async function postJson(url, body){
  const res = await fetch(url, {method:'POST', headers:{'Content-Type':'application/json'}, body: JSON.stringify(body)});
  const data = await res.json().catch(()=>({ok:false,error:'Respuesta inválida'}));
  if(!res.ok || !data.ok) throw new Error(data.error || 'Error');
  return data;
}

function addBubble(cls, text){
  const div = document.createElement('div');
  div.className = 'bubble ' + cls;
  div.textContent = text;
  document.getElementById('chatLog').appendChild(div);
  document.getElementById('chatLog').scrollTop = 999999;
}

let session = null;

function levelHint(){
  return "Escala 0–4: 0=No existe, 1=Informal, 2=Parcial, 3=Definido+mensual, 4=Controlado+KPIs.";
}

function syncAnonUI(){
  const anon = document.getElementById('anon_mode').checked;
  const leadFields = document.getElementById('leadFields');
  const consent = document.getElementById('consent');
  if(anon){
    leadFields.style.display = 'none';
    consent.checked = false;
    consent.disabled = true;
  } else {
    leadFields.style.display = '';
    consent.disabled = false;
  }
}
document.getElementById('anon_mode').addEventListener('change', syncAnonUI);
syncAnonUI();

document.getElementById('btnStart').addEventListener('click', async ()=>{
  const msg0 = document.getElementById('msg0');
  msg0.textContent = '';
  try{
    const anon = document.getElementById('anon_mode').checked;
    const consent = (!anon && document.getElementById('consent').checked) ? 1 : 0;

    if(!anon && consent !== 1){
      throw new Error('Para registrar tus datos debes marcar el consentimiento. O activa modo anónimo.');
    }

    const payload = anon ? {
      anonymous: 1,
      tipo_negocio: document.getElementById('tipo_negocio').value,
      consent: 0
    } : {
      nombre: document.getElementById('nombre').value,
      email: document.getElementById('email').value,
      whatsapp: document.getElementById('whatsapp').value,
      negocio: document.getElementById('negocio').value,
      tipo_negocio: document.getElementById('tipo_negocio').value,
      consent
    };

    session = await postJson('../api/init_lead.php', payload);

    localStorage.setItem('sp_eval360_session', JSON.stringify({
      chat_session_id: session.chat_session_id,
      session_token: session.session_token,
      diagnosis_id: session.diagnosis_id,
      public_token: session.public_token
    }));

    document.getElementById('chatBox').style.display = 'block';
    addBubble('bot', 'Iniciemos el diagnóstico. Responde con números cuando aplique.');
    addBubble('bot', levelHint());

    const step = await postJson('../api/chat_step.php', {
      chat_session_id: session.chat_session_id,
      session_token: session.session_token
    });
    addBubble('bot', step.next.question);

  } catch(e){
    msg0.textContent = e.message;
  }
});

async function sendAnswer(){
  const msg = document.getElementById('msg');
  msg.textContent = '';
  try{
    if(!session) throw new Error('Inicia el chat primero.');
    const input = document.getElementById('answer');
    const a = input.value;
    if(a.trim() === '') return;

    input.value = '';
    addBubble('user', a);

    const step = await postJson('../api/chat_step.php', {
      chat_session_id: session.chat_session_id,
      session_token: session.session_token,
      answer: a
    });

    if(step.is_complete){
      addBubble('bot', 'Listo. Calculando resultados...');
      await postJson('../api/calc_score.php', {
        chat_session_id: session.chat_session_id,
        session_token: session.session_token,
        diagnosis_id: session.diagnosis_id
      });

      try { await postJson('../api/generate_plan.php', { diagnosis_id: session.diagnosis_id }); } catch(e){}

      window.location.href = 'result.php';
      return;
    }

    if(step.next && step.next.input_type === 'level'){
      addBubble('bot', levelHint());
    }
    addBubble('bot', step.next.question);

  } catch(e){
    msg.textContent = e.message;
  }
}

document.getElementById('send').addEventListener('click', sendAnswer);
document.getElementById('answer').addEventListener('keydown', (ev)=>{
  if(ev.key === 'Enter') sendAnswer();
});