(function () {
  self.addEventListener("DOMContentLoaded", function () {
    /*! instant.page v5.1.0 - (C) 2019-2020 Alexandre Dieulot - https://instant.page/license */

    let mouseoverTimer;
    let lastTouchTimestamp;
    const prefetches = new Set();
    const prefetchElement = document.createElement("link");
    const isSupported = prefetchElement.relList &&
      prefetchElement.relList.supports &&
      prefetchElement.relList.supports("prefetch") &&
      window.IntersectionObserver &&
      "isIntersecting" in IntersectionObserverEntry.prototype;
    const allowQueryString = "instantAllowQueryString" in document.body.dataset;
    const allowExternalLinks = "instantAllowExternalLinks" in
      document.body.dataset;
    const useWhitelist = "instantWhitelist" in document.body.dataset;
    const mousedownShortcut = "instantMousedownShortcut" in
      document.body.dataset;
    const DELAY_TO_NOT_BE_CONSIDERED_A_TOUCH_INITIATED_ACTION = 1111;

    let delayOnHover = 65;
    let useMousedown = false;
    let useMousedownOnly = false;
    let useViewport = false;

    if ("instantIntensity" in document.body.dataset) {
      const intensity = document.body.dataset.instantIntensity;

      if (intensity.substr(0, "mousedown".length) == "mousedown") {
        useMousedown = true;
        if (intensity == "mousedown-only") {
          useMousedownOnly = true;
        }
      } else if (intensity.substr(0, "viewport".length) == "viewport") {
        if (
          !(navigator.connection &&
            (navigator.connection.saveData ||
              (navigator.connection.effectiveType &&
                navigator.connection.effectiveType.includes("2g"))))
        ) {
          if (intensity == "viewport") {
            /* Biggest iPhone resolution (which we want): 414 × 896 = 370944
         * Small 7" tablet resolution (which we don’t want): 600 × 1024 = 614400
         * Note that the viewport (which we check here) is smaller than the resolution due to the UI’s chrome */
            if (
              document.documentElement.clientWidth *
                  document.documentElement.clientHeight < 450000
            ) {
              useViewport = true;
            }
          } else if (intensity == "viewport-all") {
            useViewport = true;
          }
        }
      } else {
        const milliseconds = parseInt(intensity);
        if (!isNaN(milliseconds)) {
          delayOnHover = milliseconds;
        }
      }
    }

    if (isSupported) {
      const eventListenersOptions = {
        capture: true,
        passive: true,
      };

      if (!useMousedownOnly) {
        document.addEventListener(
          "touchstart",
          touchstartListener,
          eventListenersOptions,
        );
      }

      if (!useMousedown) {
        document.addEventListener(
          "mouseover",
          mouseoverListener,
          eventListenersOptions,
        );
      } else if (!mousedownShortcut) {
        document.addEventListener(
          "mousedown",
          mousedownListener,
          eventListenersOptions,
        );
      }

      if (mousedownShortcut) {
        document.addEventListener(
          "mousedown",
          mousedownShortcutListener,
          eventListenersOptions,
        );
      }

      if (useViewport) {
        let triggeringFunction;
        if (window.requestIdleCallback) {
          triggeringFunction = function (callback) {
            requestIdleCallback(callback, {
              timeout: 1500,
            });
          };
        } else {
          triggeringFunction = function (callback) {
            callback();
          };
        }

        triggeringFunction(function () {
          const intersectionObserver = new IntersectionObserver(
            function (entries) {
              entries.forEach(function (entry) {
                if (entry.isIntersecting) {
                  const linkElement = entry.target;
                  intersectionObserver.unobserve(linkElement);
                  preload(linkElement.href);
                }
              });
            },
          );

          document.querySelectorAll("a").forEach(function (linkElement) {
            if (isPreloadable(linkElement)) {
              intersectionObserver.observe(linkElement);
            }
          });
        });
      }
    }

    function touchstartListener(event) {
      /* Chrome on Android calls mouseover before touchcancel so `lastTouchTimestamp`
   * must be assigned on touchstart to be measured on mouseover. */
      lastTouchTimestamp = performance.now();

      const linkElement = event.target.closest("a");

      if (!isPreloadable(linkElement)) {
        return;
      }

      preload(linkElement.href);
    }

    function mouseoverListener(event) {
      if (
        performance.now() - lastTouchTimestamp <
          DELAY_TO_NOT_BE_CONSIDERED_A_TOUCH_INITIATED_ACTION
      ) {
        return;
      }

      const linkElement = event.target.closest("a");

      if (!isPreloadable(linkElement)) {
        return;
      }

      linkElement.addEventListener("mouseout", mouseoutListener, {
        passive: true,
      });

      mouseoverTimer = setTimeout(function () {
        preload(linkElement.href);
        mouseoverTimer = undefined;
      }, delayOnHover);
    }

    function mousedownListener(event) {
      const linkElement = event.target.closest("a");

      if (!isPreloadable(linkElement)) {
        return;
      }

      preload(linkElement.href);
    }

    function mouseoutListener(event) {
      if (
        event.relatedTarget &&
        event.target.closest("a") == event.relatedTarget.closest("a")
      ) {
        return;
      }

      if (mouseoverTimer) {
        clearTimeout(mouseoverTimer);
        mouseoverTimer = undefined;
      }
    }

    function mousedownShortcutListener(event) {
      if (
        performance.now() - lastTouchTimestamp <
          DELAY_TO_NOT_BE_CONSIDERED_A_TOUCH_INITIATED_ACTION
      ) {
        return;
      }

      const linkElement = event.target.closest("a");

      if (event.which > 1 || event.metaKey || event.ctrlKey) {
        return;
      }

      if (!linkElement) {
        return;
      }

      linkElement.addEventListener("click", function (event) {
        if (event.detail == 1337) {
          return;
        }

        event.preventDefault();
      }, { capture: true, passive: false, once: true });

      const customEvent = new MouseEvent("click", {
        view: window,
        bubbles: true,
        cancelable: false,
        detail: 1337,
      });
      linkElement.dispatchEvent(customEvent);
    }

    function isPreloadable(linkElement) {
      if (!linkElement || !linkElement.href) {
        return;
      }

      if (useWhitelist && !("instant" in linkElement.dataset)) {
        return;
      }

      if (
        !allowExternalLinks && linkElement.origin != location.origin &&
        !("instant" in linkElement.dataset)
      ) {
        return;
      }

      if (!["http:", "https:"].includes(linkElement.protocol)) {
        return;
      }

      if (linkElement.protocol == "http:" && location.protocol == "https:") {
        return;
      }

      if (
        !allowQueryString && linkElement.search &&
        !("instant" in linkElement.dataset)
      ) {
        return;
      }

      if (
        linkElement.hash &&
        linkElement.pathname + linkElement.search ==
          location.pathname + location.search
      ) {
        return;
      }

      if ("noInstant" in linkElement.dataset) {
        return;
      }

      return true;
    }

    function preload(url) {
      if (prefetches.has(url)) {
        return;
      }

      const prefetcher = document.createElement("link");
      prefetcher.rel = "prefetch";
      prefetcher.href = url;
      document.head.appendChild(prefetcher);

      prefetches.add(url);
    }
  });
})();