import fs from "node:fs";
import http from "node:http";
import path from "node:path";
import { URL } from "node:url";
import { app } from "electron";

const SHOULD_INJECT_RESKIN = process.env.FIVEETOOLS_DESKTOP_RESKIN !== "0";
const SHOULD_FORCE_NIGHT_THEME = process.env.FIVEETOOLS_DESKTOP_FORCE_NIGHT !== "0";
const SHOULD_USE_EXTERNAL_IMAGE_FALLBACK = process.env.FIVEETOOLS_DESKTOP_EXTERNAL_IMAGES !== "0";
export const DEFAULT_EXTERNAL_IMAGE_ROOT = "https://5e.tools/img/";

const MIME_TYPES: Record<string, string> = {
  ".avif": "image/avif",
  ".css": "text/css; charset=utf-8",
  ".eot": "application/vnd.ms-fontobject",
  ".gif": "image/gif",
  ".html": "text/html; charset=utf-8",
  ".ico": "image/x-icon",
  ".jpeg": "image/jpeg",
  ".jpg": "image/jpeg",
  ".js": "text/javascript; charset=utf-8",
  ".json": "application/json; charset=utf-8",
  ".map": "application/json; charset=utf-8",
  ".mjs": "text/javascript; charset=utf-8",
  ".mp3": "audio/mpeg",
  ".mp4": "video/mp4",
  ".otf": "font/otf",
  ".pdf": "application/pdf",
  ".png": "image/png",
  ".svg": "image/svg+xml",
  ".ttf": "font/ttf",
  ".txt": "text/plain; charset=utf-8",
  ".wasm": "application/wasm",
  ".webm": "video/webm",
  ".webp": "image/webp",
  ".woff": "font/woff",
  ".woff2": "font/woff2",
  ".webmanifest": "application/manifest+json; charset=utf-8",
  ".xml": "application/xml; charset=utf-8"
};

const CORS_HEADERS: Record<string, string> = {
  "Access-Control-Allow-Origin": "*",
  "Access-Control-Allow-Methods": "GET, OPTIONS",
  "Access-Control-Allow-Headers": "Content-Type"
};

function withCorsHeaders(headers: Record<string, string>): Record<string, string> {
  return {
    ...CORS_HEADERS,
    ...headers
  };
}

function getDesktopReskinBootstrap(externalImageRoot: string | null): string {
  return `
(() => {
  ${externalImageRoot ? `globalThis.DEPLOYED_IMG_ROOT = ${JSON.stringify(externalImageRoot)};` : ""}

  const root = document.documentElement;
  root.classList.add("desktop-reskin", "desktop-app-navbar-mode");

  ${
    SHOULD_FORCE_NIGHT_THEME
      ? `
  root.classList.add("ve-night-mode", "ve-night-mode--standard");
  try {
    window.localStorage.setItem("StyleSwitcher_style", "night");
  } catch {}
  `
      : ""
  }

  const doToastInfo = (content) => {
    try {
      if (globalThis.JqueryUtil?.doToast) {
        globalThis.JqueryUtil.doToast({ type: "info", content });
        return;
      }
    } catch {}

    console.info("[5ET-D]", content);
  };

  const postToDesktop = (type, payload) => {
    if (window.parent && window.parent !== window) {
      window.parent.postMessage({ type, ...(payload || {}) }, "*");
      return true;
    }

    return false;
  };

  const requestOnboardingReset = () => {
    const message = [
      "Reset onboarding and remove local 5etools data?",
      "",
      "This will clear downloaded source/images and return to first-run setup."
    ].join("\\n");

    if (!window.confirm(message)) {
      return;
    }

    if (window.parent && window.parent !== window) {
      window.parent.postMessage({ type: "5etd:reset-onboarding" }, "*");
      doToastInfo("Resetting onboarding...");
      return;
    }

    doToastInfo("Reset onboarding is unavailable in this context.");
  };

  const closeDropdown = (li, toggle) => {
    if (typeof NavBar !== "undefined" && typeof NavBar._closeDropdownElement === "function") {
      NavBar._closeDropdownElement(li);
      return;
    }

    li.classList.remove("open");
    toggle.setAttribute("aria-expanded", "false");
  };

  const addCharactersMenu = () => {
    const navbar = document.getElementById("navbar");
    if (!navbar || navbar.querySelector(".desktop-nav-characters")) return;

    const li = document.createElement("li");
    li.setAttribute("role", "presentation");
    li.className = "dropdown dropdown--navbar page__nav-hidden-mobile page__btn-nav-root desktop-nav-characters";

    const toggle = document.createElement("a");
    toggle.className = "ve-dropdown-toggle";
    toggle.href = "#";
    toggle.setAttribute("role", "button");
    toggle.setAttribute("aria-haspopup", "true");
    toggle.setAttribute("aria-expanded", "false");
    toggle.innerHTML = 'Characters <span class="caret"></span>';

    toggle.onclick = (event) => {
      if (typeof NavBar !== "undefined" && typeof NavBar._handleDropdownClick === "function") {
        NavBar._handleDropdownClick(toggle, event, false);
        return;
      }

      event.preventDefault();
      event.stopPropagation();

      const isOpen = li.classList.contains("open");
      [...navbar.querySelectorAll(":scope > li.dropdown--navbar.open")]
        .forEach((it) => it.classList.remove("open"));

      li.classList.toggle("open", !isOpen);
      toggle.setAttribute("aria-expanded", String(!isOpen));
    };

    li.onmouseenter = function () {
      if (typeof NavBar !== "undefined" && typeof NavBar._handleItemMouseEnter === "function") {
        NavBar._handleItemMouseEnter(this);
      }
    };

    const menu = document.createElement("ul");
    menu.setAttribute("role", "menu");
    menu.className = "ve-dropdown-menu ve-dropdown-menu--top";
    menu.onclick = (event) => event.stopPropagation();

    const addMenuItem = (label, onClick) => {
      const menuItem = document.createElement("li");
      menuItem.setAttribute("role", "presentation");

      const link = document.createElement("a");
      link.href = "#";
      link.textContent = label;
      link.onclick = (event) => {
        event.preventDefault();
        event.stopPropagation();
        onClick();
        closeDropdown(li, toggle);
      };

      menuItem.append(link);
      menu.append(menuItem);
    };

    addMenuItem("New", () => {
      if (!postToDesktop("5etd:characters:new")) {
        doToastInfo("Characters menu is unavailable in this context.");
      }
    });
    addMenuItem("Load from JSON", () => {
      if (!postToDesktop("5etd:characters:load-json")) {
        doToastInfo("Characters menu is unavailable in this context.");
      }
    });
    addMenuItem("My Characters", () => {
      if (!postToDesktop("5etd:characters:list")) {
        doToastInfo("Characters menu is unavailable in this context.");
      }
    });

