import type { ResolvedConfig } from '../../types/config';
import type {
  ConfigSettingsCategory,
  ConfigSettingsControl,
  ConfigSettingsField,
  ConfigSettingsRestartBehavior,
} from '../../types/settings';
import { CONFIG_OPTION_REGISTRY, DEFAULT_CONFIG } from '../definitions';
import {
  getSubtitleCssManagedConfigPaths,
  getSubtitleCssScopeForPath,
} from '../../settings/subtitle-style-css';

type Leaf = {
  path: string;
  value: unknown;
};

export const LEGACY_HIDDEN_CONFIG_PATHS = [
  'ankiConnect.deck',
  'ankiConnect.wordField',
  'ankiConnect.audioField',
  'ankiConnect.imageField',
  'ankiConnect.sentenceField',
  'ankiConnect.miscInfoField',
  'ankiConnect.miscInfoPattern',
  'ankiConnect.generateAudio',
  'ankiConnect.generateImage',
  'ankiConnect.imageType',
  'ankiConnect.imageFormat',
  'ankiConnect.imageQuality',
  'ankiConnect.imageMaxWidth',
  'ankiConnect.imageMaxHeight',
  'ankiConnect.animatedFps',
  'ankiConnect.animatedMaxWidth',
  'ankiConnect.animatedMaxHeight',
  'ankiConnect.animatedCrf',
  'ankiConnect.syncAnimatedImageToWordAudio',
  'ankiConnect.audioPadding',
  'ankiConnect.fallbackDuration',
  'ankiConnect.maxMediaDuration',
  'ankiConnect.overwriteAudio',
  'ankiConnect.overwriteImage',
  'ankiConnect.mediaInsertMode',
  'ankiConnect.highlightWord',
  'ankiConnect.notificationType',
  'ankiConnect.autoUpdateNewCards',
  'ankiConnect.nPlusOne.highlightEnabled',
  'ankiConnect.nPlusOne.refreshMinutes',
  'ankiConnect.nPlusOne.matchMode',
  'ankiConnect.nPlusOne.decks',
  'ankiConnect.nPlusOne.knownWord',
  'ankiConnect.nPlusOne.nPlusOne',
  'ankiConnect.knownWords.color',
  'ankiConnect.behavior.nPlusOneHighlightEnabled',
  'ankiConnect.behavior.nPlusOneRefreshMinutes',
  'ankiConnect.behavior.nPlusOneMatchMode',
  'ankiConnect.isLapis.sentenceCardSentenceField',
  'ankiConnect.isLapis.sentenceCardAudioField',
  'controller.bindings',
  'controller.preferredGamepadId',
  'controller.preferredGamepadLabel',
  'controller.profiles',
  'youtubeSubgen.primarySubLanguages',
  'anilist.characterDictionary.refreshTtlHours',
  'anilist.characterDictionary.evictionPolicy',
  'jellyfin.accessToken',
  'jellyfin.userId',
  'jellyfin.clientName',
  'jellyfin.clientVersion',
  'jellyfin.defaultLibraryId',
  'jellyfin.deviceId',
  'controller.buttonIndices',
  'subtitleSidebar.toggleKey',
  'jellyfin.recentServers',
] as const;

const EXCLUDED_PREFIXES = ['controller.buttonIndices', 'youtubeSubgen'] as const;

const JSON_OBJECT_FIELDS = new Set([
  'keybindings',
  'controller.bindings',
  'controller.profiles',
  'ankiConnect.knownWords.decks',
  'subtitleStyle.css',
  'subtitleStyle.secondary.css',
  'subtitleSidebar.css',
]);

const SECRET_PATHS = new Set(['ai.apiKey', 'jimaku.apiKey', 'anilist.accessToken']);

const COLOR_SUFFIXES = new Set(['Color', 'color', 'backgroundColor', 'singleColor']);
const SUBTITLE_CSS_MANAGED_CONFIG_PATHS = new Set([
  ...getSubtitleCssManagedConfigPaths('primary'),
  ...getSubtitleCssManagedConfigPaths('secondary'),
  ...getSubtitleCssManagedConfigPaths('sidebar'),
]);

