import { showLoader, hideLoader, showAlert } from '../ui.js';
import { downloadFile, formatBytes } from '../utils/helpers.js';
import { state } from '../state.js';
import { createIcons, icons } from 'lucide';

document.addEventListener('DOMContentLoaded', () => {
  state.files = [];

  const fileInput = document.getElementById('file-input') as HTMLInputElement;
  const dropZone = document.getElementById('drop-zone');
  const convertOptions = document.getElementById('convert-options');
  const fileDisplayArea = document.getElementById('file-display-area');
  const fileControls = document.getElementById('file-controls');
  const addMoreBtn = document.getElementById('add-more-btn');
  const clearFilesBtn = document.getElementById('clear-files-btn');
  const backBtn = document.getElementById('back-to-tools');
  const processBtn = document.getElementById('process-btn');

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

  const updateUI = async () => {
    if (!convertOptions) return;

    if (state.files.length > 0) {
      if (fileDisplayArea) {
        fileDisplayArea.innerHTML = '';

        for (let index = 0; index < state.files.length; index++) {
          const file = state.files[index];
          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 = file.name;

          const metaSpan = document.createElement('div');
          metaSpan.className = 'text-xs text-gray-400';
          metaSpan.textContent = formatBytes(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 = () => {
            state.files = state.files.filter((_, i) => i !== index);
            updateUI();
          };

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

        createIcons({ icons });
      }
      if (fileControls) fileControls.classList.remove('hidden');
      convertOptions.classList.remove('hidden');
    } else {
      if (fileDisplayArea) fileDisplayArea.innerHTML = '';
      if (fileControls) fileControls.classList.add('hidden');
      convertOptions.classList.add('hidden');
    }
  };

  const resetState = () => {
    state.files = [];
    state.pdfDoc = null;
    updateUI();
  };

  const convertToPdf = async () => {
    try {
      console.log('[CSV2PDF] Starting conversion...');
      console.log('[CSV2PDF] Number of files:', state.files.length);

      if (state.files.length === 0) {
        showAlert('No Files', 'Please select at least one CSV file.');
        hideLoader();
        return;
      }

      const { convertCsvToPdf } = await import('../utils/csv-to-pdf.js');

      if (state.files.length === 1) {
        const originalFile = state.files[0];
        console.log(
          '[CSV2PDF] Converting single file:',
          originalFile.name,
          'Size:',
          originalFile.size,
          'bytes'
        );

        const pdfBlob = await convertCsvToPdf(originalFile, {
          onProgress: (percent, message) => {
            console.log(`[CSV2PDF] Progress: ${percent}% - ${message}`);
            showLoader(message, percent);
          },
        });

        console.log(
          '[CSV2PDF] Conversion complete! PDF size:',
          pdfBlob.size,
          'bytes'
        );

        const fileName = originalFile.name.replace(/\.csv$/i, '') + '.pdf';
        downloadFile(pdfBlob, fileName);
        console.log('[CSV2PDF] File downloaded:', fileName);

        hideLoader();

        showAlert(
          'Conversion Complete',
          `Successfully converted ${originalFile.name} to PDF.`,
          'success',
          () => resetState()
        );
      } else {
        console.log('[CSV2PDF] Converting multiple files:', state.files.length);
        showLoader('Preparing conversion...');
        const JSZip = (await import('jszip')).default;
        const zip = new JSZip();

        for (let i = 0; i < state.files.length; i++) {
          const file = state.files[i];
          console.log(
            `[CSV2PDF] Converting file ${i + 1}/${state.files.length}:`,
            file.name
          );

          const pdfBlob = await convertCsvToPdf(file, {
            onProgress: (percent) => {
              const overallPercent =
                (i / state.files.length) * 100 + percent / state.files.length;
              showLoader(
                `Converting ${i + 1}/${state.files.length}: ${file.name}...`,
                overallPercent
              );
            },
          });

          console.log(
            `[CSV2PDF] Converted ${file.name}, PDF size:`,
            pdfBlob.size
          );

          const baseName = file.name.replace(/\.csv$/i, '');
          const pdfBuffer = await pdfBlob.arrayBuffer();
          zip.file(`${baseName}.pdf`, pdfBuffer);
        }

        console.log('[CSV2PDF] Generating ZIP file...');
        showLoader('Creating ZIP archive...');
        const zipBlob = await zip.generateAsync({ type: 'blob' });
        console.log('[CSV2PDF] ZIP size:', zipBlob.size);

        downloadFile(zipBlob, 'csv-converted.zip');

        hideLoader();

        showAlert(
          'Conversion Complete',
          `Successfully converted ${state.files.length} CSV file(s) to PDF.`,
          'success',
          () => resetState()
        );
      }
    } catch (e: unknown) {
      console.error('[CSV2PDF] ERROR:', e);
      console.error(
        '[CSV2PDF] Error stack:',
        e instanceof Error ? e.stack : ''
      );
      hideLoader();
      showAlert(
        'Error',
        `An error occurred during conversion. Error: ${e instanceof Error ? e.message : String(e)}`
      );
    }
  };

  const handleFileSelect = (files: FileList | null) => {
    if (files && files.length > 0) {
      state.files = [...state.files, ...Array.from(files)];
      updateUI();
    }
  };

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

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

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

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

    // Clear value on click to allow re-selecting the same file
    fileInput.addEventListener('click', () => {
      fileInput.value = '';
    });
  }

  if (addMoreBtn) {
    addMoreBtn.addEventListener('click', () => {
      fileInput.click();
    });
  }

  if (clearFilesBtn) {
    clearFilesBtn.addEventListener('click', () => {
      resetState();
    });
  }

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

  updateUI();
});