/* korrespond.js — page-scoped UI for /korrespond.php
   Two-pass wizard: Pass 1 may return clarify questions; Pass 2 returns Norwegian
   + working-language drafts side by side with verified law citations.
*/
(function () {
  'use strict';

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

  const LANG_LABELS = { en: 'English', no: 'Norsk', uk: 'Українська', pl: 'Polski' };

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

    Object.assign(els, {
      form:           document.getElementById('korrForm'),
      status:         document.getElementById('korrStatus'),
      runButton:      document.getElementById('korrRunButton'),
      results:        document.getElementById('korrResults'),
      langButtons:    Array.from(document.querySelectorAll('#korrLangSwitcher .lang-btn')),
      modeRadios:     Array.from(document.querySelectorAll('input[name="korrMode"]')),
      bodySelect:     document.getElementById('korrBody'),
      outputRadios:   Array.from(document.querySelectorAll('input[name="korrOutput"]')),
      toneRadios:     Array.from(document.querySelectorAll('input[name="korrTone"]')),
      caseRef:        document.getElementById('korrCaseRef'),
      where:          document.getElementById('korrWhere'),
      deadline:       document.getElementById('korrDeadline'),
      parties:        document.getElementById('korrParties'),
      narrative:      document.getElementById('korrNarrative'),
      goal:           document.getElementById('korrGoal'),
      goalChips:      Array.from(document.querySelectorAll('#korrGoalChips .korr-chip')),
      uploadZone:     document.getElementById('korrUploadZone'),
      uploadInput:    document.getElementById('korrUploadInput'),
      uploadPrompt:   document.getElementById('korrUploadPrompt'),
      uploadFileInfo: document.getElementById('korrUploadFileInfo'),
      uploadFileList: document.getElementById('korrUploadFileList'),
      uploadClear:    document.getElementById('korrUploadClear'),
      clarifyPanel:   document.getElementById('korrClarifyPanel'),
      clarifyList:    document.getElementById('korrClarifyList'),
      clarifyContinue:document.getElementById('korrClarifyContinue'),
      clarifyForce:   document.getElementById('korrClarifyForce'),
    });

    if (!els.form) return;

    bindLang();
    bindGoalChips();
    bindUpload();
    bindClarify();
    els.form.addEventListener('submit', (e) => { e.preventDefault(); runRequest(false); });
  });

  // ── Language switcher ───────────────────────────────────────────────────────
  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);
      });
    });
  }

  function bindGoalChips() {
    els.goalChips.forEach((chip) => {
      chip.addEventListener('click', () => {
        els.goal.value = chip.dataset.goal || '';
        els.goalChips.forEach((c) => c.classList.remove('is-active'));
        chip.classList.add('is-active');
      });
    });
  }

  // ── File upload ─────────────────────────────────────────────────────────────
  function bindUpload() {
    if (!els.uploadZone) return;
    const onFiles = (fileList) => {
      const files = Array.from(fileList || []).slice(0, 4);
      if (uploadFiles.length + files.length > 4) {
        setStatus('At most 4 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">${esc(f.name)}</span><span class="upload-chars">${kb} KB</span></li>`;
    }).join('');
  }

  // ── Clarify panel ───────────────────────────────────────────────────────────
  function bindClarify() {
    els.clarifyContinue?.addEventListener('click', () => {
      pendingClarifications = collectClarifications();
      hideClarify();
      runRequest(false);
    });
    els.clarifyForce?.addEventListener('click', () => {
      pendingClarifications = collectClarifications();
      hideClarify();
      runRequest(true);
    });
  }

  function showClarify(questions) {
    els.clarifyList.innerHTML = (questions || []).map((q, i) => `
      <div class="korr-clarify-item">
        <label for="clarify_${i}"><strong>${esc(q.question || '')}</strong></label>
        <input type="text" id="clarify_${i}" data-key="${esc(q.key || '')}" placeholder="(optional)">
      </div>
    `).join('');
    els.clarifyPanel.classList.remove('is-hidden');
    els.clarifyPanel.scrollIntoView({ behavior: 'smooth', block: 'start' });
  }

  function hideClarify() {
    els.clarifyPanel.classList.add('is-hidden');
  }

  function collectClarifications() {
    const inputs = els.clarifyList.querySelectorAll('input[data-key]');
    const out = {};
    inputs.forEach((inp) => {
      const v = (inp.value || '').trim();
      if (v) out[inp.dataset.key] = v;
    });
    return out;
  }

