const API = '/api';
let state = {
  categories: [],
  activeCategoryId: null,
  subcategories: [],
  activeSubcategoryId: null,
  links: []
};

const globeSVG = `<svg class="globe-icon" viewBox="0 0 20 20" fill="none" xmlns="http://www.w3.org/2000/svg">
  <circle cx="10" cy="10" r="9" stroke="#e8722a" stroke-width="1"/>
  <ellipse cx="10" cy="10" rx="4.5" ry="9" stroke="#e8722a" stroke-width="1"/>
  <line x1="1" y1="7" x2="19" y2="7" stroke="#e8722a" stroke-width="1"/>
  <line x1="1" y1="13" x2="19" y2="13" stroke="#e8722a" stroke-width="1"/>
  <line x1="10" y1="1" x2="10" y2="19" stroke="#e8722a" stroke-width="1"/>
</svg>`;

// Sortable instances — kept so we can destroy/recreate on re-render
let categorySortable = null;
let subcategorySortable = null;
let linkSortable = null;

async function api(method, path, body) {
  const opts = {
    method,
    headers: body ? { 'Content-Type': 'application/json' } : {}
  };
  if (body) opts.body = JSON.stringify(body);
  const res = await fetch(API + path, opts);
  if (!res.ok) throw new Error(await res.text());
  return res.json();
}

const get = (path) => api('GET', path);
const post = (path, body) => api('POST', path, body);
const put = (path, body) => api('PUT', path, body);
const del = (path) => api('DELETE', path);

async function reorder(type, ids) {
  await put('/reorder', { type, ids });
}

async function loadCategories() {
  state.categories = await get('/categories');
  renderCategoryNav();
  if (state.categories.length > 0) {
    await selectCategory(
      state.activeCategoryId && state.categories.find(c => c.id === state.activeCategoryId)
        ? state.activeCategoryId
        : state.categories[0].id
    );
  }
}

function renderCategoryNav() {
  const nav = document.getElementById('category-nav');
  nav.innerHTML = '';

  state.categories.forEach(cat => {
    const btn = document.createElement('button');
    btn.className = 'cat-tab' + (cat.id === state.activeCategoryId ? ' active' : '');
    btn.dataset.id = cat.id;
    btn.innerHTML = `<i class="ti ${cat.icon || 'ti-folder'}"></i>${cat.name}`;
    btn.onclick = () => selectCategory(cat.id);
    btn.oncontextmenu = (e) => { e.preventDefault(); openEditCategoryModal(cat); };
    nav.appendChild(btn);
  });

  // Destroy old instance before creating new one
  if (categorySortable) categorySortable.destroy();
  categorySortable = Sortable.create(nav, {
    animation: 150,
    ghostClass: 'sortable-ghost',
    chosenClass: 'sortable-chosen',
    onEnd: async (evt) => {
      const ids = [...nav.querySelectorAll('button[data-id]')]
        .map(el => parseInt(el.dataset.id));
      state.categories = ids.map((id, i) => {
        const cat = state.categories.find(c => c.id === id);
        return { ...cat, position: i };
      });
      await reorder('categories', ids);
    }
  });
}

async function selectCategory(id) {
  state.activeCategoryId = id;
  state.subcategories = await get('/subcategories/' + id);
  state.activeSubcategoryId = null;
  renderCategoryNav();
  renderSubcategoryBar();
  if (state.subcategories.length > 0) {
    await selectSubcategory(state.subcategories[0].id);
  } else {
    state.links = [];
    renderLinkGrid();
  }
}

function renderSubcategoryBar() {
  const bar = document.getElementById('subcategory-bar');
  bar.innerHTML = '';

  state.subcategories.forEach(sub => {
    const btn = document.createElement('button');
    btn.className = 'sub-tab' + (sub.id === state.activeSubcategoryId ? ' active' : '');
    btn.dataset.id = sub.id;
    btn.textContent = sub.name;
    btn.onclick = () => selectSubcategory(sub.id);
    btn.oncontextmenu = (e) => { e.preventDefault(); openEditSubcategoryModal(sub); };
    bar.appendChild(btn);
  });

