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>`;

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);
  });
  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);
  });
}

// Build the category+subcategory select HTML for link modals.
// selectedCatId / selectedSubId pre-select the dropdowns (used in edit mode).
function buildLocationFields(selectedCatId, selectedSubId) {
  const catOptions = state.categories.map(c =>
    `<option value="${c.id}" ${c.id === selectedCatId ? 'selected' : ''}>${c.name}</option>`
  ).join('');
  return `
    <div class="field">
      <label>Category</label>
      <select id="f-cat">${catOptions}</select>
    </div>
    <div class="field">
      <label>Subcategory</label>
      <select id="f-sub"><option value="">Loading…</option></select>
    </div>
  `;
}

// Populate the subcategory dropdown for the given category id.
// If targetSubId is provided, pre-select it.
async function populateSubSelect(catId, targetSubId) {
  const subEl = document.getElementById('f-sub');
  if (!subEl) return;
  subEl.innerHTML = '<option value="">Loading…</option>';
  const subs = await get('/subcategories/' + catId);
  if (subs.length === 0) {
    subEl.innerHTML = '<option value="">(no subcategories)</option>';
    return;
  }
  subEl.innerHTML = subs.map(s =>
    `<option value="${s.id}" ${s.id === targetSubId ? 'selected' : ''}>${s.name}</option>`
  ).join('');
}

function openAddLinkModal() {
  const defaultCatId = state.activeCategoryId || (state.categories[0] && state.categories[0].id);
  const defaultSubId = state.activeSubcategoryId;

  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>
    ${buildLocationFields(defaultCatId, defaultSubId)}
    <div class="field favicon-field">
      <label>Favicon</label>
      <div class="favicon-preview-row">
        <div id="f-favicon-preview" class="favicon-preview-box"></div>
        <span id="f-favicon-status" class="favicon-status"></span>
        <button type="button" class="btn-ghost favicon-upload-btn" id="f-favicon-upload-btn" style="display:none">
          <i class="ti ti-upload"></i> Upload manually
        </button>
        <input type="file" id="f-favicon-file" accept="image/*" style="display:none" />
        <input type="hidden" id="f-favicon" value="" />
      </div>
    </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();
    const subId = parseInt(document.getElementById('f-sub').value);
    if (!label || !url || !subId) return;
    // Find position: end of the target subcategory's links
    const targetLinks = await get('/links/' + subId);
    await post('/links', {
      subcategory_id: subId,
      label,
      url,
      favicon: favicon || null,
      position: targetLinks.length
    });
    closeModal();
    // If we added to the currently-viewed subcategory, refresh it; otherwise navigate there
    if (subId === state.activeSubcategoryId) {
      await selectSubcategory(state.activeSubcategoryId);
    } else {
      // Find the category for this subcategory and navigate
      const allCats = state.categories;
      for (const cat of allCats) {
        const subs = await get('/subcategories/' + cat.id);
        if (subs.find(s => s.id === subId)) {
          await selectCategory(cat.id);
          await selectSubcategory(subId);
          break;
        }
      }
    }
  });

  // Populate subcategory dropdown for the initial category
  populateSubSelect(defaultCatId, defaultSubId);

  // When category changes, reload subcategory dropdown
  setTimeout(() => {
    const catEl = document.getElementById('f-cat');
    if (catEl) {
      catEl.addEventListener('change', () => {
        populateSubSelect(parseInt(catEl.value), null);
      });
    }
  }, 0);

  setupFaviconFetch('f-url', 'f-favicon', 'f-favicon-preview', 'f-favicon-status', 'f-favicon-upload-btn', 'f-favicon-file');
}

async function openEditLinkModal(link, e) {
  e.preventDefault();
  e.stopPropagation();

  // Determine which category owns this link's subcategory so we can pre-select it
  let ownerCatId = state.activeCategoryId;
  // Search all categories for the one that contains link.subcategory_id
  for (const cat of state.categories) {
    const subs = await get('/subcategories/' + cat.id);
    if (subs.find(s => s.id === link.subcategory_id)) {
      ownerCatId = cat.id;
      break;
    }
  }

