add basic i18n

src/i18n/mod.rs

@@ -0,0 +1,87 @@
+use rmcp::serde_json;
+use serde::Deserialize;
+use std::collections::HashMap;
+use std::sync::{LazyLock, OnceLock, RwLock};
+
+#[derive(Debug, Deserialize)]
+struct Language {
+    translations: HashMap<String, String>,
+}
+
+static LANGUAGES: OnceLock<HashMap<Locale, Language>> = OnceLock::new();
+static LOCALE_SELECTION: LazyLock<RwLock<Locale>> = LazyLock::new(|| RwLock::new(Locale::DE));
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
+pub enum Locale {
+    DE,
+}
+
+#[macro_export]
+macro_rules! include_language {
+    ($file:expr) => {
+        serde_json::from_str::<Language>(include_str!($file)).unwrap()
+    };
+}
+
+fn load_languages() -> &'static HashMap<Locale, Language> {
+    LANGUAGES
+        .get_or_init(|| HashMap::from([(Locale::DE, include_language!("translations/de.json"))]))
+}
+
+///
+/// # Examples
+///
+/// ```
+/// let formatted = format_dynamically("{...} is cool!".to_string(),
+/// vec!["Rust".to_string()]);
+/// assert_eq!(formatted, "Rust is cool!");
+/// ```
+fn format_dynamically(mut template: String, arguments: Vec<impl Into<String>>) -> String {
+    let replaced_str = "{...}";
+
+    for arg in arguments {
+        template = template.replacen(replaced_str, arg.into().as_str(), 1);
+    }
+
+    template
+}
+
+pub fn translate(template_name: String, arguments: Vec<impl Into<String>>) -> String {
+    let locale: Locale = LOCALE_SELECTION.read().unwrap().clone();
+    let languages = load_languages();
+    let translation = languages
+        .get(&locale)
+        .unwrap()
+        .translations
+        .get(&template_name)
+        .unwrap();
+    format_dynamically(translation.clone(), arguments)
+}
+
+#[macro_export]
+macro_rules! tlt {
+    ($template_name:tt) => {
+        translate($template_name.to_string(), Vec::<String>::new())
+    };
+    ($template_name:tt, $($args:tt)*) => {
+        translate($template_name.to_string(), vec![$($args)*])
+    };
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_dynamic_formatting() {
+        let formatted = format_dynamically("{...} is cool!".to_string(), vec!["Rust".to_string()]);
+        assert_eq!(formatted, "Rust is cool!");
+
+        let formatted = format_dynamically("{...}, {...} and {...} are three consecutive numbers.".to_string(), vec![
+            "1".to_string(),
+            "2".to_string(),
+            "3".to_string(),
+        ]);
+        assert_eq!(formatted, "1, 2 and 3 are three consecutive numbers.");
+    }
+}