  const addBtn = document.createElement('button');
  addBtn.className = 'btn-add-sub';
  addBtn.id = 'add-sub-btn';
  addBtn.innerHTML = '<i class="ti ti-plus"></i> Add subcategory';
  addBtn.onclick = () => openAddSubcategoryModal();
  bar.appendChild(addBtn);

  if (subcategorySortable) subcategorySortable.destroy();
  subcategorySortable = Sortable.create(bar, {
    animation: 150,
    ghostClass: 'sortable-ghost',
    chosenClass: 'sortable-chosen',
    filter: '#add-sub-btn',
    onEnd: async (evt) => {
      const ids = [...bar.querySelectorAll('button[data-id]')]
        .map(el => parseInt(el.dataset.id));
      state.subcategories = ids.map((id, i) => {
        const sub = state.subcategories.find(s => s.id === id);
        return { ...sub, position: i };
      });
      await reorder('subcategories', ids);
    }
  });
}

async function selectSubcategory(id) {
  state.activeSubcategoryId = id;
  state.links = await get('/links/' + id);
  renderSubcategoryBar();
  renderLinkGrid();
}

function renderLinkGrid() {
  const grid = document.getElementById('link-grid');
  grid.innerHTML = '';

  state.links.forEach(link => {
    const a = document.createElement('a');
    a.className = 'link-card';
    a.href = link.url;
    a.target = '_blank';
    a.rel = 'noopener noreferrer';
    a.dataset.id = link.id;

    const favicon = document.createElement('div');
    favicon.className = 'link-favicon';
    if (link.favicon) {
      const img = document.createElement('img');
      img.src = '/favicons/' + link.favicon;
      img.width = 20;
      img.height = 20;
      img.onerror = () => { favicon.innerHTML = globeSVG; };
      favicon.appendChild(img);
    } else {
      favicon.innerHTML = globeSVG;
    }

    const label = document.createElement('span');
    label.className = 'link-label';
    label.textContent = link.label;

    const actions = document.createElement('div');
    actions.className = 'link-actions';
    actions.innerHTML = `
      <button class="link-action-btn" title="Edit" onclick="openEditLinkModal(${JSON.stringify(link).replace(/"/g, '&quot;')}, event)">
        <i class="ti ti-pencil"></i>
      </button>
      <button class="link-action-btn" title="Delete" onclick="deleteLink(${link.id}, event)">
        <i class="ti ti-trash"></i>
      </button>
    `;

    a.appendChild(favicon);
    a.appendChild(label);
    a.appendChild(actions);
    grid.appendChild(a);
  });

  const addCard = document.createElement('button');
  addCard.className = 'add-link-card';
  addCard.id = 'add-link-card';
  addCard.innerHTML = '<i class="ti ti-plus"></i> Add link';
  addCard.onclick = () => openAddLinkModal();
  grid.appendChild(addCard);

  if (linkSortable) linkSortable.destroy();
  linkSortable = Sortable.create(grid, {
    animation: 150,
    ghostClass: 'sortable-ghost',
    chosenClass: 'sortable-chosen',
    filter: '#add-link-card',
    draggable: 'a.link-card',
    onEnd: async (evt) => {
      const ids = [...grid.querySelectorAll('a.link-card[data-id]')]
        .map(el => parseInt(el.dataset.id));
      state.links = ids.map((id, i) => {
        const link = state.links.find(l => l.id === id);
        return { ...link, position: i };
      });
      await reorder('links', ids);
    }
  });
}

