exif-data.el

(defun format-gps-coordinates (latitude longitude)
  "Format latitude and longitude into a human-readable string."
  (let ((lat-hem (if (string-match "S" latitude) "S" "N"))
        (long-hem (if (string-match "W" longitude) "W" "E")))
    (format "%s, %s"
            (replace-regexp-in-string " deg.*" "" latitude)
            (replace-regexp-in-string " deg.*" "" longitude))))

(defun extract-exif-geolocation (file)
  "Extract and format the EXIF geolocation data from an image file."
  (let ((exif-output (shell-command-to-string (format "exiftool -gpslatitude -gpslongitude -n -T %s" (shell-quote-argument file)))))
    (if (string-match "\\([-+]?[0-9.]+\\)[ \t]+\\([-+]?[0-9.]+\\)" exif-output)
        (let ((latitude (match-string 1 exif-output))
              (longitude (match-string 2 exif-output)))
          (format-gps-coordinates latitude longitude))
      "No geolocation data")))

(defun generate-org-gallery-with-exif ()
  "Generate an Org mode gallery file with EXIF geolocation data."
  (interactive)
  (let ((image-dir "~/code/writing/assets/shrines")
        (org-file "~/code/writing/blog/shrines.org")
        (files (directory-files "~/code/writing/assets/shrines" t "\\(jpg\\|jpeg\\|png\\|gif\\)$")))
    (with-temp-file org-file
      (insert "#+TITLE: Shrines\n")
      (insert "#+AUTHOR: Peixian\n")
      (insert "#+DATE: 2023-11-26\n")
      (insert "#+URI: /shrines/\n\n")
      (insert "Photographs of various shrines I've seen. A shrine here is basically anything I consider to have spiritual significance.\n\n")
      (dolist (file files)
        (unless (or (string-equal (file-name-nondirectory file) ".")
                    (string-equal (file-name-nondirectory file) ".."))
          (let ((exif-data (extract-exif-geolocation file)))
            (insert (format "[[file:../assets/shrines/%s]]\n" (file-relative-name file image-dir)))
            (insert (format "</%s/>\n\n" exif-data))))))))