document.addEventListener('DOMContentLoaded', () => {
  // --- Helper Functions ---
  function downloadBibtex(bibtexContent, filename) {
    if (!bibtexContent || !filename) {
      console.error('BibTeX content or filename missing for download.');
      alert('Could not prepare BibTeX for download.');
      return;
    }
    try {
      // Parse the JSON string to get the actual BibTeX content
      const parsedBibtexContent = JSON.parse(bibtexContent);
      const blob = new Blob([parsedBibtexContent], { type: 'application/x-bibtex;charset=utf-8' });
      const link = document.createElement('a');
      link.href = URL.createObjectURL(blob);
      link.download = filename;
      document.body.appendChild(link);
      link.click();
      document.body.removeChild(link);
      URL.revokeObjectURL(link.href);
    } catch (e) {
      console.error('Error parsing BibTeX JSON from data attribute for download:', e);
      alert('Could not prepare BibTeX for download. Invalid data format.');
    }
  }

  function copyToClipboard(bibtexJsonContent, buttonElement) {
    if (!bibtexJsonContent) {
      console.error('No BibTeX JSON content provided to copy.');
      return;
    }
    try {
      const textToCopy = JSON.parse(bibtexJsonContent); // Parse the JSON string
      navigator.clipboard.writeText(textToCopy).then(() => {
        if (buttonElement) {
          const originalText = buttonElement.innerHTML; // Store full HTML content
          buttonElement.innerHTML = '<i class="fas fa-check"></i> Copied!';
          buttonElement.disabled = true;
          setTimeout(() => {
            buttonElement.innerHTML = originalText;
            buttonElement.disabled = false;
          }, 2000);
        }
      }).catch(err => {
        console.error('Could not copy text: ', err);
        alert('Failed to copy BibTeX. Ensure you are on a secure connection (HTTPS) or check browser permissions.');
        // Basic fallback (less likely to be needed for navigator.clipboard modern support)
        try {
            const textArea = document.createElement('textarea');
            textArea.value = textToCopy;
            textArea.style.position = 'fixed'; // Avoid scrolling to bottom
            document.body.appendChild(textArea);
            textArea.focus();
            textArea.select();
            document.execCommand('copy');
            document.body.removeChild(textArea);
             if (buttonElement) {
                const originalText = buttonElement.innerHTML;
                buttonElement.innerHTML = '<i class="fas fa-check"></i> Copied (fallback)!';
                buttonElement.disabled = true;
                setTimeout(() => {
                    buttonElement.innerHTML = originalText;
                    buttonElement.disabled = false;
                }, 2000);
            }
        } catch (fallbackErr) {
            console.error('Fallback copy method failed:', fallbackErr);
        }
      });
    } catch (e) {
      console.error('Error parsing BibTeX JSON from data attribute for copy:', e);
      alert('Could not prepare BibTeX for copying. Invalid data format.');
    }
  }

  // --- Event Listeners ---

  // For "BibTeX Download" buttons
  document.querySelectorAll('.btnPub--bibtex-download-direct').forEach(button => {
    button.addEventListener('click', function() {
      const bibtexJson = this.dataset.bibtexJson;
      const bibtexFilename = this.dataset.bibtexFilename;
      downloadBibtex(bibtexJson, bibtexFilename);
    });
  });

  // For "Copy BibTeX" buttons
  document.querySelectorAll('.btnPub--bibtex-copy-direct').forEach(button => {
    button.addEventListener('click', function() {
      const bibtexJson = this.dataset.bibtexJson;
      copyToClipboard(bibtexJson, this);
    });
  });
});