    li.append(toggle, menu);

    const playerToggle = [...navbar.querySelectorAll(":scope > li.dropdown--navbar > a.ve-dropdown-toggle")]
      .find((it) => it.textContent?.trim().startsWith("Player"));
    const playerLi = playerToggle?.parentElement;
    const helpLi = navbar.querySelector(':scope > li[data-page^="https://wiki.tercept.net/en/5eTools"]');

    if (playerLi?.nextSibling) {
      navbar.insertBefore(li, playerLi.nextSibling);
      return;
    }

    if (playerLi) {
      navbar.append(li);
      return;
    }

    if (helpLi) {
      navbar.insertBefore(li, helpLi);
      return;
    }

    navbar.append(li);
  };

  const addResetOnboardingMenu = () => {
    const navbar = document.getElementById("navbar");
    if (!navbar) return;

    const settingsToggle = [...navbar.querySelectorAll(":scope > li.dropdown--navbar > a.ve-dropdown-toggle")]
      .find((it) => it.textContent?.trim().startsWith("Settings"));
    const settingsLi = settingsToggle?.parentElement;
    if (!settingsLi) return;

    const menu =
      settingsLi.querySelector(":scope > ul.ve-dropdown-menu") ||
      settingsLi.querySelector(":scope > ul.dropdown-menu");
    if (!menu || menu.querySelector(".desktop-nav-reset-onboarding")) return;

    const divider = document.createElement("li");
    divider.className = "divider desktop-nav-reset-onboarding";
    divider.setAttribute("role", "presentation");

    const item = document.createElement("li");
    item.className = "desktop-nav-reset-onboarding";
    item.setAttribute("role", "presentation");

    const link = document.createElement("a");
    link.href = "#";
    link.textContent = "Reset Onboarding";
    link.onclick = (event) => {
      event.preventDefault();
      event.stopPropagation();
      requestOnboardingReset();

      if (typeof NavBar !== "undefined" && typeof NavBar._closeDropdownElement === "function") {
        NavBar._closeDropdownElement(settingsLi);
        return;
      }

      settingsLi.classList.remove("open");
      settingsToggle?.setAttribute("aria-expanded", "false");
    };

    item.append(link);
    menu.append(divider, item);
  };

  let isAutoFocusScheduled = false;
  let hasAutoFocusedSearch = false;

  const tryAutoFocusSearch = () => {
    if (hasAutoFocusedSearch) {
      return true;
    }

    const active = document.activeElement;
    if (active && active !== document.body && active !== document.documentElement) {
      return true;
    }

    const input = document.querySelector("#navbar .omni__input, .omni__input");
    if (!(input instanceof HTMLInputElement)) {
      return false;
    }

    input.focus({ preventScroll: true });
    input.select();

    if (document.activeElement === input) {
      hasAutoFocusedSearch = true;
      return true;
    }

    return false;
  };

  const scheduleAutoFocusSearch = () => {
    if (isAutoFocusScheduled || hasAutoFocusedSearch) {
      return;
    }

    isAutoFocusScheduled = true;
    let attempts = 0;
    const maxAttempts = 80;
    const intervalMs = 75;

    const runAttempt = () => {
      if (tryAutoFocusSearch()) {
        isAutoFocusScheduled = false;
        return;
      }

      attempts += 1;
      if (attempts >= maxAttempts) {
        isAutoFocusScheduled = false;
      }
    };

    runAttempt();
    const interval = window.setInterval(() => {
      if (!isAutoFocusScheduled) {
        window.clearInterval(interval);
        return;
      }

      runAttempt();
    }, intervalMs);

    const observer = new MutationObserver(() => {
      if (tryAutoFocusSearch()) {
        isAutoFocusScheduled = false;
        observer.disconnect();
      }
    });

    const obsTarget = document.body || document.documentElement;
    if (obsTarget) {
      observer.observe(obsTarget, { childList: true, subtree: true });
    }

    window.setTimeout(() => {
      observer.disconnect();
      isAutoFocusScheduled = false;
    }, maxAttempts * intervalMs + 250);
  };

  const applyDesktopMenuExtensions = () => {
    addCharactersMenu();
    addResetOnboardingMenu();
    bindNativeNavbarSync();
    queueNativeNavbarModelPost({ isForce: true });
  };

  const NAVBAR_ACTION_ATTR = "data-5etd-nav-action-id";

  const cleanNavLabel = (value) => String(value || "").replace(/\\s+/g, " ").replace(/[▾▼►]+/g, "").trim();

  const getNavPrimaryText = (ele) => {
    for (const node of Array.from(ele.childNodes || [])) {
      if (node.nodeType === Node.TEXT_NODE) {
        const text = cleanNavLabel(node.textContent || "");
        if (text) return text;
      }
    }
    return cleanNavLabel(ele.textContent || "");
  };

  const getNavEntryMeta = (ele) => {
    if (!ele) return {};

    const out = {};
    const dateEle = ele.querySelector(":scope > .page__nav-date");
    if (dateEle) {
      const datePrefix = cleanNavLabel(dateEle.textContent || "");
      if (datePrefix) out.datePrefix = datePrefix;
    }

    const sourceEle = ele.querySelector(":scope > .nav2-list__disp-source");
    if (sourceEle instanceof HTMLElement) {
      const computed = getComputedStyle(sourceEle);
      const sourceColor = String(computed.backgroundColor || computed.borderLeftColor || "").trim();
      if (
        sourceColor &&
        sourceColor !== "transparent" &&
        !/^rgba?\\(\\s*0\\s*,\\s*0\\s*,\\s*0(?:\\s*,\\s*0)?\\s*\\)$/i.test(sourceColor)
      ) {
        out.sourceColor = sourceColor;
      }
    }

    return out;
  };

  const isActionLikeHref = (hrefRaw) => {
    const href = String(hrefRaw || "").trim().toLowerCase();
    return !href || href === "#" || href.startsWith("javascript:");
  };

  const parseNavbarMenuList = (list, idPrefix) => {
    const entries = [];
    const liElements = Array.from(list?.children || []).filter((it) => it instanceof HTMLLIElement);

    liElements.forEach((li, index) => {
      const entryId = \`\${idPrefix}-\${index}\`;
      const submenuList = li.querySelector(":scope > ul")
        || (li.classList.contains("nav2-accord__wrp") ? li.querySelector(":scope > .nav2-accord__body") : null);
      const submenuChildren = submenuList ? parseNavbarMenuList(submenuList, \`\${entryId}-submenu\`) : [];

      if (li.classList.contains("ve-dropdown-divider") || li.classList.contains("divider")) {
        entries.push({ id: \`\${entryId}-divider\`, type: "divider" });
        return;
      }

      if (li.classList.contains("nav2-list__label")) {
        const label = cleanNavLabel(li.textContent || "");
        if (label) entries.push({ id: \`\${entryId}-label\`, type: "label", label });
        return;
      }

