
+        .attach(Template::custom(|engines| {
+            use tera::Value;
+            let catalogs = load_catalogs().unwrap();
+            engines.tera.register_filter("i18n", move |value: &Value, args: &HashMap<String, Value>| {
+                i18n_filter(value, args, &catalogs)
+            })
+        }))
         .attach(SassFairing::default())
 }

src/routes/get_challenge.rs

@@ -7,12 +7,6 @@ use crate::models::{Challenge, User, Settings};
 
 #[get("/<challenge>")]
 pub async fn get_challenge(challenge: u32, cookies: &CookieJar<'_>, settings: &State<Settings>) -> Template {
-    println!(
-        "{:?}",
-        cookies
-            .get_private("user_name")
-            .map(|cookie| cookie.value().to_owned())
-    );
     Template::render(
         "index",
         context! {

templates/modal.html.tera

@@ -1,5 +1,5 @@
 <dialog>
-    <h1>Welcome to Tegaki Tuesday!</h1> 
+    <h1>Welcome to {{ "title" | i18n }}!</h1> 
     <p>In order to participate in challenges, you must be a member of a participating Discord server.</p>
     <h2>Join a participating server</h2>
     <div class="servers">