//! static file handling
//!
//! Reads files from the filesystem and prepares a `Response` for them.

use axum::{body::Body, response::Response};
use tokio_util::io::ReaderStream;

use crate::{
	RuntimeError,
	fs::{self, Mimetype, RequestPath},
};

/// 5 MiB
///
/// Files smaller than this size will be read into memory before being
/// sent back to the client.
const STREAM_AFTER: u64 = 1024 * 1024 * 5;
pub async fn send_or_stream_file(path: RequestPath) -> Result<Response, RuntimeError> {
	let meta = path.system_path().metadata()?;

	if meta.len() > STREAM_AFTER {
		tracing::trace!("File is large, Streaming");
		stream_file(path).await
	} else {
		tracing::trace!("File is small, Sending");
		send_file(path).await
	}
}

pub async fn send_file(path: RequestPath) -> Result<Response, RuntimeError> {
	let mime = path.guess_mime();

	let body = match mime.mimetype() {
		Mimetype::Text => {
			let text = fs::read_file_to_string(path.system_path()).await?;
			Body::from(text)
		}
		Mimetype::Media => {
			let data = fs::read_file(path.system_path()).await?;
			Body::from(data)
		}
	};

	Response::builder()
		.status(200)
		.header("Content-Type", mime.as_ref())
		.body(body)
		.map_err(|_| RuntimeError::unknown())
}

pub async fn stream_file(path: RequestPath) -> Result<Response, RuntimeError> {
	let mime = path.guess_mime();

	let file = fs::open_file(path.system_path()).await?;
	let stream = ReaderStream::new(file);

	Response::builder()
		.status(200)
		.header("Content-Type", mime.as_ref())
		.body(Body::from_stream(stream))
		.map_err(|_| RuntimeError::unknown())
}