      if (li.classList.contains("dropdown--navbar")) {
        const toggle = li.querySelector(":scope > a");
        const label = toggle ? getNavPrimaryText(toggle) : "";
        if (!label) return;

        entries.push({
          id: \`\${entryId}-submenu\`,
          type: "submenu",
          label,
          ...getNavEntryMeta(toggle),
          children: submenuChildren
        });
        return;
      }

      if (li.classList.contains("nav2-accord__wrp")) {
        const headPrimary = li.querySelector(":scope > .nav2-accord__head > :first-child");
        const label = headPrimary ? getNavPrimaryText(headPrimary) : "";
        if (!label || !submenuChildren.length) return;

        entries.push({
          id: \`\${entryId}-accordion\`,
          type: "submenu",
          label,
          ...getNavEntryMeta(headPrimary),
          children: submenuChildren
        });
        return;
      }

      const link = li.querySelector(":scope > a");
      if (link) {
        const label = getNavPrimaryText(link);
        const href = String(link.getAttribute("href") || "").trim();
        if (submenuChildren.length) {
          if (isActionLikeHref(href)) {
            const actionId = \`\${entryId}-submenu-action\`;
            link.setAttribute(NAVBAR_ACTION_ATTR, actionId);
            entries.push({
              id: \`\${entryId}-submenu-link\`,
              type: "submenu",
              label: label || "Section",
              ...getNavEntryMeta(link),
              actionId,
              children: submenuChildren
            });
            return;
          }

          entries.push({
            id: \`\${entryId}-submenu-link\`,
            type: "submenu",
            label: label || href,
            ...getNavEntryMeta(link),
            href,
            isExternal: link.target === "_blank" || /^https?:\\/\\//i.test(href),
            children: submenuChildren
          });
          return;
        }

        if (isActionLikeHref(href)) {
          const actionId = \`\${entryId}-action\`;
          link.setAttribute(NAVBAR_ACTION_ATTR, actionId);
          entries.push({ id: \`\${entryId}-action\`, type: "action", label: label || "Action", actionId });
          return;
        }

        entries.push({
          id: \`\${entryId}-link\`,
          type: "link",
          label: label || href,
          ...getNavEntryMeta(link),
          href,
          isExternal: link.target === "_blank" || /^https?:\\/\\//i.test(href)
        });
        return;
      }

      const spans = Array.from(li.querySelectorAll(":scope > span")).filter((it) => it instanceof HTMLSpanElement);
      if (submenuChildren.length && spans.length) {
        const first = spans[0];
        const label = cleanNavLabel(first.textContent || first.title || "");
        const actionId = \`\${entryId}-submenu-span\`;
        first.setAttribute(NAVBAR_ACTION_ATTR, actionId);
        entries.push({
          id: \`\${entryId}-submenu-span\`,
          type: "submenu",
          label: label || "Section",
          ...getNavEntryMeta(first),
          actionId,
          children: submenuChildren
        });
        return;
      }

      spans.forEach((span, spanIndex) => {
        const label = cleanNavLabel(span.textContent || span.title || "");
        const actionId = \`\${entryId}-span-\${spanIndex}\`;
        span.setAttribute(NAVBAR_ACTION_ATTR, actionId);
        entries.push({
          id: \`\${entryId}-span-\${spanIndex}\`,
          type: "action",
          label: label || "Action",
          ...getNavEntryMeta(span),
          actionId
        });
      });
    });

    return entries;
  };

  const buildNativeNavbarGroups = () => {
    const navbar = document.getElementById("navbar");
    if (!navbar) return [];

    const groups = [];
    const rootItems = Array.from(navbar.children).filter((it) => it instanceof HTMLLIElement);

    rootItems.forEach((li, index) => {
      if (
        li.classList.contains("omni__wrp-input") ||
        li.classList.contains("desktop-nav-characters")
      ) {
        return;
      }

      if (li.classList.contains("dropdown--navbar")) {
        const toggle = li.querySelector(":scope > a");
        const menuList = li.querySelector(":scope > ul");
        const label = toggle ? getNavPrimaryText(toggle) : "";
        if (!label) return;

        groups.push({
          id: \`root-\${index}-dropdown\`,
          kind: "dropdown",
          label,
          items: menuList ? parseNavbarMenuList(menuList, \`root-\${index}-list\`) : []
        });
        return;
      }

      const link = li.querySelector(":scope > a");
      if (!link) return;

      const label = getNavPrimaryText(link);
      const href = String(link.getAttribute("href") || "").trim();
      if (!label) return;

      if (isActionLikeHref(href)) {
        const actionId = \`root-\${index}-action\`;
        link.setAttribute(NAVBAR_ACTION_ATTR, actionId);
        groups.push({
          id: \`root-\${index}-action\`,
          kind: "action",
          label,
          actionId
        });
        return;
      }

      groups.push({
        id: \`root-\${index}-link\`,
        kind: "link",
        label,
        href,
        isExternal: link.target === "_blank" || /^https?:\\/\\//i.test(href)
      });
    });

    return groups;
  };

  let navbarModelLastSignature = "";
  let isNavbarModelPostQueued = false;

  const postNativeNavbarModel = ({ isForce = false } = {}) => {
    if (!window.parent || window.parent === window) return;
    const groups = buildNativeNavbarGroups();
    let nextSignature = "";
    try {
      nextSignature = JSON.stringify(groups);
    } catch {
      nextSignature = \`groups:\${groups.length}:\${Date.now()}\`;
    }

    if (!isForce && nextSignature === navbarModelLastSignature) {
      return;
    }
    navbarModelLastSignature = nextSignature;

    window.parent.postMessage(
      {
        type: "5etd:native-navbar-data",
        groups
      },
      "*"
    );
  };

  const queueNativeNavbarModelPost = ({ isForce = false } = {}) => {
    if (isForce) {
      isNavbarModelPostQueued = false;
      postNativeNavbarModel({ isForce: true });
      return;
    }

    if (isNavbarModelPostQueued) {
      return;
    }
    isNavbarModelPostQueued = true;
    window.setTimeout(() => {
      isNavbarModelPostQueued = false;
      postNativeNavbarModel();
    }, 80);
  };

  let navbarSyncObserver = null;
  const bindNativeNavbarSync = () => {
    const navbar = document.getElementById("navbar");
    if (!navbar || navbar.dataset.desktopNavSyncBound === "1") {
      return;
    }

    navbar.dataset.desktopNavSyncBound = "1";
    navbarSyncObserver?.disconnect?.();
    navbarSyncObserver = new MutationObserver(() => {
      queueNativeNavbarModelPost();
    });
    navbarSyncObserver.observe(navbar, { childList: true, subtree: true });
  };

