/* barnevernet.js — page-scoped UI for /barnevernet.php */
(function () {
  'use strict';

  const els = {};
  let lang = window.DBN_TOOLS_LANG || localStorage.getItem('dbn-ui-lang') || 'en';
  let uploadFiles = [];
  let lastResult = null;
  let branchContext = null;

  const SLICE_DEFS = [
    { id: 'child_welfare',    label: 'Child Welfare' },
    { id: 'echr',             label: 'ECHR' },
    { id: 'family_core',      label: 'Family Law Core' },
    { id: 'bufdir_guidance',  label: 'Bufdir Guidance' },
    { id: 'norwegian_courts', label: 'Norwegian Courts' },
    { id: 'hague',            label: 'Hague Convention' },
    { id: 'broader_legal',    label: 'Broader Legal Support' },
    { id: 'dbn_resources',    label: 'DBN Resources' },
  ];

  const STEP_LABELS = [
    'Document classification',
    'Party extraction',
    'Timeline extraction',
    'Sub-question generation',
    'Corpus retrieval',
    'Synthesis',
    'Citation confidence',
  ];

  const stepKeyToIndex = {
    doc_classify:      0,
    party_extract:     1,
    timeline_extract:  2,
    sub_question_gen:  3,
    slice_resolution:  3,  // shown under sub-question gen phase
    upload_indexing:   4,
    retrieval:         4,
    synthesis:         5,
    confidence:        6,
  };

  document.addEventListener('DOMContentLoaded', () => {
    if (!document.body.dataset.activeTool || document.body.dataset.activeTool !== 'barnevernet') return;

    Object.assign(els, {
      form:           document.getElementById('bvjForm'),
      notes:          document.getElementById('bvjNotes'),
      status:         document.getElementById('bvjStatus'),
      runButton:      document.getElementById('bvjRunButton'),
      results:        document.getElementById('bvjResults'),
      traceList:      document.getElementById('traceList'),
      roleSelect:     document.getElementById('bvjRoleSelect'),
      roleCustom:     document.getElementById('bvjRoleCustom'),
      slices:         Array.from(document.querySelectorAll('.adv-slice')),
      langButtons:    Array.from(document.querySelectorAll('#bvjLangSwitcher .lang-btn')),
      engineRadios:   Array.from(document.querySelectorAll('input[name="bvjEngine"]')),
      subQ:           document.getElementById('bvjSubQ'),
      subQVal:        document.getElementById('bvjSubQValue'),
      chunkLimit:     document.getElementById('bvjChunkLimit'),
      chunkLimitVal:  document.getElementById('bvjChunkLimitValue'),
      sim:            document.getElementById('bvjSim'),
      simVal:         document.getElementById('bvjSimValue'),
      topK:           document.getElementById('bvjTopK'),
      topKVal:        document.getElementById('bvjTopKValue'),
      temp:           document.getElementById('bvjTemp'),
      tempVal:        document.getElementById('bvjTempValue'),
      uploadZone:     document.getElementById('bvjUploadZone'),
      uploadInput:    document.getElementById('bvjUploadInput'),
      uploadPrompt:   document.getElementById('bvjUploadPrompt'),
      uploadFileInfo: document.getElementById('bvjUploadFileInfo'),
      uploadFileList: document.getElementById('bvjUploadFileList'),
      uploadClear:    document.getElementById('bvjUploadClear'),
      modal:          document.getElementById('bvjSourceModal'),
      modalClose:     document.getElementById('bvjSourceModalClose'),
      modalTitle:     document.getElementById('bvjSourceModalTitle'),
      modalEyebrow:   document.getElementById('bvjSourceModalEyebrow'),
      modalMeta:      document.getElementById('bvjSourceModalMeta'),
      modalText:      document.getElementById('bvjSourceModalText'),
      branchPanel:    document.getElementById('bvjBranchPanel'),
      branchClear:    document.getElementById('bvjBranchClear'),
      branchOrigin:   document.getElementById('bvjBranchOrigin'),
      branchSummary:  document.getElementById('bvjBranchSummary'),
      branchNotes:    document.getElementById('bvjBranchNotes'),
    });

    if (!els.form) return;

    bindRole();
    bindSlices();
    bindLang();
    bindRanges();
    bindUpload();
    bindModal();
    bindBranch();
    els.form.addEventListener('submit', onSubmit);
    els.results.addEventListener('click', (e) => {
      const btn = e.target.closest('.dr-branch-btn');
      if (btn) branchFromSubQ(btn.dataset.question || '');
    });

    renderTrace(STEP_LABELS.map((label) => ({ label, detail: 'Waiting…', status: 'idle' })));
  });

  // ── Role binding ───────────────────────────────────────────────────────────

  function bindRole() {
    if (!els.roleSelect) return;
    els.roleSelect.addEventListener('change', () => {
      const isOther = els.roleSelect.value === '__other__';
      els.roleCustom.classList.toggle('is-hidden', !isOther);
      if (isOther) els.roleCustom.focus();
    });
  }

  function getAdvocateRole() {
    if (!els.roleSelect) return '';
    if (els.roleSelect.value === '__other__') {
      return (els.roleCustom ? els.roleCustom.value.trim() : '');
    }
    return els.roleSelect.value;
  }