const OPTION_BY_PATH = new Map(CONFIG_OPTION_REGISTRY.map((entry) => [entry.path, entry]));

const CATEGORY_ORDER: ConfigSettingsCategory[] = [
  'appearance',
  'behavior',
  'mining-anki',
  'input',
  'integrations',
  'tracking-app',
  'advanced',
];

const SECTION_ORDER = new Map<string, number>(
  [
    'Annotation Display',
    'Known Words',
    'N+1',
    'Frequency Highlighting',
    'Primary Subtitle Appearance',
    'Secondary Subtitle Appearance',
    'Subtitle Sidebar Appearance',
    'Playback Pause Behavior',
    'Subtitle Behavior',
    'Subtitle Sidebar Behavior',
    'Visible Overlay Auto-Start',
    'YouTube Playback Settings',
    'MPV Launcher',
    'Note Fields',
    'Media Capture',
    'Kiku/Lapis Features',
    'Anki AI',
    'AnkiConnect',
    'AnkiConnect Proxy',
    'Jimaku',
    'Subtitle Sync',
    'MPV Keybindings',
    'Overlay Shortcuts',
    'Controller',
    'Character Dictionary',
  ].map((section, index) => [section, index]),
);

const PATH_ORDER = new Map<string, number>(
  [
    'ankiConnect.enabled',
    'ankiConnect.proxy.enabled',
    'ankiConnect.isLapis.enabled',
    'ankiConnect.isKiku.enabled',
    'subtitleStyle.fontColor',
    'subtitleStyle.backgroundColor',
    'subtitleStyle.hoverTokenColor',
    'subtitleStyle.hoverTokenBackgroundColor',
    'subtitleStyle.css',
    'subtitleStyle.primaryDefaultMode',
    'subtitleStyle.secondary.fontColor',
    'subtitleStyle.secondary.backgroundColor',
    'subtitleStyle.secondary.css',
    'subtitleSidebar.css',
    'secondarySub.defaultMode',
    'secondarySub.secondarySubLanguages',
    'mpv.autoStartSubMiner',
    'auto_start_overlay',
    'mpv.pauseUntilOverlayReady',
    'mpv.socketPath',
    'mpv.backend',
    'mpv.subminerBinaryPath',
    'mpv.aniskipEnabled',
    'mpv.aniskipButtonKey',
    'mpv.launchMode',
    'mpv.executablePath',
  ].map((path, index) => [path, index]),
);

const SUBSECTION_ORDER = new Map<string, number>(
  [
    'Known Words',
    'N+1',
    'JLPT',
    'Frequency Highlighting',
    'Character Names',
    'Mining & Clipboard',
    'Toggle & Visibility',
    'Open Panels',
    'Playback',
    'Timing',
    'Default Fold State',
  ].map((subsection, index) => [subsection, index]),
);

const LABEL_OVERRIDES: Record<string, string> = {
  'ankiConnect.knownWords.highlightEnabled': 'Enabled',
  'ankiConnect.nPlusOne.enabled': 'Enabled',
  'ankiConnect.isLapis.enabled': 'Enable Lapis Features',
  'ankiConnect.isKiku.enabled': 'Enable Kiku Features',
  'stats.toggleKey': 'Toggle Stats Overlay',
  'shortcuts.openCharacterDictionary': 'Open AniList Override',
  'subtitleSidebar.pauseVideoOnHover': 'Pause Video On Hover - Sidebar',
  'subtitleStyle.autoPauseVideoOnHover': 'Pause Video On Hover - Subtitles',
  'subtitleStyle.autoPauseVideoOnYomitanPopup': 'Pause Video On Yomitan Popup',
  'subtitleStyle.primaryDefaultMode': 'Primary Subtitle Visibility Mode',
  'subtitleStyle.frequencyDictionary.mode': 'Frequency Mode',
  'subtitleStyle.css': 'CSS Declarations',
  'subtitleStyle.secondary.css': 'CSS Declarations',
  'subtitleSidebar.css': 'CSS Declarations',
  'secondarySub.defaultMode': 'Secondary Subtitle Visibility Mode',
  'subtitlePosition.yPercent': 'Subtitle Position',
  'mpv.executablePath': 'mpv Executable Path',
  'mpv.subminerBinaryPath': 'SubMiner Binary Path',
  'mpv.socketPath': 'mpv IPC Socket Path',
  'mpv.autoStartSubMiner': 'Auto-start SubMiner',
  'mpv.pauseUntilOverlayReady': 'Pause Until Overlay Ready',
  'mpv.aniskipEnabled': 'Enable AniSkip',
  'mpv.aniskipButtonKey': 'AniSkip Button Key',
};