  const runNativeNavbarAction = (actionId) => {
    const id = String(actionId || "").trim();
    if (!id) return;

    const navbar = document.getElementById("navbar");
    if (!navbar) return;

    const actionEle = navbar.querySelector(\`[\${NAVBAR_ACTION_ATTR}="\${id}"]\`);
    if (!(actionEle instanceof HTMLElement)) {
      return;
    }

    actionEle.dispatchEvent(new MouseEvent("click", { bubbles: true, cancelable: true, view: window }));
    actionEle.click();
  };

  window.addEventListener("message", (event) => {
    const data = event?.data;
    if (!data || typeof data !== "object") {
      return;
    }

    if (data.type === "5etd:reset-onboarding-result" && data.ok === false) {
      const reason = typeof data.error === "string" && data.error ? data.error : "unknown error";
      doToastInfo(\`Reset onboarding failed: \${reason}\`);
      return;
    }

    if (data.type === "5etd:native-navbar-request") {
      bindNativeNavbarSync();
      queueNativeNavbarModelPost({ isForce: true });
      return;
    }

    if (data.type === "5etd:native-navbar-run-action") {
      runNativeNavbarAction(data.actionId);
    }
  });

  window.addEventListener("DOMContentLoaded", applyDesktopMenuExtensions);
  window.addEventListener("load", applyDesktopMenuExtensions);
})();
`;
}

const DESKTOP_RESKIN_STYLE = `
html.desktop-reskin {
  --desktop-shell-gutter: 14px;
  --desktop-topbar-pad-x: 18px;
  --desktop-nav-top-offset: 10px;
  --desktop-nav-reserved-height: 92px;
}

html.desktop-reskin body {
  padding-top: calc(var(--safe-area-inset-top) + var(--desktop-nav-reserved-height)) !important;
  background:
    radial-gradient(circle at 13% -2%, rgba(77, 140, 222, 0.3), transparent 40%),
    radial-gradient(circle at 86% -4%, rgba(241, 176, 92, 0.24), transparent 38%),
    linear-gradient(180deg, #0c1422 0%, #0a1019 100%) !important;
  color: #dce7f6;
}

html.desktop-reskin .viewport-wrapper {
  inset: calc(var(--safe-area-inset-top) + var(--desktop-nav-reserved-height)) 0 0 0 !important;
  height: auto !important;
  min-height: calc(100vh - (var(--safe-area-inset-top) + var(--desktop-nav-reserved-height)));
}

html.desktop-reskin .page__header {
  margin: 8px var(--desktop-shell-gutter) 0 !important;
  padding: 0 !important;
  border: 1px solid rgba(109, 164, 223, 0.32) !important;
  border-radius: 18px;
  background: linear-gradient(115deg, rgba(17, 29, 47, 0.98), rgba(24, 38, 58, 0.96) 64%, rgba(87, 58, 32, 0.88));
  // backdrop-filter: blur(14px);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.24);
}

html.desktop-reskin .page__header .container {
  width: 100% !important;
  max-width: none !important;
  padding: 10px var(--desktop-topbar-pad-x) !important;
}

html.desktop-reskin .page__header .ve-flex-v-baseline {
  flex-wrap: wrap;
  row-gap: 4px;
}

html.desktop-reskin .page__title {
  margin: 0 !important;
  color: #ebf4ff !important;
  font-size: clamp(2.8rem, 4.6vw, 7rem);
  line-height: 1;
}

html.desktop-reskin .page__subtitle {
  margin: 0 0 0 14px !important;
  color: #bccce0 !important;
  font-size: clamp(1.2rem, 1.75vw, 3.1rem);
}

html.desktop-reskin #navigation.page__nav {
  margin: 0 !important;
  padding: 0 !important;
  position: fixed;
  top: calc(var(--safe-area-inset-top) + var(--desktop-nav-top-offset));
  left: var(--desktop-shell-gutter);
  right: var(--desktop-shell-gutter);
  width: auto !important;
  max-width: none !important;
  border: 1px solid rgba(109, 164, 223, 0.32) !important;
  border-radius: 18px;
  background: linear-gradient(180deg, rgba(12, 21, 35, 0.96), rgba(8, 15, 27, 0.98));
  box-shadow: 0 12px 26px rgba(0, 0, 0, 0.28);
  z-index: 3600 !important;
}

html.desktop-reskin #navigation.page__nav .page__nav-inner {
  width: 100% !important;
  margin: 0 !important;
  padding: 10px var(--desktop-topbar-pad-x) !important;
  overflow: visible;
}

html.desktop-reskin #navbar {
  background: transparent !important;
  border-bottom: 0 !important;
  box-shadow: none;
  display: flex;
  align-items: stretch;
  flex-wrap: wrap;
  gap: 4px;
  min-width: 0;
  max-width: 100%;
  overflow: visible;
  position: relative;
  z-index: 3001 !important;
}

html.desktop-reskin #navbar > li {
  float: none !important;
  flex: 0 0 auto;
  min-width: 0;
}

html.desktop-reskin #navbar > li > a {
  border: 1px solid rgba(107, 159, 214, 0.28);
  background: rgba(19, 31, 49, 0.9);
  border-radius: 8px;
  margin: 0 !important;
  display: flex;
  align-items: center;
  height: 100%;
  transition: background-color 120ms ease, border-color 120ms ease;
}

html.desktop-reskin #navbar > li.page__btn-nav-root > a {
  border-color: rgba(116, 174, 233, 0.44) !important;
  background: linear-gradient(180deg, rgba(22, 37, 58, 0.94), rgba(14, 24, 39, 0.97)) !important;
  box-shadow: inset 0 1px 0 rgba(162, 214, 255, 0.12);
}

html.desktop-reskin #navbar > li.dropdown--navbar > a.ve-dropdown-toggle {
  border-color: rgba(116, 174, 233, 0.44) !important;
  background: linear-gradient(180deg, rgba(22, 37, 58, 0.94), rgba(14, 24, 39, 0.97)) !important;
  box-shadow: inset 0 1px 0 rgba(162, 214, 255, 0.12);
}

html.desktop-reskin #navbar .navbar-brand,
html.desktop-reskin #navbar > li > a,
html.desktop-reskin #navbar > li > a .caret {
  color: #e6f1ff !important;
}

html.desktop-reskin #navbar > li > a:hover {
  background: rgba(65, 121, 191, 0.32);
  border-color: rgba(118, 184, 247, 0.56);
}

html.desktop-reskin #navbar > li.page__btn-nav-root > a:hover,
html.desktop-reskin #navbar > li.page__btn-nav-root > a:focus {
  background: linear-gradient(145deg, rgba(52, 102, 161, 0.78), rgba(31, 86, 142, 0.82)) !important;
  border-color: rgba(136, 202, 255, 0.84) !important;
}