  // ── Corpus slice toggles ───────────────────────────────────────────────────

  function bindSlices() {
    els.slices.forEach((btn) => {
      btn.addEventListener('click', () => {
        const isOn = btn.classList.toggle('is-on');
        btn.setAttribute('aria-pressed', isOn ? 'true' : 'false');
        const badge = btn.querySelector('.dr-slice__badge');
        if (badge) badge.textContent = isOn ? 'on' : 'off';
      });
    });
  }

  function getSelectedSlices() {
    const out = {};
    SLICE_DEFS.forEach((s) => {
      const btn = els.slices.find((b) => b.dataset.slice === s.id);
      out[s.id] = !!(btn && btn.classList.contains('is-on'));
    });
    return out;
  }

  // ── Language ───────────────────────────────────────────────────────────────

  function bindLang() {
    els.langButtons.forEach((b) => {
      b.classList.toggle('is-active', b.dataset.lang === lang);
      b.addEventListener('click', () => {
        els.langButtons.forEach((x) => x.classList.remove('is-active'));
        b.classList.add('is-active');
        lang = b.dataset.lang || 'en';
        localStorage.setItem('dbn-ui-lang', lang);
      });
    });
  }

  // ── Range controls ─────────────────────────────────────────────────────────

  function bindRanges() {
    const pairs = [
      [els.subQ, els.subQVal, (v) => v],
      [els.chunkLimit, els.chunkLimitVal, (v) => v],
      [els.sim, els.simVal, (v) => Number(v).toFixed(2)],
      [els.topK, els.topKVal, (v) => v],
      [els.temp, els.tempVal, (v) => Number(v).toFixed(2)],
    ];
    pairs.forEach(([range, label, fmt]) => {
      if (!range || !label) return;
      const sync = () => { label.textContent = fmt(range.value); };
      range.addEventListener('input', sync);
      sync();
    });
  }

  function getControls() {
    return {
      sub_q_count:          parseInt(els.subQ.value, 10),
      chunk_limit:          parseInt(els.chunkLimit.value, 10),
      similarity_threshold: parseFloat(els.sim.value),
      reranker_top_k:       parseInt(els.topK.value, 10),
      temperature:          parseFloat(els.temp.value),
    };
  }

  function getEngine() {
    const checked = els.engineRadios.find((r) => r.checked);
    return checked ? checked.value : 'azure_mini';
  }

  // ── File upload ────────────────────────────────────────────────────────────

  function bindUpload() {
    if (!els.uploadZone) return;
    const onFiles = (fileList) => {
      const files = Array.from(fileList || []).slice(0, 5);
      if (uploadFiles.length + files.length > 5) {
        setStatus('At most 5 files can be uploaded per request.', 'error');
        return;
      }
      files.forEach((f) => {
        if (f.size > 8 * 1024 * 1024) {
          setStatus(`${f.name} exceeds the 8 MB limit.`, 'error');
          return;
        }
        const ext = (f.name.split('.').pop() || '').toLowerCase();
        if (!['pdf', 'docx', 'txt'].includes(ext)) {
          setStatus(`${f.name} is not a supported file type (PDF, DOCX, TXT).`, 'error');
          return;
        }
        uploadFiles.push(f);
      });
      renderUploadList();
    };
    els.uploadInput.addEventListener('change', (e) => onFiles(e.target.files));
    els.uploadZone.addEventListener('dragover', (e) => { e.preventDefault(); els.uploadZone.classList.add('is-drop'); });
    els.uploadZone.addEventListener('dragleave', () => els.uploadZone.classList.remove('is-drop'));
    els.uploadZone.addEventListener('drop', (e) => {
      e.preventDefault();
      els.uploadZone.classList.remove('is-drop');
      onFiles(e.dataTransfer?.files);
    });
    els.uploadClear?.addEventListener('click', () => {
      uploadFiles = [];
      els.uploadInput.value = '';
      renderUploadList();
    });
  }

  function renderUploadList() {
    if (!uploadFiles.length) {
      els.uploadFileInfo.classList.add('is-hidden');
      els.uploadPrompt.classList.remove('is-hidden');
      return;
    }
    els.uploadPrompt.classList.add('is-hidden');
    els.uploadFileInfo.classList.remove('is-hidden');
    els.uploadFileList.innerHTML = uploadFiles.map((f) => {
      const kb = (f.size / 1024).toFixed(0);
      return `<li><span class="upload-filename">${escapeHtml(f.name)}</span><span class="upload-chars">${kb} KB</span></li>`;
    }).join('');
  }

  // ── Source modal ───────────────────────────────────────────────────────────

  function bindModal() {
    els.modalClose?.addEventListener('click', closeModal);
    els.modal?.addEventListener('click', (e) => {
      if (e.target === els.modal) closeModal();
    });
    document.addEventListener('keydown', (e) => {
      if (e.key === 'Escape' && els.modal && !els.modal.classList.contains('is-hidden')) closeModal();
    });
  }

