Extend "AO3: Kudosed and seen history" | Export/Import + Standalone Light/Dark mode toggle

Add Export/Import history to TXT buttons at the bottom of the page │ Fix back-navigation not being collapsed │ Color and rename the Seen/Unseen buttons │ Add skip button │ Enhance the title │ Fix "Mark as seen on open" triggering on external links ║ Standalone feature: Light/Dark site skin toggle button.

目前为 2025-05-21 提交的版本,查看 最新版本

// ==UserScript==
// @name         Extend "AO3: Kudosed and seen history" | Export/Import + Standalone Light/Dark mode toggle
// @description  Add Export/Import history to TXT buttons at the bottom of the page │ Fix back-navigation not being collapsed │ Color and rename the Seen/Unseen buttons │ Add skip button │ Enhance the title │ Fix "Mark as seen on open" triggering on external links ║ Standalone feature: Light/Dark site skin toggle button.
// @author       C89sd
// @version      1.41
// @match        https://archiveofourown.org/*
// @grant        GM_addStyle
// @namespace    https://greasyfork.org/users/1376767
// @noframes
// ==/UserScript==
'use strict';

const ENHANCED_SEEN_BUTTON   = true; // Seen button is colored and renamed / Immediately mark seen / Blink when navigating back
    const COLORED_TITLE_LINK = true; // |- Title becomes a colored link

const ENHANCED_MARK_SEEN_ON_OPEN = true; // Autoclick the seen button on open. Change text to "SEEN Now" or "Old SEEN" based on original state (can only do that if original setting is disabled because this script runs after.)
    const IGNORE_EXTERNAL_LINKS  = true; // |- Mark as seen when a link is clicked on AO3, not from other sites (e.g. link on reddit). If false, autosee all links but still mark 'SEEN Now' to you if it was a new or old link.

const SITE_SKINS = [ "Default", "Reversi" ];

//---------------------------------------------------------------------------
//  Local Storage
//---------------------------------------------------------------------------

const khx_version = '2.02'; // Min: @version	2.2.1

// Patch for the fact that Min's script only stores version on !username,
// but out Import function restores the username, so it can be left unset.
//
//    @TODO: Export the version, and when restoring set it to '2.02' if missing.
//
let stored_version = localStorage.getItem('kudoshistory_lastver');
if (!stored_version) {
  localStorage.setItem('kudoshistory_lastver', khx_version);
  stored_version = khx_version;
}

// Version mismatch safety.
let same_version = true;
if (khx_version < stored_version) {
  same_version = false;
  const message_key = 'khx_version_mismatch_' + khx_version;
  const message_seen = localStorage.getItem(message_key) || "false";
  if (message_seen === "false") {
    alert(`
[ExtendAO3KH][ERROR] Version mismatch with Min's "AO3: Kudosed and seen history".\n
min 's script version = ${stored_version}
extend script version = ${khx_version}\n
Writing has been disabled to prevent accidental overwrite in case the data storage changed. The script will need to be reviewed and updated.\n
This message will not repeat.
`)
    localStorage.setItem(message_key, "true");
  }
  console.log('[ExtendAO3KH] Writing disabled: version mismatch', khx_version, stored_version)
}

// Modified from @Min_ https://greasyfork.org/en/scripts/5835-ao3-kudosed-and-seen-history
// note: removed the 200_000 chars cutoff, we can store ~5_000_000 chars
//       KH loses entries above 25_000...
const KHList = {
  init: function(name) {
    this.name = name;
    this.list = localStorage.getItem('kudoshistory_' + this.name) || ',';
    console.log(this.list)
    return this;
  },
  reload: function() {
    this.list = localStorage.getItem('kudoshistory_' + this.name) || ',';
    return this;
  },
  save: function() {
    if (same_version) localStorage.setItem('kudoshistory_' + this.name, this.list);
    return this;
  },
  hasId: function(work_id) {
    if (this.list.indexOf(',' + work_id + ',') > -1) {
      // this.list = ',' + work_id + this.list.replace(',' + work_id + ',', ','); // Pointless if there isn't a cutoff.
      return true;
    }
    return false;
  },
  add: function(work_id) {
    this.list = ',' + work_id + this.list.replace(',' + work_id + ',', ',');
    return this;
  },
  remove: function(work_id) {
    this.list = this.list.replace(',' + work_id + ',', ',');
    return this;
  },
};