html.desktop-reskin #navbar > li.dropdown--navbar > a.ve-dropdown-toggle:hover,
html.desktop-reskin #navbar > li.dropdown--navbar > a.ve-dropdown-toggle:focus {
  background: linear-gradient(145deg, rgba(52, 102, 161, 0.78), rgba(31, 86, 142, 0.82)) !important;
  border-color: rgba(136, 202, 255, 0.84) !important;
}

html.desktop-reskin #navbar > li.active > a,
html.desktop-reskin #navbar > li.open > a {
  background: linear-gradient(140deg, rgba(33, 126, 209, 0.9), rgba(25, 95, 167, 0.94));
  border-color: rgba(123, 196, 255, 0.86);
  color: #f4f9ff !important;
}

html.desktop-reskin #navbar > li.dropdown--navbar.open > a.ve-dropdown-toggle,
html.desktop-reskin #navbar > li.dropdown--navbar.active > a.ve-dropdown-toggle {
  background: linear-gradient(140deg, rgba(34, 127, 210, 0.92), rgba(25, 95, 167, 0.96)) !important;
  border-color: rgba(139, 207, 255, 0.92) !important;
  box-shadow: inset 0 1px 0 rgba(229, 245, 255, 0.22);
}

html.desktop-reskin #navbar > li.page__btn-nav-root.active > a,
html.desktop-reskin #navbar > li.page__btn-nav-root.open > a {
  background: linear-gradient(140deg, rgba(34, 127, 210, 0.92), rgba(25, 95, 167, 0.96)) !important;
  border-color: rgba(139, 207, 255, 0.92) !important;
  box-shadow: inset 0 1px 0 rgba(229, 245, 255, 0.22);
}

html.desktop-reskin #navbar > li.dropdown--navbar > a.ve-dropdown-toggle > .caret {
  border-top-color: #c9e6ff !important;
  opacity: 0.95;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav {
  margin: 0 !important;
  width: 48px !important;
  min-width: 48px !important;
  height: 44px !important;
  padding: 0 !important;
  border: 1px solid rgba(116, 174, 233, 0.52) !important;
  border-radius: 12px !important;
  background: linear-gradient(180deg, rgba(22, 36, 56, 0.95), rgba(13, 23, 38, 0.98)) !important;
  box-shadow: inset 0 1px 0 rgba(172, 220, 255, 0.16) !important;
  position: relative;
  overflow: hidden;
  text-indent: -9999px;
  color: transparent !important;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav::before,
html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  height: 2px;
  border-radius: 2px;
  background: #ddebff;
  transition: transform 150ms ease, top 150ms ease, box-shadow 150ms ease;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav::before {
  top: 50%;
  transform: translateY(-8px);
  box-shadow: 0 7px 0 #ddebff;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav::after {
  top: 50%;
  transform: translateY(8px);
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav:hover,
html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav:focus {
  border-color: rgba(137, 204, 255, 0.88) !important;
  background: linear-gradient(145deg, rgba(51, 101, 160, 0.82), rgba(31, 84, 139, 0.86)) !important;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav.active {
  border-color: rgba(139, 207, 255, 0.92) !important;
  background: linear-gradient(140deg, rgba(34, 127, 210, 0.92), rgba(25, 95, 167, 0.96)) !important;
  box-shadow: inset 0 1px 0 rgba(229, 245, 255, 0.22) !important;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav.active::before {
  top: 50%;
  transform: translateY(0) rotate(45deg);
  box-shadow: none;
}

html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav.active::after {
  top: 50%;
  transform: translateY(0) rotate(-45deg);
}

html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) {
  margin-left: auto !important;
  flex: 1 1 320px;
  min-width: 220px;
  max-width: 460px;
}

html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) .omni__input {
  min-width: 0 !important;
  width: 100%;
  border-right: 1px solid rgba(102, 155, 210, 0.42) !important;
  border-top-right-radius: 12px !important;
  border-bottom-right-radius: 12px !important;
}

html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) .omni__submit {
  display: none !important;
}

html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) .omni__btn-clear {
  right: 12px !important;
}

@media (max-width: 1400px) {
  html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) {
    flex-basis: 260px;
    min-width: 190px;
  }
}

@media (max-width: 1180px) {
  html.desktop-reskin {
    --desktop-topbar-pad-x: 12px;
    --desktop-nav-reserved-height: 108px;
  }

  html.desktop-reskin #navbar {
    gap: 3px;
  }

  html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) {
    margin-left: 0 !important;
    flex-basis: 100%;
    max-width: 100%;
  }
}

@media (max-width: 991px) {
  html.desktop-reskin {
    --desktop-nav-reserved-height: 84px;
  }

  html.desktop-reskin #navigation.page__nav {
    display: grid !important;
    grid-template-columns: auto minmax(0, 1fr);
    column-gap: 10px;
    row-gap: 8px;
    align-items: center;
    width: auto !important;
    padding: 10px 12px 0 !important;
  }

  html.desktop-reskin #navigation.page__nav .page__btn-toggle-nav {
    grid-column: 1;
    grid-row: 1;
    align-self: stretch;
  }

  html.desktop-reskin #navigation.page__nav .page__nav-inner {
    grid-column: 2;
    grid-row: 1;
    margin: 0 !important;
    padding: 0 !important;
    width: 100% !important;
  }

  html.desktop-reskin #navbar {
    flex-direction: column;
    align-items: stretch;
    flex-wrap: nowrap;
    gap: 8px;
    margin: 0 !important;
    padding: 0 !important;
  }

  html.desktop-reskin #navbar > li {
    width: 100%;
  }

  html.desktop-reskin #navbar > li > a {
    width: 100%;
    min-height: 46px;
    padding: 10px 16px !important;
    justify-content: flex-start;
  }

  html.desktop-reskin #navbar > .omni__wrp-input,
  html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) {
    order: -1;
    margin: 0 !important;
    width: 100%;
    max-width: 100%;
    flex: 0 0 auto;
  }

  html.desktop-reskin #navbar > .omni__wrp-input .omni__input,
  html.desktop-reskin #navbar > .omni__wrp-input:not(.omni__wrp-input--scrolled) .omni__input {
    width: 100%;
    min-width: 0 !important;
  }

  html.desktop-reskin #navbar > li.page__nav-hidden-mobile {
    margin: 0 !important;
  }

  html.desktop-reskin #navbar > li.dropdown--navbar.open > .dropdown-menu,
  html.desktop-reskin #navbar > li.dropdown--navbar.open > .ve-dropdown-menu {
    position: static !important;
    float: none !important;
    width: 100% !important;
    margin: 6px 0 0 !important;
  }

  html.desktop-reskin #navbar .ve-dropdown-menu--side {
    margin-left: 0 !important;
  }
}

