import type { Dataset, FullComparisonResult } from '../types';

const triggerDownload = (blob: Blob, filename: string) => {
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = filename;
  document.body.appendChild(a);
  a.click();
  document.body.removeChild(a);
  URL.revokeObjectURL(url);
};

export const downloadJson = (data: object, filename: string) => {
  const jsonString = JSON.stringify(data, null, 2);
  const blob = new Blob([jsonString], { type: 'application/json' });
  triggerDownload(blob, filename);
};

export const downloadCsv = (dataset: Dataset, filename:string) => {
  if (!dataset.fullComparison) {
    console.error("No full comparison data to download.");
    alert("Full comparison data is not available for this dataset.");
    return;
  }

  const { fullComparison, data } = dataset;

  const headers = [
    'id',
    'image_to_mesh_image', 'image_to_mesh_mesh',
    'mesh_to_image_mesh', 'mesh_to_image_image',
    'text_to_mesh_text', 'text_to_mesh_mesh',
    'mesh_to_text_mesh', 'mesh_to_text_text',
    'image_to_text_image', 'image_to_text_text',
    'text_to_image_text', 'text_to_image_image',
  ];

  let csvContent = headers.join(',') + '\n';

  const imageMap = new Map(fullComparison.images.map(item => [item.source, item.matches]));
  const textMap = new Map(fullComparison.texts.map(item => [item.source, item.matches]));
  const meshMap = new Map(fullComparison.meshes.map(item => [item.source, item.matches]));

  const maxItems = Math.max(
    data.images.length,
    data.texts.length,
    data.meshes.length
  );
  
  const formatMatches = (matches: { item: string; confidence: number }[] | undefined): string => {
    if (!matches || matches.length === 0) return '';
    const items = matches.map(m => `'${m.item}'`);
    return `[${items.join(', ')}]`;
  };

  for (let i = 0; i < maxItems; i++) {
    const row: Record<string, string | number> = {};
    headers.forEach(h => row[h] = ''); // Initialize with empty strings
    row.id = i;

    // Image to X
    const imageItem = data.images[i];
    if (imageItem) {
      const matches = imageMap.get(imageItem.name);
      if (matches) {
        if (matches.mesh && matches.mesh.length > 0) {
          row.image_to_mesh_image = imageItem.name;
          row.image_to_mesh_mesh = formatMatches(matches.mesh);
        }
        if (matches.text && matches.text.length > 0) {
          row.image_to_text_image = imageItem.name;
          row.image_to_text_text = formatMatches(matches.text);
        }
      }
    }

    // Mesh to X
    const meshItem = data.meshes[i];
    if (meshItem) {
      const matches = meshMap.get(meshItem.name);
      if (matches) {
        if (matches.image && matches.image.length > 0) {
          row.mesh_to_image_mesh = meshItem.name;
          row.mesh_to_image_image = formatMatches(matches.image);
        }
        if (matches.text && matches.text.length > 0) {
          row.mesh_to_text_mesh = meshItem.name;
          row.mesh_to_text_text = formatMatches(matches.text);
        }
      }
    }

    // Text to X
    const textItem = data.texts[i];
    if (textItem) {
      const matches = textMap.get(textItem.name);
      if (matches) {
        if (matches.mesh && matches.mesh.length > 0) {
          row.text_to_mesh_text = textItem.name;
          row.text_to_mesh_mesh = formatMatches(matches.mesh);
        }
        if (matches.image && matches.image.length > 0) {
          row.text_to_image_text = textItem.name;
          row.text_to_image_image = formatMatches(matches.image);
        }
      }
    }

    const rowValues = headers.map(h => {
        const value = String(row[h]);
        // Quote the value if it contains a comma or a quote
        return value.includes(',') || value.includes('"') ? `"${value.replace(/"/g, '""')}"` : value;
    });

    csvContent += rowValues.join(',') + '\n';
  }

  const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
  triggerDownload(blob, filename);
};