upstream-affine/blocksuite/affine/shared/src/adapters/utils/file-path.ts

function safeDecodePathReference(path: string): string {
  try {
    return decodeURIComponent(path);
  } catch {
    return path;
  }
}

export function normalizeFilePathReference(path: string): string {
  return safeDecodePathReference(path)
    .trim()
    .replace(/\\/g, '/')
    .replace(/^\.\/+/, '')
    .replace(/^\/+/, '')
    .replace(/\/+/g, '/');
}

/**
 * Normalizes a relative path by resolving all relative path segments
 * @param basePath The base path (markdown file's directory)
 * @param relativePath The relative path to normalize
 * @returns The full path
 */
function resolveFullPath(basePath: string, relativePath: string): string {
  // Split both paths into segments
  const baseSegments = basePath.split('/').filter(Boolean);
  const relativeSegments = relativePath.split('/').filter(Boolean);

  // Handle each segment of the relative path
  for (const segment of relativeSegments) {
    if (segment === '.') {
      // Current directory, do nothing
      continue;
    } else if (segment === '..') {
      // Parent directory, remove last segment from base
      if (baseSegments.length > 0) {
        baseSegments.pop();
      }
    } else {
      // Regular directory or file, add to base
      baseSegments.push(segment);
    }
  }

  // Join segments back into a path
  return baseSegments.join('/');
}

/**
 * Get the full path of the reference image from the file path and the image reference
 * @param filePath The full path of the file containing the image reference
 * @param imageReference The image reference from the file (can be relative or absolute path)
 * @returns The full path of the reference image
 */
export function getImageFullPath(
  filePath: string,
  imageReference: string
): string {
  // Decode the image reference in case it contains URL-encoded characters
  const decodedReference = safeDecodePathReference(imageReference);

  // Get the directory of the file path
  const markdownDir = filePath.substring(0, filePath.lastIndexOf('/'));

  // Check if the image reference is a relative path
  const isRelative = !decodedReference.startsWith('/');

  // If the image reference is a relative path, resolve it against the file path's directory
  // Otherwise, it is an absolute path, remove the leading slash if it exists
  return isRelative
    ? resolveFullPath(markdownDir, decodedReference)
    : decodedReference.replace(/^\//, '');
}