/* ============================================================
   HanziLearn – dictionary.js
   Schema: Vocab(id, kanji, pinyin, sino, vietnamese, hsk_level,
                 topic_name, hsk_level_label, collocations[])
   ============================================================ */

   (() => {
    /* ── DOM refs ─────────────────────────────────────────── */
    const searchInput   = document.getElementById('dictSearch');
    const clearBtn      = document.getElementById('clearBtn');
    const skeletonWrap  = document.getElementById('skeletonWrap');
    const resultsList   = document.getElementById('resultsList');
    const emptyState    = document.getElementById('emptyState');
    const initialState  = document.getElementById('initialState');
    const searchHint    = document.getElementById('searchHint');
    const wordModal     = new bootstrap.Modal(document.getElementById('wordModal'));
    const wordModalBody = document.getElementById('wordModalBody');
  
    let debounceTimer = null;
    let lastQuery     = '';
  
    /* ── Search input ─────────────────────────────────────── */
    searchInput.addEventListener('input', () => {
      const q = searchInput.value.trim();
      clearBtn.classList.toggle('d-none', !q);
      clearTimeout(debounceTimer);
      if (!q) { showState('initial'); return; }
      debounceTimer = setTimeout(() => doSearch(q), 350);
    });
  
    clearBtn.addEventListener('click', () => {
      searchInput.value = '';
      clearBtn.classList.add('d-none');
      lastQuery = '';
      showState('initial');
      searchInput.focus();
    });
  
    searchInput.addEventListener('keydown', e => {
      if (e.key === 'Escape') clearBtn.click();
    });
  
    /* ── Fetch & render ───────────────────────────────────── */
    async function doSearch(query) {
      if (query === lastQuery) return;
      lastQuery = query;
      showState('loading');
      searchHint.textContent = `Searching for "${query}"…`;
  
      try {
        const res  = await fetch(`/dictionary/search?q=${encodeURIComponent(query)}`);
        const json = await res.json();
        if (!json.success) throw new Error(json.message);
  
        if (!json.data.length) { showState('empty'); return; }
  
        renderResults(json.data);
        searchHint.textContent = `${json.count} result${json.count !== 1 ? 's' : ''} for "${query}"`;
        showState('results');
      } catch (err) {
        searchHint.textContent = 'Error: ' + err.message;
        showState('empty');
      }
    }
  
    /* ── Result cards ─────────────────────────────────────── */
    function renderResults(words) {
      resultsList.innerHTML = words.map(w => `
        <div class="dict-card" data-id="${w.id}" tabindex="0" role="button"
             aria-label="${esc(w.kanji)} – ${esc(w.sino)}">
          <div class="dict-hanzi">${esc(w.kanji || '?')}</div>
          <div class="dict-info">
            <div class="dict-pinyin">${esc(w.pinyin || '')}</div>
            <div class="dict-meaning">${esc(w.sino || '')}</div>
            ${w.vietnamese ? `<div class="dict-vi">${esc(w.vietnamese)}</div>` : ''}
          </div>
          <div class="dict-card-meta">
            ${w.topic_name ? `<span class="dict-tag">${esc(w.topic_name)}</span>` : ''}
            ${w.hsk_level  ? `<span class="dict-hsk hsk${w.hsk_level}">HSK ${w.hsk_level}</span>` : ''}
          </div>
        </div>
      `).join('');
  
      resultsList.querySelectorAll('.dict-card').forEach(card => {
        const open = () => openWordDetail(card.dataset.id);
        card.addEventListener('click', open);
        card.addEventListener('keydown', e => { if (e.key === 'Enter' || e.key === ' ') open(); });
      });
    }
  
    /* ── Word detail modal ────────────────────────────────── */
    async function openWordDetail(id) {
      wordModalBody.innerHTML = `
        <div class="py-4 text-center">
          <div class="learn-spinner"></div>
        </div>`;
      wordModal.show();
  
      try {
        const res  = await fetch(`/dictionary/word/${id}`);
        const json = await res.json();
        if (!json.success) throw new Error(json.message);
        renderWordModal(json.data);
      } catch (err) {
        wordModalBody.innerHTML = `<p class="text-danger py-3">Failed to load: ${esc(err.message)}</p>`;
      }
    }
  
    function renderWordModal(w) {
      /* Collocations section */
      let collHtml = '';
      if (w.collocations && w.collocations.length) {
        const items = w.collocations.map(c => `
          <div class="coll-item">
            <span class="coll-kanji">${esc(c.kanji || '')}</span>
            <span class="coll-pinyin">${esc(c.pinyin || '')}</span>
          </div>
        `).join('');
        collHtml = `
          <div class="word-detail-row">
            <div class="word-detail-label">Collocations</div>
            <div class="coll-list">${items}</div>
          </div>`;
      }
  
      wordModalBody.innerHTML = `
        <!-- Hanzi & Pinyin -->
        <div class="word-modal-hanzi">${esc(w.kanji || '?')}</div>
        <div class="word-modal-pinyin">${esc(w.pinyin || '')}</div>
  
        <!-- Badges -->
        <div class="d-flex justify-content-center gap-2 mb-3 flex-wrap">
          ${w.hsk_level  ? `<span class="hsk-badge hsk${w.hsk_level}">HSK ${w.hsk_level}</span>` : ''}
          ${w.topic_name ? `<span class="dict-tag">${esc(w.topic_name)}</span>` : ''}
        </div>
  
        <!-- Meanings -->
        ${detailRow('Meaning (Sino)', w.sino)}
        ${detailRow('Vietnamese',     w.vietnamese)}
  
        <!-- Collocations -->
        ${collHtml}
      `;
    }
  
    /* ── Helpers ──────────────────────────────────────────── */
    function detailRow(label, value) {
      if (!value) return '';
      return `
        <div class="word-detail-row">
          <div class="word-detail-label">${label}</div>
          <div class="word-detail-value">${esc(value)}</div>
        </div>`;
    }
  
    function showState(state) {
      skeletonWrap.classList.toggle('d-none',  state !== 'loading');
      resultsList.classList.toggle('d-none',   state !== 'results');
      emptyState.classList.toggle('d-none',    state !== 'empty');
      initialState.classList.toggle('d-none',  state !== 'initial');
    }
  
    function esc(str = '') {
      const d = document.createElement('div');
      d.textContent = str;
      return d.innerHTML;
    }
  })();