function openModal(title, bodyHTML, onConfirm) {
  document.getElementById('modal-title').textContent = title;
  document.getElementById('modal-body').innerHTML = bodyHTML + `
    <div class="modal-actions">
      <button class="btn-secondary" id="modal-cancel">Cancel</button>
      <button class="btn-primary" id="modal-confirm">Save</button>
    </div>
  `;
  document.getElementById('modal-overlay').classList.remove('hidden');
  document.getElementById('modal-cancel').onclick = closeModal;
  document.getElementById('modal-close').onclick = closeModal;
  document.getElementById('modal-confirm').onclick = onConfirm;
}

function closeModal() {
  document.getElementById('modal-overlay').classList.add('hidden');
}

function openAddCategoryModal() {
  openModal('Add category', `
    <div class="field">
      <label>Name</label>
      <input type="text" id="f-name" placeholder="Homelab" />
    </div>
    <div class="field">
      <label>Icon (Tabler icon name)</label>
      <input type="text" id="f-icon" placeholder="ti-server" />
    </div>
  `, async () => {
    const name = document.getElementById('f-name').value.trim();
    const icon = document.getElementById('f-icon').value.trim();
    if (!name) return;
    await post('/categories', { name, icon, position: state.categories.length });
    closeModal();
    await loadCategories();
  });
}

function openEditCategoryModal(cat) {
  openModal('Edit category', `
    <div class="field">
      <label>Name</label>
      <input type="text" id="f-name" value="${cat.name}" />
    </div>
    <div class="field">
      <label>Icon (Tabler icon name)</label>
      <input type="text" id="f-icon" value="${cat.icon || ''}" />
    </div>
    <div class="modal-actions" style="justify-content:flex-start; margin-top:0">
      <button class="btn-secondary" style="color:#e8722a;border-color:#e8722a"
        onclick="deleteCategory(${cat.id})">Delete category</button>
    </div>
  `, async () => {
    const name = document.getElementById('f-name').value.trim();
    const icon = document.getElementById('f-icon').value.trim();
    if (!name) return;
    await put('/categories/' + cat.id, { name, icon, position: cat.position });
    closeModal();
    await loadCategories();
  });
}

function openAddSubcategoryModal() {
  openModal('Add subcategory', `
    <div class="field">
      <label>Name</label>
      <input type="text" id="f-name" placeholder="Self-hosted" />
    </div>
  `, async () => {
    const name = document.getElementById('f-name').value.trim();
    if (!name) return;
    await post('/subcategories', {
      category_id: state.activeCategoryId,
      name,
      position: state.subcategories.length
    });
    closeModal();
    await selectCategory(state.activeCategoryId);
  });
}

function openEditSubcategoryModal(sub) {
  openModal('Edit subcategory', `
    <div class="field">
      <label>Name</label>
      <input type="text" id="f-name" value="${sub.name}" />
    </div>
    <div class="modal-actions" style="justify-content:flex-start; margin-top:0">
      <button class="btn-secondary" style="color:#e8722a;border-color:#e8722a"
        onclick="deleteSubcategory(${sub.id})">Delete subcategory</button>
    </div>
  `, async () => {
    const name = document.getElementById('f-name').value.trim();
    if (!name) return;
    await put('/subcategories/' + sub.id, {
      category_id: state.activeCategoryId,
      name,
      position: sub.position
    });
    closeModal();
    await selectCategory(state.activeCategoryId);
  });
}

function openAddLinkModal() {
  openModal('Add link', `
    <div class="field">
      <label>Label</label>
      <input type="text" id="f-label" placeholder="Forgejo" />
    </div>
    <div class="field">
      <label>URL</label>
      <input type="text" id="f-url" placeholder="https://..." />
    </div>
    <div class="field">
      <label>Favicon filename (optional)</label>
      <input type="text" id="f-favicon" placeholder="forgejo.png" />
    </div>
  `, async () => {
    const label = document.getElementById('f-label').value.trim();
    const url = document.getElementById('f-url').value.trim();
    const favicon = document.getElementById('f-favicon').value.trim();
    if (!label || !url) return;
    await post('/links', {
      subcategory_id: state.activeSubcategoryId,
      label,
      url,
      favicon: favicon || null,
      position: state.links.length
    });
    closeModal();
    await selectSubcategory(state.activeSubcategoryId);
  });
}

