import {
  TELEGRAM_EMOJI_GROUPS,
  getTelegramEmojiAssetUrl,
  getTelegramEmojiPreviewUrl,
} from './telegram-emoji-catalog.js?v=202607151545';

const RECENT_STORAGE_KEY = 'shine-ui-recent-emojis-v1';
const MAX_RECENT = 28;
const ALL_EMOJI_ITEMS = TELEGRAM_EMOJI_GROUPS.flatMap((group) => group.items);
const EMOJI_ASSET_BY_CHAR = new Map(ALL_EMOJI_ITEMS.map((item) => [item.emoji, item]));
const TELEGRAM_EMOJI_MATCHER = new RegExp(
  [...EMOJI_ASSET_BY_CHAR.keys()]
    .sort((left, right) => right.length - left.length)
    .map((emoji) => emoji.replace(/[\\^$.*+?()[\]{}|]/g, '\\$&'))
    .join('|'),
  'gu',
);
const DEFAULT_RECENT = ALL_EMOJI_ITEMS.slice(0, 7).map((item) => item.emoji);
let activeAnimation = null;

function loadRecent() {
  try {
    const parsed = JSON.parse(localStorage.getItem(RECENT_STORAGE_KEY) || '[]');
    return Array.isArray(parsed)
      ? parsed.filter((item) => typeof item === 'string' && item).slice(0, MAX_RECENT)
      : [];
  } catch {
    return [];
  }
}

function saveRecent(items) {
  try {
    localStorage.setItem(RECENT_STORAGE_KEY, JSON.stringify(items.slice(0, MAX_RECENT)));
  } catch {
    // Selection remains usable when browser storage is unavailable.
  }
}

function appendAnimatedAsset(root, item) {
  const previewUrl = item.previewUrl || getTelegramEmojiPreviewUrl(item.file);
  const animatedUrl = item.animatedUrl || getTelegramEmojiAssetUrl(item.file);
  const image = document.createElement('img');
  image.className = 'telegram-emoji-image';
  image.alt = '';
  image.decoding = 'async';
  image.setAttribute('aria-hidden', 'true');

  let isActive = false;
  let sourceVersion = 0;

  const setSource = (source) => {
    const requestedVersion = sourceVersion + 1;
    sourceVersion = requestedVersion;
    root.classList.remove('is-error');
    image.onload = () => {
      if (requestedVersion !== sourceVersion) return;
      if (isActive) root.classList.remove('is-loading');
    };
    image.onerror = () => {
      if (requestedVersion !== sourceVersion) return;
      if (isActive) {
        isActive = false;
        root.classList.remove('is-active', 'is-loading');
        if (activeAnimation?.root === root) activeAnimation = null;
        setSource(previewUrl);
        return;
      }
      root.classList.add('is-error');
      image.removeAttribute('src');
    };
    image.src = source;
  };

  const deactivate = () => {
    isActive = false;
    root.classList.remove('is-active', 'is-loading', 'is-error');
    if (activeAnimation?.root === root) activeAnimation = null;
    setSource(previewUrl);
  };

  const activate = () => {
    if (activeAnimation?.root && activeAnimation.root !== root) {
      activeAnimation.deactivate();
    }
    activeAnimation = { root, deactivate };
    isActive = true;
    root.classList.add('is-active', 'is-loading');
    setSource(animatedUrl);
  };

  const onPointerOver = (event) => {
    if (event.relatedTarget && root.contains(event.relatedTarget)) return;
    if (event.pointerType === 'mouse') activate();
  };

  const onPointerOut = (event) => {
    if (event.relatedTarget && root.contains(event.relatedTarget)) return;
    if (event.pointerType === 'mouse') deactivate();
  };

  const onPointerDown = (event) => {
    if (event.pointerType === 'mouse') return;
    root.setPointerCapture?.(event.pointerId);
    activate();
  };

  const onPointerEnd = (event) => {
    if (event.pointerType === 'mouse') return;
    if (root.hasPointerCapture?.(event.pointerId)) root.releasePointerCapture?.(event.pointerId);
    deactivate();
  };

  root.addEventListener('pointerover', onPointerOver);
  root.addEventListener('pointerout', onPointerOut);
  root.addEventListener('pointerdown', onPointerDown);
  root.addEventListener('pointerup', onPointerEnd);
  root.addEventListener('pointercancel', onPointerEnd);
  root.addEventListener('lostpointercapture', deactivate);
  setSource(previewUrl);
  root.append(image);
}

export function stopAllTelegramEmojiAnimations() {
  activeAnimation?.deactivate();
  activeAnimation = null;
}