const DESCRIPTION_OVERRIDES: Record<string, string> = {
  'ankiConnect.pollingRate':
    'Polling interval in milliseconds. Ignored while the local AnkiConnect proxy is enabled because push-based enrichment is used instead.',
  'ankiConnect.isKiku.enabled':
    'Enable Kiku-specific mining behavior. Kiku supersedes Lapis: Lapis features still work, and Kiku adds duplicate handling and field grouping.',
  'ankiConnect.isLapis.enabled':
    'Enable Lapis-specific mining behavior and sentence-card model targeting. When Kiku is enabled, Lapis features still work and Kiku-specific features are added on top.',
  'ankiConnect.isLapis.sentenceCardModel':
    'Anki note type used for Lapis sentence cards. Select from note types reported by AnkiConnect.',
  'subtitleStyle.css':
    'CSS declarations applied to primary subtitles. Includes color, background-color, and all font properties.',
  'subtitleStyle.secondary.css':
    'CSS declarations applied to secondary subtitles. Includes color, background-color, and all font properties.',
  'subtitleSidebar.css':
    'CSS declarations applied to the subtitle sidebar. Includes color, background-color, all font properties, and sidebar CSS variables.',
};

function isRecord(value: unknown): value is Record<string, unknown> {
  return value !== null && typeof value === 'object' && !Array.isArray(value);
}

function pathStartsWith(path: string, prefix: string): boolean {
  return path === prefix || path.startsWith(`${prefix}.`);
}

function isLegacyHidden(path: string): boolean {
  return (
    LEGACY_HIDDEN_CONFIG_PATHS.some((hiddenPath) => pathStartsWith(path, hiddenPath)) ||
    EXCLUDED_PREFIXES.some((prefix) => pathStartsWith(path, prefix))
  );
}

function flattenConfigLeaves(value: unknown, prefix = ''): Leaf[] {
  if (JSON_OBJECT_FIELDS.has(prefix)) {
    return [{ path: prefix, value }];
  }

  if (Array.isArray(value)) {
    return [{ path: prefix, value }];
  }

  if (isRecord(value)) {
    const entries = Object.entries(value).filter(([, child]) => child !== undefined);
    if (entries.length === 0) {
      return [{ path: prefix, value }];
    }
    return entries.flatMap(([key, child]) =>
      flattenConfigLeaves(child, prefix ? `${prefix}.${key}` : key),
    );
  }

  return prefix ? [{ path: prefix, value }] : [];
}

function humanizePath(path: string): string {
  const override = LABEL_OVERRIDES[path];
  if (override) {
    return override;
  }
  const key = path.split('.').at(-1) ?? path;
  const spaced = key
    .replace(/_/g, ' ')
    .replace(/([a-z0-9])([A-Z])/g, '$1 $2')
    .replace(/\bai\b/i, 'AI')
    .replace(/\bmpv\b/i, 'mpv')
    .replace(/\byomitan\b/i, 'Yomitan')
    .replace(/\bjimaku\b/i, 'Jimaku')
    .replace(/\banilist\b/i, 'AniList')
    .replace(/\banki\b/i, 'Anki');
  return spaced.charAt(0).toUpperCase() + spaced.slice(1);
}

