use std::{convert::Infallible, sync::Arc};
use axum::{
async_trait,
extract::{FromRef, FromRequestParts},
http::request::Parts,
};
use axum_extra::typed_header::TypedHeader;
use mas_axum_utils::language_detection::AcceptLanguage;
use mas_i18n::{locale, DataLocale, Translator};
pub struct PreferredLanguage(pub DataLocale);
#[async_trait]
impl<S> FromRequestParts<S> for PreferredLanguage
where
S: Send + Sync,
Arc<Translator>: FromRef<S>,
{
type Rejection = Infallible;
async fn from_request_parts(parts: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
let translator: Arc<Translator> = FromRef::from_ref(state);
let accept_language: Option<TypedHeader<AcceptLanguage>> =
FromRequestParts::from_request_parts(parts, state).await?;
let iter = accept_language
.iter()
.flat_map(|TypedHeader(accept_language)| accept_language.iter())
.flat_map(|lang| {
let lang = DataLocale::from(lang);
if lang == locale!("zh-CN").into() {
vec![lang, locale!("zh-Hans").into()]
} else {
vec![lang]
}
});
let locale = translator.choose_locale(iter);
Ok(PreferredLanguage(locale))
}
}