//---------------------------------------------------------------------------
//  Skip Button
//---------------------------------------------------------------------------

let currentSkipState;
let skipped;

function getWorkId() {
    const match = location.pathname.match(/\/works\/(\d+)/);
    return match ? match[1] : null;
}

const skipOff = ''; // '·'
const skipOn  = 'skipped';
function createSkipButton(workId, seenBtn) {
    skipped = Object.create(KHList).init('skipped');

    const li = document.createElement('li');
    li.style.padding = '0'

    const a = document.createElement('a');
    currentSkipState = skipped.hasId(workId);
    a.textContent = currentSkipState ? skipOn : skipOff;
    a.className = 'khx-skip-btn';

    a.style.color = getComputedStyle(seenBtn).color; // default text color is gray? copy other buttons.

    if (currentSkipState) {
        a.classList.add('hkx-skipped');
    }

    a.addEventListener('click', function(e) {
        skipped.reload();
        currentSkipState = skipped.hasId(workId);
        if (currentSkipState) {
            skipped.remove(workId);
            a.textContent = skipOff;
            a.classList.remove('hkx-skipped');
        } else {
            skipped.add(workId);
            a.textContent = skipOn;
            a.classList.add('hkx-skipped');
        }
        currentSkipState = !currentSkipState;
        skipped.save();
        a.blur()
    });

    li.appendChild(a);
    return li;
}

function insertSkipButton() {
    const workId = getWorkId();
    if (!workId) return;

    const seenBtn = document.querySelector('#main .kh-seen-button');
    if (!seenBtn || !seenBtn.parentNode) return;

    const skipBtnLi = createSkipButton(workId, seenBtn);

    // wrap both buttons in container so they don't get separated
    const container = document.createElement('div');
    container.style.display = 'inline-block';
    seenBtn.parentNode.insertBefore(container, seenBtn);
    container.appendChild(skipBtnLi);
    container.appendChild(seenBtn);
    // seenBtn.parentNode.insertBefore(skipBtnLi, seenBtn.nextSibling);
}

GM_addStyle(`
.khx-skip-btn {
  padding: 0.23em 0.5em !important;
  box-shadow: none !important;
  background-image: none !important;
  background-clip: padding-box !important;
    border-radius: 0.25em 0 0 0.25em !important;
    border-right: 0px !important;
}
.khx-seen-btn {
    border-radius: 0 0.25em 0.25em 0 !important;
  padding: 0.23em 0.5em !important;
  box-shadow: none !important;
  background-image: none !important;
  background-clip: padding-box !important;
  width: 8ch !important;
}
.hkx-skipped {
  background-color: rgb(238, 151, 40) !important;
  padding: 0.23em 0.5em !important;
}
`);
insertSkipButton();


// --------------------------------------------------------------------------
//                Collapse links clicked from search page
// --------------------------------------------------------------------------

// The AO3 Kudosed History script requires a manual reload after a link is clicked:
// - Clicked fics are not collpased and when navigating back.
// - Seen changes made from the other page are not taken into account.
//
// To fix this:
//   Intercept clicks on links to immediately trigger the 'seen' button collapse and various blink effects.
//   Write the current fic id/state to localStorage from fics.
//   When back-navigating, read it back and try to find its link on-screen to update its collapsed status.

let currentSeenState = null; // Updated inside of fics (MutationObserver on the fic's seen button).

if (ENHANCED_SEEN_BUTTON) {
  const isWork = /^https:\/\/archiveofourown\.org(?:\/collections\/[^\/]+)?(\/works\/\d+)/

  let refererData = {}; // {} | { workSlashId + seenState + skipState } of the referrer page (lastest when navigating back and forth).

