// Configs for what to do with requests
const ALLOWED_USERS = [
    "ewpratten",
    "bgptools"
];
const DEFAULT_USER = "ewpratten";

// Info needed in order to partially parse OCIDS API endpoints.
const POSSIBLE_ACTION_TOKENS = ["blobs", "manifests", "tags", "referrers"];

export function onRequest(context) {

    // Parse the path out of the url
    const url = new URL(context.request.url);

    // The first segment of the path is probably the user
    var path_split = url.pathname.split("/");

    // The image name is the part between `/vx/` and the first action token
    var image_name = "";
    for (var token of path_split) {
        if (token == "v2" || token == "") {
            continue;
        }
        if (POSSIBLE_ACTION_TOKENS.includes(token)) {
            break;
        }
        image_name += token + "/";
    }

    // The action_url is everything after the image name
    var action_url = url.pathname.replace(`/v2/${image_name}`, "");

    // If there is a slash and the first part is not an allowed user, fail
    var image_name_parts = image_name.split("/");
    if (image_name_parts.length > 1 && !ALLOWED_USERS.includes(image_name_parts[0])) {
        return new Response(`User does not exist ${image_name_parts[0]}`, { status: 404 });
    }

    // If there is no slash, add the default user to the image name
    if (image_name_parts.length == 1) {
        image_name = `${DEFAULT_USER}/${image_name}`;
    }

    return Response.redirect(`https://ghcr.io/v2/${image_name}/${action_url}`, 302);
}