  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>
    ${buildLocationFields(ownerCatId, link.subcategory_id)}
    <div class="field favicon-field">
      <label>Favicon</label>
      <div class="favicon-preview-row">
        <div id="f-favicon-preview" class="favicon-preview-box"></div>
        <span id="f-favicon-status" class="favicon-status"></span>
        <button type="button" class="btn-ghost favicon-upload-btn" id="f-favicon-upload-btn" style="display:none">
          <i class="ti ti-upload"></i> Upload manually
        </button>
        <input type="file" id="f-favicon-file" accept="image/*" style="display:none" />
        <input type="hidden" id="f-favicon" value="${link.favicon || ''}" />
      </div>
    </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();
    const newSubId = parseInt(document.getElementById('f-sub').value);
    if (!label || !url || !newSubId) return;

    const isMoving = newSubId !== link.subcategory_id;
    let position = link.position;
    if (isMoving) {
      // Place at end of the destination subcategory
      const targetLinks = await get('/links/' + newSubId);
      position = targetLinks.length;
    }

    await put('/links/' + link.id, {
      subcategory_id: newSubId,
      label,
      url,
      favicon: favicon || null,
      position
    });
    closeModal();

    if (!isMoving) {
      // Same subcategory — just refresh current view
      await selectSubcategory(state.activeSubcategoryId);
    } else {
      // Link moved away — refresh current subcategory (link is gone from here)
      // Then optionally navigate to the destination
      await selectSubcategory(state.activeSubcategoryId);
    }
  });

  // Populate subcategory dropdown for the owner category
  populateSubSelect(ownerCatId, link.subcategory_id);

  // When category changes, reload subcategory dropdown
  setTimeout(() => {
    const catEl = document.getElementById('f-cat');
    if (catEl) {
      catEl.addEventListener('change', () => {
        populateSubSelect(parseInt(catEl.value), null);
      });
    }
  }, 0);

  setupFaviconFetch('f-url', 'f-favicon', 'f-favicon-preview', 'f-favicon-status', 'f-favicon-upload-btn', 'f-favicon-file', link.favicon);
}

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 = '';
});

// Favicon auto-fetch + manual upload helper
function setupFaviconFetch(urlId, faviconId, previewId, statusId, uploadBtnId, fileInputId, existingFavicon) {
  const urlEl = document.getElementById(urlId);
  const faviconEl = document.getElementById(faviconId);
  const previewEl = document.getElementById(previewId);
  const statusEl = document.getElementById(statusId);
  const uploadBtn = document.getElementById(uploadBtnId);
  const fileInput = document.getElementById(fileInputId);

  function showPreview(filename) {
    if (filename) {
      previewEl.innerHTML = '<img src="/favicons/' + filename + '" width="20" height="20" onerror="this.parentNode.innerHTML=\'<span style=opacity:.4>?</span>\'" />';
    } else {
      previewEl.innerHTML = '';
    }
  }

  if (existingFavicon) {
    showPreview(existingFavicon);
    statusEl.textContent = existingFavicon;
    uploadBtn.style.display = 'inline-flex';
  }

  async function doFetch(url) {
    if (!url || !url.startsWith('http')) return;
    statusEl.textContent = 'Fetching…';
    uploadBtn.style.display = 'none';
    try {
      const res = await fetch(API + '/favicons/fetch', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ url })
      });
      const data = await res.json();
      if (data.favicon) {
        faviconEl.value = data.favicon;
        showPreview(data.favicon);
        statusEl.textContent = data.favicon;
        uploadBtn.style.display = 'inline-flex';
      } else {
        faviconEl.value = '';
        previewEl.innerHTML = '';
        statusEl.textContent = 'Not found';
        uploadBtn.style.display = 'inline-flex';
      }
    } catch (err) {
      statusEl.textContent = 'Failed';
      uploadBtn.style.display = 'inline-flex';
    }
  }

  urlEl.addEventListener('blur', () => doFetch(urlEl.value.trim()));

  uploadBtn.addEventListener('click', () => fileInput.click());

  fileInput.addEventListener('change', async (e) => {
    const file = e.target.files[0];
    if (!file) return;
    const formData = new FormData();
    formData.append('file', file);
    statusEl.textContent = 'Uploading…';
    try {
      const res = await fetch(API + '/favicons/upload', { method: 'POST', body: formData });
      const data = await res.json();
      if (data.favicon) {
        faviconEl.value = data.favicon;
        showPreview(data.favicon);
        statusEl.textContent = data.favicon;
      }
    } catch (err) {
      statusEl.textContent = 'Upload failed';
    }
    e.target.value = '';
  });
}