function createEmojiButton(item, onSelect) {
  const button = document.createElement('button');
  button.type = 'button';
  button.className = 'emoji-picker-item';
  button.setAttribute('aria-label', `Add ${item.emoji}`);
  button.title = item.emoji;
  button.addEventListener('pointerdown', (event) => event.preventDefault());
  button.addEventListener('click', () => onSelect(item.emoji));

  const preview = document.createElement('span');
  preview.className = 'emoji-picker-preview';
  appendAnimatedAsset(preview, item);
  button.append(preview);
  return button;
}

export function isTelegramAnimatedEmoji(emoji) {
  return EMOJI_ASSET_BY_CHAR.has(emoji);
}

export function createTelegramAnimatedEmoji(emoji, { className = '' } = {}) {
  const item = EMOJI_ASSET_BY_CHAR.get(emoji);
  const root = document.createElement('span');
  root.className = `telegram-emoji ${className}`.trim();
  root.setAttribute('aria-label', emoji);
  root.setAttribute('role', 'img');

  if (!item) {
    root.textContent = emoji;
    return root;
  }

  appendAnimatedAsset(root, item);
  return root;
}

export function appendTelegramAnimatedText(root, text, { className = '' } = {}) {
  const source = String(text || '');
  let cursor = 0;
  let found = false;

  TELEGRAM_EMOJI_MATCHER.lastIndex = 0;
  for (const match of source.matchAll(TELEGRAM_EMOJI_MATCHER)) {
    const index = Number(match.index || 0);
    if (index > cursor) root.append(document.createTextNode(source.slice(cursor, index)));
    root.append(createTelegramAnimatedEmoji(match[0], { className }));
    cursor = index + match[0].length;
    found = true;
  }

  if (!found) {
    root.textContent = source;
    return false;
  }

  if (cursor < source.length) root.append(document.createTextNode(source.slice(cursor)));
  return true;
}

export function createEmojiPicker({ onSelect }) {
  const root = document.createElement('section');
  root.className = 'emoji-picker';
  root.setAttribute('aria-label', 'Emoji picker');

  const recentSection = document.createElement('section');
  recentSection.className = 'emoji-picker-section emoji-picker-recent';
  const recentTitle = document.createElement('strong');
  recentTitle.className = 'emoji-picker-section-title';
  recentTitle.textContent = 'Recent';
  const recentGrid = document.createElement('div');
  recentGrid.className = 'emoji-picker-grid';
  recentSection.append(recentTitle, recentGrid);

  const categoryTabs = document.createElement('div');
  categoryTabs.className = 'emoji-picker-tabs';
  categoryTabs.setAttribute('role', 'tablist');

  const categorySection = document.createElement('section');
  categorySection.className = 'emoji-picker-section';
  const categoryTitle = document.createElement('strong');
  categoryTitle.className = 'emoji-picker-section-title';
  const categoryGrid = document.createElement('div');
  categoryGrid.className = 'emoji-picker-grid';
  categorySection.append(categoryTitle, categoryGrid);

  let activeGroup = TELEGRAM_EMOJI_GROUPS[0];
  const tabs = new Map();

  const rememberAndSelect = (emoji) => {
    const recent = [emoji, ...loadRecent().filter((item) => item !== emoji)];
    saveRecent(recent);
    renderRecent();
    onSelect?.(emoji);
  };

  const renderRecent = () => {
    const recentItems = (loadRecent().length ? loadRecent() : DEFAULT_RECENT)
      .map((emoji) => EMOJI_ASSET_BY_CHAR.get(emoji))
      .filter(Boolean);
    stopAllTelegramEmojiAnimations();
    recentGrid.replaceChildren(...recentItems.map((item) => createEmojiButton(item, rememberAndSelect)));
  };

  const renderGroup = () => {
    categoryTitle.textContent = activeGroup.label;
    stopAllTelegramEmojiAnimations();
    categoryGrid.replaceChildren(...activeGroup.items.map((item) => createEmojiButton(item, rememberAndSelect)));
    tabs.forEach((tab, groupId) => {
      const active = groupId === activeGroup.id;
      tab.classList.toggle('is-active', active);
      tab.setAttribute('aria-selected', String(active));
    });
  };

  TELEGRAM_EMOJI_GROUPS.forEach((group) => {
    const tab = document.createElement('button');
    tab.type = 'button';
    tab.className = 'emoji-picker-tab';
    tab.textContent = group.icon;
    tab.title = group.label;
    tab.setAttribute('aria-label', group.label);
    tab.setAttribute('role', 'tab');
    tab.addEventListener('click', () => {
      activeGroup = group;
      renderGroup();
    });
    tabs.set(group.id, tab);
    categoryTabs.append(tab);
  });

  root.append(recentSection, categoryTabs, categorySection);
  renderRecent();
  renderGroup();
  return root;
}