// ──────────────────────────────────────────
// State
// ──────────────────────────────────────────
const state = {
  step: 1,
  started: false,

  // Step 1
  meta: { country: '', age: '', gender: '', timestamp: null },

  // Step 2
  shuffledCases: [],
  caseIndex: 0,
  currentJudgment: null,   // 1-5 Likert
  caseStartTime: null,
  intuitive_judgments: [],

  // Step 3
  pairIndex: 0,
  sliderValues: Array(10).fill(0),
  pairwiseRaw: null,
  ahpResult: null,
  crWarningShown: false,
  crWarningPending: false,

  // Step 4 / 5
  comparison: [],
  post_survey: { q1: null, q2: null, q3: null, q4: null, open_response: '' },
  submitted: false,
  _payload: null,
};

// ──────────────────────────────────────────
// Render entry point
// ──────────────────────────────────────────
function renderApp() {
  renderHeader();
  renderMain();
}

function renderHeader() {
  const el = document.getElementById('app-header');
  if (!el) return;
  el.innerHTML = `
    <div class="header-inner">
      <span class="header-title">${t('appTitle')}</span>
      <button class="lang-btn" onclick="switchLang()">${t('langBtn')}</button>
    </div>
  `;
}

function renderMain() {
  const el = document.getElementById('app-main');
  if (!el) return;
  switch (state.step) {
    case 1: el.innerHTML = renderStep1(); bindStep1(); break;
    case 2: el.innerHTML = renderStep2(); bindStep2(); break;
    case 3: el.innerHTML = renderStep3(); bindStep3(); break;
    case 4: el.innerHTML = renderStep4(); break;
    case 5: el.innerHTML = renderStep5(); bindStep5(); break;
    case 'complete': el.innerHTML = renderComplete(); bindComplete(); break;
  }
}

// ──────────────────────────────────────────
// STEP 1
// ──────────────────────────────────────────
const COUNTRIES = [
  'Afghanistan','Albania','Algeria','Angola','Argentina','Armenia','Australia','Austria',
  'Azerbaijan','Bangladesh','Belarus','Belgium','Bolivia','Bosnia and Herzegovina','Brazil',
  'Bulgaria','Cambodia','Cameroon','Canada','Chile','China','Colombia','Congo','Costa Rica',
  'Croatia','Cuba','Czech Republic','Denmark','Dominican Republic','Ecuador','Egypt',
  'El Salvador','Ethiopia','Finland','France','Georgia','Germany','Ghana','Greece',
  'Guatemala','Haiti','Honduras','Hungary','India','Indonesia','Iran','Iraq','Ireland',
  'Israel','Italy','Jamaica','Japan','Jordan','Kazakhstan','Kenya','Kuwait','Kyrgyzstan',
  'Laos','Lebanon','Libya','Lithuania','Malaysia','Mexico','Moldova','Mongolia','Morocco',
  'Mozambique','Myanmar','Nepal','Netherlands','New Zealand','Nicaragua','Nigeria','Norway',
  'Pakistan','Palestine','Panama','Paraguay','Peru','Philippines','Poland','Portugal',
  'Romania','Russia','Rwanda','Saudi Arabia','Senegal','Serbia','Singapore','Slovakia',
  'Somalia','South Africa','South Korea','Spain','Sri Lanka','Sudan','Sweden','Switzerland',
  'Syria','Taiwan','Tajikistan','Tanzania','Thailand','Tunisia','Turkey','Turkmenistan',
  'Uganda','Ukraine','United Arab Emirates','United Kingdom','United States','Uruguay',
  'Uzbekistan','Venezuela','Vietnam','Yemen','Zambia','Zimbabwe','Other',
];

function renderStep1() {
  const { meta } = state;
  const notices = t('step1Notices').map(n => `<p>${n}</p>`).join('');
  const countryOpts = COUNTRIES.map(c =>
    `<option value="${c}" ${meta.country === c ? 'selected' : ''}>${c}</option>`
  ).join('');
  const genderOpts = t('step1Q3opts').map(o => `
    <label class="radio-label ${meta.gender === o ? 'selected' : ''}">
      <input type="radio" name="gender" value="${o}" ${meta.gender === o ? 'checked' : ''} />
      ${o}
    </label>
  `).join('');

  return `
    <div class="step-wrap">
      <div class="card">
        <h1 class="section-title">${t('step1Title')}</h1>
        <p class="section-subtitle">${t('step1Intro')}</p>

