// Handle page scroll and adjust sidebar accordingly.

// Each page has two scrolls: the main scroll, which is moving the content of the page;
// and the sidebar scroll, which is moving the navigation in the sidebar.
// We want the logo to gradually disappear as the main content is scrolled, giving
// more room to the navigation on the left. This means adjusting the height
// available to the navigation on the fly. There is also a banner below the navigation
// that must be dealt with simultaneously.
const registerOnScrollEvent = (function(){
    // Configuration.

    // The number of pixels the user must scroll by before the logo is completely hidden.
    const scrollTopPixels = 84;
    // The target margin to be applied to the navigation bar when the logo is hidden.
    const menuTopMargin = 70;
    // The max-height offset when the logo is completely visible.
    const menuHeightOffset_default = 162;
    // The max-height offset when the logo is completely hidden.
    const menuHeightOffset_fixed = 80;
    // The distance between the two max-height offset values above; used for intermediate values.
    const menuHeightOffset_diff = (menuHeightOffset_default - menuHeightOffset_fixed);

    // Media query handler.
    return function(mediaQuery) {
      // We only apply this logic to the "desktop" resolution (defined by a media query at the bottom).
      // This handler is executed when the result of the query evaluation changes, which means that
      // the page has moved between "desktop" and "mobile" states.

      // When entering the "desktop" state, we register scroll events and adjust elements on the page.
      // When entering the "mobile" state, we clean up any registered events and restore elements on the page
      // to their initial state.

      const $window = $(window);
      const $sidebar = $('.wy-side-scroll');
      const $search = $sidebar.children('.wy-side-nav-search');
      const $menu = $sidebar.children('.wy-menu-vertical');
      const $ethical = $sidebar.children('.ethical-rtd');

      // This padding is needed to correctly adjust the height of the scrollable area in the sidebar.
      // It has to have the same height as the ethical block, if there is one.
      let $menuPadding = $menu.children('.wy-menu-ethical-padding');
      if ($menuPadding.length == 0) {
        $menuPadding = $('<div class="wy-menu-ethical-padding"></div>');
        $menu.append($menuPadding);
      }

      if (mediaQuery.matches) {
        // Entering the "desktop" state.

        // The main scroll event handler.
        // Executed as the page is scrolled and once immediately as the page enters this state.
        const handleMainScroll = (currentScroll) => {
          if (currentScroll >= scrollTopPixels) {
            // After the page is scrolled below the threshold, we fix everything in place.
            $search.css('margin-top', `-${scrollTopPixels}px`);
            $menu.css('margin-top', `${menuTopMargin}px`);
            $menu.css('max-height', `calc(100% - ${menuHeightOffset_fixed}px)`);
          }
          else {
            // Between the top of the page and the threshold we calculate intermediate values
            // to guarantee a smooth transition.
            $search.css('margin-top', `-${currentScroll}px`);
            $menu.css('margin-top', `${menuTopMargin + (scrollTopPixels - currentScroll)}px`);

            if (currentScroll > 0) {
              const scrolledPercent = (scrollTopPixels - currentScroll) / scrollTopPixels;
              const offsetValue = menuHeightOffset_fixed + menuHeightOffset_diff * scrolledPercent;
              $menu.css('max-height', `calc(100% - ${offsetValue}px)`);
            } else {
              $menu.css('max-height', `calc(100% - ${menuHeightOffset_default}px)`);
            }
          }
        };

        // The sidebar scroll event handler.
        // Executed as the sidebar is scrolled as well as after the main scroll. This is needed
        // because the main scroll can affect the scrollable area of the sidebar.
        const handleSidebarScroll = () => {
          const menuElement = $menu.get(0);
          const menuScrollTop = $menu.scrollTop();
          const menuScrollBottom = menuElement.scrollHeight - (menuScrollTop + menuElement.offsetHeight);

          // As the navigation is scrolled we add a shadow to the top bar hanging over it.
          if (menuScrollTop > 0) {
            $search.addClass('fixed-and-scrolled');
          } else {
            $search.removeClass('fixed-and-scrolled');
          }

          // Near the bottom we start moving the sidebar banner into view.
          if (menuScrollBottom < ethicalOffsetBottom) {
            $ethical.css('display', 'block');
            $ethical.css('margin-top', `-${ethicalOffsetBottom - menuScrollBottom}px`);
          } else {
            $ethical.css('display', 'none');
            $ethical.css('margin-top', '0px');
          }
        };

        $search.addClass('fixed');
        $ethical.addClass('fixed');

        // Adjust the inner height of navigation so that the banner can be overlaid there later.
        const ethicalOffsetBottom = $ethical.height() || 0;
        if (ethicalOffsetBottom) {
          $menuPadding.css('height', `${ethicalOffsetBottom}px`);
        } else {
          $menuPadding.css('height', `0px`);
        }

        $window.scroll(function() {
          handleMainScroll(window.scrollY);
          handleSidebarScroll();
        });

        $menu.scroll(function() {
          handleSidebarScroll();
        });

        handleMainScroll(window.scrollY);
        handleSidebarScroll();
      } else {
        // Entering the "mobile" state.