  // When clicking a link & navigating back before the page is loaded, it doesn't blink.
  // To make it blink, we push the clicked link to localStorage, notifying ourselves.
  let clickedLink = false;
  let clickedLinkHref;
  let clickedLinkSeen;

  // About to leave page: write state for the next page to load.
  window.addEventListener("pagehide", function (event) {
    // Note: Doing this in 'unload'(desktop) or 'beforeunload'(mobile) caused 'event.persisted' to be false.
    const match = (clickedLink ? clickedLinkHref : window.location.href).match(isWork);
    if (match) {
      // Note: sessionStorage did not work on desktop; and GM_setValue bechmarked 27% slower than localStorage.

      if (clickedLink) {
        // Link clicked on AO3. The DB will be updated after the original script finises loading (work loaded). If we navigate back before, it will not be marked seen!
        // To prevent this, we write ourselves a message that the work was clicked. I we navigate back before the next page load we will see this message and close it ourselves, else it will be overwritten on the other side.
        localStorage.setItem("C89AO3_state", JSON.stringify({"workSlashId": match[1], "seenState": (clickedLinkSeen), "skipState": (currentSkipState)}));
      } else if (currentSeenState === null && refererData?.workSlashId === match[1]) {
        // Carry seenState back over adult content warning pages (they have no seen button).
        localStorage.setItem("C89AO3_state", JSON.stringify({"workSlashId": match[1], "seenState": (refererData?.seenState), "skipState": (refererData?.skipState)}));
      } else {
        localStorage.setItem("C89AO3_state", JSON.stringify({"workSlashId": match[1], "seenState": (currentSeenState), "skipState": (currentSkipState)}));
      }
    }
    else {
      localStorage.setItem("C89AO3_state", '{}');
    }
  });

  // Navigated back: load state communicated from originating page.
  // updated on page load/back navigation/etc.
  window.addEventListener("pageshow", function (event) {
    let data = localStorage.getItem("C89AO3_state");
    refererData = JSON.parse(data ? data : '{}');

    //console.log('navigated back: data=', data, ', persisted=', event.persisted)
  });

  // Blink functionality.
  const flashCSS = `
@keyframes flash-glow {
  0% {
    box-shadow: 0 0 4px currentColor;
  }
  100% {
    box-shadow: 0 0 4px transparent;
  }
}

@keyframes slide-left {
  0% {
    transform: translateX(6px);
  }
  100% {
    transform: translateX(0);
  }
}

/* When opening, slide down */
li[role="article"]:not(.marked-seen).blink div.header.module {
  transition: all 0.25s ease-out; //0.15s
}

/* Always blink border */
li.blink {
  animation: flash-glow 0.25s ease-in 1;
}

/* When closing, slide title left */
//li.blink.marked-seen div.header.module {
//  animation: slide-left 0.15s ease-out 1;
//}
//li.blink.marked-seen {
//  animation: flash-glow 0.2s ease-out 1;
//}

/* When collapsing, slide title in */
//li[role="article"].blink.marked-seen * h4.heading {
//  transition: all 0.300s ease-out;
//}
//li[role="article"]:not(.marked-seen) * ul.required-tags {
//  transition: all 0.1s ease-out;
//}`;

  GM_addStyle(flashCSS);

  let blinkTimeout;
  function blink(article) {
    // console.log("BLINK from ", article)
    clearTimeout(blinkTimeout);
    article.classList.remove('blink');

    void article.offsetWidth; // reflow

    article.classList.add('blink');
    blinkTimeout = setTimeout(() => {
      article.classList.remove('blink');
    }, 250);
  }

  // Navigated back: blink + update seen state.
  window.addEventListener('pageshow', (event) => {
    //console.log("navigated back, persisted=", event.persisted, ', referer=', refererData)

    if (event.persisted) { // If we navigated back.
      if (refererData?.workSlashId) { // If we read a fic id from localStorage.

