/* ──────────────────────────── Three.js 3D PDF icon ──── */
(function () {
  const container = document.getElementById('three-header');
  if (!container || typeof THREE === "undefined") return;

  const W = 120, H = 120;

  const renderer = new THREE.WebGLRenderer({ antialias: true, alpha: true });
  renderer.setPixelRatio(window.devicePixelRatio);
  renderer.setSize(W, H);
  container.appendChild(renderer.domElement);

  const scene = new THREE.Scene();
  const camera = new THREE.PerspectiveCamera(38, W / H, 0.1, 100);
  camera.position.set(0, 0, 5);

  scene.add(new THREE.AmbientLight(0xffffff, 0.6));
  const dirLight = new THREE.DirectionalLight(0xffffff, 0.9);
  dirLight.position.set(4, 6, 4);
  scene.add(dirLight);

  const bodyGeo = new THREE.BoxGeometry(1.4, 1.8, 0.12);
  const bodyMat = new THREE.MeshStandardMaterial({ color: 0xffffff });
  const body = new THREE.Mesh(bodyGeo, bodyMat);
  scene.add(body);

  const cornerShape = new THREE.Shape();
  cornerShape.moveTo(0, 0);
  cornerShape.lineTo(0.38, 0);
  cornerShape.lineTo(0, -0.38);
  cornerShape.closePath();

  const cornerGeo = new THREE.ExtrudeGeometry(cornerShape, { depth: 0.13, bevelEnabled: false });
  const cornerMat = new THREE.MeshStandardMaterial({ color: 0x5048c8 });
  const corner = new THREE.Mesh(cornerGeo, cornerMat);
  corner.position.set(0.7, 0.9, 0);
  scene.add(corner);

  const stripeGeo = new THREE.BoxGeometry(0.9, 0.06, 0.14);
  const stripeMat = new THREE.MeshStandardMaterial({ color: 0xe24b4a });

  [-0.2, 0.1, 0.4].forEach(y => {
    const s = new THREE.Mesh(stripeGeo, stripeMat);
    s.position.set(-0.12, y, 0);
    scene.add(s);
  });

  const planeGeo = new THREE.PlaneGeometry(1.45, 1.85);
  const planeMat = new THREE.MeshStandardMaterial({ color: 0x5048c8 });
  const plane = new THREE.Mesh(planeGeo, planeMat);
  plane.position.set(0.10, -0.10, -0.20);
  scene.add(plane);

  function animate() {
    requestAnimationFrame(animate);
    body.rotation.y += 0.012;
    corner.rotation.y = body.rotation.y;
    plane.rotation.y = body.rotation.y;
    scene.children.forEach(c => {
      if (c.isMesh) c.rotation.y = body.rotation.y;
    });
    renderer.render(scene, camera);
  }

  animate();
})();

/* ──────────────────────────── App state ───────────────── */
const FREE_LIMIT = 15;
let selectedFiles = [];

const dropZone = document.getElementById('drop-zone');
const fileInput = document.getElementById('file-input');
const previewGrid = document.getElementById('preview-grid');
const counterBar = document.getElementById('counter-bar');
const countNum = document.getElementById('count-num');
const countDot = document.getElementById('count-dot');
const countLimit = document.getElementById('count-limit-text');
const convertBtn = document.getElementById('convert-btn');
const btnLabel = document.getElementById('btn-label');
const loadingBar = document.getElementById('loading-bar');
const clearBtn = document.getElementById('clear-btn');
const overlay = document.getElementById('overlay');
const toast = document.getElementById('toast');

if (dropZone && fileInput) {
  dropZone.addEventListener('dragover', e => {
    e.preventDefault();
    dropZone.classList.add('drag-over');
  });

  dropZone.addEventListener('dragleave', () => dropZone.classList.remove('drag-over'));

  dropZone.addEventListener('drop', e => {
    e.preventDefault();
    dropZone.classList.remove('drag-over');
    addFiles(e.dataTransfer.files);
  });

  fileInput.addEventListener('change', () => {
    addFiles(fileInput.files);
    fileInput.value = '';
  });
}

function addFiles(fileList) {
  const incoming = Array.from(fileList).filter(f => f.type.startsWith('image/'));
  const newTotal = selectedFiles.length + incoming.length;

