import logging
logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)

allowed_exts=[
  "tif","tiff",                         # TIFF
  "jpeg","jpg","pjpeg","pjpg","jpe",    # JPEG
  "webp",                               # Webp
# "wav","wave",                         # RIFF Wave
  "png","apng"                          # PNG (since 1.2)
]

def backupMetadata(file):
  from PIL import Image, ExifTags
  
  logging.debug(f"loading file {file}")
  img = Image.open(file)
  logging.debug("file loaded. getting exif")
  img_exif = img.getexif()
  
  full=[]
  
  if img_exif is None:
    logging.warning("Could not load EXIF Data... Either something happened with Pillow, the file disappeared, or you don't have access to the file. Try running verbose!")
    break
  else:
    logging.debug("loaded tags")
    for key, val in img_exif.items():
      logging.debug(f"for key:'{key}', val:'{val}' in img_exif.items()")
      if key in ExifTags.TAGS:
        logging.debug(f"{key} is known exif tag! ({ExifTags.TAGS[key]})")
        full.append({
          'tagName': str(key),
          'realName': str(ExifTags.TAGS[key]),
          'value': str(val)
        })
      else:
        logging.warning(f"{key} is an unknown exif tag!")
        full.append({
          'tagName': str(key),
          'realName': None,
          'value': str(val)
        })
    
    logging.info("writing backup data")
    import json
    
    #import tempfile
    #temp = tempfile.TemporaryFile(mode='w+')
    #json.dump(full,temp,sort_keys=True)
    with open(f"{file}.exif_backup.json.xz",'w+b') as bfile
      logging.debug(f"writing to {bfile}")
      import lzma
      bfile.write(lzma.compress(
        bytes(json.dumps(full,sort_keys=True)),
        format=FORMAT_XZ,
        check=CHECK_SHA256,
        preset=9
      ))
      logging.debug("wrote backup data")
    
    logging.info("backup done!")
    
def writeTags(file,tags):
  from PIL import Image
  image=Image.open(file)
  exif = image.getexif()
  
  if artist in tags:
    if type(tag.artist) == str:
      exif[0x013b] = tags.artist
    elif tags.category == "deviantart":
      exif[0x013b] = tags.artist.username
  
  if title in tags:
    exif[0x0010e] = tags.title
   
  if description in tags:
    exif[0x9286] = tags.description