        // Try finding the link of the fic we navigated back from and toggle its parent visibility.
        // Note: use *= because there can be: '.com/works/123' or '.com/collections/u1/works/132' or ?foo at the end.
        const titleLink = document.querySelector(`h4.heading > a[href*="${refererData.workSlashId}"]`);
        if (titleLink) {

          const article = titleLink.closest('li[role="article"]');
          if (article) {

            blink(article);

            if (       refererData?.seenState === true && !article.classList.contains('marked-seen')) {
              article.classList.add('marked-seen');
            } else if (refererData?.seenState === false && article.classList.contains('marked-seen')) {
              article.classList.remove('marked-seen');
            }

            if (     refererData?.skipState === true ) { article.classList.add('skipped-work'); }
            else if (refererData?.skipState === false) { article.classList.remove('skipped-work'); }
          }
        }
      }
    }
  });

  // Floating seen button click: blink.
  // The AO3 script calls event.stopPropagation() so document.addEventListener('click') does not work, we do his:
  function onKhToggleClick(e) {
    // console.log("click (floating seen .kh-toggle) ", event.target)
    const article = event.target.closest('li[role="article"]');
    if (article) {
      if (e.target.textContent === 'seen') blink(article);
    }
  }
  function attachToAll() {
    document.querySelectorAll('.kh-toggle').forEach(el => {
      // avoid double-binding
      if (!el.__khListenerAttached) {
        el.addEventListener('click', onKhToggleClick, /* capture */ true);
        el.__khListenerAttached = true;
      }
    });
  }
  attachToAll();

  // Title click: blink + send click event to floating seen button + redirect.
  document.addEventListener('click', function(event) {
    // console.log("click (title) ", event.target)

    const titleLink = event.target.closest('h4.heading > a');
    if (titleLink) {
      const article = titleLink.closest('li[role="article"]');
      if (article) {
        const seenButton = article.querySelector('div.kh-toggles>a')
        if (seenButton) {

          // Give the "seen" action time to execute before loading the page.
          event.preventDefault();

          blink(article);

          // Click the seen button (unless the fic is collapsed - that would unmark it!).
          if (!article.classList.contains('marked-seen')) {
            seenButton.click();
          }

          // Wait for seenButton.click() to complete before reloading.
          requestIdleCallback(() => {
            clickedLink     = true;
            clickedLinkHref = titleLink.href;
            clickedLinkSeen = article.classList.contains('marked-seen');

            window.location.href = titleLink.href;
          });
        }
      }
    }
  });

}

// -----------------------------------------------------------------------
// Light / Dark Skin Toggle
// -----------------------------------------------------------------------

async function toggleLightDark(e) {
  e.target.disabled = true;
  e.target.style.filter = 'brightness(30%)';

  // Get the username
  const greetingEl = document.querySelector('#greeting a');
  if (!greetingEl) {
    alert('[ExtendAO3KH][ERROR][light/dark toggle] username not found in top right corner "Hi, $user!"');
    return;
  }
  const user = greetingEl.href.split('/').pop();

  // ---------- GET preferences

  let html = await fetch(`https://archiveofourown.org/users/${user}/preferences`, {
    credentials: 'include'
  }).then(response => {
    if (response.ok) return response.text();
    alert('[ExtendAO3KH][ERROR][light/dark toggle] preferences !ok Error: ' + response.status);
    return null;
  }).catch(err => {
    alert('[ExtendAO3KH][ERROR][light/dark toggle] preferences Network Error: ' + err.message);
    return null;
  });
  if (!html) return;

