const rx_any = /./;
const rx_http = /^https?:\/\//;
const rx_relative_path = /^\.\.?\//;
const rx_absolute_path = /^\//;

async function load_http_module(href) {
  return fetch(href).then((response) =>
    response
      .text()
      .then((text) =>
        response.ok
          ? { contents: text, loader: "js" }
          : Promise.reject(
              new Error(`Failed to load module '${href}'': ${text}`),
            ),
      ),
  );
}

Bun.plugin({
  name: "http_imports",
  setup(build) {
    build.onResolve({ filter: rx_relative_path }, (args) => {
      if (rx_http.test(args.importer)) {
        return { path: new URL(args.path, args.importer).href };
      }
    });
    build.onResolve({ filter: rx_absolute_path }, (args) => {
      if (rx_http.test(args.importer)) {
        return { path: new URL(args.path, args.importer).href };
      }
    });
    build.onLoad({ filter: rx_any, namespace: "http" }, (args) =>
      load_http_module(`http:${args.path}`),
    );
    build.onLoad({ filter: rx_any, namespace: "https" }, (args) =>
      load_http_module(`https:${args.path}`),
    );
  },
});