html.desktop-reskin #navbar .form-control,
html.desktop-reskin #navbar input[type="search"] {
  background: rgba(8, 14, 24, 0.96) !important;
  border: 1px solid rgba(102, 155, 210, 0.42) !important;
  color: #e4effb !important;
  height: 44px !important;
  border-radius: 12px !important;
}

html.desktop-reskin #navbar .form-control::placeholder,
html.desktop-reskin #navbar input[type="search"]::placeholder {
  color: #96adc8 !important;
}

html.desktop-reskin #navbar .btn {
  border-radius: 12px !important;
  border-color: rgba(102, 155, 210, 0.42) !important;
  background: rgba(14, 24, 40, 0.95) !important;
  color: #d9e8fb !important;
}

html.desktop-reskin #navbar .omni__submit,
html.desktop-reskin #navbar .omni__submit.ve-btn {
  display: none !important;
}

html.desktop-reskin #navbar .dropdown-menu,
html.desktop-reskin #navbar .ve-dropdown-menu {
  border: 1px solid rgba(102, 155, 210, 0.42) !important;
  border-radius: 12px !important;
  background: linear-gradient(180deg, rgba(13, 22, 37, 0.98), rgba(9, 17, 30, 0.99)) !important;
  padding: 4px !important;
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.34);
  z-index: 3200 !important;
}

html.desktop-reskin #navbar .ve-dropdown-menu--top {
  margin-top: 4px !important;
}

html.desktop-reskin #navbar .ve-dropdown-menu--side {
  margin-left: 4px !important;
}

html.desktop-reskin #navbar .dropdown-menu > li > a,
html.desktop-reskin #navbar .ve-dropdown-menu > li > a,
html.desktop-reskin #navbar .ve-dropdown-menu > li > span {
  color: #dce9fa !important;
  border-radius: 8px;
  padding: 6px 12px !important;
  transition: background-color 100ms ease, color 100ms ease;
}

html.desktop-reskin #navbar .dropdown-menu > li > a:hover,
html.desktop-reskin #navbar .dropdown-menu > li > a:focus,
html.desktop-reskin #navbar .ve-dropdown-menu > li > a:hover,
html.desktop-reskin #navbar .ve-dropdown-menu > li > a:focus,
html.desktop-reskin #navbar .ve-dropdown-menu > li > span:hover,
html.desktop-reskin #navbar .ve-dropdown-menu > li > span:focus {
  background: rgba(58, 108, 170, 0.34) !important;
  color: #f2f8ff !important;
}

html.desktop-reskin #navbar .dropdown-menu > li.active > a,
html.desktop-reskin #navbar .ve-dropdown-menu > li.active > a,
html.desktop-reskin #navbar .ve-dropdown-menu > li.active > span {
  background: linear-gradient(140deg, rgba(36, 124, 202, 0.92), rgba(28, 95, 161, 0.94)) !important;
  color: #f5fbff !important;
}

html.desktop-reskin #navbar .dropdown-menu > li.disabled > a,
html.desktop-reskin #navbar .ve-dropdown-menu > li.disabled > a,
html.desktop-reskin #navbar .ve-dropdown-menu > li.disabled > span {
  color: #8aa2bd !important;
}

html.desktop-reskin #navbar .ve-dropdown-divider,
html.desktop-reskin #navbar .dropdown-menu .divider {
  margin: 6px 4px !important;
  height: 1px;
  background: rgba(106, 156, 213, 0.42) !important;
}

html.desktop-reskin #navbar .ve-dropdown-ext-link > .glyphicon {
  color: #9ec9f3 !important;
}

html.desktop-reskin .input-xs,
html.desktop-reskin .form-control,
html.desktop-reskin select,
html.desktop-reskin input,
html.desktop-reskin textarea {
  border-radius: 8px !important;
  border-color: rgba(115, 170, 226, 0.45) !important;
}

html.desktop-reskin .btn,
html.desktop-reskin .ve-btn {
  border-radius: 9px !important;
}

html.desktop-reskin .omni__wrp-output {
  position: relative;
  z-index: 3400 !important;
}

html.desktop-reskin .omni__output {
  border: 1px solid rgba(114, 171, 232, 0.45) !important;
  border-radius: 12px !important;
  background: linear-gradient(180deg, rgba(15, 25, 41, 0.98), rgba(9, 17, 29, 0.99)) !important;
  box-shadow: 0 16px 30px rgba(0, 0, 0, 0.42);
  color: #dce9f8 !important;
}

html.desktop-reskin .omni__output .ve-btn,
html.desktop-reskin .omni__output .btn {
  border: 1px solid rgba(112, 167, 225, 0.42) !important;
  background: rgba(22, 36, 56, 0.92) !important;
  color: #dce9f8 !important;
}

html.desktop-reskin .omni__output .ve-btn.active,
html.desktop-reskin .omni__output .btn.active,
html.desktop-reskin .omni__output .ve-btn:hover,
html.desktop-reskin .omni__output .btn:hover {
  background: rgba(53, 95, 145, 0.58) !important;
  border-color: rgba(139, 204, 255, 0.72) !important;
}

html.desktop-reskin .omni__row-result {
  padding: 3px 6px;
  border-radius: 8px;
  border-bottom: 1px solid rgba(105, 151, 205, 0.3);
  color: #d7e6f7 !important;
}

html.desktop-reskin .omni__row-result:nth-child(odd) {
  background: rgba(43, 71, 105, 0.38) !important;
}

html.desktop-reskin .omni__row-result:hover {
  background: rgba(63, 103, 151, 0.52) !important;
}

html.desktop-reskin .omni__lnk-name {
  color: #8ec9ff !important;
}

html.desktop-reskin .omni__disp-srd,
html.desktop-reskin .omni__disp-source-marker,
html.desktop-reskin .omni__wrp-page {
  color: #aecaec !important;
}

html.desktop-reskin .omni__wrp-paginate {
  margin-top: 4px;
  padding-top: 6px;
  border-top: 1px solid rgba(107, 156, 211, 0.35);
}

html.desktop-reskin .omni__paginate-ctrl {
  color: #c8def8;
}

html.desktop-reskin .omni__paginate-ctrl:hover {
  color: #8dc9ff !important;
}

html.desktop-reskin .list,
html.desktop-reskin .list-display-only,
html.desktop-reskin .lst__row,
html.desktop-reskin .ui-list__row,
html.desktop-reskin .list li {
  color: #dce8f8;
}

html.desktop-reskin .lst__row,
html.desktop-reskin .ui-list__row,
html.desktop-reskin .list li,
html.desktop-reskin .lst__row-border,
html.desktop-reskin .lst__row-inner,
html.desktop-reskin .veapp__list-row {
  border-radius: 10px;
}

html.desktop-reskin .lst__row-border,
html.desktop-reskin .lst__row-inner,
html.desktop-reskin .veapp__list-row,
html.desktop-reskin .lst__wrp-cells {
  border-color: rgba(112, 165, 222, 0.42) !important;
  color: #dce8f8 !important;
}

