//! Compiled-in static assets: the stylesheet, fonts and icons.

use axum::extract::Path;
use axum::http::{header, StatusCode};
use axum::response::{IntoResponse, Response};

const CSS: &str = include_str!("../../../../templates/style.css");
const FAVICON: &str = include_str!("../../../../assets/icons/oxygenhub.svg");

/// A short hash of the stylesheets and script the pages link, put in their
/// URLs (`?v=…`): they are served for a long time and cached by any proxy
/// in front of the hub (Cloudflare held a day-old stylesheet), so a new
/// version must have a new URL.
pub fn assets_version() -> &'static str {
    static V: std::sync::OnceLock<String> = std::sync::OnceLock::new();
    V.get_or_init(|| {
        let mut h = blake3::Hasher::new();
        h.update(CSS.as_bytes());
        for a in ASSETS.iter().filter(|a| {
            matches!(
                a.path,
                "github.css"
                    | "hub.js"
                    | "early.js"
                    | "pulse.js"
                    | "backdrop-boot.js"
                    | "report-frame.js"
                    | "report.css"
                    | "backdrop/backdrop.js"
                    | "backdrop/backdrop_bg.wasm"
            )
        }) {
            h.update(a.bytes);
        }
        h.finalize().to_hex()[..12].to_string()
    })
}

struct Asset {
    path: &'static str,
    mime: &'static str,
    bytes: &'static [u8],
}

const ASSETS: &[Asset] = &[
    Asset { path: "fonts/Barlow-300.woff2", mime: "font/woff2", bytes: include_bytes!("../../../../assets/fonts/Barlow-300.woff2") },
    Asset { path: "fonts/Barlow-400.woff2", mime: "font/woff2", bytes: include_bytes!("../../../../assets/fonts/Barlow-400.woff2") },
    Asset { path: "fonts/Barlow-500.woff2", mime: "font/woff2", bytes: include_bytes!("../../../../assets/fonts/Barlow-500.woff2") },
    Asset { path: "fonts/Barlow-600.woff2", mime: "font/woff2", bytes: include_bytes!("../../../../assets/fonts/Barlow-600.woff2") },
    Asset {
        path: "fonts/PressStart2P-400.woff2",
        mime: "font/woff2",
        bytes: include_bytes!("../../../../assets/fonts/PressStart2P-400.woff2"),
    },
    Asset { path: "github.css", mime: "text/css; charset=utf-8", bytes: include_bytes!("../../../../assets/github.css") },
    Asset { path: "hub.js", mime: "text/javascript; charset=utf-8", bytes: include_bytes!("../../../../assets/hub.js") },
    // What pages ran inline before the CSP was enforced (#227): the look
    // and theme before first paint, the pulse chart, the backdrop's start.
    Asset { path: "early.js", mime: "text/javascript; charset=utf-8", bytes: include_bytes!("../../../../assets/early.js") },
    Asset { path: "pulse.js", mime: "text/javascript; charset=utf-8", bytes: include_bytes!("../../../../assets/pulse.js") },
    Asset {
        path: "backdrop-boot.js",
        mime: "text/javascript; charset=utf-8",
        bytes: include_bytes!("../../../../assets/backdrop-boot.js"),
    },
    // For report frames (#127): the size and theme bridge the hub adds to
    // a report's pages, and the stylesheet a report may link.
    Asset { path: "report-frame.js", mime: "text/javascript; charset=utf-8", bytes: include_bytes!("../../../../assets/report-frame.js") },
    Asset { path: "report.css", mime: "text/css; charset=utf-8", bytes: include_bytes!("../../../../assets/report.css") },
    // Backdrops (docs/backgrounds.md, #157): the engine, Rust compiled to
    // WebAssembly (crates/backdrop), and its wasm-bindgen glue, both
    // written by `make backdrop`.
    Asset {
        path: "backdrop/backdrop.js",
        mime: "text/javascript; charset=utf-8",
        bytes: include_bytes!("../../../../assets/backdrop/backdrop.js"),
    },
    Asset {
        path: "backdrop/backdrop_bg.wasm",
        mime: "application/wasm",
        bytes: include_bytes!("../../../../assets/backdrop/backdrop_bg.wasm"),
    },
    Asset {
        path: "vendor/editor.js",
        mime: "text/javascript; charset=utf-8",
        bytes: include_bytes!("../../../../assets/vendor/editor.js"),
    },
    Asset {
        path: "vendor/easymde.min.js",
        mime: "text/javascript; charset=utf-8",
        bytes: include_bytes!("../../../../assets/vendor/easymde.min.js"),
    },
    // Mermaid 12.1.0 (MIT, assets/vendor/mermaid.LICENSE), from npm's
    // mermaid package, dist/mermaid.min.js; loaded only by pages with a
    // diagram.
    Asset {
        path: "vendor/mermaid.min.js",
        mime: "text/javascript; charset=utf-8",
        bytes: include_bytes!("../../../../assets/vendor/mermaid.min.js"),
    },
    Asset { path: "wasi-worker.js", mime: "text/javascript; charset=utf-8", bytes: include_bytes!("../../../../assets/wasi-worker.js") },
    Asset { path: "wasm-tab.js", mime: "text/javascript; charset=utf-8", bytes: include_bytes!("../../../../assets/wasm-tab.js") },
    Asset {
        path: "vendor/easymde.min.css",
        mime: "text/css; charset=utf-8",
        bytes: include_bytes!("../../../../assets/vendor/easymde.min.css"),
    },
];

const CACHE: &str = "public, max-age=86400";

pub async fn style() -> Response {
    ([(header::CONTENT_TYPE, "text/css; charset=utf-8"), (header::CACHE_CONTROL, CACHE)], CSS).into_response()
}

pub async fn favicon() -> Response {
    ([(header::CONTENT_TYPE, "image/svg+xml"), (header::CACHE_CONTROL, CACHE)], FAVICON).into_response()
}

pub async fn asset(Path(path): Path<String>) -> Response {
    match ASSETS.iter().find(|a| a.path == path) {
        // Readable across origins: a report's sandboxed frame has an
        // opaque origin, and loads fonts in CORS mode (#127).
        Some(a) => (
            [
                (header::CONTENT_TYPE, a.mime),
                (header::CACHE_CONTROL, "public, max-age=31536000, immutable"),
                (header::ACCESS_CONTROL_ALLOW_ORIGIN, "*"),
            ],
            a.bytes,
        )
            .into_response(),
        None => StatusCode::NOT_FOUND.into_response(),
    }
}