use bevy::{
asset::io::{AssetReaderError, ErasedAssetReader, PathStream, Reader, VecReader},
tasks::BoxedFuture,
};
use js_sys::{JSON, Uint8Array};
use std::{
path::{Path, PathBuf},
sync::Arc,
};
use wasm_bindgen::{JsCast, JsValue};
use wasm_bindgen_futures::JsFuture;
use web_sys::Response;
use crate::path::deserialize_path;
pub struct BlobAssetReader;
impl BlobAssetReader {
async fn fetch_bytes<'a>(&self, path: PathBuf) -> Result<Vec<u8>, AssetReaderError> {
let window = web_sys::window().unwrap();
let resp_value = JsFuture::from(window.fetch_with_str(path.to_str().unwrap()))
.await
.map_err(js_value_to_err("fetch path"))?;
let resp = resp_value
.dyn_into::<Response>()
.map_err(js_value_to_err("convert fetch to Response"))?;
match resp.status() {
200 => {
let data = JsFuture::from(resp.array_buffer().unwrap()).await.unwrap();
let bytes = Uint8Array::new(&data).to_vec();
Ok(bytes)
}
404 => Err(AssetReaderError::NotFound(path)),
status => Err(AssetReaderError::Io(Arc::new(std::io::Error::new(
std::io::ErrorKind::Other,
format!("Encountered unexpected HTTP status {status}"),
)))),
}
}
async fn fetch_reader<'a>(
&self,
path: PathBuf,
) -> Result<Box<dyn Reader + 'a>, AssetReaderError> {
let bytes = self.fetch_bytes(path).await?;
let reader = Box::new(VecReader::new(bytes));
Ok(reader)
}
}
impl ErasedAssetReader for BlobAssetReader {
fn read<'a>(
&'a self,
path: &'a Path,
) -> BoxedFuture<'a, Result<Box<dyn Reader + 'a>, AssetReaderError>> {
Box::pin(async move {
let path = deserialize_path(path);
self.fetch_reader(path).await
})
}
fn read_meta<'a>(
&'a self,
path: &'a Path,
) -> BoxedFuture<'a, Result<Box<dyn Reader + 'a>, AssetReaderError>> {
Box::pin(async move {
let path = deserialize_path(path);
self.fetch_reader(path).await
})
}
fn read_meta_bytes<'a>(
&'a self,
path: &'a Path,
) -> BoxedFuture<'a, Result<Vec<u8>, AssetReaderError>> {
Box::pin(async move {
let path = deserialize_path(path);
self.fetch_bytes(path).await
})
}
fn read_directory<'a>(
&'a self,
_path: &'a Path,
) -> BoxedFuture<'a, Result<Box<PathStream>, AssetReaderError>> {
Box::pin(async move {
Err(AssetReaderError::Io(Arc::new(std::io::Error::new(
std::io::ErrorKind::Other,
"BlobAssetReader does not support reading directories",
))))
})
}
fn is_directory<'a>(
&'a self,
_path: &'a Path,
) -> BoxedFuture<'a, Result<bool, AssetReaderError>> {
Box::pin(async move {
Err(AssetReaderError::Io(Arc::new(std::io::Error::new(
std::io::ErrorKind::Other,
"BlobAssetReader does not support reading directories",
))))
})
}
}
fn js_value_to_err<'a>(context: &'a str) -> impl FnOnce(JsValue) -> std::io::Error + 'a {
move |value| {
let message = match JSON::stringify(&value) {
Ok(js_str) => format!("Failed to {context}: {js_str}"),
Err(_) => {
format!("Failed to {context} and also failed to stringify the JSValue of the error")
}
};
std::io::Error::new(std::io::ErrorKind::Other, message)
}
}