  function closeModal() {
    els.modal?.classList.add('is-hidden');
  }

  function openModal(source) {
    if (!source) return;
    els.modalEyebrow.textContent = source.source_origin === 'upload' ? 'Uploaded file' : 'Corpus source';
    els.modalTitle.textContent = source.title || 'Source';
    const metaRows = [
      ['Number', `[${source.n}]`],
      source.section ? ['Section', source.section] : null,
      ['Corpus / package', source.package_or_corpus || '—'],
      source.authority_type ? ['Authority', source.authority_type] : null,
      source.jurisdiction ? ['Jurisdiction', source.jurisdiction] : null,
      source.similarity != null ? ['Similarity', String(source.similarity)] : null,
      source.reranker_score != null ? ['Rerank score', String(source.reranker_score)] : null,
      source.matched_sub_questions?.length ? ['Matched sub-Q', source.matched_sub_questions.join(', ')] : null,
    ].filter(Boolean);
    els.modalMeta.innerHTML = '<dl>' + metaRows.map(([k, v]) => `<dt>${escapeHtml(k)}</dt><dd>${escapeHtml(String(v))}</dd>`).join('') + '</dl>';

    const summary = source.summary || '';
    const chunkText = source.chunk_text || source.excerpt || '';
    const isUpload = source.source_origin === 'upload';
    const hasDocId = source.document_id != null;

    let html = summary
      ? `<div class="dr-modal-summary">${escapeHtml(summary)}</div>`
      : `<div class="dr-modal-summary dr-modal-summary--empty"><em>Summary not yet generated — showing raw chunk below.</em></div>`;

    if (chunkText) {
      html += `<button class="dr-modal-chunk-toggle" type="button">Show matching chunk ▼</button>`;
      html += `<div class="dr-modal-chunk-text is-hidden">${escapeHtml(chunkText)}</div>`;
    }
    if (!isUpload && hasDocId) {
      html += `<button class="dr-modal-all-chunks" type="button" data-document-id="${source.document_id}">View all document chunks →</button>`;
      html += `<div class="dr-modal-chunks-list"></div>`;
    }

    els.modalText.innerHTML = html;

    const chunkToggle = els.modalText.querySelector('.dr-modal-chunk-toggle');
    const chunkDiv = els.modalText.querySelector('.dr-modal-chunk-text');
    chunkToggle?.addEventListener('click', () => {
      const isHidden = chunkDiv.classList.toggle('is-hidden');
      chunkToggle.textContent = isHidden ? 'Show matching chunk ▼' : 'Hide matching chunk ▲';
    });

    const allChunksBtn = els.modalText.querySelector('.dr-modal-all-chunks');
    const chunksListDiv = els.modalText.querySelector('.dr-modal-chunks-list');
    if (allChunksBtn && chunksListDiv) {
      allChunksBtn.addEventListener('click', async () => {
        allChunksBtn.disabled = true;
        allChunksBtn.textContent = 'Loading…';
        try {
          const res = await fetch(`api/document-chunks.php?document_id=${source.document_id}`, { credentials: 'same-origin' });
          const data = await res.json();
          if (data.ok && data.chunks) {
            chunksListDiv.innerHTML =
              `<div class="dr-modal-chunks-head">${escapeHtml(data.document?.title || '')} · ${data.chunks.length} chunks</div>` +
              data.chunks.map((c) => `<div class="dr-modal-chunk-item">
                <span class="dr-modal-chunk-idx">#${c.chunk_index + 1}${c.section_title ? ' · ' + escapeHtml(c.section_title) : ''}</span>
                <p class="dr-modal-chunk-preview">${escapeHtml(truncate(c.content, 300))}</p>
              </div>`).join('');
            allChunksBtn.remove();
          } else {
            allChunksBtn.textContent = 'Could not load chunks.';
            allChunksBtn.disabled = false;
          }
        } catch (_) {
          allChunksBtn.textContent = 'Error loading chunks.';
          allChunksBtn.disabled = false;
        }
      });
    }

    els.modal.classList.remove('is-hidden');
  }

  // ── Branch context ─────────────────────────────────────────────────────────

  function bindBranch() {
    if (!els.branchClear) return;
    els.branchClear.addEventListener('click', clearBranch);
  }

  function clearBranch() {
    branchContext = null;
    if (els.branchPanel) els.branchPanel.classList.add('is-hidden');
    if (els.branchNotes) els.branchNotes.value = '';
  }

  function branchFromSubQ(question) {
    if (!lastResult || !question) return;
    branchContext = {
      original_query: lastResult.query || '',
      brief_summary:  (lastResult.advocacy_brief || '').slice(0, 600),
      what_we_found:  lastResult.what_we_found || '',
      top_sources:    (lastResult.sources || []).slice(0, 5).map((s) => ({
        n: s.n, title: s.title, excerpt: (s.excerpt || '').slice(0, 200),
      })),
    };
    // Pre-fill notes textarea (branch uses notes field, not a query textarea)
    if (els.notes) els.notes.value = question;
    if (els.branchOrigin) els.branchOrigin.textContent = 'Original query: ' + branchContext.original_query;
    if (els.branchSummary) els.branchSummary.textContent = branchContext.brief_summary;
    if (els.branchPanel) els.branchPanel.classList.remove('is-hidden');
    els.form.scrollIntoView({ behavior: 'smooth', block: 'start' });
  }