function categoryAndSection(path: string): { category: ConfigSettingsCategory; section: string } {
  if (
    path === 'subtitleStyle.autoPauseVideoOnHover' ||
    path === 'subtitleStyle.autoPauseVideoOnYomitanPopup' ||
    path === 'subtitleSidebar.pauseVideoOnHover'
  ) {
    return { category: 'behavior', section: 'Playback Pause Behavior' };
  }
  if (path === 'subtitleStyle.preserveLineBreaks') {
    return { category: 'behavior', section: 'Subtitle Behavior' };
  }
  if (
    path === 'ankiConnect.knownWords.addMinedWordsImmediately' ||
    path === 'ankiConnect.knownWords.decks' ||
    path === 'ankiConnect.knownWords.matchMode' ||
    path === 'ankiConnect.knownWords.refreshMinutes'
  ) {
    return { category: 'behavior', section: 'Known Words' };
  }
  if (path === 'ankiConnect.nPlusOne.minSentenceWords') {
    return { category: 'behavior', section: 'N+1' };
  }
  if (
    path === 'subtitleStyle.frequencyDictionary.matchMode' ||
    path === 'subtitleStyle.frequencyDictionary.mode' ||
    path === 'subtitleStyle.frequencyDictionary.sourcePath' ||
    path === 'subtitleStyle.frequencyDictionary.topX'
  ) {
    return { category: 'behavior', section: 'Frequency Highlighting' };
  }
  if (
    path.startsWith('ankiConnect.knownWords.') ||
    path.startsWith('ankiConnect.nPlusOne.') ||
    path.startsWith('subtitleStyle.frequencyDictionary.') ||
    path.startsWith('subtitleStyle.jlptColors.') ||
    path === 'subtitleStyle.enableJlpt' ||
    path === 'subtitleStyle.knownWordColor' ||
    path === 'subtitleStyle.nPlusOneColor' ||
    path === 'subtitleStyle.nameMatchEnabled' ||
    path === 'subtitleStyle.nameMatchColor'
  ) {
    return { category: 'appearance', section: 'Annotation Display' };
  }
  if (path.startsWith('subtitleStyle.secondary.')) {
    return { category: 'appearance', section: 'Secondary Subtitle Appearance' };
  }
  if (path === 'subtitleStyle.primaryDefaultMode') {
    return { category: 'behavior', section: 'Subtitle Behavior' };
  }
  if (path.startsWith('subtitleStyle.')) {
    return { category: 'appearance', section: 'Primary Subtitle Appearance' };
  }
  if (path.startsWith('subtitleSidebar.')) {
    const sidebarBehaviorPaths = new Set([
      'subtitleSidebar.enabled',
      'subtitleSidebar.autoOpen',
      'subtitleSidebar.autoScroll',
      'subtitleSidebar.layout',
    ]);
    return sidebarBehaviorPaths.has(path)
      ? { category: 'behavior', section: 'Subtitle Sidebar Behavior' }
      : { category: 'appearance', section: 'Subtitle Sidebar Appearance' };
  }
  if (path.startsWith('subtitlePosition.') || path.startsWith('secondarySub.')) {
    return { category: 'behavior', section: 'Subtitle Behavior' };
  }
  if (path.startsWith('ankiConnect.fields.')) {
    return { category: 'mining-anki', section: 'Note Fields' };
  }
  if (path.startsWith('ankiConnect.media.')) {
    return { category: 'mining-anki', section: 'Media Capture' };
  }
  if (path.startsWith('ankiConnect.isKiku.') || path.startsWith('ankiConnect.isLapis.')) {
    return { category: 'mining-anki', section: 'Kiku/Lapis Features' };
  }
  if (path.startsWith('ankiConnect.ai.')) {
    return { category: 'mining-anki', section: 'Anki AI' };
  }
  if (path.startsWith('ankiConnect.proxy.')) {
    return { category: 'mining-anki', section: 'AnkiConnect Proxy' };
  }
  if (path.startsWith('ankiConnect.')) {
    return { category: 'mining-anki', section: 'AnkiConnect' };
  }
  if (path === 'auto_start_overlay') {
    return { category: 'behavior', section: topSection(path) };
  }
  if (path.startsWith('mpv.') || path.startsWith('youtube.')) {
    return { category: 'behavior', section: topSection(path) };
  }
  if (path.startsWith('jimaku.')) {
    return { category: 'integrations', section: topSection(path) };
  }
  if (path.startsWith('subsync.')) {
    return { category: 'integrations', section: topSection(path) };
  }
  if (path === 'stats.toggleKey' || path === 'stats.markWatchedKey') {
    return { category: 'input', section: 'Overlay Shortcuts' };
  }
  if (path.startsWith('shortcuts.')) {
    return { category: 'input', section: 'Overlay Shortcuts' };
  }
  if (path === 'keybindings') {
    return { category: 'input', section: 'MPV Keybindings' };
  }
  if (path.startsWith('controller.')) {
    return { category: 'input', section: 'Controller' };
  }
  if (
    path.startsWith('ai.') ||
    path.startsWith('yomitan.') ||
    path.startsWith('jellyfin.') ||
    path.startsWith('discordPresence.') ||
    path.startsWith('websocket.') ||
    path.startsWith('annotationWebsocket.') ||
    path.startsWith('texthooker.')
  ) {
    return { category: 'integrations', section: topSection(path) };
  }
  if (path.startsWith('anilist.characterDictionary.')) {
    return { category: 'integrations', section: 'Character Dictionary' };
  }
  if (path.startsWith('anilist.')) {
    return { category: 'integrations', section: 'AniList' };
  }
  if (
    path.startsWith('immersionTracking.') ||
    path.startsWith('stats.') ||
    path.startsWith('updates.') ||
    path.startsWith('startupWarmups.') ||
    path.startsWith('logging.')
  ) {
    return { category: 'tracking-app', section: topSection(path) };
  }
  return { category: 'advanced', section: 'Advanced' };
}