        <div class="notice-box">${notices}</div>

        <div class="form-group">
          <label>${t('step1Q1')}</label>
          <select id="sel-country" class="form-select">
            <option value="">${t('step1Q1placeholder')}</option>
            ${countryOpts}
          </select>
        </div>

        <div class="form-group">
          <label>${t('step1Q2')}</label>
          <input type="number" id="inp-age" class="form-input" min="10" max="99"
            placeholder="${t('step1Q2placeholder')}" value="${meta.age}" />
        </div>

        <div class="form-group">
          <label>${t('step1Q3')}</label>
          <div class="radio-group" id="rg-gender">${genderOpts}</div>
        </div>

        <div class="btn-row" style="margin-top:1.5rem">
          <button class="btn btn-primary btn-lg btn-full" id="btn-start">${t('startBtn')}</button>
        </div>
      </div>
    </div>
  `;
}

function bindStep1() {
  document.getElementById('sel-country').addEventListener('change', e => {
    state.meta.country = e.target.value;
  });

  document.getElementById('inp-age').addEventListener('input', e => {
    state.meta.age = e.target.value;
  });

  document.getElementById('rg-gender').addEventListener('click', e => {
    const lbl = e.target.closest('label');
    if (!lbl) return;
    const val = lbl.querySelector('input').value;
    state.meta.gender = val;
    document.querySelectorAll('#rg-gender label').forEach(l =>
      l.classList.toggle('selected', l.querySelector('input').value === val));
  });

  document.getElementById('btn-start').addEventListener('click', () => {
    if (!state.meta.country || !state.meta.age || !state.meta.gender) {
      alert(t('alertFillAll')); return;
    }
    state.meta.timestamp = Date.now();
    state.shuffledCases = shuffleCases();
    state.caseIndex = 0;
    state.started = true;
    enableLeaveWarning();
    goStep(2);
  });
}

// ──────────────────────────────────────────
// STEP 2
// ──────────────────────────────────────────
function renderStep2() {
  const total = state.shuffledCases.length;
  const idx = state.caseIndex;
  const pct = Math.round((idx / total) * 100);
  const c = state.shuffledCases[idx];
  const varNames = t('varNames');

  const varRows = VARS.map(key => {
    const score = c[key];
    const level = getScoreLevel(score);
    return `
      <div class="var-row">
        <span class="var-name">${varNames[key]}</span>
        <div class="var-bar-track">
          <div class="var-bar-fill" data-level="${level}" style="width:${score}%"></div>
        </div>
        <span class="var-score">${score}</span>
      </div>
    `;
  }).join('');

  const scale = t('judgmentScale');
  const likertBtns = scale.map((label, i) => {
    const val = i + 1;
    const active = state.currentJudgment === val;
    return `
      <button class="judgment-likert-btn ${active ? 'active' : ''}" data-val="${val}">
        <span class="jl-num">${val}</span>
        <span class="jl-label">${label.replace('\n', '<br>')}</span>
      </button>
    `;
  }).join('');

  return `
    <div class="step-wrap">
      <div class="progress-bar-wrap">
        <div class="progress-label">
          <span>${idx + 1} / ${total}</span>
        </div>
        <div class="progress-track">
          <div class="progress-fill" style="width:${pct}%"></div>
        </div>
      </div>

      <div class="card case-card">
        <div class="case-header">
          <span class="team-badge">Team ${c.teamLetter}</span>
        </div>

        <div>${varRows}</div>

        <div class="judgment-section">
          <p class="judgment-label">${t('judgmentLabel')}</p>
          <div class="judgment-likert-row" id="jl-row">${likertBtns}</div>
        </div>

        <div class="btn-row end" style="margin-top:1.2rem">
          <button class="btn btn-primary" id="btn-case-next" ${state.currentJudgment === null ? 'disabled' : ''}>${t('btnNext')}</button>
        </div>
      </div>

