const $ = (id) => document.getElementById(id);
const state = { sessionId: null, isComplete: false };

const stageLabels = {
  intro: 'تمهيد', exploration: 'استكشاف', usecase: 'حالات الاستخدام',
  evaluation: 'تقييم', done: 'مكتمل'
};

$('start-btn').addEventListener('click', startSession);
$('project-title').addEventListener('keydown', e => { if (e.key === 'Enter') startSession(); });
$('send-btn').addEventListener('click', sendMessage);
$('input').addEventListener('keydown', e => {
  if (e.key === 'Enter' && !e.shiftKey) { e.preventDefault(); sendMessage(); }
});
$('input').addEventListener('input', e => {
  e.target.style.height = 'auto';
  e.target.style.height = Math.min(e.target.scrollHeight, 140) + 'px';
});
$('export-btn').addEventListener('click', () => {
  if (state.sessionId) window.open(`/report/${state.sessionId}`, '_blank');
});

async function startSession() {
  const title = $('project-title').value.trim();
  if (!title) { $('project-title').focus(); return; }
  $('start-btn').disabled = true;
  try {
    const res = await fetch('/api/start', {
      method: 'POST', headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ title })
    });
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || 'فشل');
    state.sessionId = data.sessionId;
    $('welcome').classList.add('hidden');
    $('app').classList.remove('hidden');
    $('project-name').textContent = title;
    addAgentMessage(data.reply, true);
    updateState(data);
  } catch (e) {
    alert('خطأ: ' + e.message);
    $('start-btn').disabled = false;
  }
}

async function sendMessage() {
  const input = $('input');
  const text = input.value.trim();
  if (!text || !state.sessionId) return;
  addUserMessage(text);
  input.value = '';
  input.style.height = 'auto';
  $('send-btn').disabled = true;
  const thinkingEl = addAgentMessage('يفكّر...', false, true);
  try {
    const res = await fetch('/api/message', {
      method: 'POST', headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ sessionId: state.sessionId, message: text })
    });
    const data = await res.json();
    if (!res.ok) throw new Error(data.error || 'فشل');
    thinkingEl.remove();
    addAgentMessage(data.reply, true);
    updateState(data);
  } catch (e) {
    thinkingEl.querySelector('.bubble').textContent = '⚠️ ' + e.message;
    thinkingEl.classList.remove('thinking');
  } finally {
    $('send-btn').disabled = false;
    $('input').focus();
  }
}

function addUserMessage(text) {
  const el = document.createElement('div');
  el.className = 'msg user';
  el.innerHTML = `<div class="avatar">أنا</div><div class="bubble"></div>`;
  el.querySelector('.bubble').textContent = text;
  $('messages').appendChild(el);
  scrollMsgs();
}

function addAgentMessage(text, typewriter = false, thinking = false) {
  document.querySelectorAll('.msg.agent.fresh').forEach(e => e.classList.remove('fresh'));
  const el = document.createElement('div');
  el.className = 'msg agent fresh' + (thinking ? ' thinking' : '');
  el.innerHTML = `<div class="avatar">AI</div><div class="bubble${thinking ? ' typing' : ''}"></div>`;
  $('messages').appendChild(el);
  const bubble = el.querySelector('.bubble');
  if (typewriter) typeText(bubble, text);
  else bubble.textContent = text;
  scrollMsgs();
  return el;
}

function typeText(el, text) {
  el.textContent = '';
  const cursor = document.createElement('span');
  cursor.className = 'cursor';
  el.appendChild(cursor);
  let i = 0;
  const speed = Math.max(8, Math.min(28, 1200 / text.length));
  const tick = () => {
    if (i < text.length) {
      cursor.insertAdjacentText('beforebegin', text[i]);
      i++;
      scrollMsgs();
      setTimeout(tick, speed);
    } else {
      cursor.remove();
    }
  };
  tick();
}

function scrollMsgs() {
  const m = $('messages');
  m.scrollTop = m.scrollHeight;
}

function updateState(data) {
  const fps = data.functionPoints || [];
  const ucs = data.useCases || [];
  const actors = data.actors || [];
  $('fp-count').textContent = fps.length;
  $('uc-count').textContent = ucs.length;
  $('fp-total').textContent = fps.reduce((s, f) => s + (Number(f.fpScore) || 0), 0);
  $('stage-pill').textContent = stageLabels[data.stage] || data.stage || '—';

  // Tree
  const tree = $('tree');
  if (!actors.length && !fps.length) {
    tree.innerHTML = '<div class="tree-empty">ستظهر الـ Actors والوظائف هنا تلقائياً.</div>';
  } else {
    let html = '';
    if (actors.length) {
      actors.forEach(a => {
        html += `<div class="tree-actor">${esc(a)}</div>`;
      });
    }
    fps.forEach(f => {
      html += `<div class="tree-fp">${esc(f.id || '')} · ${esc(f.name || '')}</div>`;
    });
    tree.innerHTML = html;
  }

  // Live preview
  const prev = $('preview-content');
  let html = '';
  if (data.scope) html += `<h3>نطاق النظام</h3><div class="scope">${esc(data.scope)}</div>`;
  if (actors.length) {
    html += `<h3>المستخدمون</h3><div class="scope">${actors.map(esc).join(' · ')}</div>`;
  }
  if (fps.length) {
    html += `<h3>المتطلبات الوظيفية (${fps.length})</h3>`;
    fps.forEach(f => {
      html += `<div class="uc-prev"><b>${esc(f.id || '')}</b> ${esc(f.name || '')} <span style="color:#888">— ${esc(f.complexity || '')} (FP ${esc(String(f.fpScore || ''))})</span></div>`;
    });
  }
  if (ucs.length) {
    html += `<h3>حالات الاستخدام (${ucs.length})</h3>`;
    ucs.forEach(u => {
      html += `<div class="uc-prev"><b>${esc(u.id || '')}</b> ${esc(u.title || '')}<br><span style="color:#888">الفاعل: ${esc(u.actor || '')}</span></div>`;
    });
  }
  prev.innerHTML = html || '<div class="preview-empty">سيتشكّل النص الهندسي للتقرير هنا أثناء الحوار.</div>';

  // Show export when there's enough content or marked complete
  if (data.isComplete || (fps.length >= 3 && ucs.length >= 1)) {
    $('export-btn').classList.remove('hidden');
  }
  state.isComplete = !!data.isComplete;
}

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