function topSection(path: string): string {
  const top = path.split('.')[0] ?? path;
  const labels: Record<string, string> = {
    ai: 'Shared AI provider',
    anilist: 'AniList',
    annotationWebsocket: 'Annotation WebSocket',
    discordPresence: 'Discord Rich Presence',
    immersionTracking: 'Immersion tracking',
    jimaku: 'Jimaku',
    jellyfin: 'Jellyfin',
    logging: 'Logging',
    mpv: 'MPV Launcher',
    stats: 'Stats dashboard',
    startupWarmups: 'Startup warmups',
    subsync: 'Subtitle Sync',
    texthooker: 'Texthooker',
    updates: 'Updates',
    websocket: 'WebSocket server',
    yomitan: 'Yomitan',
    youtube: 'YouTube Playback Settings',
    youtubeSubgen: 'YouTube subtitle generation',
    auto_start_overlay: 'Visible Overlay Auto-Start',
  };
  return labels[top] ?? humanizePath(top);
}

function controlForPath(path: string, value: unknown): ConfigSettingsControl {
  if (SECRET_PATHS.has(path)) return 'secret';
  if (getSubtitleCssScopeForPath(path)) return 'css-declarations';
  if (path === 'keybindings') return 'mpv-keybindings';
  if (path === 'ankiConnect.knownWords.decks') return 'known-words-decks';
  if (path === 'ankiConnect.isLapis.sentenceCardModel') return 'anki-note-type';
  if (path.startsWith('ankiConnect.fields.')) return 'anki-field';
  if (path.startsWith('shortcuts.'))
    return path.endsWith('multiCopyTimeoutMs') ? 'number' : 'keyboard-shortcut';
  if (path === 'mpv.aniskipButtonKey') return 'mpv-key';
  if (
    path === 'subtitleSidebar.toggleKey' ||
    path === 'stats.toggleKey' ||
    path === 'stats.markWatchedKey'
  ) {
    return 'key-code';
  }
  if (path.startsWith('subtitleStyle.jlptColors.')) return 'color';
  if (path === 'subtitleStyle.frequencyDictionary.bandedColors') return 'color-list';
  if (OPTION_BY_PATH.get(path)?.enumValues?.length) return 'select';
  if (JSON_OBJECT_FIELDS.has(path)) return 'json';
  if (Array.isArray(value)) return 'string-list';
  if (typeof value === 'boolean') return 'boolean';
  if (typeof value === 'number') return 'number';
  if (typeof value === 'string') {
    const leaf = path.split('.').at(-1) ?? path;
    if ([...COLOR_SUFFIXES].some((suffix) => leaf.endsWith(suffix))) return 'color';
    if (leaf.toLowerCase().includes('prompt')) return 'textarea';
    return 'text';
  }
  return 'json';
}