  // ---------- Find nextSkinId

  const parser = new DOMParser();
  const doc = parser.parseFromString(html, 'text/html');

  const form = doc.querySelector('.edit_preference');
  if (!form) { alert(`[ExtendAO3KH][ERROR][light/dark] form not found`); throw new Error("form not found"); }

  const form_url = form.getAttribute('action');
  if (!form_url) { alert(`[ExtendAO3KH][ERROR][light/dark] form_url not found`); throw new Error("form_url not found"); }
  // const form_url2 = 'https://archiveofourown.org' + form_url;

  const skin_list = form.querySelector('#preference_skin_id');
  if (!skin_list) { alert(`[ExtendAO3KH][ERROR][light/dark] skin_list not found`); throw new Error("skin_list not found"); }

  const options = Array.from(skin_list.options);
  // options.forEach(opt => { console.log(`Skin: ${opt.text}, Value: ${opt.value}, Selected: ${opt.selected}`); });
  const currentSkinName = options.find(opt => opt.selected)?.text || null;

  let nextSkinName;
  if (!currentSkinName) {
    nextSkinName = SITE_SKINS[0];
    alert(`[ExtendAO3KH][INFO][light/dark] no skin selected, applying first skin "${nextSkinName}"`)
  } else {
    const currentIndex = SITE_SKINS.indexOf(currentSkinName);
    if (currentIndex === -1) {
      nextSkinName = SITE_SKINS[0];
      alert(`[ExtendAO3KH][INFO][light/dark] "${currentSkinName}" is not part of the cycle, applying first skin "${nextSkinName}"`)
    } else {
      nextSkinName = SITE_SKINS[(currentIndex + 1) % SITE_SKINS.length];
    }
  }

  const nextSkinOption = options.find(opt => opt.text === nextSkinName);
  if (!nextSkinOption) {
    alert(`[ExtendAO3KH][ERROR][light/dark] next skin "${nextSkinName}" has an invalid name, it does not exist in the preferences list`);
    return;
  }
  const nextSkinId = nextSkinOption.value;

  // ---------- POST form

  // Note: the form's token doesn't work, this one does.
  const authenticity_token2 = document.querySelector('meta[name="csrf-token"]')?.content;
  if (!authenticity_token2) { alert(`[ExtendAO3KH][ERROR][light/dark] authenticity_token2 not found.`); throw new Error("Authenticity token 2 not found."); }

  // Emulate the form data at https://archiveofourown.org/users/$user/skins
  const formData = new URLSearchParams();
  formData.append('_method', 'put');
  formData.append('authenticity_token', authenticity_token2);
  formData.append('preference[skin_id]', nextSkinId);
  formData.append('commit', 'Use'); // skin 'Use' VS pref 'Update'?

  let reload = false;
  await fetch(form_url, {
    method: 'POST',
    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
    body: formData.toString(),
    credentials: 'include',
    redirect: 'manual'
  }).then(response => {
    // For some reason does a redirect !ok, so we kill the redirect and treat it as ok.
    if (response.type === 'opaqueredirect' || response.ok) {
      reload = true;
      return;
    }
    else alert('[ExtendAO3KH][ERROR][light/dark toggle] skins !ok Error: ' + response.status);
  }).catch(err => {
    alert('[ExtendAO3KH][ERROR][light/dark toggle] skins Network Error: ' + err.message);
  });

  e.target.disabled = false;
  e.target.style.filter = '';
  if (reload) window.location.reload();
}

// --------------------------------------------------------------------------
//                     Bottom bar + Import/Export
// --------------------------------------------------------------------------