function openEditLinkModal(link, e) {
  e.preventDefault();
  e.stopPropagation();
  openModal('Edit link', `
    <div class="field">
      <label>Label</label>
      <input type="text" id="f-label" value="${link.label}" />
    </div>
    <div class="field">
      <label>URL</label>
      <input type="text" id="f-url" value="${link.url}" />
    </div>
    <div class="field">
      <label>Favicon filename</label>
      <input type="text" id="f-favicon" value="${link.favicon || ''}" />
    </div>
    <div class="modal-actions" style="justify-content:flex-start; margin-top:0">
      <button class="btn-secondary" style="color:#e8722a;border-color:#e8722a"
        onclick="deleteLink(${link.id}, event)">Delete link</button>
    </div>
  `, async () => {
    const label = document.getElementById('f-label').value.trim();
    const url = document.getElementById('f-url').value.trim();
    const favicon = document.getElementById('f-favicon').value.trim();
    if (!label || !url) return;
    await put('/links/' + link.id, {
      subcategory_id: state.activeSubcategoryId,
      label,
      url,
      favicon: favicon || null,
      position: link.position
    });
    closeModal();
    await selectSubcategory(state.activeSubcategoryId);
  });
}

async function deleteCategory(id) {
  closeModal();
  await del('/categories/' + id);
  state.activeCategoryId = null;
  await loadCategories();
}

async function deleteSubcategory(id) {
  closeModal();
  await del('/subcategories/' + id);
  await selectCategory(state.activeCategoryId);
}

async function deleteLink(id, e) {
  e.preventDefault();
  e.stopPropagation();
  await del('/links/' + id);
  await selectSubcategory(state.activeSubcategoryId);
}

document.getElementById('search-form').addEventListener('submit', (e) => {
  e.preventDefault();
  const q = document.getElementById('search-input').value.trim();
  if (q) window.open('https://kagi.com/search?q=' + encodeURIComponent(q), '_blank');
});

document.getElementById('add-category-btn').onclick = openAddCategoryModal;

document.getElementById('modal-overlay').addEventListener('click', (e) => {
  if (e.target === document.getElementById('modal-overlay')) closeModal();
});

loadCategories();

// Export
function exportBookmarks(format) {
  document.getElementById('export-dropdown').classList.remove('open');
  const a = document.createElement('a');
  a.href = API + '/export/' + format;
  a.download = format === 'json' ? 'startpage-bookmarks.json' : 'startpage-bookmarks.html';
  document.body.appendChild(a);
  a.click();
  document.body.removeChild(a);
}

// Export dropdown toggle
document.getElementById('export-btn').addEventListener('click', (e) => {
  e.stopPropagation();
  document.getElementById('export-dropdown').classList.toggle('open');
});

document.addEventListener('click', () => {
  document.getElementById('export-dropdown').classList.remove('open');
});

// Import
function triggerImport() {
  document.getElementById('export-dropdown').classList.remove('open');
  document.getElementById('import-file-input').click();
}

document.getElementById('import-file-input').addEventListener('change', async (e) => {
  const file = e.target.files[0];
  if (!file) return;
  const formData = new FormData();
  formData.append('file', file);
  try {
    const res = await fetch(API + '/import/html', { method: 'POST', body: formData });
    if (!res.ok) throw new Error(await res.text());
    const result = await res.json();
    const i = result.imported;
    alert('Imported: ' + i.categories + ' categories, ' + i.subcategories + ' subcategories, ' + i.links + ' links.');
    await loadCategories();
  } catch (err) {
    alert('Import failed: ' + err.message);
  }
  e.target.value = '';
});