function subsectionForPath(path: string): string | undefined {
  if (path === 'ankiConnect.knownWords.highlightEnabled') return 'Known Words';
  if (path === 'ankiConnect.nPlusOne.enabled') return 'N+1';
  if (path === 'subtitleStyle.knownWordColor') return 'Known Words';
  if (path === 'subtitleStyle.nPlusOneColor') return 'N+1';
  if (path === 'subtitleStyle.enableJlpt' || path.startsWith('subtitleStyle.jlptColors.')) {
    return 'JLPT';
  }
  if (
    path === 'subtitleStyle.frequencyDictionary.enabled' ||
    path === 'subtitleStyle.frequencyDictionary.singleColor' ||
    path === 'subtitleStyle.frequencyDictionary.bandedColors'
  ) {
    return 'Frequency Highlighting';
  }
  if (path === 'subtitleStyle.nameMatchEnabled' || path === 'subtitleStyle.nameMatchColor') {
    return 'Character Names';
  }
  if (path === 'anilist.characterDictionary.collapsibleSections.description') {
    return 'Default Fold State';
  }
  if (path === 'anilist.characterDictionary.collapsibleSections.characterInformation') {
    return 'Default Fold State';
  }
  if (path === 'anilist.characterDictionary.collapsibleSections.voicedBy') {
    return 'Default Fold State';
  }
  if (path === 'stats.toggleKey' || path === 'stats.markWatchedKey') {
    return 'Toggle & Visibility';
  }
  if (path.startsWith('shortcuts.')) {
    const leaf = path.split('.').at(-1) ?? '';
    if (leaf === 'multiCopyTimeoutMs') return 'Timing';
    if (
      leaf === 'copySubtitle' ||
      leaf === 'copySubtitleMultiple' ||
      leaf === 'mineSentence' ||
      leaf === 'mineSentenceMultiple' ||
      leaf === 'updateLastCardFromClipboard' ||
      leaf === 'triggerFieldGrouping' ||
      leaf === 'markAudioCard'
    ) {
      return 'Mining & Clipboard';
    }
    if (
      leaf === 'toggleVisibleOverlayGlobal' ||
      leaf === 'toggleSubtitleSidebar' ||
      leaf === 'toggleSecondarySub' ||
      leaf === 'toggleStatsOverlay' ||
      leaf === 'markWatched'
    ) {
      return 'Toggle & Visibility';
    }
    if (
      leaf === 'openCharacterDictionary' ||
      leaf === 'openRuntimeOptions' ||
      leaf === 'openJimaku' ||
      leaf === 'openSessionHelp' ||
      leaf === 'openControllerSelect' ||
      leaf === 'openControllerDebug'
    ) {
      return 'Open Panels';
    }
    if (leaf === 'triggerSubsync') return 'Playback';
    return undefined;
  }
  return undefined;
}

function isFeatureToggle(field: ConfigSettingsField): boolean {
  if (field.control !== 'boolean') return false;
  const leaf = field.configPath.split('.').at(-1) ?? field.configPath;
  return (
    leaf === 'enabled' ||
    leaf.startsWith('enable') ||
    leaf.endsWith('Enabled') ||
    field.label.startsWith('Enable ')
  );
}

function fieldTypeRank(field: ConfigSettingsField): number {
  if (field.control !== 'boolean') return 2;
  return isFeatureToggle(field) ? 0 : 1;
}

function compareFields(a: ConfigSettingsField, b: ConfigSettingsField): number {
  const category = CATEGORY_ORDER.indexOf(a.category) - CATEGORY_ORDER.indexOf(b.category);
  if (category !== 0) return category;

  const section =
    (SECTION_ORDER.get(a.section) ?? Number.MAX_SAFE_INTEGER) -
    (SECTION_ORDER.get(b.section) ?? Number.MAX_SAFE_INTEGER);
  if (section !== 0) return section;

  const sectionName = a.section.localeCompare(b.section);
  if (sectionName !== 0) return sectionName;

