namespace DigitalData.EmailProfiler.Application.Interfaces.Services;

/// <summary>
/// PDF processing service interface for validation and embedded file extraction.
/// </summary>
public interface IPdfProcessingService
{
    /// <summary>
    /// Validate if file is a valid PDF.
    /// </summary>
    Task<bool> IsValidPdfAsync(string filePath, CancellationToken cancellationToken = default);

    /// <summary>
    /// Validate if stream contains a valid PDF.
    /// </summary>
    Task<bool> IsValidPdfAsync(Stream stream, CancellationToken cancellationToken = default);

    /// <summary>
    /// Extract embedded files from PDF (e.g., ZUGFeRD XML).
    /// </summary>
    Task<IEnumerable<EmbeddedFile>> ExtractEmbeddedFilesAsync(string pdfPath, CancellationToken cancellationToken = default);

    /// <summary>
    /// Extract embedded files from PDF stream.
    /// </summary>
    Task<IEnumerable<EmbeddedFile>> ExtractEmbeddedFilesAsync(Stream pdfStream, CancellationToken cancellationToken = default);

    /// <summary>
    /// Check if PDF contains ZUGFeRD data.
    /// </summary>
    Task<bool> HasZugFeRDDataAsync(string pdfPath, CancellationToken cancellationToken = default);

    /// <summary>
    /// Extract ZUGFeRD XML from PDF.
    /// </summary>
    Task<string?> ExtractZugFeRDXmlAsync(string pdfPath, CancellationToken cancellationToken = default);

    /// <summary>
    /// Get PDF metadata (title, author, creation date, etc.).
    /// </summary>
    Task<PdfMetadata> GetMetadataAsync(string pdfPath, CancellationToken cancellationToken = default);
}

/// <summary>
/// Represents an embedded file extracted from a PDF.
/// </summary>
public record EmbeddedFile(string FileName, byte[] Content, string? Description = null);

/// <summary>
/// Represents PDF metadata.
/// </summary>
public record PdfMetadata(
    string? Title,
    string? Author,
    string? Subject,
    string? Keywords,
    DateTime? CreationDate,
    DateTime? ModificationDate,
    int PageCount);