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

const PER_PAGE = 8;
const WATCHED = false;
let currentPage = 1;
let linksData = [];

function extractReelId(url) {
  // Example: https://www.instagram.com/reel/ABC123xyz/
  const match = url.match(/instagram\.com\/reel\/([a-zA-Z0-9_-]+)/);
  return match ? match[1] : null;
}

function loadLinks() {
  const cacheKeyWatched = `links_cache_page_${currentPage}_per_${PER_PAGE}&watched='true'`;
  const cachedWatched = localStorage.getItem(cacheKeyWatched);

  const cacheKey = `links_cache_page_${currentPage}_per_${PER_PAGE}`;
  const cached = localStorage.getItem(cacheKey);

  if (cachedWatched) {
    const data = JSON.parse(cachedWatched);
    linksData = data.results;
    renderPaginatedList(
      linksData,watchedLinksContainer,true,data.page,data.pages
    );
  }

  if (cached) {
    const data = JSON.parse(cached);
    linksData = data.results;
    renderPaginatedList(
      linksData,watchedLinksContainer,true,data.page,data.pages
    );
  }

  // Always fetch fresh data in the background
  fetch(`/api/links/?page=${currentPage}&per_page=${PER_PAGE}&watched='true'`)
    .then(response => response.json())
    .then(data => {
      localStorage.setItem(cacheKeyWatched, JSON.stringify(data));
      if (!cachedWatched) {
        linksData = data.results;
        renderPaginatedList(
          linksData,watchedLinksContainer,true,data.page,data.pages
        );
      }
    })
    .catch(err => console.error(err));

  fetch(`/api/links/?page=${currentPage}&per_page=${PER_PAGE}`)
    .then(response => response.json())
    .then(data => {
      localStorage.setItem(cacheKey, JSON.stringify(data));
      if (!cached) {
        linksData = data.results;
        renderPaginatedList(
          linksData,newLinksContainer,false,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 column = document.createElement('div');
      column.className = 'col-12 col-sm-6 col-md-4 col-lg-3';
      column.appendChild(createLinkElement(link, isWatched));
      row.appendChild(column);
    });

  container.appendChild(row);

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

    const previousBtn = document.createElement('button');
    previousBtn.innerText = '← Previous';
    previousBtn.className = 'btn btn-outline-primary';
    previousBtn.disabled = page <= 1;
    previousBtn.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();
    };

    navigation.appendChild(previousBtn);
    navigation.appendChild(nextBtn);
    container.appendChild(navigation);
  }

  reinitializeInstagramEmbeds();
}

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

  const reelId = extractReelId(link.url);
  if (!reelId) {
    wrapper.innerText = 'Invalid Instagram Reel URL';
    return wrapper;
  }

  // Clean iframe embed
  const iframeWrapper = document.createElement('div');
  iframeWrapper.style.width = '100%';
  iframeWrapper.style.height = '600px';
  iframeWrapper.style.overflow = 'hidden';
  iframeWrapper.style.borderRadius = '10px';

  const iframe = document.createElement('iframe');
  iframe.src = `https://www.instagram.com/reel/${reelId}/embed`;
  iframe.width = '100%';
  iframe.height = '700'; // taller to allow for cropping
  iframe.style.border = 'none';
  iframe.allow="fullscreen";
  iframe.loading = 'lazy';

  iframeWrapper.appendChild(iframe);
  wrapper.appendChild(iframeWrapper);

  const btnGroup = document.createElement('div');
  btnGroup.className = 'mt-2 d-flex gap-2';


  // 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);
    btnGroup.appendChild(watchButton);
  }

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

  wrapper.appendChild(btnGroup);

  return wrapper;
}

function deleteLink(linkId) {
  fetch(`/api/links/${linkId}/delete/`, {
    method: 'DELETE'
  })
  .then(response => {
    if (response.ok) {
      linksData = linksData.filter(link => link.id !== linkId);
      currentPage = 1;
      loadLinks();
      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(response => response.json())
    .then(updatedLink => {
      // Update the local array
      const idx = linksData.findIndex(link => link.id === updatedLink.id);
      if (idx !== -1) {
        linksData[idx] = updatedLink;
      }
      loadLinks();
      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(response => response.json())
    .then(addedLink => {
      // update local data
      linksData.push(addedLink);
      newLinkInput.value = '';
      currentPage = 1;
      loadLinks();
      reinitializeInstagramEmbeds();
    })
    .catch(err => console.error(err));
});

// On page load
loadLinks();