import {
  formatBytes,
  readFileAsArrayBuffer,
  getPDFDocument,
} from '../utils/helpers';
import { initializeGlobalShortcuts } from '../utils/shortcuts-init.js';
import { createIcons, icons } from 'lucide';
import { loadPdfWithPasswordPrompt } from '../utils/password-prompt.js';

let selectedFile: File | null = null;
let viewerIframe: HTMLIFrameElement | null = null;
let currentBlobUrl: string | null = null;

const pdfInput = document.getElementById('pdfFile') as HTMLInputElement;
const fileListDiv = document.getElementById('fileList') as HTMLDivElement;
const viewerContainer = document.getElementById(
  'stamp-viewer-container'
) as HTMLDivElement;
const viewerCard = document.getElementById(
  'viewer-card'
) as HTMLDivElement | null;
const saveStampedBtn = document.getElementById(
  'save-stamped-btn'
) as HTMLButtonElement;
const backToToolsBtn = document.getElementById(
  'back-to-tools'
) as HTMLButtonElement | null;
const toolUploader = document.getElementById(
  'tool-uploader'
) as HTMLDivElement | null;
const usernameInput = document.getElementById(
  'stamp-username'
) as HTMLInputElement | null;

function resetState() {
  selectedFile = null;
  if (currentBlobUrl) {
    URL.revokeObjectURL(currentBlobUrl);
    currentBlobUrl = null;
  }
  if (
    viewerIframe &&
    viewerContainer &&
    viewerIframe.parentElement === viewerContainer
  ) {
    viewerContainer.removeChild(viewerIframe);
  }
  viewerIframe = null;

  if (viewerCard) viewerCard.classList.add('hidden');
  if (saveStampedBtn) saveStampedBtn.classList.add('hidden');

  if (viewerContainer) {
    viewerContainer.style.height = '';
    viewerContainer.style.aspectRatio = '';
  }

  const isFullWidth = localStorage.getItem('fullWidthMode') !== 'false';
  if (toolUploader && !isFullWidth) {
    toolUploader.classList.remove('max-w-6xl');
    toolUploader.classList.add('max-w-2xl');
  }

  updateFileList();
  if (pdfInput) pdfInput.value = '';
}

function updateFileList() {
  if (!selectedFile) {
    fileListDiv.classList.add('hidden');
    fileListDiv.innerHTML = '';
    return;
  }

  fileListDiv.classList.remove('hidden');
  fileListDiv.innerHTML = '';

  // Expand container width for viewer if NOT in full width mode (default to true if not set)
  const isFullWidth = localStorage.getItem('fullWidthMode') !== 'false';
  if (toolUploader && !isFullWidth) {
    toolUploader.classList.remove('max-w-2xl');
    toolUploader.classList.add('max-w-6xl');
  }

  const wrapper = document.createElement('div');
  wrapper.className =
    'bg-gray-700 p-3 rounded-lg border border-gray-600 hover:border-indigo-500 transition-colors';

  const innerDiv = document.createElement('div');
  innerDiv.className = 'flex items-center justify-between';

  const infoDiv = document.createElement('div');
  infoDiv.className = 'flex-1 min-w-0';

  const nameSpan = document.createElement('p');
  nameSpan.className = 'truncate font-medium text-white';
  nameSpan.textContent = selectedFile.name;

  const sizeSpan = document.createElement('p');
  sizeSpan.className = 'text-gray-400 text-sm';
  sizeSpan.textContent = formatBytes(selectedFile.size);

  infoDiv.append(nameSpan, sizeSpan);

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

  innerDiv.append(infoDiv, deleteBtn);
  wrapper.appendChild(innerDiv);
  fileListDiv.appendChild(wrapper);

  createIcons({ icons });
}

async function adjustViewerHeight(file: File) {
  if (!viewerContainer) return;
  try {
    const arrayBuffer = await file.arrayBuffer();
    const loadingTask = getPDFDocument({ data: arrayBuffer });
    const pdf = await loadingTask.promise;
    const page = await pdf.getPage(1);
    const viewport = page.getViewport({ scale: 1 });

    // Add ~50px for toolbar height relative to page height
    const aspectRatio = viewport.width / (viewport.height + 50);

    viewerContainer.style.height = 'auto';
    viewerContainer.style.aspectRatio = `${aspectRatio}`;
  } catch (e) {
    console.error('Error adjusting viewer height:', e);
    // Fallback if calculation fails
    viewerContainer.style.height = '70vh';
  }
}

async function loadPdfInViewer(file: File) {
  if (!viewerContainer) return;

  if (viewerCard) {
    viewerCard.classList.remove('hidden');
  }

  // Clear existing iframe and blob URL
  if (viewerIframe && viewerIframe.parentElement === viewerContainer) {
    viewerContainer.removeChild(viewerIframe);
  }
  if (currentBlobUrl) {
    URL.revokeObjectURL(currentBlobUrl);
    currentBlobUrl = null;
  }
  viewerIframe = null;