        $window.unbind('scroll');
        $menu.unbind('scroll');

        $search.removeClass('fixed');
        $ethical.removeClass('fixed');

        $search.css('margin-top', `0px`);
        $menu.css('margin-top', `0px`);
        $menu.css('max-height', 'initial');
        $menuPadding.css('height', `0px`);
        $ethical.css('margin-top', '0px');
        $ethical.css('display', 'block');
      }
    };
  })();

  // Subscribe to DOM changes in the sidebar container, because there is a
  // banner that gets added at a later point, that we might not catch otherwise.
  const registerSidebarObserver = (function(){
    return function(callback) {
      const sidebarContainer = document.querySelector('.wy-side-scroll');

      let sidebarEthical = null;
      const registerEthicalObserver = () => {
        if (sidebarEthical) {
          // Do it only once.
          return;
        }

        sidebarEthical = sidebarContainer.querySelector('.ethical-rtd');
        if (!sidebarEthical) {
          // Do it only after we have the element there.
          return;
        }

        // This observer watches over the ethical block in sidebar, and all of its subtree.
        const ethicalObserverConfig = { childList: true, subtree: true };
        const ethicalObserverCallback = (mutationsList, observer) => {
          for (let mutation of mutationsList) {
            if (mutation.type !== 'childList') {
              continue;
            }

            callback();
          }
        };

        const ethicalObserver = new MutationObserver(ethicalObserverCallback);
        ethicalObserver.observe(sidebarEthical, ethicalObserverConfig);
      };
      registerEthicalObserver();

      // This observer watches over direct children of the main sidebar container.
      const observerConfig = { childList: true };
      const observerCallback = (mutationsList, observer) => {
        for (let mutation of mutationsList) {
          if (mutation.type !== 'childList') {
            continue;
          }

          callback();
          registerEthicalObserver();
        }
      };

      const observer = new MutationObserver(observerCallback);
      observer.observe(sidebarContainer, observerConfig);

      // Default TOC tree has links that immediately navigate to the selected page. Our
      // theme adds an extra button to fold and unfold the tree without navigating away.
      // But that means that the buttons are added after the initial load, so we need to
      // improvise to detect clicks on these buttons.
      const scrollElement = document.querySelector('.wy-menu-vertical');
      const registerLinkHandler = (linkChildren) => {
        linkChildren.forEach(it => {
          if (it.nodeType === Node.ELEMENT_NODE && it.classList.contains('toctree-expand')) {
            it.addEventListener('click', () => {
              // Toggling a different item will close the currently opened one,
              // which may shift the clicked item out of the view. We correct for that.
              const menuItem = it.parentNode;
              const baseScrollOffset = scrollElement.scrollTop + scrollElement.offsetTop;
              const maxScrollOffset = baseScrollOffset + scrollElement.offsetHeight;

              if (menuItem.offsetTop < baseScrollOffset || menuItem.offsetTop > maxScrollOffset) {
                menuItem.scrollIntoView();
              }

              callback();
            });
          }
        });
      }

      const navigationSections = document.querySelectorAll('.wy-menu-vertical ul');
      navigationSections.forEach(it => {
        if (it.previousSibling == null || typeof it.previousSibling === 'undefined' || it.previousSibling.tagName != 'A') {
          return;
        }

        const navigationLink = it.previousSibling;
        registerLinkHandler(navigationLink.childNodes);

        const linkObserverConfig = { childList: true };
        const linkObserverCallback = (mutationsList, observer) => {
          for (let mutation of mutationsList) {
            registerLinkHandler(mutation.addedNodes);
          }
        };

        const linkObserver = new MutationObserver(linkObserverCallback);
        linkObserver.observe(navigationLink, linkObserverConfig);
      });
    };
  })();

  $(document).ready(() => {
    // Remove the search match highlights from the page, and adjust the URL in the
    // navigation history.
    const url = new URL(location.href);
    if (url.searchParams.has('highlight')) {
      Documentation.hideSearchWords();
    }

    // Initialize handlers for page scrolling and our custom sidebar.
    const mediaQuery = window.matchMedia('only screen and (min-width: 769px)');

    registerOnScrollEvent(mediaQuery);
    mediaQuery.addListener(registerOnScrollEvent);

    registerSidebarObserver(() => {
      registerOnScrollEvent(mediaQuery);
    });

