Function createImageMetadataText

src/utils/imageResizer.ts:835–880

(
  dims: ImageDimensions,
  sourcePath?: string,
)

 * Returns null if no useful metadata is available.
 */
export function createImageMetadataText(
  dims: ImageDimensions,
  sourcePath?: string,
): string | null {
  const { originalWidth, originalHeight, displayWidth, displayHeight } = dims
  // Skip if dimensions are not available or invalid
  // Note: checks for undefined/null and zero to prevent division by zero
  if (
    !originalWidth ||
    !originalHeight ||
    !displayWidth ||
    !displayHeight ||
    displayWidth <= 0 ||
    displayHeight <= 0
  ) {
    // If we have a source path but no valid dimensions, still return source info
    if (sourcePath) {
      return `[Image source: ${sourcePath}]`
    }
    return null
  }
  // Check if image was resized
  const wasResized =
    originalWidth !== displayWidth || originalHeight !== displayHeight

  // Only include metadata if there's useful info (resized or has source path)
  if (!wasResized && !sourcePath) {
    return null
  }

  // Build metadata parts
  const parts: string[] = []

  if (sourcePath) {
    parts.push(`source: ${sourcePath}`)
  }

  if (wasResized) {
    const scaleFactor = originalWidth / displayWidth
    parts.push(
      `original ${originalWidth}x${originalHeight}, displayed at ${displayWidth}x${displayHeight}. Multiply coordinates by ${scaleFactor.toFixed(2)} to map to original image.`,
    )
  }

  return `[Image: ${parts.join(', ')}]`
}