  // ── Submit ──────────────────────────────────────────────────────────────────
  function getRadio(list) {
    const checked = list.find((r) => r.checked);
    return checked ? checked.value : '';
  }

  function buildPayload(forceDraft) {
    const deadlines = [];
    if (els.deadline.value.trim()) deadlines.push(els.deadline.value.trim());
    return {
      mode:           getRadio(els.modeRadios) || 'initiate',
      recipient_body: els.bodySelect.value || 'other',
      output_type:    getRadio(els.outputRadios) || 'email',
      tone:           getRadio(els.toneRadios) || 'neutral',
      language:       lang,
      case_ref:       els.caseRef.value.trim(),
      where:          els.where.value.trim(),
      deadlines,
      parties_text:   els.parties.value.trim(),
      narrative:      els.narrative.value.trim(),
      goal:           els.goal.value.trim(),
      clarifications: pendingClarifications,
      force_draft:    !!forceDraft,
    };
  }

  async function runRequest(forceDraft) {
    const payload = buildPayload(forceDraft);
    if (!payload.recipient_body) {
      setStatus('Pick a recipient body before drafting.', 'error');
      return;
    }
    if (payload.mode === 'initiate' && !payload.narrative) {
      setStatus('Describe the situation in "What happened" first.', 'error');
      return;
    }
    if (payload.mode === 'reply' && !uploadFiles.length && !payload.narrative) {
      setStatus('Reply mode needs the received letter (upload or paste it).', 'error');
      return;
    }

    setStatus('Analyserer…', 'busy');
    els.runButton.disabled = true;
    els.results.innerHTML = `<div class="empty-state"><h3>Working…</h3><p>Pass 1 extracts facts. If anything is missing we'll ask for clarification. Otherwise Pass 2 runs hard-RAG retrieval + draft + self-check + translate.</p></div>`;

    const form = new FormData();
    form.append('payload', JSON.stringify(payload));
    uploadFiles.forEach((f) => form.append('files[]', f));

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

    if (!response.ok || !response.body) {
      if (response.status === 402 || response.status === 429) {
        const d = await response.json().catch(() => ({}));
        if (typeof window.dbnFreeTierError === 'function') window.dbnFreeTierError(response.status, d);
      } else {
        setStatus(`Request failed (${response.status}).`, 'error');
      }
      els.runButton.disabled = false;
      return;
    }
    const creditsRemaining = response.headers.get('X-Credits-Remaining');
    if (creditsRemaining !== null && typeof window.dbnUpdateCredits === 'function') {
      window.dbnUpdateCredits(parseInt(creditsRemaining, 10));
    }

    const reader = response.body.getReader();
    const decoder = new TextDecoder('utf-8');
    let buffer = '';
    let finalResult = null;
    let errorEvent = null;
    let clarifyEvent = null;

    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; }
          if (!evt || !evt.event) continue;
          if (evt.event === 'progress') { setStatus(evt.detail || 'Working…', 'busy'); continue; }
          if (evt.event === 'start')    { setStatus(`Started — ${evt.body} / ${evt.output_type}`, 'busy'); continue; }
          if (evt.event === 'classify') { lastClassify = evt.result; renderClassifySummary(evt.result); continue; }
          if (evt.event === 'retrieval'){ setStatus(`Hentet ${evt.sources_count} lovkilder for ${(evt.applicable_acts || []).join(', ')}…`, 'busy'); continue; }
          if (evt.event === 'clarify')  { clarifyEvent = evt; continue; }
          if (evt.event === 'final')    { finalResult = evt.result; continue; }
          if (evt.event === 'error')    { errorEvent = evt; continue; }
        }
      }
      if (done) break;
    }

    els.runButton.disabled = false;

    if (errorEvent) {
      setStatus(`${errorEvent.code}: ${errorEvent.message}`, 'error');
      return;
    }
    if (clarifyEvent) {
      setStatus('Need clarification before drafting.', 'busy');
      showClarify(clarifyEvent.questions);
      return;
    }
    if (!finalResult) {
      setStatus('Stream ended without a draft.', 'error');
      return;
    }

    setStatus(`Done in ${Math.round((finalResult.latency_ms || 0) / 1000)} s · ${(finalResult.cited_law || []).length} cited source(s)`, 'ok');
    renderFinal(finalResult);
    pendingClarifications = {}; // reset for next run
  }

  // ── Rendering ───────────────────────────────────────────────────────────────
  function renderClassifySummary(c) {
    if (!c || !c.summary) return;
    let block = els.results.querySelector('#korrClassifyBlock');
    if (!block) {
      block = document.createElement('div');
      block.id = 'korrClassifyBlock';
      block.className = 'dr-result-block';
      els.results.innerHTML = '';
      els.results.appendChild(block);
    }
    block.innerHTML = `
      <h3 style="margin:0 0 10px;font-size:0.95rem;color:var(--ink)">Sammendrag (Pass 1)</h3>
      <p>${esc(c.summary)}</p>
      ${c.applicable_acts && c.applicable_acts.length ? `<p class="upload-hint"><strong>Antatt rettslig grunnlag:</strong> ${c.applicable_acts.map(esc).join(', ')}</p>` : ''}
      ${c.deadlines && c.deadlines.length ? `<p class="upload-hint"><strong>Frister:</strong> ${c.deadlines.map(esc).join(', ')}</p>` : ''}
    `;
  }