      <p class="text-muted text-center" style="font-size:.8rem;margin-top:.75rem">${t('step2Instruction')}</p>
    </div>
  `;
}

function bindStep2() {
  const caseStart = Date.now();

  document.getElementById('jl-row').addEventListener('click', e => {
    const btn = e.target.closest('.judgment-likert-btn');
    if (!btn) return;
    const val = parseInt(btn.dataset.val);
    state.currentJudgment = val;
    document.querySelectorAll('.judgment-likert-btn').forEach(b =>
      b.classList.toggle('active', parseInt(b.dataset.val) === val));
    document.getElementById('btn-case-next').disabled = false;
  });

  document.getElementById('btn-case-next').addEventListener('click', () => {
    if (state.currentJudgment === null) { alert(t('alertSelectJudgment')); return; }
    const elapsed = Date.now() - caseStart;
    const c = state.shuffledCases[state.caseIndex];
    state.intuitive_judgments.push({
      case_id: c.id,
      presented_order: state.caseIndex + 1,
      judgment: state.currentJudgment,   // 1-5
      response_time_ms: elapsed,
    });
    state.caseIndex++;
    state.currentJudgment = null;
    if (state.caseIndex >= state.shuffledCases.length) {
      goStep(3);
    } else {
      renderMain();
      window.scrollTo({ top: 0, behavior: 'smooth' });
    }
  });
}

// ──────────────────────────────────────────
// STEP 3
// ──────────────────────────────────────────
const AHP_PAIR_LABELS_KO = [
  ['안정성', '수익 가능성'],
  ['안정성', '자금 효율성'],
  ['안정성', '사업 계획 완성도'],
  ['안정성', '사회적 가치'],
  ['수익 가능성', '자금 효율성'],
  ['수익 가능성', '사업 계획 완성도'],
  ['수익 가능성', '사회적 가치'],
  ['자금 효율성', '사업 계획 완성도'],
  ['자금 효율성', '사회적 가치'],
  ['사업 계획 완성도', '사회적 가치'],
];

const AHP_PAIR_LABELS_EN = [
  ['Stability', 'Revenue Potential'],
  ['Stability', 'Capital Efficiency'],
  ['Stability', 'Business Plan Quality'],
  ['Stability', 'Social Value'],
  ['Revenue Potential', 'Capital Efficiency'],
  ['Revenue Potential', 'Business Plan Quality'],
  ['Revenue Potential', 'Social Value'],
  ['Capital Efficiency', 'Business Plan Quality'],
  ['Capital Efficiency', 'Social Value'],
  ['Business Plan Quality', 'Social Value'],
];

function getPairLabels(idx) {
  return currentLang === 'en' ? AHP_PAIR_LABELS_EN[idx] : AHP_PAIR_LABELS_KO[idx];
}

function getAHPDescription(sliderPos, leftLabel, rightLabel) {
  if (sliderPos === 0) return t('ahpEqual');
  const ahpVal = Math.abs(sliderToStored(sliderPos)); // 3,5,7,9
  const level = t('ahpLevels')[ahpVal] || String(ahpVal);
  if (sliderPos < 0) return t('ahpLeftMore', leftLabel, level);
  return t('ahpRightMore', rightLabel, level);
}

function renderStep3() {
  const idx = state.pairIndex;
  const total = AHP_PAIRS.length;
  const pct = Math.round((idx / total) * 100);
  const [left, right] = getPairLabels(idx);
  const sliderVal = state.sliderValues[idx];
  const desc = getAHPDescription(sliderVal, left, right);

  const leftActive = sliderVal < 0 ? 'crit-active-left' : '';
  const rightActive = sliderVal > 0 ? 'crit-active-right' : '';

  return `
    <div class="step-wrap">
      <div class="progress-bar-wrap">
        <div class="progress-label">
          <span>${idx + 1} / ${total}</span>
        </div>
        <div class="progress-track">
          <div class="progress-fill" style="width:${pct}%"></div>
        </div>
      </div>

      <div class="card">
        <h2 class="section-title" style="font-size:1.1rem">${t('step3Title')}</h2>
        <p class="section-subtitle">${t('step3Instruction')}</p>

        <div class="ahp-pair-card">
          <div class="pair-criteria">
            <div class="crit crit-left ${leftActive}" id="crit-left">${left}</div>
            <div class="vs-badge">VS</div>
            <div class="crit crit-right ${rightActive}" id="crit-right">${right}</div>
          </div>