  if (newTotal > FREE_LIMIT) {
    const allowed = incoming.slice(0, FREE_LIMIT - selectedFiles.length);
    allowed.forEach(pushFile);
    updateUI();
    showPremiumDialog();
    return;
  }

  incoming.forEach(pushFile);
  updateUI();
}

function pushFile(file) {
  const url = URL.createObjectURL(file);
  selectedFiles.push({ file, url });
}

function removeFile(index) {
  URL.revokeObjectURL(selectedFiles[index].url);
  selectedFiles.splice(index, 1);
  updateUI();
}

function clearAll() {
  selectedFiles.forEach(f => URL.revokeObjectURL(f.url));
  selectedFiles = [];
  updateUI();
}

function updateUI() {
  const n = selectedFiles.length;

  if (n > 0) {
    counterBar.classList.add('visible');
    countNum.textContent = n;
    countLimit.textContent = `${n} / ${FREE_LIMIT} free slots used`;

    if (countDot) {
      countDot.className = 'count-dot' + (n >= FREE_LIMIT ? ' danger' : n >= 10 ? ' warn' : '');
    }
  } else {
    counterBar.classList.remove('visible');
  }

  previewGrid.innerHTML = '';

  selectedFiles.forEach(({ url }, i) => {
    const item = document.createElement('div');
    item.className = 'preview-item';
    item.innerHTML = `
      <img src="${url}" alt="preview ${i + 1}" loading="lazy" />
      <span class="order-badge">${i + 1}</span>
      <button class="remove-btn" onclick="removeFile(${i})" title="Remove">
        <svg viewBox="0 0 24 24" fill="none" stroke-width="2.5" stroke-linecap="round">
          <line x1="18" y1="6" x2="6" y2="18"></line>
          <line x1="6" y1="6" x2="18" y2="18"></line>
        </svg>
      </button>
    `;
    previewGrid.appendChild(item);
  });

  convertBtn.disabled = n === 0;
  clearBtn.style.display = n > 0 ? 'block' : 'none';
}

async function convertToPDF() {
  if (selectedFiles.length === 0) {
    showToast("Please select at least one image.");
    return;
  }

  if (selectedFiles.length > FREE_LIMIT) {
    showPremiumDialog();
    return;
  }

  setLoading(true);

  const formData = new FormData();
  selectedFiles.forEach(({ file }) => {
    formData.append('images', file);
  });

  try {
    const res = await fetch('/convert', {
      method: 'POST',
      body: formData
    });

    const contentType = res.headers.get("content-type") || "";

    if (!res.ok) {
      let errorMessage = "Conversion failed.";

      if (contentType.includes("application/json")) {
        const json = await res.json();

        if (json.error === "limit_exceeded") {
          showPremiumDialog();
          errorMessage = json.message || "Free limit reached.";
        } else {
          errorMessage = json.error || json.message || errorMessage;
        }
      }

      showToast(errorMessage);
      return;
    }

    const blob = await res.blob();
    const url = window.URL.createObjectURL(blob);

    const a = document.createElement('a');
    a.href = url;
    a.download = 'converted.pdf';
    document.body.appendChild(a);
    a.click();
    a.remove();

    window.URL.revokeObjectURL(url);
    showToast('PDF downloaded successfully!');
  } catch (err) {
    console.error(err);
    showToast('Server error. Please try again.');
  } finally {
    setLoading(false);
  }
}

function setLoading(on) {
  convertBtn.disabled = on;
  btnLabel.style.display = on ? 'none' : 'inline';
  loadingBar.style.display = on ? 'block' : 'none';
}

function showPremiumDialog() {
  overlay.classList.add('show');
}

function closeDialog(e) {
  if (!e || e.target === overlay) {
    overlay.classList.remove('show');
  }
}

function showToast(msg) {
  toast.textContent = msg;
  toast.classList.add('show');
  setTimeout(() => toast.classList.remove('show'), 3000);
}

window.removeFile = removeFile;
window.clearAll = clearAll;
window.convertToPDF = convertToPDF;
window.closeDialog = closeDialog;
window.showToast = showToast;