  function renderFinal(data) {
    const userLang = data.draft_user_lang || 'en';
    const userLangLabel = LANG_LABELS[userLang] || userLang.toUpperCase();
    const flags = data.self_check || {};
    const cited = data.cited_law || [];

    const flagBadge = (key, label) => {
      const v = flags[key] || 'ok';
      const cls = v === 'ok' ? 'is-ok' : (v === 'warn' ? 'is-warn' : 'is-error');
      const icon = v === 'ok' ? '✓' : '!';
      return `<span class="korr-flag ${cls}">${icon} ${esc(label)}</span>`;
    };

    const draftNo = data.draft_no || '';
    const draftUser = data.draft_user || '';
    const isSameLang = userLang === 'no';

    els.results.innerHTML = `
      <div class="korr-result-head">
        <span class="tool-badge">${esc(data.recipient_body || '')} · ${esc(data.output_type || '')} · ${esc(data.tone || '')}</span>
        <div class="korr-flags">
          ${flagBadge('citations_verified', 'Citations verified')}
          ${flagBadge('deadline_mentioned', 'Deadline')}
          ${flagBadge('goal_addressed', 'Goal addressed')}
          ${flagBadge('tone', 'Tone')}
        </div>
      </div>

      <div class="korr-drafts ${isSameLang ? 'is-single' : ''}">
        <div class="korr-draft-col">
          <div class="korr-draft-head">
            <h3>Norsk (bokmål) — kanonisk</h3>
            <div class="korr-draft-actions">
              <button type="button" class="secondary-button" data-copy="no">Copy</button>
              <button type="button" class="secondary-button" data-download="no">Download .txt</button>
            </div>
          </div>
          <pre class="korr-draft-body" id="korrDraftNo">${esc(draftNo)}</pre>
        </div>
        ${isSameLang ? '' : `
        <div class="korr-draft-col">
          <div class="korr-draft-head">
            <h3>${esc(userLangLabel)} — reference</h3>
            <div class="korr-draft-actions">
              <button type="button" class="secondary-button" data-copy="user">Copy</button>
              <button type="button" class="secondary-button" data-download="user">Download .txt</button>
            </div>
          </div>
          <pre class="korr-draft-body" id="korrDraftUser">${esc(draftUser)}</pre>
        </div>`}
      </div>

      ${cited.length ? `
      <details class="korr-cited" open>
        <summary><strong>Cited law (${cited.length})</strong> — each reference traces to a real corpus passage</summary>
        <div class="korr-cited-list">
          ${cited.map((s) => `
            <div class="korr-cited-item">
              <div class="korr-cited-head"><strong>[${s.n}] ${esc(s.title)}</strong>${s.section ? ' — ' + esc(s.section) : ''}</div>
              <p class="korr-cited-excerpt">${esc(s.excerpt || '')}</p>
              ${s.source_url ? `<a href="${esc(s.source_url)}" target="_blank" rel="noopener">View source</a>` : ''}
            </div>
          `).join('')}
        </div>
      </details>
      ` : '<p class="upload-hint"><em>No cited law sources — draft is plain-language (no § references available from corpus).</em></p>'}

      ${data.disclaimer ? `<p class="upload-hint" style="margin-top:16px;font-style:italic">${esc(data.disclaimer)}</p>` : ''}
    `;

    // Wire copy/download
    els.results.querySelectorAll('[data-copy]').forEach((btn) => {
      btn.addEventListener('click', () => {
        const target = btn.dataset.copy === 'no' ? draftNo : draftUser;
        navigator.clipboard?.writeText(target).then(
          () => { btn.textContent = 'Copied ✓'; setTimeout(() => btn.textContent = 'Copy', 1500); },
          () => { btn.textContent = 'Failed'; }
        );
      });
    });
    els.results.querySelectorAll('[data-download]').forEach((btn) => {
      btn.addEventListener('click', () => {
        const target = btn.dataset.download === 'no' ? draftNo : draftUser;
        const suffix = btn.dataset.download === 'no' ? 'no' : userLang;
        downloadText(`korrespond-${data.recipient_body}-${suffix}.txt`, target);
      });
    });
  }

  // ── utils ───────────────────────────────────────────────────────────────────
  function setStatus(message, kind) {
    if (!els.status) return;
    els.status.textContent = message || '';
    els.status.dataset.kind = kind || '';
  }

  function esc(s) {
    return String(s == null ? '' : s)
      .replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;').replace(/'/g, '&#39;');
  }

  function downloadText(filename, text) {
    const blob = new Blob([text], { type: 'text/plain;charset=utf-8' });
    const url = URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url; a.download = filename;
    document.body.appendChild(a); a.click(); a.remove();
    URL.revokeObjectURL(url);
  }
})();