this_algorithm/web/src/static_assets.rs

use rocket::get;
use rocket::http::ContentType;
use rust_embed::RustEmbed;

use std::borrow::Cow;
use std::ffi::OsStr;
use std::path::PathBuf;

#[derive(RustEmbed)]
#[folder = "../build/"]
struct Asset;

#[get("/<file..>")]
pub(crate) fn dist(file: PathBuf) -> Option<(ContentType, Cow<'static, [u8]>)> {
    eprintln!("file: {file:?}");
    if let Some(a) = Asset::get(&format!("{}", file.display().to_string())) {
        let content_type = file
            .extension()
            .and_then(OsStr::to_str)
            .and_then(ContentType::from_extension)
            .unwrap_or(ContentType::Bytes);

        return Some((content_type, a.data));
    }

    [".html", "/index.html"].iter().find_map(|ext| {
        Asset::get(&format!("{}{}", file.display().to_string(), ext))
            .map(|a| (ContentType::HTML, a.data))
    })
}

#[get("/")]
pub(crate) fn index() -> Option<(ContentType, Cow<'static, [u8]>)> {
    Asset::get(&"index.html").map(|a| (ContentType::HTML, a.data))
}