  const aSubOrder =
    a.subsection === undefined
      ? -1
      : (SUBSECTION_ORDER.get(a.subsection) ?? Number.MAX_SAFE_INTEGER);
  const bSubOrder =
    b.subsection === undefined
      ? -1
      : (SUBSECTION_ORDER.get(b.subsection) ?? Number.MAX_SAFE_INTEGER);
  const subsection = aSubOrder - bSubOrder;
  if (subsection !== 0) return subsection;

  const subsectionName = (a.subsection ?? '').localeCompare(b.subsection ?? '');
  if (subsectionName !== 0) return subsectionName;

  const type = fieldTypeRank(a) - fieldTypeRank(b);
  if (type !== 0) return type;

  const pathOrder =
    (PATH_ORDER.get(a.configPath) ?? Number.MAX_SAFE_INTEGER) -
    (PATH_ORDER.get(b.configPath) ?? Number.MAX_SAFE_INTEGER);
  if (pathOrder !== 0) return pathOrder;

  const label = a.label.localeCompare(b.label);
  if (label !== 0) return label;
  return a.configPath.localeCompare(b.configPath);
}

function restartBehaviorForPath(path: string): ConfigSettingsRestartBehavior {
  if (
    path === 'keybindings' ||
    pathStartsWith(path, 'shortcuts') ||
    pathStartsWith(path, 'subtitleStyle') ||
    pathStartsWith(path, 'subtitleSidebar') ||
    path === 'secondarySub.defaultMode' ||
    pathStartsWith(path, 'ankiConnect.ai') ||
    path === 'stats.toggleKey' ||
    path === 'stats.markWatchedKey'
  ) {
    return 'hot-reload';
  }
  return 'restart';
}

function fieldForLeaf(leaf: Leaf): ConfigSettingsField {
  const option = OPTION_BY_PATH.get(leaf.path);
  const { category, section } = categoryAndSection(leaf.path);
  const description = DESCRIPTION_OVERRIDES[leaf.path] ?? option?.description;
  return {
    id: leaf.path,
    label: option?.path === leaf.path ? humanizePath(leaf.path) : humanizePath(leaf.path),
    description: description ?? `${humanizePath(leaf.path)} setting.`,
    configPath: leaf.path,
    category,
    section,
    ...(subsectionForPath(leaf.path) ? { subsection: subsectionForPath(leaf.path) } : {}),
    control: controlForPath(leaf.path, leaf.value),
    defaultValue: leaf.value,
    ...(option?.enumValues ? { enumValues: option.enumValues } : {}),
    restartBehavior: restartBehaviorForPath(leaf.path),
    advanced:
      leaf.path.startsWith('controller.') ||
      leaf.path.startsWith('immersionTracking.retention.') ||
      leaf.path.startsWith('youtubeSubgen.'),
    secret: SECRET_PATHS.has(leaf.path),
    settingsHidden: SUBTITLE_CSS_MANAGED_CONFIG_PATHS.has(leaf.path),
  };
}

export function buildConfigSettingsRegistry(
  defaultConfig: ResolvedConfig = DEFAULT_CONFIG,
): ConfigSettingsField[] {
  const leaves = flattenConfigLeaves(defaultConfig).filter((leaf) => !isLegacyHidden(leaf.path));
  return leaves.map(fieldForLeaf).sort(compareFields);
}

export function getConfigSettingsCoverage(
  defaultConfig: ResolvedConfig,
  fields: ConfigSettingsField[],
): { uncoveredDefaultPaths: string[] } {
  const visibleFields = fields.filter((field) => !field.legacyHidden);
  const uncoveredDefaultPaths = flattenConfigLeaves(defaultConfig)
    .map((leaf) => leaf.path)
    .filter((path) => !isLegacyHidden(path))
    .filter(
      (path) =>
        !visibleFields.some(
          (field) =>
            field.configPath === path ||
            (field.control === 'json' && pathStartsWith(path, field.configPath)),
        ),
    )
    .sort();

  return { uncoveredDefaultPaths };
}

export function getConfigValueAtPath(root: unknown, path: string): unknown {
  let current = root;
  for (const segment of path.split('.')) {
    if (!isRecord(current)) return undefined;
    current = current[segment];
  }
  return current;
}