1package fileop
  2
  3import (
  4	"math"
  5	"time"
  6
  7	"github.com/barasher/go-exiftool"
  8
  9	"git.sr.ht/~gabrielgio/img/pkg/components/media"
 10)
 11
 12func ReadExif(path string) (*media.MediaEXIF, error) {
 13	et, err := exiftool.NewExiftool()
 14	if err != nil {
 15		return nil, err
 16	}
 17	defer et.Close()
 18
 19	newExif := &media.MediaEXIF{}
 20	fileInfo := et.ExtractMetadata(path)[0]
 21
 22	// Get description
 23	description, err := fileInfo.GetString("ImageDescription")
 24	if err == nil {
 25		newExif.Description = &description
 26	}
 27
 28	// Get camera model
 29	model, err := fileInfo.GetString("Model")
 30	if err == nil {
 31		newExif.Camera = &model
 32	}
 33
 34	// Get Camera make
 35	make, err := fileInfo.GetString("Make")
 36	if err == nil {
 37		newExif.Maker = &make
 38	}
 39
 40	// Get Image Size
 41	width, err := fileInfo.GetFloat("ImageWidth")
 42	if err == nil {
 43		newExif.Width = &width
 44	}
 45
 46	height, err := fileInfo.GetFloat("ImageHeight")
 47	if err == nil {
 48		newExif.Height = &height
 49	}
 50
 51	// Get lens
 52	lens, err := fileInfo.GetString("LensModel")
 53	if err == nil {
 54		newExif.Lens = &lens
 55	}
 56
 57	//Get time of photo
 58	createDateKeys := []string{
 59		"CreationDate",
 60		"DateTimeOriginal",
 61		"CreateDate",
 62		"TrackCreateDate",
 63		"MediaCreateDate",
 64		"FileCreateDate",
 65		"ModifyDate",
 66		"TrackModifyDate",
 67		"MediaModifyDate",
 68		"FileModifyDate",
 69	}
 70	for _, createDateKey := range createDateKeys {
 71		date, err := fileInfo.GetString(createDateKey)
 72		if err == nil {
 73			layout := "2006:01:02 15:04:05"
 74			dateTime, err := time.Parse(layout, date)
 75			if err == nil {
 76				newExif.DateShot = &dateTime
 77			} else {
 78				layoutWithOffset := "2006:01:02 15:04:05+02:00"
 79				dateTime, err = time.Parse(layoutWithOffset, date)
 80				if err == nil {
 81					newExif.DateShot = &dateTime
 82				}
 83			}
 84			break
 85		}
 86	}
 87
 88	// Get exposure time
 89	exposureTime, err := fileInfo.GetFloat("ExposureTime")
 90	if err == nil {
 91		newExif.Exposure = &exposureTime
 92	}
 93
 94	// Get aperture
 95	aperture, err := fileInfo.GetFloat("Aperture")
 96	if err == nil {
 97		newExif.Aperture = &aperture
 98	}
 99
100	// Get ISO
101	iso, err := fileInfo.GetInt("ISO")
102	if err == nil {
103		newExif.Iso = &iso
104	}
105
106	// Get focal length
107	focalLen, err := fileInfo.GetFloat("FocalLength")
108	if err == nil {
109		newExif.FocalLength = &focalLen
110	}
111
112	// Get flash info
113	flash, err := fileInfo.GetInt("Flash")
114	if err == nil {
115		newExif.Flash = &flash
116	}
117
118	// Get orientation
119	orientation, err := fileInfo.GetInt("Orientation")
120	if err == nil {
121		newExif.Orientation = &orientation
122	}
123
124	// Get exposure program
125	expProgram, err := fileInfo.GetInt("ExposureProgram")
126	if err == nil {
127		newExif.ExposureProgram = &expProgram
128	}
129
130	// GPS coordinates - longitude
131	longitudeRaw, err := fileInfo.GetFloat("GPSLongitude")
132	if err == nil {
133		newExif.GPSLongitude = &longitudeRaw
134	}
135
136	// GPS coordinates - latitude
137	latitudeRaw, err := fileInfo.GetFloat("GPSLatitude")
138	if err == nil {
139		newExif.GPSLatitude = &latitudeRaw
140	}
141
142	sanitizeEXIF(newExif)
143
144	return newExif, nil
145}
146
147// isFloatReal returns true when the float value represents a real number
148// (different than +Inf, -Inf or NaN)
149func isFloatReal(v float64) bool {
150	if math.IsInf(v, 1) {
151		return false
152	} else if math.IsInf(v, -1) {
153		return false
154	} else if math.IsNaN(v) {
155		return false
156	}
157	return true
158}
159
160// sanitizeEXIF removes any EXIF float64 field that is not a real number (+Inf,
161// -Inf or Nan)
162func sanitizeEXIF(exif *media.MediaEXIF) {
163	if exif.Exposure != nil && !isFloatReal(*exif.Exposure) {
164		exif.Exposure = nil
165	}
166	if exif.Aperture != nil && !isFloatReal(*exif.Aperture) {
167		exif.Aperture = nil
168	}
169	if exif.FocalLength != nil && !isFloatReal(*exif.FocalLength) {
170		exif.FocalLength = nil
171	}
172	if (exif.GPSLatitude != nil && !isFloatReal(*exif.GPSLatitude)) ||
173		(exif.GPSLongitude != nil && !isFloatReal(*exif.GPSLongitude)) {
174		exif.GPSLatitude = nil
175		exif.GPSLongitude = nil
176	}
177}