#!/bin/env python3
# vim: noexpandtab ts=4 ft=python :

"""
Rename all jpg images in the current folder. If there is a NEF image with the same same,
rename it as well.
"""

import os
import re
import datetime
import operator
import PIL.Image
import PIL.ExifTags

def get_date(filename):
	"""
	Get date and time from image exif tag and return string with format %Y%m%d_%H%M%S
	"""
	try:
		img = PIL.Image.open(filename)
		e = img._getexif()
		if 306 in e:
			index = 306
		elif 36867 in e:
			index = 36867
		elif 36838 in e:
			index = 36868
		d = datetime.datetime.strptime(e[index], "%Y:%m:%d %H:%M:%S")
		img.close()
		return d.strftime("%Y%m%d_%H%M%S")
	except Exception as e:
		print(e)
		exit(2)
		return None

def print_new_filename(number, date, name, original_filename):
	ext = original_filename.split('.')[-1]
	return "%s_%s_%03d.%s" % (date, name, number, ext.lower())

def rename_file_and_nef(number, date, name, original_filename):
	ext = original_filename.split('.')[-1].lower()
	plain = ".".join(original_filename.split('.')[:-1])
	name = "%s_%s_%03d" % (date, name, number)
	print("Handling file %s..." % (original_filename, ))
	print("  Renaming from '%s' to '%s'" % (original_filename, name + "." + ext))
	os.rename(os.path.join(os.getcwd(), original_filename), os.path.join(os.getcwd(), name + "." + ext))
	if os.path.isfile(os.path.join(os.getcwd(), plain + ".NEF")):
		print("  Renaming from '%s' to '%s'" % (plain + ".NEF", name + ".nef"))
		os.rename(os.path.join(os.getcwd(), plain + ".NEF"), os.path.join(os.getcwd(), name + ".nef"))
	elif os.path.isfile(os.path.join(os.getcwd(), plain + ".nef")):
		print("  Renaming from '%s' to '%s'" % (plain + ".nef", name + ".nef"))
		os.rename(os.path.join(os.getcwd(), plain + ".nef"), os.path.join(os.getcwd(), name + ".nef"))

if PIL.ExifTags.TAGS[306] != "DateTime":
	print("Warning: EXIF index for DateTime changed!")
	exit(2)

images = [[get_date(os.path.join(os.getcwd(), f)), f] for f in os.listdir(os.getcwd()) if os.path.isfile(os.path.join(os.getcwd(), f)) and re.search(r'\.jpe?g$', f, flags=re.IGNORECASE)]
images = sorted(images, key=operator.itemgetter(0, 1))

i = 1
for img in images:
	rename_file_and_nef(i, img[0], "mfg-who-am-i", img[1])
	i += 1