          <div class="ahp-slider-wrap">
            <div class="ahp-scale-labels">
              <span>9</span><span>7</span><span>5</span><span>3</span>
              <span class="sc-mid">1</span>
              <span>3</span><span>5</span><span>7</span><span>9</span>
            </div>
            <input type="range" class="ahp-slider" id="ahp-slider"
              min="-4" max="4" step="1" value="${sliderVal}" />
          </div>

          <div class="ahp-description" id="ahp-desc">${desc}</div>
        </div>

        ${state.crWarningPending ? `
          <div class="cr-warning">
            <p>${t('crWarning')}</p>
            <div class="btn-row">
              <button class="btn btn-outline" id="btn-redo">${t('btnRedo')}</button>
              <button class="btn btn-gray" id="btn-cr-continue">${t('btnContinue')}</button>
            </div>
          </div>
        ` : `
          <div class="btn-row end" style="margin-top:1.2rem">
            <button class="btn btn-primary" id="btn-pair-next">${t('btnNext')}</button>
          </div>
        `}
      </div>
    </div>
  `;
}

function bindStep3() {
  const idx = state.pairIndex;
  const [left, right] = getPairLabels(idx);

  const slider = document.getElementById('ahp-slider');
  if (slider) {
    slider.addEventListener('input', e => {
      const val = parseInt(e.target.value);
      state.sliderValues[idx] = val;
      document.getElementById('ahp-desc').textContent = getAHPDescription(val, left, right);
      document.getElementById('crit-left').className = `crit crit-left ${val < 0 ? 'crit-active-left' : ''}`;
      document.getElementById('crit-right').className = `crit crit-right ${val > 0 ? 'crit-active-right' : ''}`;
    });
  }

  const nextBtn = document.getElementById('btn-pair-next');
  if (nextBtn) nextBtn.addEventListener('click', advancePair);

  const redoBtn = document.getElementById('btn-redo');
  if (redoBtn) redoBtn.addEventListener('click', () => {
    state.crWarningPending = false;
    state.pairIndex = 0;
    state.sliderValues = Array(10).fill(0);
    renderMain();
  });

  const contBtn = document.getElementById('btn-cr-continue');
  if (contBtn) contBtn.addEventListener('click', () => {
    state.crWarningPending = false;
    finalizeAHP();
    goStep(4);
  });
}

function advancePair() {
  const total = AHP_PAIRS.length;
  if (state.pairIndex < total - 1) {
    state.pairIndex++;
    renderMain();
    window.scrollTo({ top: 0, behavior: 'smooth' });
  } else {
    const raw = state.sliderValues.map(s => sliderToStored(s));
    state.pairwiseRaw = raw;
    const result = runAHP(raw);
    state.ahpResult = result;

    if (result.CR > 0.10) {
      state.crWarningPending = true;
      state.crWarningShown = true;
      renderMain();
    } else {
      finalizeAHP();
      goStep(4);
    }
  }
}

// Convert Likert 1-5 to judgment category for comparison with model
function likertToJudgment(likert) {
  if (likert >= 4) return 'select';
  if (likert <= 2) return 'reject';
  return 'neutral'; // 3
}

function finalizeAHP() {
  const weights = state.ahpResult.weights;
  state.comparison = state.shuffledCases.map((c, i) => {
    const modelScore = calcModelScore(c, weights);
    const modelJudgment = modelScore >= 50 ? 'select' : 'reject';
    const rawLikert = state.intuitive_judgments[i]?.judgment ?? null;
    const intuitiveCategory = rawLikert !== null ? likertToJudgment(rawLikert) : null;
    const match = intuitiveCategory === 'neutral' ? null
                : intuitiveCategory === modelJudgment ? true : false;
    return {
      case_id: c.id,
      team: c.teamLetter,
      type: c.type,
      model_score: Math.round(modelScore * 10) / 10,
      model_judgment: modelJudgment,
      intuitive_likert: rawLikert,
      intuitive_category: intuitiveCategory,
      match,
    };
  });
}

