/*
 * Copyright (C) 2026 Mateusz Gruszczyński @linuxiarz.pl
 * Source-Available Code / Dual-Licensed.
 * 
 * Free for non-commercial and evaluation use under terms of BSL/GPLv3.
 * Commercial or production use requires a valid paid license.
 * See LICENSE file in repository root for details.
 */

import { EMOJI_GROUPS } from "@rustpad/emoji-groups";
import { t } from "@rustpad/i18n";

const RECENTS_KEY = "rustpad:recent-emojis";
const MAX_RECENTS = 24;
const GROUP_KEYS = new Map([
  ["Smileys & Emotion", "emoji.group.smileysEmotion"],
  ["People & Body", "emoji.group.peopleBody"],
  ["Animals & Nature", "emoji.group.animalsNature"],
  ["Food & Drink", "emoji.group.foodDrink"],
  ["Travel & Places", "emoji.group.travelPlaces"],
  ["Activities", "emoji.group.activities"],
  ["Objects", "emoji.group.objects"],
  ["Symbols", "emoji.group.symbols"],
  ["Flags", "emoji.group.flags"],
]);

function groupLabel(name) {
  if (name === "Recently Used") return t("emoji.recentGroup", {}, "Recently Used");
  const key = GROUP_KEYS.get(name);
  return key ? t(key, {}, name) : name;
}

function itemLabel(item) {
  return t("emoji.itemLabel", { emoji: item.emoji }, `Emoji ${item.emoji}`);
}

function loadRecents() {
  try {
    const values = JSON.parse(localStorage.getItem(RECENTS_KEY) || "[]");
    return Array.isArray(values) ? values.filter(value => typeof value === "string").slice(0, MAX_RECENTS) : [];
  } catch {
    return [];
  }
}

function saveRecent(emoji) {
  const next = [emoji, ...loadRecents().filter(value => value !== emoji)].slice(0, MAX_RECENTS);
  localStorage.setItem(RECENTS_KEY, JSON.stringify(next));
  return next;
}

function normalize(value) {
  return String(value || "").toLocaleLowerCase().normalize("NFD").replace(/[\u0300-\u036f]/g, "");
}

function insertAtSelection(editor, text) {
  const start = editor.selectionStart;
  editor.setRangeText(text, start, editor.selectionEnd, "end");
  editor.focus();
  editor.dispatchEvent(new Event("input", { bubbles: true }));
}

export function bindEmojiPicker({ editor, details, search, categories, grid, empty }) {
  if (!editor || !details || !search || !categories || !grid) return;

  let activeGroup = EMOJI_GROUPS[0]?.name || "";
  let recents = loadRecents();

  const groups = () => {
    const recentItems = recents.map(value => {
      for (const group of EMOJI_GROUPS) {
        const found = group.items.find(item => item.emoji === value);
        if (found) return found;
      }
      return { emoji: value, name: t("emoji.recentItem", {}, "Recent emoji"), keywords: "recent" };
    });
    return recentItems.length ? [{ name: "Recently Used", items: recentItems }, ...EMOJI_GROUPS] : EMOJI_GROUPS;
  };

  function renderCategories() {
    const available = groups();
    if (!available.some(group => group.name === activeGroup)) activeGroup = available[0]?.name || "";
    categories.replaceChildren(...available.map(group => {
      const button = document.createElement("button");
      button.type = "button";
      button.className = "emoji-category";
      button.dataset.emojiGroup = group.name;
      button.textContent = group.items[0]?.emoji || "•";
      const label = groupLabel(group.name);
      button.title = label;
      button.setAttribute("aria-label", label);
      button.setAttribute("aria-pressed", String(group.name === activeGroup));
      return button;
    }));
  }

  function renderGrid() {
    const query = normalize(search.value.trim());
    let items;
    if (query) {
      items = EMOJI_GROUPS.flatMap(group => group.items.map(item => ({ item, group })))
        .filter(({ item, group }) => normalize(`${item.name} ${item.keywords} ${groupLabel(group.name)}`).includes(query))
        .map(({ item }) => item);
    } else {
      items = groups().find(group => group.name === activeGroup)?.items || [];
    }

    const fragment = document.createDocumentFragment();
    for (const item of items) {
      const button = document.createElement("button");
      button.type = "button";
      button.className = "emoji-item";
      button.dataset.emoji = item.emoji;
      const label = itemLabel(item);
      button.title = label;
      button.setAttribute("aria-label", label);
      button.textContent = item.emoji;
      fragment.append(button);
    }
    grid.replaceChildren(fragment);
    if (empty) empty.hidden = items.length > 0;
  }

  function render() {
    renderCategories();
    renderGrid();
  }

  details.addEventListener("toggle", () => {
    if (!details.open) return;
    render();
    requestAnimationFrame(() => search.focus());
  });

  search.addEventListener("input", renderGrid);
  categories.addEventListener("click", event => {
    const button = event.target.closest("[data-emoji-group]");
    if (!button) return;
    activeGroup = button.dataset.emojiGroup;
    search.value = "";
    render();
  });
  grid.addEventListener("click", event => {
    const button = event.target.closest("[data-emoji]");
    if (!button) return;
    insertAtSelection(editor, button.dataset.emoji);
    recents = saveRecent(button.dataset.emoji);
    renderCategories();
  });
  document.addEventListener("pointerdown", event => {
    if (details.open && !details.contains(event.target)) details.removeAttribute("open");
  });
  document.addEventListener("rustpad:languagechange", () => {
    if (details.open) render();
  });

  if (details.open) {
    render();
    requestAnimationFrame(() => search.focus());
  }
}