(function() {
    const footer = document.createElement('div');
    footer.style.width = '100%';
    footer.style.paddingTop = '5px';
    footer.style.paddingBottom = '5px';
    footer.style.display = 'flex';
    footer.style.justifyContent = 'center';
    footer.style.gap = '10px';
    footer.classList.add('footer');

    var firstH1link = null;
    if (ENHANCED_SEEN_BUTTON && COLORED_TITLE_LINK) {
      // Turn title into a link
      const firstH1 = document.querySelector('h2.title.heading');

      if (firstH1) {
          const title = firstH1.lastChild ? firstH1.lastChild : firstH1;
          const titleLink = document.createElement('a');
          titleLink.href = window.location.origin + window.location.pathname + window.location.search; // Keeps "?view_full_work=true", drops "#summary"
          if (title) {
              const titleClone = title.cloneNode(true);
              titleLink.appendChild(titleClone);
              title.parentNode.replaceChild(titleLink, title);
          }

        firstH1link = titleLink;
      }
    }

    const BTN_1 = ['button'];
    const BTN_2 = ['button', 'button--link'];

    // Create Light/Dark Button
    const lightDarkButton = document.createElement('button');
    lightDarkButton.textContent = 'Light/Dark';
    lightDarkButton.classList.add(...['button']);
    lightDarkButton.addEventListener('click', toggleLightDark);
    footer.appendChild(lightDarkButton);

    // Create Export Button
    const exportButton = document.createElement('button');
    exportButton.textContent = 'Export';
    exportButton.classList.add(...BTN_1);
    exportButton.addEventListener('click', exportToJson);
    footer.appendChild(exportButton);

    // Create Import Button
    const importButton = document.createElement('button');
    importButton.textContent = 'Import';
    importButton.classList.add(...BTN_1);

    // Create hidden file input
    const fileInput = document.createElement('input');
    fileInput.type = 'file';
    fileInput.accept = '.txt, .json';
    fileInput.style.display = 'none'; // Hide the input element

    // Trigger file input on "Restore" button click
    importButton.addEventListener('click', () => {
        fileInput.click(); // Open the file dialog when the button is clicked
    });

    // Listen for file selection and handle the import
    fileInput.addEventListener('change', importFromJson);
    footer.appendChild(importButton);

    // Append footer to the page
    const ao3Footer = document.querySelector('body > div > div#footer');
    if (ao3Footer) {
        ao3Footer.insertAdjacentElement('beforebegin', footer);
    } else {
        document.body.appendChild(footer);
    }

    const strip = /^\[?,?|,?\]?$/g;
    // Export function
    function exportToJson() {
        const export_lists = {
            username:   localStorage.getItem('kudoshistory_username'),
            settings:   localStorage.getItem('kudoshistory_settings'),
            kudosed:    localStorage.getItem('kudoshistory_kudosed')    || ',',
            bookmarked: localStorage.getItem('kudoshistory_bookmarked') || ',',
            skipped:    localStorage.getItem('kudoshistory_skipped')    || ',',
            seen:       localStorage.getItem('kudoshistory_seen')       || ',',
            checked:    localStorage.getItem('kudoshistory_checked')    || ','
        };

        const pad = (num) => String(num).padStart(2, '0');
        const now = new Date();
        const year = now.getFullYear();
        const month = pad(now.getMonth() + 1);
        const day = pad(now.getDate());
        const hours = pad(now.getHours());
        const minutes = pad(now.getMinutes());
        const seconds = pad(now.getSeconds()); // Add seconds
        const username = export_lists.username || "none";
        var size = ['kudosed', 'bookmarked', 'skipped', 'seen', 'checked']
            .map(key => (String(export_lists[key]) || '').replace(strip, '').split(',').length);

        var textToSave = JSON.stringify(export_lists, null, 2);
        var blob = new Blob([textToSave], {
            type: "text/plain"
        });
        var a = document.createElement('a');
        a.href = URL.createObjectURL(blob);
        a.download = `AO3_history_${year}_${month}_${day}_${hours}${minutes}${seconds} ${username}+${size}.txt`; //Include seconds
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
    }

