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import { Plugin } from "$fresh/server.ts";
export interface Options {  /** Attempt higher priority fetch (low or high) */  priority?: boolean;  /** Allowed origins to prefetch (empty allows all) */  origins?: string[];  /** Timeout after which prefetching will occur */  timeout?: number;  /**   * The concurrency limit for prefetching   * @default 10   */  throttle?: number;  /** The area percentage of each link that must have entered the viewport to be fetched */  threshold?: number;  /** The total number of prefetches to allow */  limit?: number;  /** Time each link needs to stay inside viewport before prefetching (milliseconds) */  delay?: number;  /** Option to switch from prefetching and use prerendering only */  prerender?: boolean;  /** Option to use both prerendering and prefetching */  prerenderAndPrefetch?: boolean;  /**   * Strategy to prefetch.   *   * set opt-in to prefetch only anchor tags containing the data-prefetch attribute   * set opt-out to ignore only those links with the data-noprefetch attribute   * set aggresive to prefetch all links   *   * @default undefined   */  strategy?: "opt-in" | "opt-out";}
const prefetch = (options: Options = {  throttle: 10,}): Plugin => {  const main = `data:application/javascript,    import { listen as qlListen } from "https://esm.sh/quicklink@2.3.0";
    function getOptions (options) {      if (options.strategy) {        options.ignores = [          ...(options.ignores ?? []),          options.strategy === 'opt-in'            ? (_uri, elem) => !elem.hasAttribute('data-prefetch')            : (_uri, elem) => elem.hasAttribute('data-noprefetch')        ];      }
      return options;    };
    function listen (options) {      return qlListen(getOptions(options))    };
    export default function(options) {      if (document.readyState === "complete" || document.readyState === "loaded"  || document.readyState === "interactive") {        listen(options);      } else {        document.addEventListener("DOMContentLoaded", () => listen(options));      }    };`;
  return {    name: "prefetch",    entrypoints: { main },    render: (ctx) => {      ctx.render();
      return {        scripts: [{ entrypoint: "main", state: options }],      };    },  };};
export default prefetch;