  // ── Form submission ────────────────────────────────────────────────────────

  async function onSubmit(e) {
    e.preventDefault();

    const advocateRole = getAdvocateRole();
    if (!advocateRole) {
      setStatus('Select who you are representing before running.', 'error');
      return;
    }
    if (!uploadFiles.length) {
      setStatus('Upload at least one BVJ document before running.', 'error');
      return;
    }
    const slices = getSelectedSlices();
    if (!Object.values(slices).some(Boolean)) {
      setStatus('Enable at least one corpus slice.', 'error');
      return;
    }

    const engine = getEngine();
    const additionalNotes = (els.notes ? els.notes.value : '').trim();
    const expectedDuration = engine === 'azure_full'
      ? '90–180 seconds with Azure gpt-4o'
      : (engine === 'gpu' ? '45–90 seconds on GPU'
      : (engine === 'dbn_legal' ? '60–120 seconds with Norwegian specialist'
      : '30–60 seconds with Azure gpt-4o-mini'));

    setStatus(`Analysing document for ${advocateRole}… (${expectedDuration})`, 'busy');
    els.runButton.disabled = true;
    // Clear results area but leave room for progressive renders
    els.results.innerHTML = `<div class="empty-state"><h3>Analysing…</h3><p>Document classification, party extraction, and timeline are running. Legal corpus retrieval and advocacy synthesis follow. Expect ${expectedDuration}.</p></div>`;

    const stepState = STEP_LABELS.map((label) => ({ label, detail: 'Queued', status: 'idle' }));
    renderTrace(stepState);

    const payload = {
      advocate_role:    advocateRole,
      engine,
      language:         lang,
      slices,
      controls:         getControls(),
      additional_notes: additionalNotes,
    };

    if (branchContext) {
      payload.prior_context = branchContext;
      payload.branch_notes  = (els.branchNotes ? els.branchNotes.value : '').trim();
    }

    // Always multipart — files are required
    const form = new FormData();
    form.append('payload', JSON.stringify(payload));
    uploadFiles.forEach((f) => form.append('files[]', f));

    let response;
    try {
      response = await fetch('api/barnevernet.php', { method: 'POST', body: form, credentials: 'same-origin' });
    } catch (err) {
      setStatus(`Network error: ${err.message || err}`, 'error');
      els.runButton.disabled = false;
      stepState[0] = { ...stepState[0], status: 'error', detail: String(err) };
      renderTrace(stepState);
      return;
    }

    if (!response.ok || !response.body) {
      setStatus(`Request failed (${response.status}).`, 'error');
      els.runButton.disabled = false;
      return;
    }

    const reader = response.body.getReader();
    const decoder = new TextDecoder('utf-8');
    let buffer = '';
    let finalResult = null;
    let errorEvent = null;
    // Track whether progressive sections have been rendered
    let docMetaRendered = false;
    let partiesRendered = false;
    let timelineRendered = false;

    function handleStreamEvent(evt) {
      if (!evt || !evt.event) return;

      if (evt.event === 'progress') {
        if (evt.detail) setStatus(evt.detail, 'busy');
        return;
      }
      if (evt.event === 'start') {
        setStatus(`Running… engine=${evt.engine}, files=${evt.file_count || 0}`, 'busy');
        return;
      }
      if (evt.event === 'step') {
        const idx = stepKeyToIndex[evt.step];
        if (idx !== undefined) {
          if (evt.status === 'running' && stepState[idx].status !== 'running') {
            stepState[idx] = { label: evt.label || stepState[idx].label, detail: evt.detail || 'Running…', status: 'running' };
          } else if (evt.status !== 'running') {
            stepState[idx] = {
              label:  evt.label  || stepState[idx].label,
              detail: evt.detail || stepState[idx].detail,
              status: evt.status || stepState[idx].status,
            };
          }
          renderTrace(stepState);
        }
        return;
      }
      if (evt.event === 'doc_meta') {
        if (!docMetaRendered) {
          renderDocMetaIntoResults(evt.result || {});
          docMetaRendered = true;
        }
        return;
      }
      if (evt.event === 'parties') {
        if (!partiesRendered && Array.isArray(evt.parties)) {
          renderPartiesIntoResults(evt.parties);
          partiesRendered = true;
        }
        return;
      }
      if (evt.event === 'timeline') {
        if (!timelineRendered && Array.isArray(evt.events)) {
          renderTimelineIntoResults(evt.events);
          timelineRendered = true;
        }
        return;
      }
      if (evt.event === 'subq') {
        setStatus(`Retrieving sub-question ${evt.index}/${evt.total}: ${String(evt.question || '').slice(0, 80)}${String(evt.question || '').length > 80 ? '…' : ''}`, 'busy');
        return;
      }
      if (evt.event === 'final') {
        finalResult = evt.result;
        return;
      }
      if (evt.event === 'error') {
        errorEvent = evt;
        return;
      }
    }

    while (true) {
      let chunk;
      try {
        chunk = await reader.read();
      } catch (err) {
        setStatus(`Stream error: ${err.message || err}`, 'error');
        els.runButton.disabled = false;
        return;
      }
      const { done, value } = chunk;
      if (value) {
        buffer += decoder.decode(value, { stream: true });
        const lines = buffer.split('\n');
        buffer = lines.pop();
        for (const line of lines) {
          const trimmed = line.trim();
          if (!trimmed) continue;
          let evt;
          try { evt = JSON.parse(trimmed); } catch (_) { continue; }
          handleStreamEvent(evt);
        }
      }
      if (done) break;
    }

    if (errorEvent) {
      setStatus(`${errorEvent.code}: ${errorEvent.message}`, 'error');
      els.runButton.disabled = false;
      const runningIdx = stepState.findIndex((s) => s.status === 'running');
      if (runningIdx >= 0) {
        stepState[runningIdx] = { ...stepState[runningIdx], status: 'error', detail: errorEvent.message };
        renderTrace(stepState);
      }
      return;
    }

    if (!finalResult) {
      setStatus('Stream ended without a final result.', 'error');
      els.runButton.disabled = false;
      return;
    }

    lastResult = finalResult;
    const meta = finalResult.trace_metadata || {};
    setStatus(
      `Done in ${Math.round((finalResult.latency_ms || 0) / 1000)} s · ${meta.source_count || 0} sources · confidence ${meta.citation_confidence || '?'}`,
      'ok'
    );
    els.runButton.disabled = false;
    renderTrace(finalResult.trace || []);
    renderFinalResults(finalResult);
  }

