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import type { Middleware } from "../core/server.ts";
const HOUR = 3600000;const DAY = HOUR * 24;const WEEK = DAY * 7;
export interface Options {  /** The default duration for unknown types */  defaultDuration: number;
  /** List of types with the cache duration */  durations: Record<string, number>;}
export const defaults: Options = {  defaultDuration: WEEK,  durations: {    "text/html": 0,    "application/json": 0,    "application/xml": 0,    "application/atom+xml": HOUR,    "application/rdf+xml": HOUR,    "application/rss+xml": HOUR,  },};
/** Set the Expires header for better caching */export default function expires(userOptions?: Partial<Options>): Middleware {  const options = { ...defaults, ...userOptions };
  return async (request, next) => {    const response = await next(request);    const { headers } = response;    const type = headers.get("Content-Type")?.split(";").shift()?.trim();    const duration = (type && type in options.durations)      ? options.durations[type]      : options.defaultDuration;    headers.set("Expires", new Date(Date.now() + duration).toUTCString());
    return response;  };}