  // Calculate and apply dynamic height
  await adjustViewerHeight(file);

  const arrayBuffer = await readFileAsArrayBuffer(file);
  const blob = new Blob([arrayBuffer as BlobPart], { type: 'application/pdf' });
  currentBlobUrl = URL.createObjectURL(blob);

  try {
    const existingPrefsRaw = localStorage.getItem('pdfjs.preferences');
    const existingPrefs = existingPrefsRaw ? JSON.parse(existingPrefsRaw) : {};
    delete (existingPrefs as Record<string, unknown>).annotationEditorMode;
    const newPrefs = {
      ...existingPrefs,
      enablePermissions: false,
    };
    localStorage.setItem('pdfjs.preferences', JSON.stringify(newPrefs));
  } catch (e) {
    console.warn('Failed to update pdfjs.preferences in localStorage', e);
  }

  const iframe = document.createElement('iframe');
  iframe.className = 'w-full h-full border-0';
  iframe.allowFullscreen = true;

  const viewerUrl = new URL(
    import.meta.env.BASE_URL + 'pdfjs-annotation-viewer/web/viewer.html',
    window.location.origin
  );
  const stampUserName = usernameInput?.value?.trim() || '';
  // ae_username is the hash parameter used by pdfjs-annotation-extension to set the username
  const hashParams = stampUserName
    ? `#ae_username=${encodeURIComponent(stampUserName)}`
    : '';
  iframe.src = `${viewerUrl.toString()}?file=${encodeURIComponent(currentBlobUrl)}${hashParams}`;

  iframe.addEventListener('load', () => {
    setupAnnotationViewer(iframe);
  });

  viewerContainer.appendChild(iframe);
  viewerIframe = iframe;
}

function setupAnnotationViewer(iframe: HTMLIFrameElement) {
  try {
    const win = iframe.contentWindow as
      | (Window & {
          PDFViewerApplication?: {
            initializedPromise?: Promise<void>;
            eventBus?: { _on?: (event: string, callback: () => void) => void };
          };
        })
      | null;
    const doc = win?.document as Document | null;
    if (!win || !doc) return;

    const initialize = async () => {
      try {
        const app = win.PDFViewerApplication;
        if (app?.initializedPromise) {
          await app.initializedPromise;
        }

        const eventBus = app?.eventBus;
        if (eventBus && typeof eventBus._on === 'function') {
          eventBus._on('annotationeditoruimanager', () => {
            try {
              const stampBtn = doc.getElementById(
                'editorStampButton'
              ) as HTMLButtonElement | null;
              stampBtn?.click();
            } catch (e) {
              console.warn(
                'Failed to auto-click stamp button in annotation editor',
                e
              );
            }
          });
        }

        const root = doc.querySelector(
          '.PdfjsAnnotationExtension'
        ) as HTMLElement | null;
        if (root) {
          root.classList.add('PdfjsAnnotationExtension_Comment_hidden');
        }
      } catch (e) {
        console.error(
          'Failed to initialize annotation viewer for Add Stamps:',
          e
        );
      }
    };

    void initialize();
  } catch (e) {
    console.error('Error wiring Add Stamps viewer:', e);
  }
}

async function onPdfSelected(file: File) {
  const result = await loadPdfWithPasswordPrompt(file);
  if (!result) return;
  result.pdf.destroy();
  selectedFile = result.file;
  updateFileList();
  if (saveStampedBtn) saveStampedBtn.classList.remove('hidden');
  await loadPdfInViewer(result.file);
}

if (pdfInput) {
  pdfInput.addEventListener('change', async (e) => {
    const target = e.target as HTMLInputElement;
    if (target.files && target.files.length > 0) {
      const file = target.files[0];
      await onPdfSelected(file);
    }
  });
}

// Add drag/drop support
const dropZone = document.getElementById('drop-zone');
if (dropZone) {
  dropZone.addEventListener('dragover', (e) => {
    e.preventDefault();
    dropZone.classList.add('border-indigo-500');
  });
  dropZone.addEventListener('dragleave', () => {
    dropZone.classList.remove('border-indigo-500');
  });
  dropZone.addEventListener('drop', async (e) => {
    e.preventDefault();
    dropZone.classList.remove('border-indigo-500');
    const file = e.dataTransfer?.files[0];
    if (file && file.type === 'application/pdf') {
      await onPdfSelected(file);
    }
  });
}

if (saveStampedBtn) {
  saveStampedBtn.addEventListener('click', () => {
    if (!viewerIframe) {
      alert(
        'Viewer not ready. Please upload a PDF and wait for it to finish loading.'
      );
      return;
    }

    try {
      const win = viewerIframe.contentWindow as
        | (Window & {
            pdfjsAnnotationExtensionInstance?: {
              exportPdf?: () => Promise<void>;
            };
          })
        | null;
      const extensionInstance = win?.pdfjsAnnotationExtensionInstance;

      if (
        extensionInstance &&
        typeof extensionInstance.exportPdf === 'function'
      ) {
        const result = extensionInstance.exportPdf();
        if (result && typeof result.then === 'function') {
          result
            .then(() => {
              // Reset state after successful export
              setTimeout(() => resetState(), 500);
            })
            .catch((err: unknown) => {
              console.error(
                'Error while exporting stamped PDF via annotation extension:',
                err
              );
            });
        }
        return;
      }

      alert(
        'Could not access the stamped-PDF exporter. Please use the Export → PDF button in the viewer toolbar as a fallback.'
      );
    } catch (e) {
      console.error('Failed to trigger stamped PDF export:', e);
      alert(
        'Could not export the stamped PDF. Please use the Export → PDF button in the viewer toolbar as a fallback.'
      );
    }
  });
}

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

initializeGlobalShortcuts();