  // ── Progressive rendering (renders as stream events arrive) ────────────────

  function ensureResultsReady() {
    // If the empty-state is still shown, clear it for progressive inserts
    const emptyState = els.results.querySelector('.empty-state');
    if (emptyState) emptyState.remove();
  }

  function renderDocMetaIntoResults(meta) {
    ensureResultsReady();
    const existing = els.results.querySelector('#bvjDocMetaSection');
    if (existing) existing.remove();

    const docType = meta.doc_type || 'BVJ Document';
    const docDate = meta.doc_date || '';
    const authority = meta.issuing_authority || '';
    const refNo = meta.reference_number || '';
    const childInfo = meta.child_info || '';

    const fields = [
      docDate    ? ['Date', docDate] : null,
      authority  ? ['Issuing authority', authority] : null,
      refNo      ? ['Reference', refNo] : null,
      childInfo  ? ['Child', childInfo] : null,
    ].filter(Boolean);

    const section = document.createElement('div');
    section.id = 'bvjDocMetaSection';
    section.className = 'bvj-doc-meta';
    section.innerHTML = `
      <div class="bvj-doc-meta__head">
        <span class="bvj-doc-meta__authority">${escapeHtml(authority || docType)}</span>
        <span class="bvj-doc-type-badge">${escapeHtml(docType)}</span>
      </div>
      ${fields.length ? `<div class="bvj-doc-meta__fields">
        ${fields.map(([k, v]) => `<span class="bvj-doc-meta__field"><strong>${escapeHtml(k)}:</strong> ${escapeHtml(String(v))}</span>`).join('')}
      </div>` : ''}
    `;
    els.results.insertBefore(section, els.results.firstChild);
  }

  function renderPartiesIntoResults(parties) {
    ensureResultsReady();
    const existing = els.results.querySelector('#bvjPartiesSection');
    if (existing) existing.remove();
    if (!parties.length) return;

    const roleClass = (role) => {
      const r = (role || '').toLowerCase();
      if (r.includes('bvv') || r.includes('barnevern') || r.includes('saksbehandler') || r.includes('casework') || r.includes('melder')) return 'bvj-party-role--bvv';
      if (r.includes('mother') || r.includes('mor') || r.includes('father') || r.includes('far') || r.includes('parent') || r.includes('foreldre') || r.includes('foster')) return 'bvj-party-role--parent';
      if (r.includes('child') || r.includes('barn')) return 'bvj-party-role--child';
      if (r.includes('third') || r.includes('tredje') || r.includes('politi') || r.includes('police')) return 'bvj-party-role--third';
      return 'bvj-party-role--other';
    };

    const section = document.createElement('div');
    section.id = 'bvjPartiesSection';
    section.className = 'dr-result-block';
    section.innerHTML = `
      <h3 style="margin:0 0 10px;font-size:0.95rem;color:var(--ink)">Parties identified (${parties.length})</h3>
      <div class="bvj-parties-grid">
        ${parties.map((p) => `
          <div class="bvj-party-card">
            <span class="bvj-party-role ${roleClass(p.role || '')}">${escapeHtml(p.role || 'Unknown')}</span>
            <div class="bvj-party-card__name">${escapeHtml(p.name || '—')}</div>
            ${p.organization ? `<div class="bvj-party-card__org">${escapeHtml(p.organization)}</div>` : ''}
            ${p.relationship_to_child ? `<div class="bvj-party-card__rel">${escapeHtml(p.relationship_to_child)}</div>` : ''}
          </div>
        `).join('')}
      </div>
    `;
    // Insert after doc meta
    const docMeta = els.results.querySelector('#bvjDocMetaSection');
    if (docMeta && docMeta.nextSibling) {
      els.results.insertBefore(section, docMeta.nextSibling);
    } else {
      els.results.appendChild(section);
    }
  }

  function renderTimelineIntoResults(events) {
    ensureResultsReady();
    const existing = els.results.querySelector('#bvjTimelineSection');
    if (existing) existing.remove();
    if (!events.length) return;

    const sigClass = (sig) => `bvj-timeline-event--${sig === 'high' ? 'high' : (sig === 'medium' ? 'medium' : 'low')}`;

    const section = document.createElement('div');
    section.id = 'bvjTimelineSection';
    section.className = 'dr-result-block';
    section.innerHTML = `
      <h3 style="margin:0 0 10px;font-size:0.95rem;color:var(--ink)">Timeline (${events.length} events)</h3>
      <div class="bvj-timeline-wrap">
        ${events.map((ev) => {
          const sig = ev.significance || 'low';
          const timeStr = ev.time_of_day ? `<br>${escapeHtml(ev.time_of_day)}` : '';
          return `<div class="bvj-timeline-event ${sigClass(sig)}">
            <div class="bvj-timeline-date">${escapeHtml(ev.date || '?')}${timeStr}</div>
            <div class="bvj-timeline-body">
              <div class="bvj-timeline-actor">${escapeHtml(ev.actor || '')}</div>
              <div class="bvj-timeline-action">${escapeHtml(ev.action || '')}</div>
            </div>
          </div>`;
        }).join('')}
      </div>
    `;
    // Insert after parties section (or doc meta if no parties)
    const parties = els.results.querySelector('#bvjPartiesSection');
    const docMeta = els.results.querySelector('#bvjDocMetaSection');
    const anchor = parties || docMeta;
    if (anchor && anchor.nextSibling) {
      els.results.insertBefore(section, anchor.nextSibling);
    } else {
      els.results.appendChild(section);
    }
  }