    // Import function
    function importFromJson(event) {
        var file = event.target.files[0];
        if (!file) return;

        var reader = new FileReader();
        reader.onload = function(e) {
            try {
                var importedData = JSON.parse(e.target.result);
                if (!importedData.kudosed || !importedData.seen || !importedData.bookmarked || !importedData.skipped || !importedData.checked) {
                    throw new Error("Missing kudosed/seen/bookmarked/skipped/checked data fields.");
                }

                var notes = ""
                var sizes_before = ['kudoshistory_kudosed', 'kudoshistory_bookmarked', 'kudoshistory_skipped', 'kudoshistory_seen', 'kudoshistory_checked']
                    .map(key => (String(localStorage.getItem(key)) || '').replace(strip, '').split(',').length);
                var sizes_after = ['kudosed', 'bookmarked', 'skipped', 'seen', 'checked']
                    .map(key => (String(importedData[key]) || '').replace(strip, '').split(',').length);

                localStorage.setItem('kudoshistory_kudosed',    importedData.kudosed);
                localStorage.setItem('kudoshistory_bookmarked', importedData.bookmarked);
                localStorage.setItem('kudoshistory_skipped',    importedData.skipped);
                localStorage.setItem('kudoshistory_seen',       importedData.seen);
                localStorage.setItem('kudoshistory_checked',    importedData.checked);

                var diff = sizes_after.reduce((a, b) => a + b, 0) - sizes_before.reduce((a, b) => a + b, 0);
                diff = diff == 0 ? "no change" :
                       diff > 0 ? "added +" + diff :
                       "removed " + diff;
                notes += "\n- Entries: " + diff;
                notes += "\n    " + sizes_before;
                notes += "\n    " + sizes_after;

                if (!importedData.username) {
                  notes += "\n- Username: not present in file ";
                } else if (localStorage.getItem('kudoshistory_username') == "null" && importedData.username && importedData.username != "null") {
                  localStorage.setItem('kudoshistory_username', importedData.username);
                  notes += "\n- Username: updated to " + importedData.username;
                } else {
                  notes += "\n- Username: no change"
                }

                if (!importedData.settings) {
                  notes += "\n- Settings: not present in file ";
                } else if (importedData.settings && importedData.settings != localStorage.getItem('kudoshistory_settings')) {
                  const oldSettings = localStorage.getItem('kudoshistory_settings');
                  localStorage.setItem('kudoshistory_settings', importedData.settings);
                  notes += "\n- Settings: updated to";
                  notes += "\n    old:  " + oldSettings;
                  notes += "\n    new: " + importedData.settings;
                } else {
                  notes += "\n- Settings: no change"
                }

                alert("[userscript:Extend AO3] Success" + notes);
            } catch (error) {
                alert("[userscript:Extend AO3] Error\nInvalid file format / missing data.");
            }
        };
        reader.readAsText(file);
    }


// --------------------------------------------------------------------------
//                       Monitor+Enhance seen button
// --------------------------------------------------------------------------

if (ENHANCED_SEEN_BUTTON) {
    let wasClicked = false;

    // Step 1: Wait for the button to exist and click it if it shows "Seen"
    function waitForSeenButton() {
        const delays = [0, 100, 250, 500, 1000, 2000]; // exponential delays in ms
        //console.log("Planned delays (ms):", delays);

        let step = 0;
        function tryCheckButton() {
            //console.log('Attempt', step + 1);
            const seenButton = document.querySelector('.kh-seen-button a');

            if (seenButton) {
                if (seenButton.textContent.includes('Seen ✓')) {
                    if (ENHANCED_MARK_SEEN_ON_OPEN) {
                        if (!IGNORE_EXTERNAL_LINKS || document.referrer.includes("archiveofourown.org")) {
                            seenButton.click();
                            wasClicked = true;
                        }
                    }
                } else {
                    wasClicked = false;
                }
                setupButtonObserver();
            } else if (step < delays.length - 1) {
                step++;
                setTimeout(tryCheckButton, delays[step]);
            }
        }
        setTimeout(tryCheckButton, delays[0]);
    }

