Wp2ghost/GhostImageManager/Services/ExifService.cs

using MetadataExtractor;
using MetadataExtractor.Formats.Exif;

namespace GhostImageManager.Services;

public class ExifData
{
    public string? CameraMake { get; set; }
    public string? CameraModel { get; set; }
    public string? Lens { get; set; }
    public string? Aperture { get; set; }
    public string? ShutterSpeed { get; set; }
    public string? Iso { get; set; }
    public string? FocalLength { get; set; }
    public DateTime? CaptureDate { get; set; }
}

public class ExifService
{
    private readonly ILogger<ExifService> _logger;

    public ExifService(ILogger<ExifService> logger)
    {
        _logger = logger;
    }

    public ExifData ExtractExifData(string filePath)
    {
        var result = new ExifData();

        try
        {
            if (!File.Exists(filePath))
            {
                _logger.LogWarning("EXIF-Extraktion: Datei nicht gefunden {FilePath}", filePath);
                return result;
            }

            var directories = ImageMetadataReader.ReadMetadata(filePath);
            var ifd0Directory = directories.OfType<ExifIfd0Directory>().FirstOrDefault();
            var subIfdDirectory = directories.OfType<ExifSubIfdDirectory>().FirstOrDefault();
            var exifDirectory = directories.OfType<ExifDirectoryBase>().FirstOrDefault();

            // Kamera
            if (ifd0Directory != null)
            {
                result.CameraMake = ifd0Directory.GetDescription(ExifDirectoryBase.TagMake);
                result.CameraModel = ifd0Directory.GetDescription(ExifDirectoryBase.TagModel);
            }

            // Aufnahmedatum
            if (exifDirectory != null && exifDirectory.TryGetDateTime(ExifDirectoryBase.TagDateTimeOriginal, out var captureDate))
            {
                result.CaptureDate = captureDate;
            }
            else if (exifDirectory != null && exifDirectory.TryGetDateTime(ExifDirectoryBase.TagDateTime, out var dateTime))
            {
                result.CaptureDate = dateTime;
            }

            if (subIfdDirectory != null)
            {
                // Blende
                result.Aperture = subIfdDirectory.GetDescription(ExifDirectoryBase.TagAperture);
                if (string.IsNullOrEmpty(result.Aperture))
                    result.Aperture = subIfdDirectory.GetDescription(ExifDirectoryBase.TagFNumber);

                // Verschlusszeit
                result.ShutterSpeed = subIfdDirectory.GetDescription(ExifDirectoryBase.TagExposureTime);

                // ISO
                result.Iso = subIfdDirectory.GetDescription(ExifDirectoryBase.TagIsoEquivalent);

                // Brennweite
                result.FocalLength = subIfdDirectory.GetDescription(ExifDirectoryBase.TagFocalLength);

                // Objektiv
                result.Lens = subIfdDirectory.GetDescription(ExifDirectoryBase.TagLensModel);
                if (string.IsNullOrEmpty(result.Lens))
                    result.Lens = subIfdDirectory.GetDescription(ExifDirectoryBase.TagLensSpecification);
            }

            _logger.LogDebug("EXIF-Daten für {File} extrahiert", Path.GetFileName(filePath));
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "Fehler beim Extrahieren der EXIF-Daten für {FilePath}", filePath);
        }

        return result;
    }
}