  // ── Final render (after stream completes) ──────────────────────────────────

  function renderFinalResults(data) {
    const sources    = data.sources || [];
    const subs       = data.sub_questions || [];
    const role       = data.advocate_role || '';
    const redFlags   = Array.isArray(data.procedural_red_flags) ? data.procedural_red_flags : [];
    const strengths  = Array.isArray(data.client_strengths) ? data.client_strengths : [];
    const weaknesses = Array.isArray(data.opposing_weaknesses) ? data.opposing_weaknesses : [];

    // Remove any previously rendered progressive sections (will be re-inserted in order below)
    const toRemove = ['#bvjDocMetaSection', '#bvjPartiesSection', '#bvjTimelineSection'];
    toRemove.forEach((sel) => els.results.querySelector(sel)?.remove());

    // Rebuild progressive sections from final data (authoritative)
    const docMeta = data.doc_meta || {};
    const parties = data.parties || [];
    const timeline = data.timeline || {};

    // Re-render progressive sections now that we have final data
    renderDocMetaIntoResults(docMeta);
    if (parties.length) renderPartiesIntoResults(parties);
    if ((timeline.events || []).length) renderTimelineIntoResults(timeline.events);

    // 4. Advocate banner
    const bannerHtml = role ? `
      <div class="bvj-banner">
        <span class="bvj-banner__label">Representing</span>
        <strong class="bvj-banner__role">${escapeHtml(role)}</strong>
      </div>` : '';

    // 5. Client strengths
    const strengthsHtml = strengths.length ? `
      <div class="dr-result-block adv-strengths">
        <h3 class="adv-strengths__head">Your strongest arguments</h3>
        <ul class="adv-strengths__list">
          ${strengths.map((s) => `<li class="adv-strengths__item">${renderInlineCitations(escapeHtml(String(s)), sources)}</li>`).join('')}
        </ul>
      </div>` : '';

    // 6. Advocacy brief
    const briefHtml = renderBrief(data.advocacy_brief || '', sources);

    // 7. Procedural red flags
    const redFlagsHtml = redFlags.length ? `
      <div class="dr-result-block">
        <h3 style="margin:0 0 10px;font-size:0.95rem;color:var(--ink)">Procedural red flags (${redFlags.length})</h3>
        <div class="bvj-red-flags">
          ${redFlags.map((f) => renderRedFlag(f, sources)).join('')}
        </div>
      </div>` : '';

    // 8. Opposing weaknesses
    const weaknessesHtml = weaknesses.length ? `
      <div class="dr-result-block adv-weaknesses">
        <h3 class="adv-weaknesses__head">Gaps in the opposing position</h3>
        <ul class="adv-weaknesses__list">
          ${weaknesses.map((w) => `<li class="adv-weaknesses__item">${renderInlineCitations(escapeHtml(String(w)), sources)}</li>`).join('')}
        </ul>
      </div>` : '';

    // 9. Sub-Q cards
    const subQReportsHtml = subs.length ? `
      <div class="dr-result-block">
        <div class="dr-sources-head">
          <h3>What each sub-question researched</h3>
          <small>${subs.length} sub-question${subs.length === 1 ? '' : 's'} framed for ${escapeHtml(role || 'your client')}</small>
        </div>
        <div class="dr-subq-list">
          ${subs.map((sq, i) => renderSubQReport(sq, i)).join('')}
        </div>
      </div>` : '';

    // 10. Sources
    const sourcesHtml = sources.length ? `
      <div class="dr-result-block">
        <div class="dr-sources-head">
          <h3>All sources (${sources.length})</h3>
          <small>Click a card to see the full source · external link opens the original article</small>
        </div>
        <div class="dr-source-list">
          ${sources.map((s) => renderSourceCard(s)).join('')}
        </div>
      </div>` : '';

    // 11. Uncertainty + next step
    const uncertHtml = (data.what_remains_uncertain || []).length ? `
      <div class="dr-result-block">
        <h3 style="margin:0 0 8px;font-size:0.95rem;color:var(--muted)">What remains uncertain</h3>
        <ul style="padding-left:1.2em;margin:0;color:var(--muted);line-height:1.55">
          ${(data.what_remains_uncertain || []).map((u) => `<li>${escapeHtml(String(u))}</li>`).join('')}
        </ul>
      </div>` : '';

    const nextHtml = data.next_practical_step ? `
      <div class="dr-result-block">
        <h3 style="margin:0 0 6px;font-size:0.95rem">Next practical step</h3>
        <p style="margin:0;color:var(--ink);line-height:1.5">${escapeHtml(data.next_practical_step)}</p>
      </div>` : '';