html.desktop-reskin .list .lst__row:nth-child(odd) .lst__row-border,
html.desktop-reskin .list .lst__row:nth-child(odd) .lst__row-inner,
html.desktop-reskin .list .lst__row:nth-child(odd).lst__row-border,
html.desktop-reskin .list .lst__row:nth-child(odd).veapp__list-row {
  background: rgba(34, 57, 86, 0.36);
}

html.desktop-reskin .list .lst__row:nth-child(even) .lst__row-border,
html.desktop-reskin .list .lst__row:nth-child(even) .lst__row-inner,
html.desktop-reskin .list .lst__row:nth-child(even).lst__row-border,
html.desktop-reskin .list .lst__row:nth-child(even).veapp__list-row {
  background: rgba(18, 30, 48, 0.38);
}

html.desktop-reskin .list .lst__row:hover .lst__row-border,
html.desktop-reskin .list .lst__row:hover .lst__row-inner,
html.desktop-reskin .list .lst__row:hover.lst__row-border,
html.desktop-reskin .list .lst__row:hover.veapp__list-row {
  background: rgba(64, 105, 151, 0.48) !important;
}

html.desktop-reskin .lst__row a,
html.desktop-reskin .veapp__list-row a,
html.desktop-reskin .lst__wrp-cells a {
  color: inherit;
}

html.desktop-reskin .lst__form-top > *,
html.desktop-reskin .lst__form-top .form-control,
html.desktop-reskin .lst__form-top .btn,
html.desktop-reskin .lst__form-top .ve-btn {
  border-color: rgba(112, 167, 225, 0.48) !important;
  background: rgba(15, 25, 40, 0.94) !important;
  color: #dce8f8 !important;
}

html.desktop-reskin .lst__form-top .form-control::placeholder {
  color: #99b2cf !important;
}

html.desktop-reskin .fltr__pill,
html.desktop-reskin .fltr__mini-pill,
html.desktop-reskin .fltr__btn_nest {
  border-color: rgba(109, 163, 221, 0.45) !important;
  background: rgba(20, 32, 50, 0.92) !important;
  color: #dce8f8 !important;
}

html.desktop-reskin .fltr__pill[data-state="yes"],
html.desktop-reskin .fltr__mini-pill[data-state="yes"] {
  background: linear-gradient(140deg, rgba(38, 120, 196, 0.9), rgba(27, 89, 151, 0.94)) !important;
  border-color: rgba(131, 196, 255, 0.84) !important;
}

html.desktop-reskin .fltr__pill[data-state="no"],
html.desktop-reskin .fltr__mini-pill[data-state="no"] {
  background: linear-gradient(140deg, rgba(136, 55, 55, 0.92), rgba(109, 44, 44, 0.94)) !important;
  border-color: rgba(206, 132, 132, 0.7) !important;
}

html.desktop-reskin .wrp-stats-table {
  border-top: 1px solid rgba(114, 171, 232, 0.5) !important;
  border-bottom: 1px solid rgba(114, 171, 232, 0.5) !important;
  background: rgba(9, 15, 25, 0.5);
}

html.desktop-reskin .table,
html.desktop-reskin table {
  color: #dce8f8;
}

html.desktop-reskin .table > thead > tr > th,
html.desktop-reskin .table > tbody > tr > th,
html.desktop-reskin .table > tfoot > tr > th,
html.desktop-reskin .table > thead > tr > td,
html.desktop-reskin .table > tbody > tr > td,
html.desktop-reskin .table > tfoot > tr > td,
html.desktop-reskin table > thead > tr > th,
html.desktop-reskin table > tbody > tr > th,
html.desktop-reskin table > tfoot > tr > th,
html.desktop-reskin table > thead > tr > td,
html.desktop-reskin table > tbody > tr > td,
html.desktop-reskin table > tfoot > tr > td {
  border-color: rgba(104, 154, 209, 0.42) !important;
}

html.desktop-reskin .table > thead > tr > th,
html.desktop-reskin table > thead > tr > th {
  background: rgba(33, 59, 92, 0.62);
  color: #e8f2ff;
}

html.desktop-reskin .table-striped > tbody > tr:nth-of-type(odd),
html.desktop-reskin .stripe-odd-table > tbody > tr:nth-child(odd),
html.desktop-reskin .stripe-even-table > tbody > tr:nth-child(even),
html.desktop-reskin .stripe-odd:nth-child(odd),
html.desktop-reskin .stripe-even:nth-child(even) {
  background: rgba(42, 70, 104, 0.38) !important;
}

html.desktop-reskin .hwin,
html.desktop-reskin .ve-window,
html.desktop-reskin .modal__inner {
  border: 1px solid rgba(115, 170, 226, 0.35) !important;
  border-radius: 12px !important;
  box-shadow: 0 16px 28px rgba(0, 0, 0, 0.35);
}

/* App-managed top bar mode: keep 5etools content, hide native header/nav chrome */
html.desktop-reskin.desktop-app-navbar-mode body {
  padding-top: 0 !important;
}

html.desktop-reskin.desktop-app-navbar-mode .viewport-wrapper {
  inset: 0 !important;
  height: auto !important;
  min-height: 100vh !important;
}

html.desktop-reskin.desktop-app-navbar-mode header.page__header,
html.desktop-reskin.desktop-app-navbar-mode .page__header,
html.desktop-reskin.desktop-app-navbar-mode #navigation,
html.desktop-reskin.desktop-app-navbar-mode nav.page__nav,
html.desktop-reskin.desktop-app-navbar-mode #navigation.page__nav,
html.desktop-reskin.desktop-app-navbar-mode .page__nav,
html.desktop-reskin.desktop-app-navbar-mode .page__disp-download-progress {
  display: none !important;
}
`;

export interface WikiServer {
  readonly rootDir: string;
  readonly url: string;
  close: () => Promise<void>;
}

export interface StartWikiServerOptions {
  rootDir?: string;
  externalImageRoot?: string | null;
}

function getWikiRootCandidates(explicitRootDir?: string): string[] {
  const envDir = process.env.FIVEETOOLS_SRC_DIR;

  return [
    explicitRootDir,
    envDir,
    path.resolve(app.getAppPath(), "..", "5etools-src"),
    path.resolve(app.getAppPath(), "5etools-src"),
    path.resolve(process.cwd(), "..", "5etools-src"),
    path.resolve(process.cwd(), "5etools-src"),
    path.resolve(process.resourcesPath, "5etools-src")
  ].filter((it): it is string => Boolean(it));
}

function isWikiRootDir(candidate: string): boolean {
  const indexPath = path.join(candidate, "5etools.html");
  const dataPath = path.join(candidate, "data");
  return fs.existsSync(indexPath) && fs.existsSync(dataPath);
}

