window.API = {
  async get(url) { const r = await fetch(url,{credentials:'same-origin'}); if(!r.ok)throw new Error(await r.text()); return r.json(); },
  async post(url,data) { const r = await fetch(url,{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify(data),credentials:'same-origin'}); if(!r.ok)throw new Error(await r.text()); return r.json(); },
  async put(url,data) { const r = await fetch(url,{method:'PUT',headers:{'Content-Type':'application/json'},body:JSON.stringify(data),credentials:'same-origin'}); if(!r.ok)throw new Error(await r.text()); return r.json(); },
  async del(url) { const r = await fetch(url,{method:'DELETE',credentials:'same-origin'}); if(!r.ok)throw new Error(await r.text()); return r.json(); }
};

window.$ = (sel) => document.querySelector(sel);
window.$$ = (sel) => document.querySelectorAll(sel);

window.notify = function(msg, type) {
  var el = document.createElement('div');
  el.className = 'notification ' + (type || '');
  el.textContent = msg;
  document.body.appendChild(el);
  setTimeout(function() { el.remove(); }, 3000);
};

window.undoState = null;

window.updateUndoBar = function() {
  API.get('/api/undo/state').then(function(s) {
    undoState = s;
    var uBtn = $('.undo-btn');
    var rBtn = $('.redo-btn');
    var uLabel = $('.undo-label');
    if (uBtn) { uBtn.disabled = !s.can_undo; uBtn.title = s.undo_desc || ''; }
    if (rBtn) { rBtn.disabled = !s.can_redo; rBtn.title = s.redo_desc || ''; }
    if (uLabel) { uLabel.textContent = s.undo_desc || ''; }
  }).catch(function() {});
};

window.doUndo = function() {
  API.post('/api/undo/undo').then(function(r) { notify(r.message || 'Undo complete', 'success'); updateUndoBar(); if(r.has_duplicates) { window.location = '/'; return; } if(window.refreshPage)refreshPage(); }).catch(function(e) { notify('Undo failed: '+e.message, 'error'); });
};

window.doRedo = function() {
  API.post('/api/undo/redo').then(function(r) { notify(r.message || 'Redo complete', 'success'); updateUndoBar(); if(r.has_duplicates) { window.location = '/'; return; } if(window.refreshPage)refreshPage(); }).catch(function(e) { notify('Redo failed: '+e.message, 'error'); });
};

window.addEventListener('keydown', function(e) {
  if ((e.ctrlKey || e.metaKey) && e.key === 'z') {
    e.preventDefault();
    if (e.shiftKey) { doRedo(); } else { doUndo(); }
  }
});

window.saveForm = function(url, data, msg) {
  API.put(url, data).then(function() {
    updateUndoBar();
    notify(msg || 'Saved', 'success');
  }).catch(function(e) { notify('Save failed: '+e.message, 'error'); });
};

document.addEventListener('DOMContentLoaded', function() { updateUndoBar(); });