const newLinkInput = document.getElementById('newLinkInput');
const addLinkBtn = document.getElementById('addLinkBtn');
const newLinksContainer = document.getElementById('newLinksContainer');
const watchedLinksContainer = document.getElementById('watchedLinksContainer');

const PER_PAGE = 8;
let currentPage = 1;

function loadLinks() {
  fetch('/api/links/?page=${currentPage}&per_page=${PER_PAGE}')
    .then(res => res.json())
    .then(data => {
      linksData = data.results;
      renderPaginatedList(linksData, newLinksContainer, false, data.page, data.pages);
      renderPaginatedList(linksData.filter(l => l.watched), watchedLinksContainer, true, data.page, data.pages);
    })
    .catch(err => console.error(err));
}

function renderPaginatedList(linkList, container, isWatched, page, totalPages) {
  container.innerHTML = '';

  const row = document.createElement('div');
  row.className = 'row gy-4';

  linkList
    .filter(link => link.watched === isWatched)
    .forEach(link => {
      const col = document.createElement('div');
      col.className = 'col-12 col-sm-6 col-md-4 col-lg-3';
      col.appendChild(createLinkElement(link, isWatched));
      row.appendChild(col);
    });

  container.appendChild(row);

  // Pagination controls
  if (totalPages > 1) {
    const nav = document.createElement('div');
    nav.className = 'd-flex justify-content-center mt-4 gap-2';

    const prevBtn = document.createElement('button');
    prevBtn.innerText = '← Previous';
    prevBtn.className = 'btn btn-outline-primary';
    prevBtn.disabled = page <= 1;
    prevBtn.onclick = () => {
      currentPage--;
      loadLinks();
    };

    const nextBtn = document.createElement('button');
    nextBtn.innerText = 'Next →';
    nextBtn.className = 'btn btn-outline-primary';
    nextBtn.disabled = page >= totalPages;
    nextBtn.onclick = () => {
      currentPage++;
      loadLinks();
    };

    nav.appendChild(prevBtn);
    nav.appendChild(nextBtn);
    container.appendChild(nav);
  }

  reinitializeInstagramEmbeds();
}

// Create a DOM element for a single link
function createLinkElement(link, isWatched) {
  const wrapper = document.createElement('div');
  wrapper.className = 'mb-3';

  // Instagram embed blockquote
  const blockquote = document.createElement('blockquote');
  blockquote.className = 'instagram-media';
  blockquote.setAttribute('data-instgrm-permalink', link.url);
  blockquote.style.background = '#FFF';

  const p = document.createElement('p');
  p.innerText = 'Loading Instagram...';
  blockquote.appendChild(p);
  wrapper.appendChild(blockquote);

  // Button to mark watched if it's not watched
  if (!isWatched) {
    const watchButton = document.createElement('button');
    watchButton.className = 'btn btn-sm btn-secondary';
    watchButton.innerText = 'Mark Watched';
    watchButton.onclick = () => markLinkWatched(link.id);
    wrapper.appendChild(watchButton);
  }

  // Delete button
  const deleteButton = document.createElement('button');
  deleteButton.innerText = 'Delete';
  deleteButton.className = 'btn btn-sm btn-danger';
  deleteButton.onclick = () => deleteLink(link.id);
  wrapper.appendChild(deleteButton);

  return wrapper;
}

function deleteLink(linkId) {
  fetch(`/api/links/${linkId}/delete/`, {
    method: 'DELETE'
  })
  .then(res => {
    if (res.ok) {
      linksData = linksData.filter(link => link.id !== linkId);
      currentPage = 1;
      renderPaginatedList();
      reinitializeInstagramEmbeds();
    }
  })
  .catch(err => console.error(err));
}

// Re-run the Instagram embed script after we’ve injected new blockquotes
function reinitializeInstagramEmbeds() {
  if (window.instgrm) {
    window.instgrm.Embeds.process();
  }
}

// Mark a link as watched
function markLinkWatched(linkId) {
  fetch(`/api/links/${linkId}/watched/`, {
    method: 'PATCH'
  })
    .then(res => res.json())
    .then(updatedLink => {
      // Update the local array
      const idx = linksData.findIndex(l => l.id === updatedLink.id);
      if (idx !== -1) {
        linksData[idx] = updatedLink;
      }
      renderPaginatedList();
      reinitializeInstagramEmbeds();
    })
    .catch(err => console.error(err));
}

// Add new link
addLinkBtn.addEventListener('click', () => {
  const newUrl = newLinkInput.value.trim();
  if (!newUrl) return;

  fetch('/api/links/add/', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ url: newUrl })
  })
    .then(res => res.json())
    .then(addedLink => {
      // update local data
      linksData.push(addedLink);
      newLinkInput.value = '';
      currentPage = 1;
      renderPaginatedList();
      reinitializeInstagramEmbeds();
    })
    .catch(err => console.error(err));
});

// On page load
loadLinks();