    // Append final sections after the progressive sections
    const finalHtml = `
      ${bannerHtml}
      ${strengthsHtml}
      <div class="dr-result-block">
        <h3 style="margin:0 0 10px;font-size:1rem">Advocacy brief</h3>
        <div class="dr-brief">${briefHtml}</div>
      </div>
      ${redFlagsHtml}
      ${weaknessesHtml}
      ${subQReportsHtml}
      ${sourcesHtml}
      ${uncertHtml}
      ${nextHtml}
    `;

    // Append to results (after the progressive sections already in place)
    const finalContainer = document.createElement('div');
    finalContainer.innerHTML = finalHtml;
    while (finalContainer.firstChild) {
      els.results.appendChild(finalContainer.firstChild);
    }

    // Bind source card clicks
    els.results.querySelectorAll('.dr-source-card[data-source-n]').forEach((node) => {
      node.addEventListener('click', (e) => {
        if (e.target.closest('a')) return;
        const n = parseInt(node.dataset.sourceN, 10);
        const src = sources.find((s) => s.n === n);
        if (src) { openModal(src); flashSource(n); }
      });
    });
    els.results.querySelectorAll('.dr-cite[data-source-n]').forEach((node) => {
      node.addEventListener('click', (e) => {
        if (e.target.closest('a')) return;
        flashSource(parseInt(node.dataset.sourceN, 10));
      });
    });
  }

  // ── Component renderers ────────────────────────────────────────────────────

  function renderRedFlag(flag, sources) {
    const severity = flag.severity || 'low';
    const sevClass = `bvj-severity-${severity}`;
    const legal = flag.legal_basis || '';
    const what = flag.what_to_check || '';
    return `<div class="bvj-red-flag">
      <div class="bvj-red-flag__head">
        <div class="bvj-red-flag__desc">${renderInlineCitations(escapeHtml(flag.description || ''), sources)}</div>
        <span class="bvj-severity ${sevClass}">${escapeHtml(severity)}</span>
      </div>
      ${legal ? `<span class="bvj-red-flag__legal">${escapeHtml(legal)}</span>` : ''}
      ${what ? `<details class="bvj-red-flag__details"><summary>What to verify</summary><p class="bvj-red-flag__check">${escapeHtml(what)}</p></details>` : ''}
    </div>`;
  }

  function renderSubQReport(sq, idx) {
    const top = sq.top_sources || [];
    const sourceItems = top.length
      ? top.map((s) => {
          const link = s.deep_link || s.source_url;
          const titleHtml = link
            ? `<a href="${escapeHtml(link)}" target="_blank" rel="noopener" class="dr-mini-source__title">${escapeHtml(s.title || 'Untitled')} <span class="dr-external-link" aria-hidden="true">↗</span></a>`
            : `<span class="dr-mini-source__title">${escapeHtml(s.title || 'Untitled')}</span>`;
          const meta = [];
          if (s.section) meta.push(escapeHtml(s.section));
          if (s.authority_label) meta.push(escapeHtml(s.authority_label));
          if (s.source_origin === 'upload') meta.push('your upload');
          return `<li class="dr-mini-source">
            <span class="dr-mini-source__n">[${s.n ?? '?'}]</span>
            <div class="dr-mini-source__body">
              ${titleHtml}
              ${meta.length ? `<div class="dr-mini-source__meta">${meta.join(' · ')}</div>` : ''}
              <div class="dr-mini-source__excerpt">${escapeHtml(truncate(s.excerpt || '', 180))}</div>
            </div>
          </li>`;
        }).join('')
      : `<li class="dr-mini-source dr-mini-source--empty"><em>No sources retrieved for this sub-question.</em></li>`;

    return `<div class="dr-subq-report">
      <div class="dr-subq-report__head">
        <span class="dr-subq-report__index">${escapeHtml(sq.id || ('q' + (idx + 1)))}</span>
        <div class="dr-subq-report__body">
          <div class="dr-subq-report__question">${escapeHtml(sq.question || '')}</div>
          ${sq.rationale ? `<div class="dr-subq-report__rationale">${escapeHtml(sq.rationale)}</div>` : ''}
        </div>
        <button class="dr-branch-btn" type="button" data-question="${escapeHtml(sq.question || '')}" aria-label="Branch research from this sub-question">Branch ↓</button>
      </div>
      <ul class="dr-mini-source-list">${sourceItems}</ul>
    </div>`;
  }

  function renderSourceCard(s) {
    const score = s.reranker_score != null ? s.reranker_score : s.similarity;
    const originTagClass = s.source_origin === 'upload' ? 'dr-source-tag dr-source-tag--upload' : 'dr-source-tag';
    const originLabel = s.source_origin === 'upload' ? 'upload' : 'corpus';
    const link = s.deep_link || s.source_url;
    const titleHtml = link
      ? `<a href="${escapeHtml(link)}" target="_blank" rel="noopener" class="dr-source-title-link">${escapeHtml(s.title || 'Untitled')} <span class="dr-external-link" aria-hidden="true">↗</span></a>`
      : `${escapeHtml(s.title || 'Untitled')}`;
    return `<div class="dr-source-card" data-source-n="${s.n}" role="button" tabindex="0">
      <span class="dr-source-number">${s.n}</span>
      <div class="dr-source-body">
        <div class="dr-source-title">${titleHtml}</div>
        ${s.section ? `<div class="dr-source-meta"><span class="dr-source-tag">${escapeHtml(s.section)}</span></div>` : ''}
        <div class="dr-source-meta">
          <span class="${originTagClass}">${originLabel}</span>
          ${s.authority_label ? `<span class="dr-source-tag">${escapeHtml(s.authority_label)}</span>` : ''}
          <span class="dr-source-tag dr-source-tag--score">${escapeHtml(s.package_or_corpus || '—')}</span>
          ${(s.matched_sub_questions || []).map((q) => `<span class="dr-source-tag">${escapeHtml(q)}</span>`).join('')}
        </div>
        <p class="dr-source-excerpt">${escapeHtml(truncate(s.excerpt || '', 240))}</p>
      </div>
      <div class="dr-source-aside">
        <span>score<br><b>${score != null ? Number(score).toFixed(2) : '—'}</b></span>
        ${s.reranker_score != null && s.similarity != null ? `<span>sim<br><b>${Number(s.similarity).toFixed(2)}</b></span>` : ''}
      </div>
    </div>`;
  }

