namespace DigitalData.MessagingService.Application.Common.Interfaces;

/// <summary>
/// PDF processing service interface.
/// Operates on streams instead of file paths for flexibility.
/// </summary>
public interface IPdfProcessingService
{
    /// <summary>
    /// Validates if the provided stream contains a valid PDF document.
    /// Throws InvalidPdfException if the stream is not a valid PDF.
    /// </summary>
    Task<bool> ValidatePdfAsync(Stream pdfStream, CancellationToken cancellationToken = default);
    
    /// <summary>
    /// Extracts embedded files from PDF stream to the specified output directory.
    /// Returns a list of paths to extracted files.
    /// </summary>
    Task<IEnumerable<string>> ExtractEmbeddedFilesAsync(Stream pdfStream, string outputDirectory, CancellationToken cancellationToken = default);
    
    /// <summary>
    /// Gets the page count of the PDF document.
    /// Throws InvalidPdfException if the stream is not a valid PDF.
    /// </summary>
    Task<int> GetPageCountAsync(Stream pdfStream, CancellationToken cancellationToken = default);
}