// ──────────────────────────────────────────
// STEP 4
// ──────────────────────────────────────────
function renderStep4() {
  const weights = state.ahpResult.weights;
  const varNames = t('varNames');

  const weightRows = VARS.map((key, i) => {
    const pct = Math.round(weights[i] * 100);
    return `
      <div class="wc-row">
        <span class="wc-label">${varNames[key]}</span>
        <div class="wc-track"><div class="wc-fill" style="width:${pct}%"></div></div>
        <span class="wc-pct">${pct}%</span>
      </div>
    `;
  }).join('');

  const comp = state.comparison;
  // Exclude neutral (match===null) from mismatch counts
  const decidable = comp.filter(c => c.match !== null);
  const totalMismatch = decidable.filter(c => !c.match).length;
  const baseline  = decidable.filter(c => c.type === 'baseline');
  const spike     = decidable.filter(c => c.type === 'spike');
  const conflict  = decidable.filter(c => c.type === 'conflict');
  const { CR } = state.ahpResult;

  const rows = comp.map(c => {
    const mis = c.match === false;
    const neu = c.match === null;
    const mLabel = c.model_judgment === 'select'
      ? `<span class="badge badge-select">${t('select')}</span>`
      : `<span class="badge badge-reject">${t('reject')}</span>`;
    const iLabel = c.intuitive_category === 'select'
      ? `<span class="badge badge-select">${c.intuitive_likert}</span>`
      : c.intuitive_category === 'reject'
      ? `<span class="badge badge-reject">${c.intuitive_likert}</span>`
      : `<span class="badge badge-neutral">${c.intuitive_likert}</span>`;
    const matchBadge = c.match === true
      ? `<span class="badge badge-match">${t('colYes')}</span>`
      : c.match === false
      ? `<span class="badge badge-mismatch">${t('colNo')}</span>`
      : `<span class="badge badge-neutral">${t('colNeutral')}</span>`;
    return `
      <tr class="${mis ? 'mismatch' : neu ? 'neutral-row' : ''}">
        <td>Team ${c.team}</td>
        <td>${c.model_score}</td>
        <td>${mLabel}</td>
        <td>${iLabel}</td>
        <td>${matchBadge}</td>
      </tr>
    `;
  }).join('');

  return `
    <div class="step-wrap">
      <div class="card">
        <h2 class="section-title">${t('step4Title')}</h2>
        <h3 style="font-size:.95rem;font-weight:700;margin-bottom:.75rem">${t('weightsTitle')}</h3>
        <div class="weight-chart">${weightRows}</div>
      </div>

      <div class="card">
        <h3 style="font-size:.95rem;font-weight:700;margin-bottom:.5rem">${t('statsTitle')}</h3>
        <div class="stats-grid">
          <div class="stat-box ${totalMismatch > 7 ? 'stat-warn' : 'stat-ok'}">
            <div class="stat-val">${totalMismatch}/${decidable.length}</div>
            <div class="stat-label">${t('statTotal')}</div>
          </div>
          <div class="stat-box">
            <div class="stat-val">${baseline.filter(c=>!c.match).length}/${baseline.length}</div>
            <div class="stat-label">${t('statBaseline')}</div>
          </div>
          <div class="stat-box">
            <div class="stat-val">${spike.filter(c=>!c.match).length}/${spike.length}</div>
            <div class="stat-label">${t('statSpike')}</div>
          </div>
          <div class="stat-box">
            <div class="stat-val">${conflict.filter(c=>!c.match).length}/${conflict.length}</div>
            <div class="stat-label">${t('statConflict')}</div>
          </div>
          <div class="stat-box ${CR > 0.10 ? 'stat-warn' : 'stat-ok'}">
            <div class="stat-val">${CR.toFixed(3)}</div>
            <div class="stat-label">${t('statCR')}</div>
          </div>
        </div>
        <p class="text-muted mt-2">${t('totalMismatch', totalMismatch, decidable.length)}</p>
      </div>

      <div class="card">
        <h3 style="font-size:.95rem;font-weight:700;margin-bottom:.5rem">${t('tableTitle')}</h3>
        <div class="comparison-table-wrap">
          <table>
            <thead>
              <tr>
                <th>${t('colTeam')}</th>
                <th>${t('colModelScore')}</th>
                <th>${t('colModelJudge')}</th>
                <th>${t('colIntuition')}</th>
                <th>${t('colMatch')}</th>
              </tr>
            </thead>
            <tbody>${rows}</tbody>
          </table>
        </div>
      </div>

      <div class="btn-row center" style="margin-top:1rem">
        <button class="btn btn-primary btn-lg" onclick="goStep(5)">${t('btnGoSurvey')}</button>
      </div>
    </div>
  `;
}