    // Add line-break suggestions to the sidebar navigation items in the class reference section.
    //
    // Some class reference pages have very long PascalCase names, such as
    //    VisualShaderNodeCurveXYZTexture
    // Those create issues for our layout, as we can neither make them wrap with CSS without
    // breaking normal article titles, nor is it good to have them overflow their containers.
    // So we use a <wbr> tag to insert mid-word suggestions for appropriate splits, so the browser
    // knows that it's okay to split it like
    //    Visual Shader Node Curve XYZTexture
    // and add a new line at an opportune moment.
    const classReferenceLinks = document.querySelectorAll('.wy-menu-vertical > ul:last-of-type .reference.internal');
    for (const linkItem of classReferenceLinks) {
      let textNode = null;
      linkItem.childNodes.forEach(it => {
        if (it.nodeType === Node.TEXT_NODE) {
          // If this is a text node and if it needs to be updated, store a reference.
          let text = it.textContent;
          if (!(text.includes(" ") || text.length < 10)) {
            textNode = it;
          }
        }
      });

      if (textNode != null) {
          let text = textNode.textContent;
          // Add suggested line-breaks and replace the original text.
          // The regex looks for a lowercase letter followed by a number or an uppercase
          // letter. We avoid splitting at the last character in the name, though.
          text = text.replace(/([a-z])([A-Z0-9](?!$))/gm, '$1<wbr>$2');

          linkItem.removeChild(textNode);
          linkItem.insertAdjacentHTML('beforeend', text);
      }
    }

    // Change indentation from spaces to tabs for codeblocks.
    const codeBlocks = document.querySelectorAll('.rst-content div[class^="highlight"] pre');
    for (const codeBlock of codeBlocks) {
      const classList = codeBlock.parentNode.parentNode.classList;
      if (!classList.contains('highlight-gdscript') && !classList.contains('highlight-cpp')) {
        // Only change indentation for GDScript and C++.
        continue;
      }
      let html = codeBlock.innerHTML.replace(/^(<span class="w">)?( {4})/gm, '\t');
      let html_old = "";
      while (html != html_old) {
        html_old = html;
        html = html.replace(/\t( {4})/gm, '\t\t')
      }
      codeBlock.innerHTML = html;
    }

    // See `godot_is_latest` in conf.py
    const isLatest = document.querySelector('meta[name=doc_is_latest]').content.toLowerCase() === 'true';
    if (isLatest) {
      // Add a compatibility notice using JavaScript so it doesn't end up in the
      // automatically generated `meta description` tag.

      const baseUrl = [location.protocol, '//', location.host, location.pathname].join('');
      // These lines only work as expected in the production environment, can't test this locally.
      const fallbackUrl = baseUrl.replace('/latest/', '/stable/');
      const homeUrl = baseUrl.split('/latest/')[0] + '/stable/';
      const searchUrl = homeUrl + 'search.html?q=';

      const noticeLink = document.querySelector('.latest-notice-link');

      // Insert a placeholder to display as we're making a request.
      noticeLink.innerHTML = `
      Checking the <a class="reference" href="${homeUrl}">stable version</a>
      of the documentation...
      `;

      // Make a HEAD request to the possible stable URL to check if the page exists.
      fetch(fallbackUrl, { method: 'HEAD' })
        .then((res) => {
          // We only check the HTTP status, which should tell us if the link is valid or not.
          if (res.status === 200) {
            noticeLink.innerHTML = `
            See the <a class="reference" href="${fallbackUrl}">stable version</a>
            of this documentation page instead.
            `;
          } else {
            // Err, just to fallthrough to catch.
            throw Error('Bad request');
          }
        })
        .catch((err) => {
          let message = `
          This page does not exist in the <a class="reference" href="${homeUrl}">stable version</a>
          of the documentation.
          `;

          // Also suggest a search query using the page's title. It should work with translations as well.
          // Note that we can't use the title tag as it has a permanent suffix. OG title doesn't, though.
          const titleMeta = document.querySelector('meta[property="og:title"]');
          if (typeof titleMeta !== 'undefined') {
            const pageTitle = titleMeta.getAttribute('content');
            message += `
            You can try searching for "<a class="reference" href="${searchUrl + encodeURIComponent(pageTitle)}">${pageTitle}</a>" instead.
            `;
          }