  // ── Trace rendering ────────────────────────────────────────────────────────

  function renderTrace(steps) {
    if (!els.traceList) return;
    els.traceList.classList.add('is-rich');
    els.traceList.innerHTML = steps.map((step, i) => {
      const statusClass = step.status === 'running' ? 'is-running'
                       : step.status === 'complete' ? 'is-done'
                       : step.status === 'warning' ? 'is-warning'
                       : step.status === 'error' ? 'is-error'
                       : '';
      const marker = step.status === 'complete' ? '✓'
                   : step.status === 'warning' ? '!'
                   : step.status === 'error' ? '×'
                   : (i + 1);
      return `<li class="trace-step ${statusClass}">
        <span class="trace-step__marker">${marker}</span>
        <div>
          <span class="trace-step__label">${escapeHtml(step.label || '')}</span>
          <span class="trace-step__detail">${escapeHtml(step.detail || '')}</span>
        </div>
      </li>`;
    }).join('');
  }

  // ── Utility ────────────────────────────────────────────────────────────────

  function setStatus(message, kind) {
    els.status.textContent = message;
    els.status.style.color = kind === 'error' ? '#b41e1e' : (kind === 'ok' ? 'var(--teal-dark)' : 'var(--muted)');
  }

  function flashSource(n) {
    document.querySelectorAll('.dr-source-card.is-highlight').forEach((c) => c.classList.remove('is-highlight'));
    const target = document.querySelector(`.dr-source-card[data-source-n="${n}"]`);
    if (target) {
      target.classList.add('is-highlight');
      target.scrollIntoView({ behavior: 'smooth', block: 'center' });
      setTimeout(() => target.classList.remove('is-highlight'), 1800);
    }
  }

  function renderBrief(markdown, sources) {
    if (!markdown) return '<p><em>No brief was returned.</em></p>';
    const escaped = escapeHtml(markdown);
    const withCites = escaped.replace(/\[(\d+(?:\s*[-,]\s*\d+)*)\]/g, (_, group) => {
      const nums = expandCiteGroup(group);
      return nums.map((n) => `<span class="dr-cite" data-source-n="${n}" role="button" tabindex="0">${n}</span>`).join('');
    });
    // Also mark [DOC] references
    const withDoc = withCites.replace(/\[DOC\]/g, '<span class="dr-cite dr-cite--doc" title="Cited from uploaded document">DOC</span>');
    const withBold = withDoc
      .replace(/\*\*([^*]+)\*\*/g, '<strong>$1</strong>')
      .replace(/(^|[^*])\*([^*]+)\*(?!\*)/g, '$1<em>$2</em>')
      .replace(/`([^`]+)`/g, '<code>$1</code>');
    const paragraphs = withBold.split(/\n{2,}/).map((p) => {
      const t = p.trim();
      if (!t) return '';
      if (/^## /.test(t)) return `<h3 style="margin:16px 0 6px;color:var(--ink);font-size:1rem">${t.replace(/^## /, '')}</h3>`;
      if (/^### /.test(t)) return `<h4 style="margin:12px 0 4px;color:var(--ink);font-size:0.95rem">${t.replace(/^### /, '')}</h4>`;
      return `<p>${t.replace(/\n/g, '<br>')}</p>`;
    }).join('');
    return paragraphs;
  }

  function renderInlineCitations(escapedHtml, sources) {
    return escapedHtml.replace(/\[(\d+(?:\s*[-,]\s*\d+)*)\]/g, (_, group) => {
      const nums = expandCiteGroup(group);
      return nums.map((n) => `<span class="dr-cite" data-source-n="${n}" role="button" tabindex="0">${n}</span>`).join('');
    });
  }

  function expandCiteGroup(group) {
    const out = [];
    group.split(',').forEach((part) => {
      const range = part.trim().match(/^(\d+)\s*-\s*(\d+)$/);
      if (range) {
        const a = parseInt(range[1], 10);
        const b = parseInt(range[2], 10);
        for (let i = a; i <= b; i++) out.push(i);
      } else {
        const n = parseInt(part.trim(), 10);
        if (!Number.isNaN(n)) out.push(n);
      }
    });
    return Array.from(new Set(out));
  }

  function escapeHtml(s) {
    return String(s)
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#039;');
  }

  function truncate(s, n) {
    if (!s) return '';
    if (s.length <= n) return s;
    return s.slice(0, n - 1) + '…';
  }
})();