function resolveWikiRootDir(explicitRootDir?: string): string {
  const candidates = getWikiRootCandidates(explicitRootDir);

  for (const candidate of candidates) {
    if (isWikiRootDir(candidate)) {
      return candidate;
    }
  }

  const formatted = candidates.map((it) => `- ${it}`).join("\n");
  throw new Error(`Unable to locate 5etools-src directory. Checked:\n${formatted}`);
}

export function findWikiRootDir(explicitRootDir?: string): string | null {
  try {
    return resolveWikiRootDir(explicitRootDir);
  } catch {
    return null;
  }
}

function getMimeType(filePath: string): string {
  const ext = path.extname(filePath).toLowerCase();
  return MIME_TYPES[ext] ?? "application/octet-stream";
}

function normalizeExternalBaseUrl(url: string): string {
  const trimmed = url.trim();
  return `${trimmed.replace(/\/+$/, "")}/`;
}

function resolveExternalImageRoot(externalImageRoot?: string | null): string | null {
  if (externalImageRoot != null) {
    const trimmed = externalImageRoot.trim();
    return trimmed ? normalizeExternalBaseUrl(trimmed) : null;
  }

  if (!SHOULD_USE_EXTERNAL_IMAGE_FALLBACK) {
    return null;
  }

  const envValue = process.env.FIVEETOOLS_DESKTOP_IMG_BASE_URL || DEFAULT_EXTERNAL_IMAGE_ROOT;
  return normalizeExternalBaseUrl(envValue);
}

function getRequestPath(requestUrl: string): string {
  const parsed = new URL(requestUrl, "http://127.0.0.1");
  return decodeURIComponent(parsed.pathname);
}

function getExternalImageUrl(requestUrl: string, externalImageRoot: string | null): URL | null {
  if (!externalImageRoot) {
    return null;
  }

  let requestPath: string;
  try {
    requestPath = getRequestPath(requestUrl);
  } catch {
    return null;
  }

  if (!requestPath.startsWith("/img/")) {
    return null;
  }

  const relativePath = requestPath.slice("/img/".length);
  if (!relativePath) {
    return null;
  }

  return new URL(relativePath, externalImageRoot);
}

async function pTryServeExternalImage(
  requestUrl: string,
  res: http.ServerResponse,
  externalImageRoot: string | null
): Promise<boolean> {
  const externalImageUrl = getExternalImageUrl(requestUrl, externalImageRoot);
  if (!externalImageUrl) {
    return false;
  }

  try {
    const response = await fetch(externalImageUrl.toString());
    if (!response.ok) {
      return false;
    }

    const responseBuffer = Buffer.from(await response.arrayBuffer());
    const contentType = response.headers.get("content-type") ?? getMimeType(externalImageUrl.pathname);

    res.writeHead(200, withCorsHeaders({
      "Content-Type": contentType,
      "Cache-Control": "public, max-age=3600"
    }));
    res.end(responseBuffer);
    return true;
  } catch {
    return false;
  }
}

function injectDesktopReskin(html: string, bootstrapScript: string): string {
  if (html.includes("desktop-reskin-style")) {
    return html;
  }

  const injection = [
    `<script id="desktop-reskin-boot">${bootstrapScript}</script>`,
    `<style id="desktop-reskin-style">${DESKTOP_RESKIN_STYLE}</style>`
  ].join("");

  if (!/<\/head>/i.test(html)) {
    return `${injection}${html}`;
  }

  return html.replace(/<\/head>/i, `${injection}</head>`);
}

function resolveRequestPath(rootDir: string, requestUrl: string): string {
  const reqPath = getRequestPath(requestUrl);
  const normalizedReqPath = reqPath === "/" ? "/5etools.html" : reqPath;

  const candidate = path.resolve(rootDir, `.${normalizedReqPath}`);
  const rootResolved = path.resolve(rootDir);
  const relative = path.relative(rootResolved, candidate);

  if (relative.startsWith("..") || path.isAbsolute(relative)) {
    throw new Error("Blocked path traversal attempt");
  }

  if (fs.existsSync(candidate) && fs.statSync(candidate).isDirectory()) {
    const indexPath = path.join(candidate, "index.html");
    if (fs.existsSync(indexPath)) {
      return indexPath;
    }
  }

  return candidate;
}

export async function startWikiServer(options: StartWikiServerOptions = {}): Promise<WikiServer> {
  const rootDir = resolveWikiRootDir(options.rootDir);
  const externalImageRoot = resolveExternalImageRoot(options.externalImageRoot);
  const reskinBootstrap = getDesktopReskinBootstrap(externalImageRoot);

  return await new Promise<WikiServer>((resolve, reject) => {
    const server = http.createServer((req, res) => {
      if (req.method === "OPTIONS") {
        res.writeHead(204, withCorsHeaders({ "Content-Type": "text/plain; charset=utf-8" }));
        res.end();
        return;
      }

      const url = req.url ?? "/";

      let filePath: string;
      try {
        filePath = resolveRequestPath(rootDir, url);
      } catch {
        res.writeHead(403, withCorsHeaders({ "Content-Type": "text/plain; charset=utf-8" }));
        res.end("Forbidden");
        return;
      }

      fs.readFile(filePath, (err, data) => {
        if (err) {
          if (err.code === "ENOENT") {
            void pTryServeExternalImage(url, res, externalImageRoot).then((isServed) => {
              if (isServed) {
                return;
              }

              res.writeHead(404, withCorsHeaders({ "Content-Type": "text/plain; charset=utf-8" }));
              res.end("Not Found");
            });
            return;
          }

          res.writeHead(500, withCorsHeaders({ "Content-Type": "text/plain; charset=utf-8" }));
          res.end("Internal Server Error");
          return;
        }

        const extension = path.extname(filePath).toLowerCase();
        const transformedBody =
          extension === ".html" && SHOULD_INJECT_RESKIN ? injectDesktopReskin(data.toString("utf8"), reskinBootstrap) : data;

        res.writeHead(200, withCorsHeaders({
          "Content-Type": getMimeType(filePath),
          "Cache-Control": "no-store"
        }));

        if (typeof transformedBody === "string") {
          res.end(transformedBody, "utf8");
          return;
        }

        res.end(transformedBody);
      });
    });

    server.once("error", reject);

    server.listen(0, "127.0.0.1", () => {
      const address = server.address();
      if (!address || typeof address === "string") {
        reject(new Error("Failed to resolve local wiki server address"));
        return;
      }

      const url = `http://127.0.0.1:${address.port}`;

      resolve({
        rootDir,
        url,
        close: () =>
          new Promise<void>((closeResolve, closeReject) => {
            server.close((closeErr) => {
              if (closeErr) {
                closeReject(closeErr);
                return;
              }
              closeResolve();
            });
          })
      });
    });
  });
}