          noticeLink.innerHTML = message;
        });
    }

    // Load instant.page to prefetch pages upon hovering. This makes navigation feel
    // snappier. The script is dynamically appended as Read the Docs doesn't have
    // a way to add scripts with a "module" attribute.
    const instantPageScript = document.createElement('script');
    instantPageScript.toggleAttribute('module');
    /*! instant.page v5.1.0 - (C) 2019-2020 Alexandre Dieulot - https://instant.page/license */
    instantPageScript.innerText = 'let t,e;const n=new Set,o=document.createElement("link"),i=o.relList&&o.relList.supports&&o.relList.supports("prefetch")&&window.IntersectionObserver&&"isIntersecting"in IntersectionObserverEntry.prototype,s="instantAllowQueryString"in document.body.dataset,a="instantAllowExternalLinks"in document.body.dataset,r="instantWhitelist"in document.body.dataset,c="instantMousedownShortcut"in document.body.dataset,d=1111;let l=65,u=!1,f=!1,m=!1;if("instantIntensity"in document.body.dataset){const t=document.body.dataset.instantIntensity;if("mousedown"==t.substr(0,"mousedown".length))u=!0,"mousedown-only"==t&&(f=!0);else if("viewport"==t.substr(0,"viewport".length))navigator.connection&&(navigator.connection.saveData||navigator.connection.effectiveType&&navigator.connection.effectiveType.includes("2g"))||("viewport"==t?document.documentElement.clientWidth*document.documentElement.clientHeight<45e4&&(m=!0):"viewport-all"==t&&(m=!0));else{const e=parseInt(t);isNaN(e)||(l=e)}}if(i){const n={capture:!0,passive:!0};if(f||document.addEventListener("touchstart",function(t){e=performance.now();const n=t.target.closest("a");if(!h(n))return;v(n.href)},n),u?c||document.addEventListener("mousedown",function(t){const e=t.target.closest("a");if(!h(e))return;v(e.href)},n):document.addEventListener("mouseover",function(n){if(performance.now()-e<d)return;const o=n.target.closest("a");if(!h(o))return;o.addEventListener("mouseout",p,{passive:!0}),t=setTimeout(()=>{v(o.href),t=void 0},l)},n),c&&document.addEventListener("mousedown",function(t){if(performance.now()-e<d)return;const n=t.target.closest("a");if(t.which>1||t.metaKey||t.ctrlKey)return;if(!n)return;n.addEventListener("click",function(t){1337!=t.detail&&t.preventDefault()},{capture:!0,passive:!1,once:!0});const o=new MouseEvent("click",{view:window,bubbles:!0,cancelable:!1,detail:1337});n.dispatchEvent(o)},n),m){let t;(t=window.requestIdleCallback?t=>{requestIdleCallback(t,{timeout:1500})}:t=>{t()})(()=>{const t=new IntersectionObserver(e=>{e.forEach(e=>{if(e.isIntersecting){const n=e.target;t.unobserve(n),v(n.href)}})});document.querySelectorAll("a").forEach(e=>{h(e)&&t.observe(e)})})}}function p(e){e.relatedTarget&&e.target.closest("a")==e.relatedTarget.closest("a")||t&&(clearTimeout(t),t=void 0)}function h(t){if(t&&t.href&&(!r||"instant"in t.dataset)&&(a||t.origin==location.origin||"instant"in t.dataset)&&["http:","https:"].includes(t.protocol)&&("http:"!=t.protocol||"https:"!=location.protocol)&&(s||!t.search||"instant"in t.dataset)&&!(t.hash&&t.pathname+t.search==location.pathname+location.search||"noInstant"in t.dataset))return!0}function v(t){if(n.has(t))return;const e=document.createElement("link");e.rel="prefetch",e.href=t,document.head.appendChild(e),n.add(t)}';
    document.head.appendChild(instantPageScript);

    // Make sections in the sidebar togglable.
    let hasCurrent = false;
    let menuHeaders = document.querySelectorAll('.wy-menu-vertical .caption[role=heading]');
    menuHeaders.forEach(it => {
        let connectedMenu = it.nextElementSibling;

        // Enable toggling.
        it.addEventListener('click', () => {
            if (connectedMenu.classList.contains('active')) {
              connectedMenu.classList.remove('active');
              it.classList.remove('active');
            } else {
              connectedMenu.classList.add('active');
              it.classList.add('active');
            }

            // Hide other sections.
            menuHeaders.forEach(ot => {
              if (ot !== it && ot.classList.contains('active')) {
                ot.nextElementSibling.classList.remove('active');
                ot.classList.remove('active');
              }
            });

            registerOnScrollEvent(mediaQuery);
        }, true);

        // Set the default state, expand our current section.
        if (connectedMenu.classList.contains('current')) {
          connectedMenu.classList.add('active');
          it.classList.add('active');

          hasCurrent = true;
        }
    });

    // Unfold the first (general information) section on the home page.
    if (!hasCurrent && menuHeaders.length > 0) {
      menuHeaders[0].classList.add('active');
      menuHeaders[0].nextElementSibling.classList.add('active');

      registerOnScrollEvent(mediaQuery);
    }
  });

  // Override the default implementation from doctools.js to avoid this behavior.
  Documentation.highlightSearchWords = function() {
    // Nope.
  }