import { showAlert } from '../ui.js';
import { downloadFile, formatBytes } from '../utils/helpers.js';
import { PDFDocument, PDFName } from 'pdf-lib';
import { icons, createIcons } from 'lucide';
import { loadPdfWithPasswordPrompt } from '../utils/password-prompt.js';

interface PageState {
  file: File | null;
}

const pageState: PageState = {
  file: null,
};

function removeMetadataFromDoc(pdfDoc: PDFDocument) {
  // @ts-expect-error getInfoDict is private but accessible at runtime
  const infoDict = pdfDoc.getInfoDict();
  const allKeys = infoDict.keys();
  allKeys.forEach((key: { asString: () => string }) => {
    infoDict.delete(key);
  });

  pdfDoc.setTitle('');
  pdfDoc.setAuthor('');
  pdfDoc.setSubject('');
  pdfDoc.setKeywords([]);
  pdfDoc.setCreator('');
  pdfDoc.setProducer('');

  try {
    // @ts-expect-error catalog.dict is private but accessible at runtime
    const catalogDict = pdfDoc.catalog.dict;
    if (catalogDict.has(PDFName.of('Metadata'))) {
      catalogDict.delete(PDFName.of('Metadata'));
    }
  } catch (e: unknown) {
    const msg = e instanceof Error ? e.message : String(e);
    console.warn('Could not remove XMP metadata:', msg);
  }

  try {
    const context = pdfDoc.context;
    if (context.trailerInfo) {
      delete context.trailerInfo.ID;
    }
  } catch (e: unknown) {
    const msg = e instanceof Error ? e.message : String(e);
    console.warn('Could not remove document IDs:', msg);
  }

  try {
    // @ts-expect-error catalog.dict is private but accessible at runtime
    const catalogDict = pdfDoc.catalog.dict;
    if (catalogDict.has(PDFName.of('PieceInfo'))) {
      catalogDict.delete(PDFName.of('PieceInfo'));
    }
  } catch (e: unknown) {
    const msg = e instanceof Error ? e.message : String(e);
    console.warn('Could not remove PieceInfo:', msg);
  }
}

function resetState() {
  pageState.file = null;

  const fileDisplayArea = document.getElementById('file-display-area');
  if (fileDisplayArea) fileDisplayArea.innerHTML = '';

  const toolOptions = document.getElementById('tool-options');
  if (toolOptions) toolOptions.classList.add('hidden');

  const fileInput = document.getElementById('file-input') as HTMLInputElement;
  if (fileInput) fileInput.value = '';
}

async function updateUI() {
  const fileDisplayArea = document.getElementById('file-display-area');
  const toolOptions = document.getElementById('tool-options');

  if (!fileDisplayArea) return;

  fileDisplayArea.innerHTML = '';

  if (pageState.file) {
    const fileDiv = document.createElement('div');
    fileDiv.className =
      'flex items-center justify-between bg-gray-700 p-3 rounded-lg text-sm';

    const infoContainer = document.createElement('div');
    infoContainer.className = 'flex flex-col overflow-hidden';

    const nameSpan = document.createElement('div');
    nameSpan.className = 'truncate font-medium text-gray-200 text-sm mb-1';
    nameSpan.textContent = pageState.file.name;

    const metaSpan = document.createElement('div');
    metaSpan.className = 'text-xs text-gray-400';
    metaSpan.textContent = formatBytes(pageState.file.size);

    infoContainer.append(nameSpan, metaSpan);

    const removeBtn = document.createElement('button');
    removeBtn.className = 'ml-4 text-red-400 hover:text-red-300 flex-shrink-0';
    removeBtn.innerHTML = '<i data-lucide="trash-2" class="w-4 h-4"></i>';
    removeBtn.onclick = function () {
      resetState();
    };

    fileDiv.append(infoContainer, removeBtn);
    fileDisplayArea.appendChild(fileDiv);
    createIcons({ icons });

    if (toolOptions) toolOptions.classList.remove('hidden');
  } else {
    if (toolOptions) toolOptions.classList.add('hidden');
  }
}

function handleFileSelect(files: FileList | null) {
  if (files && files.length > 0) {
    const file = files[0];
    if (
      file.type === 'application/pdf' ||
      file.name.toLowerCase().endsWith('.pdf')
    ) {
      pageState.file = file;
      updateUI();
    }
  }
}

async function removeMetadata() {
  if (!pageState.file) {
    showAlert('No File', 'Please upload a PDF file first.');
    return;
  }

  const loaderModal = document.getElementById('loader-modal');
  const loaderText = document.getElementById('loader-text');
  if (loaderModal) loaderModal.classList.remove('hidden');
  if (loaderText) loaderText.textContent = 'Removing all metadata...';

  try {
    if (loaderModal) loaderModal.classList.add('hidden');
    const result = await loadPdfWithPasswordPrompt(pageState.file);
    if (!result) {
      if (loaderModal) loaderModal.classList.add('hidden');
      return;
    }
    if (loaderModal) loaderModal.classList.remove('hidden');
    if (loaderText) loaderText.textContent = 'Removing all metadata...';
    result.pdf.destroy();
    const pdfDoc = await PDFDocument.load(result.bytes, {
      ignoreEncryption: true,
    });

    removeMetadataFromDoc(pdfDoc);

    const newPdfBytes = await pdfDoc.save();
    downloadFile(
      new Blob([newPdfBytes as BlobPart], { type: 'application/pdf' }),
      'metadata-removed.pdf'
    );
    showAlert('Success', 'Metadata removed successfully!', 'success', () => {
      resetState();
    });
  } catch (e) {
    console.error(e);
    showAlert('Error', 'An error occurred while trying to remove metadata.');
  } finally {
    if (loaderModal) loaderModal.classList.add('hidden');
  }
}

document.addEventListener('DOMContentLoaded', function () {
  const fileInput = document.getElementById('file-input') as HTMLInputElement;
  const dropZone = document.getElementById('drop-zone');
  const processBtn = document.getElementById('process-btn');
  const backBtn = document.getElementById('back-to-tools');

  if (backBtn) {
    backBtn.addEventListener('click', function () {
      window.location.href = import.meta.env.BASE_URL;
    });
  }

  if (fileInput && dropZone) {
    fileInput.addEventListener('change', function (e) {
      handleFileSelect((e.target as HTMLInputElement).files);
    });

    dropZone.addEventListener('dragover', function (e) {
      e.preventDefault();
      dropZone.classList.add('bg-gray-700');
    });

    dropZone.addEventListener('dragleave', function (e) {
      e.preventDefault();
      dropZone.classList.remove('bg-gray-700');
    });

    dropZone.addEventListener('drop', function (e) {
      e.preventDefault();
      dropZone.classList.remove('bg-gray-700');
      const files = e.dataTransfer?.files;
      if (files && files.length > 0) {
        const pdfFiles = Array.from(files).filter(function (f) {
          return (
            f.type === 'application/pdf' ||
            f.name.toLowerCase().endsWith('.pdf')
          );
        });
        if (pdfFiles.length > 0) {
          const dataTransfer = new DataTransfer();
          dataTransfer.items.add(pdfFiles[0]);
          handleFileSelect(dataTransfer.files);
        }
      }
    });

    fileInput.addEventListener('click', function () {
      fileInput.value = '';
    });
  }

  if (processBtn) {
    processBtn.addEventListener('click', removeMetadata);
  }
});