use actix_web::http::StatusCode;
use actix_web::HttpResponse;
use actix_web::HttpRequest;
use actix_web::web::resource;
use actix_web::Resource;

/// Represents a single static asset
///
/// Each asset is embeded into the binary, and can be served under the
/// `/static/{filename}` route.  All static assets should be embeded in this way, and can
/// be referenced from this module.
pub struct StaticAsset {

	/// The filename of this asset relative to `:/web/assets/` and the `/static/` route
	pub filename: &'static str,

	/// The content of the file
	pub bytes: &'static [u8],

}

impl StaticAsset {
	/// Generate a actix resource for serving this asset
	///
	/// The resource will handle requests at `/static/{filename}`.  Caching headers are
	/// applied to allow the content to be considered fresh up to one day, and are
	/// validated against the crate version after that.
	pub fn generate_resource(&self) -> Resource {
		let bytes = self.bytes;
		resource(format!("/static/{}", self.filename))
			.to(move|req: HttpRequest| async move {
				let mut response = HttpResponse::Ok();
				response
					.header("Etag", env!("CARGO_PKG_VERSION"))
					.header("Cache-Control", "max-age=86400");

				let req_etag = req.headers().get("If-None-Match");
				match req_etag {
					Some(etag) if etag == env!("CARGO_PKG_VERSION") => {
						response.status(StatusCode::from_u16(304).unwrap()).finish()
					}
					_ => {
						response.body(bytes)
					}
				}
			})
	}
}


/// Generate a [`StaticAsset`] at compiletime from a filename.
#[cfg(any(feature = "embed_static_assets", feature = "ogp_images"))]
macro_rules! static_asset {
	( $filename: expr ) => {
		StaticAsset {
			filename: $filename,
			bytes: include_bytes!(concat!("../assets/", $filename)),
		}
	}
}

/// The decorative font to be used for pronouns displayed at a very large size
#[cfg(any(feature = "embed_static_assets", feature = "ogp_images"))]
pub const FONT: StaticAsset = static_asset!("font.otf");

/// A list of static assets which should be served by the server
pub const STATIC_ASSETS: &[StaticAsset] = &[
	#[cfg(any(feature = "embed_static_assets"))]
	FONT,
];