// ──────────────────────────────────────────
// STEP 5
// ──────────────────────────────────────────
function renderStep5() {
  const qs = t('likertQ');
  const scale = t('likertScale');

  const groups = qs.map((q, qi) => {
    const opts = scale.map((label, si) => {
      const val = si + 1;
      const checked = state.post_survey[`q${qi+1}`] === val;
      return `
        <label>
          <input type="radio" name="q${qi+1}" value="${val}" ${checked ? 'checked' : ''} />
          <div class="likert-btn">${val}</div>
          <span class="likert-desc">${label.replace('\n', '<br>')}</span>
        </label>
      `;
    }).join('');
    return `
      <div class="likert-group">
        <p class="likert-q">${qi+1}. ${q}</p>
        <div class="likert-options">${opts}</div>
      </div>
    `;
  }).join('');

  return `
    <div class="step-wrap">
      <div class="card">
        <h2 class="section-title">${t('step5Title')}</h2>
        <p class="section-subtitle">${t('step5Desc')}</p>
        ${groups}
        <div class="form-group">
          <label>${t('openQ')}</label>
          <textarea class="open-textarea" id="open-resp" placeholder="${t('openPh')}">${escHtml(state.post_survey.open_response)}</textarea>
        </div>
        <div class="btn-row end" style="margin-top:1.5rem">
          <button class="btn btn-primary btn-lg" id="btn-submit">${t('btnSubmit')}</button>
        </div>
      </div>
    </div>
  `;
}

function bindStep5() {
  document.querySelectorAll('.likert-options input[type="radio"]').forEach(inp => {
    inp.addEventListener('change', e => {
      state.post_survey[e.target.name] = parseInt(e.target.value);
    });
  });
  document.getElementById('open-resp').addEventListener('input', e => {
    state.post_survey.open_response = e.target.value;
  });
  document.getElementById('btn-submit').addEventListener('click', () => {
    const { q1, q2, q3, q4 } = state.post_survey;
    if (!q1 || !q2 || !q3 || !q4) { alert(t('alertFillAll')); return; }
    submitData();
  });
}

// ──────────────────────────────────────────
// Submit & Complete
// ──────────────────────────────────────────
function buildPayload() {
  return {
    meta: { timestamp: state.meta.timestamp, country: state.meta.country, age: state.meta.age, gender: state.meta.gender },
    intuitive_judgments: state.intuitive_judgments,
    ahp: {
      pairwise_raw: state.pairwiseRaw,
      weights: state.ahpResult.weights,
      lambda_max: state.ahpResult.lambdaMax,
      CI: state.ahpResult.CI,
      CR: state.ahpResult.CR,
      cr_warning_shown: state.crWarningShown,
    },
    comparison: state.comparison,
    post_survey: state.post_survey,
  };
}

async function submitData() {
  if (state.submitted) return;
  state.submitted = true;
  disableLeaveWarning();
  const payload = buildPayload();
  try {
    await fetch('/api/submit', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload),
    });
  } catch (e) {
    console.warn('Server submit failed:', e);
  }
  state._payload = payload;
  state.step = 'complete';
  renderApp();
}

function renderComplete() {
  return `
    <div class="step-wrap">
      <div class="card">
        <div class="complete-screen">
          <div class="complete-icon">🎉</div>
          <h2 class="complete-title">${t('completeTitle')}</h2>
          <p class="complete-desc" style="white-space:pre-line">${t('completeDesc')}</p>
        </div>
      </div>
    </div>
  `;
}

function bindComplete() {}

// ──────────────────────────────────────────
// Navigation & utilities
// ──────────────────────────────────────────
function goStep(n) {
  state.step = n;
  renderApp();
  window.scrollTo({ top: 0, behavior: 'smooth' });
}

function enableLeaveWarning() {
  window._leaveHandler = e => { e.preventDefault(); e.returnValue = t('leaveWarning'); };
  window.addEventListener('beforeunload', window._leaveHandler);
}

function disableLeaveWarning() {
  if (window._leaveHandler) {
    window.removeEventListener('beforeunload', window._leaveHandler);
    window._leaveHandler = null;
  }
}

function escHtml(str) {
  return String(str)
    .replace(/&/g, '&amp;').replace(/</g, '&lt;')
    .replace(/>/g, '&gt;').replace(/"/g, '&quot;');
}

document.addEventListener('DOMContentLoaded', renderApp);