    // Step 2: Monitor the button text and toggle it
    function setupButtonObserver() {
        toggleButtonText(true, wasClicked);

        // Button to observe
        const targetNode = document.querySelector('.kh-seen-button');
        if (!targetNode) {
            return;
        }

        const observer = new MutationObserver(function(mutations) {
            mutations.forEach(function(mutation) {
                if (mutation.type === 'childList' || mutation.type === 'characterData') {
                    toggleButtonText(false, false);
                }
            });
        });

        const config = {
            childList: true,
            characterData: true,
            subtree: true
        };

        observer.observe(targetNode, config);
    }

    function toggleButtonText(isFirst = false, wasClicked = false) {
        const buttonElement = document.querySelector('.kh-seen-button a');
        if (!buttonElement) return;

        const UNSEEN   = 'Unseen';
        const SEEN     = 'Seen';
        const SEEN_NOW = 'Seen<em style="font-size: 0.85em;"> new</em>';
        const SEEN_OLD = 'Seen<em style="font-size: 0.85em;"> old</em>';

        // const UNSEEN   = "UNSEEN [<strong>mark</strong>]";
        // const SEEN     = "SEEN [<strong>unmark</strong>]";
        // const SEEN_NOW = "SEEN NOW [<strong>unmark</strong>]";
        // const SEEN_OLD = "SEEN OLD [<strong>unmark</strong>]";

        // Ignore changes we made ourselves.
        // (Since this is a mutation callback it is called again after modifying the button below.)
        if (buttonElement.innerHTML === UNSEEN   ||
            buttonElement.innerHTML === SEEN     ||
            buttonElement.innerHTML === SEEN_NOW ||
            buttonElement.innerHTML === SEEN_OLD) {
            return;
        }

        const state_seen = buttonElement.textContent.includes('Unseen ✗') ? true :
            buttonElement.textContent.includes('Seen ✓') ? false : null;

        if (state_seen === null) {
            alert('[userscript:Extend AO3]\nUnknown text: ' + buttonElement.textContent);
            return;
        }

        currentSeenState = state_seen;

        const GREEN = "#33cc70"; // "#33cc70";
        const GREEN_DARKER = "#00a13a"; // "#149b49";
        const RED = "#ff6d50";

        buttonElement.innerHTML =
          state_seen ?
            (isFirst ?
              (wasClicked ? SEEN_NOW : SEEN_OLD) :
              SEEN) :
            UNSEEN;

        const color = state_seen ? (isFirst && !wasClicked ? GREEN_DARKER : GREEN) : RED;
        buttonElement.classList.add('khx-seen-btn')
        buttonElement.style.backgroundColor = color;
        buttonElement.style.color = getComputedStyle(buttonElement).color;

        // Color title
        if (firstH1link) firstH1link.style.color = color;

        // Blink on open Unseen -> Seen
        if (isFirst && wasClicked) {
            buttonElement.style.transition = "background-color 150ms ease";
            buttonElement.style.backgroundColor = GREEN;
            setTimeout(() => {
                buttonElement.style.backgroundColor = "#00e64b";
            }, 150);
            setTimeout(() => {
                buttonElement.style.transition = "background-color 200ms linear";
                buttonElement.style.backgroundColor = GREEN;
            }, 200);
        } else if (!isFirst) {
            buttonElement.style.transition = "none"; // Clear transition for subsequent calls
            buttonElement.style.backgroundColor = state_seen ? GREEN : RED;
        }
    }

  // waitForSeenButton() polls the button, only do that on /works/
  const isWork = /^\/(?:collections\/[^\/]+\/)?works\/\d+(?:\/chapters\/\d+)?\/?$/.test(location.pathname);
  // Start the process
  if (isWork) waitForSeenButton();
}
})();