1 files changed, 165 insertions, 0 deletions
diff --git a/pkg/fileop/exif.go b/pkg/fileop/exif.go
new file mode 100644
index 0000000..48e495c
--- /dev/null
+++ b/pkg/fileop/exif.go
@@ -0,0 +1,165 @@
+package fileop
+
+import (
+	"math"
+	"time"
+
+	"git.sr.ht/~gabrielgio/img/pkg/components/media"
+	"github.com/barasher/go-exiftool"
+)
+
+func ReadExif(path string) (*media.MediaEXIF, error) {
+	et, err := exiftool.NewExiftool()
+	if err != nil {
+		return nil, err
+	}
+	defer et.Close()
+
+	newExif := &media.MediaEXIF{}
+	fileInfo := et.ExtractMetadata(path)[0]
+
+	// Get description
+	description, err := fileInfo.GetString("ImageDescription")
+	if err == nil {
+		newExif.Description = &description
+	}
+
+	// Get camera model
+	model, err := fileInfo.GetString("Model")
+	if err == nil {
+		newExif.Camera = &model
+	}
+
+	// Get Camera make
+	make, err := fileInfo.GetString("Make")
+	if err == nil {
+		newExif.Maker = &make
+	}
+
+	// Get lens
+	lens, err := fileInfo.GetString("LensModel")
+	if err == nil {
+		newExif.Lens = &lens
+	}
+
+	//Get time of photo
+	createDateKeys := []string{
+		"CreationDate",
+		"DateTimeOriginal",
+		"CreateDate",
+		"TrackCreateDate",
+		"MediaCreateDate",
+		"FileCreateDate",
+		"ModifyDate",
+		"TrackModifyDate",
+		"MediaModifyDate",
+		"FileModifyDate",
+	}
+	for _, createDateKey := range createDateKeys {
+		date, err := fileInfo.GetString(createDateKey)
+		if err == nil {
+			layout := "2006:01:02 15:04:05"
+			dateTime, err := time.Parse(layout, date)
+			if err == nil {
+				newExif.DateShot = &dateTime
+			} else {
+				layoutWithOffset := "2006:01:02 15:04:05+02:00"
+				dateTime, err = time.Parse(layoutWithOffset, date)
+				if err == nil {
+					newExif.DateShot = &dateTime
+				}
+			}
+			break
+		}
+	}
+
+	// Get exposure time
+	exposureTime, err := fileInfo.GetFloat("ExposureTime")
+	if err == nil {
+		newExif.Exposure = &exposureTime
+	}
+
+	// Get aperture
+	aperture, err := fileInfo.GetFloat("Aperture")
+	if err == nil {
+		newExif.Aperture = &aperture
+	}
+
+	// Get ISO
+	iso, err := fileInfo.GetInt("ISO")
+	if err == nil {
+		newExif.Iso = &iso
+	}
+
+	// Get focal length
+	focalLen, err := fileInfo.GetFloat("FocalLength")
+	if err == nil {
+		newExif.FocalLength = &focalLen
+	}
+
+	// Get flash info
+	flash, err := fileInfo.GetInt("Flash")
+	if err == nil {
+		newExif.Flash = &flash
+	}
+
+	// Get orientation
+	orientation, err := fileInfo.GetInt("Orientation")
+	if err == nil {
+		newExif.Orientation = &orientation
+	}
+
+	// Get exposure program
+	expProgram, err := fileInfo.GetInt("ExposureProgram")
+	if err == nil {
+		newExif.ExposureProgram = &expProgram
+	}
+
+	// GPS coordinates - longitude
+	longitudeRaw, err := fileInfo.GetFloat("GPSLongitude")
+	if err == nil {
+		newExif.GPSLongitude = &longitudeRaw
+	}
+
+	// GPS coordinates - latitude
+	latitudeRaw, err := fileInfo.GetFloat("GPSLatitude")
+	if err == nil {
+		newExif.GPSLatitude = &latitudeRaw
+	}
+
+	sanitizeEXIF(newExif)
+
+	return newExif, nil
+}
+
+// isFloatReal returns true when the float value represents a real number
+// (different than +Inf, -Inf or NaN)
+func isFloatReal(v float64) bool {
+	if math.IsInf(v, 1) {
+		return false
+	} else if math.IsInf(v, -1) {
+		return false
+	} else if math.IsNaN(v) {
+		return false
+	}
+	return true
+}
+
+// sanitizeEXIF removes any EXIF float64 field that is not a real number (+Inf,
+// -Inf or Nan)
+func sanitizeEXIF(exif *media.MediaEXIF) {
+	if exif.Exposure != nil && !isFloatReal(*exif.Exposure) {
+		exif.Exposure = nil
+	}
+	if exif.Aperture != nil && !isFloatReal(*exif.Aperture) {
+		exif.Aperture = nil
+	}
+	if exif.FocalLength != nil && !isFloatReal(*exif.FocalLength) {
+		exif.FocalLength = nil
+	}
+	if (exif.GPSLatitude != nil && !isFloatReal(*exif.GPSLatitude)) ||
+		(exif.GPSLongitude != nil && !isFloatReal(*exif.GPSLongitude)) {
+		exif.GPSLatitude = nil
+		exif.GPSLongitude = nil
+	}
+}