// searchAutocomplete.js — universal search dropdown for the scan/search input.
import { searchLocal } from './assetBrowser.js';

let _onLocalSelect  = null;
let _onRemoteSearch = null;
let _input          = null;
let _dropdown       = null;
let _items          = [];  // { type:'asset'|'syncro', asset?, serial?, contact?, customerName?, query? }
let _activeIdx      = -1;
let _inputTimer     = null;
let _blurTimer      = null;

// ── Init ──────────────────────────────────────────────────────────────────────

export function initSearchAutocomplete({ onLocalSelect, onRemoteSearch }) {
  _onLocalSelect  = onLocalSelect;
  _onRemoteSearch = onRemoteSearch;

  _input = document.getElementById('scan-input');
  if (!_input) return;

  // Append dropdown inside scan-input-wrap so it's positioned relative to it
  _dropdown = document.createElement('div');
  _dropdown.id        = 'search-autocomplete';
  _dropdown.className = 'search-autocomplete';
  _dropdown.hidden    = true;
  _input.closest('.scan-input-wrap').appendChild(_dropdown);

  _input.addEventListener('input', _onInput);

  _input.addEventListener('blur', () => {
    _blurTimer = setTimeout(_close, 150);
  });

  _input.addEventListener('focus', () => {
    clearTimeout(_blurTimer);
    if (_input.value.trim().length >= 2) _onInput();
  });

  // Prevent blur when clicking a dropdown item
  _dropdown.addEventListener('mousedown', e => e.preventDefault());

  _dropdown.addEventListener('click', e => {
    const item = e.target.closest('.ac-item');
    if (item) _selectIdx(Number(item.dataset.idx));
  });
}

// ── Key handler — called by scanner's key interceptor ─────────────────────────

export function handleAutocompleteKey(e) {
  if (_dropdown.hidden) return false;

  if (e.key === 'ArrowDown') {
    e.preventDefault();
    _setActive(Math.min(_activeIdx + 1, _items.length - 1));
    return true;
  }
  if (e.key === 'ArrowUp') {
    e.preventDefault();
    _setActive(Math.max(_activeIdx - 1, 0));
    return true;
  }
  if (e.key === 'Enter') {
    if (_activeIdx >= 0) {
      e.preventDefault();
      _selectIdx(_activeIdx);
      return true;
    }
    _close(); // close but let scanner handle Enter
    return false;
  }
  if (e.key === 'Escape') {
    _close();
    return true; // prevent scanner's clearInput
  }
  return false;
}

// ── Internal ──────────────────────────────────────────────────────────────────

function _onInput() {
  clearTimeout(_inputTimer);
  _inputTimer = setTimeout(() => {
    const query = _input.value.trim();
    if (query.length < 2) { _close(); return; }
    _renderDropdown(query);
  }, 200);
}

function _renderDropdown(query) {
  const localResults = searchLocal(query);
  _items = [
    ...localResults.map(r => ({ type: 'asset', ...r })),
    { type: 'syncro', query },
  ];

  _activeIdx = -1;
  _dropdown.innerHTML = _items.map((item, i) => {
    if (item.type === 'syncro') {
      return `<div class="ac-item ac-item-syncro" data-idx="${i}">
        <svg class="ac-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
          <circle cx="11" cy="11" r="8"/><line x1="21" y1="21" x2="16.65" y2="16.65"/>
        </svg>
        <span>Search Syncro for <em>${_esc(item.query)}</em></span>
      </div>`;
    }
    const { asset, serial, contact, customerName } = item;
    const meta = [customerName, serial, contact].filter(Boolean).join(' · ');
    return `<div class="ac-item" data-idx="${i}">
      <svg class="ac-icon" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
        <rect x="2" y="3" width="20" height="14" rx="2"/><path d="M8 21h8M12 17v4"/>
      </svg>
      <div class="ac-item-body">
        <div class="ac-item-name">${_esc(asset.name ?? `Asset ${asset.id}`)}</div>
        ${meta ? `<div class="ac-item-meta">${_esc(meta)}</div>` : ''}
      </div>
    </div>`;
  }).join('');

  _dropdown.hidden = false;
}

function _setActive(idx) {
  _activeIdx = idx;
  _dropdown.querySelectorAll('.ac-item').forEach((el, i) => {
    el.classList.toggle('ac-active', i === idx);
    if (i === idx) el.scrollIntoView({ block: 'nearest' });
  });
}

function _selectIdx(idx) {
  const item = _items[idx];
  if (!item) return;
  _close();
  _input.value = '';
  _input.dispatchEvent(new Event('input')); // sync clear-btn visibility
  if (item.type === 'asset') {
    _onLocalSelect?.(item.asset);
  } else {
    _onRemoteSearch?.(item.query);
  }
}

function _close() {
  _dropdown.hidden = true;
  _activeIdx = -1;
  _items = [];
}

function _esc(s) {
  return String(s ?? '').replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;');
}