etiquette/etiquette/helpers.py

491 lines
16 KiB
Python

'''
This file provides functions which are used in various places throughout the
codebase but don't deserve to be methods of any class.
'''
import datetime
import hashlib
import mimetypes
import os
import PIL.Image
import typing
import zipstream
from voussoirkit import bytestring
from voussoirkit import hms
from voussoirkit import imagetools
from voussoirkit import pathclass
from voussoirkit import stringtools
from . import constants
from . import exceptions
def album_as_directory_map(
album,
naming='simplified',
once_each=True,
recursive=True,
root_name=None,
):
'''
Given an album, produce a dictionary mapping Album objects to directory
names as they will appear inside the zip archive.
Sub-albums become subfolders.
once_each:
If an album is a child of multiple albums, only one instance is used.
'''
directories = {}
if root_name is not None:
pass
elif naming == 'simplified':
root_name = album.display_name
elif naming == 'unambiguous':
root_name = album.full_name
else:
raise ValueError(naming)
root_name = remove_path_badchars(root_name)
if once_each:
directories[album] = root_name
else:
directories[album] = [root_name]
if not recursive:
return directories
children = album.get_children()
if naming == 'simplified':
child_names = decollide_names(children, lambda c: c.display_name)
elif naming == 'unambiguous':
child_names = {child: child.full_name for child in children}
child_maps = (
album_as_directory_map(
child,
once_each=once_each,
recursive=True,
root_name=child_names[child],
)
for child in children
)
descendants = (
pair
for child_map in child_maps
for pair in child_map.items()
)
for (child_album, child_directory) in descendants:
if once_each:
child_directory = os.path.join(root_name, child_directory)
directories[child_album] = child_directory
else:
child_directory = [os.path.join(root_name, d) for d in child_directory]
directories.setdefault(child_album, []).extend(child_directory)
return directories
def album_photos_as_filename_map(
album,
naming='simplified',
once_each=True,
recursive=True,
root_name=None,
):
'''
Given an album, produce a dictionary mapping Photo objects to the
filenames that will appear inside the zip archive.
This includes creating subfolders for sub albums.
once_each:
If a photo appears in multiple albums, only one instance is used.
'''
arcnames = {}
directories = album_as_directory_map(
album,
once_each=once_each,
recursive=recursive,
root_name=root_name,
)
for (album, directory) in directories.items():
photos = album.get_photos()
if naming == 'simplified':
photo_names = decollide_names(photos, lambda p: p.basename)
elif naming == 'unambiguous':
photo_names = {photo: f'{photo.id} - {photo.basename}' for photo in photos}
for photo in photos:
photo_name = photo_names[photo]
if once_each:
arcname = os.path.join(directory, photo_name)
arcnames[photo] = arcname
else:
arcname = [os.path.join(d, photo_name) for d in directory]
arcnames.setdefault(photo, []).extend(arcname)
return arcnames
def decollide_names(things, namer):
'''
When generating zip files, or otherwise exporting photos to disk, it is
aesthetically preferable to export them using just their basename. But,
since multiple photos might have the same basename, we occasionally need to
use their IDs to disambiguate them.
This function automates that by keeping the basename wherever possible, and
prefixing items with their ID in the case of a name collision.
This function takes `things`, which is a collection of either Albums or
Photos, and `namer` which is a callable that gives us the preferred name
of the thing (in practice, just a lambda returning Album title,
Photo basename), and returns a map of {thing: name}. If there are duplicate
names, they will be disambiguated by adding "id - " to the front.
'''
# The majority of this algorithm is dedicated to solving the case where some
# prankster has named their album such that it contains the ID of another
# album.
# For example, consider three Albums (1, "A"), (2, "A"), (3, "1 - A").
# So when 1 and 2 get disambiguated to (1, "1 - A"), (2, "2 - A"),
# then suddenly there is a new collision between (1, "1 - A") and
# (3, "1 - A"), and we need to disambiguate by renaming 3 to "3 - 1 - A".
# I'm not totally happy with how this function looks, but as long as I get
# it working I'll just stop looking at it and problem solved!
collisions = {}
final = {}
for thing in things:
name = namer(thing)
collisions.setdefault(name, []).append(thing)
final[thing] = name
# When the thing is disambiguated by adding its ID, it's done being
# decollided and can be locked. This ensures that if disambiguating one
# thing causes a new collision with a prank entry, only the prank needs to
# get renamed on the second pass. We don't need to keep prefixing the
# thing's ID onto the same thing over and over again.
locked = set()
while True:
collision = {
name: set(things).difference(locked)
for (name, things) in collisions.items()
if len(things) > 1
}
if not collision:
break
for (name, things) in collision.items():
for thing in things:
myname = f'{thing.id} - {name}'
locked.add(thing)
collisions[name].remove(thing)
collisions.setdefault(myname, []).append(thing)
final[thing] = myname
return final
def dict_to_tuple(d) -> tuple:
return tuple(sorted(d.items()))
def generate_image_thumbnail(filepath, width, height) -> PIL.Image:
if not os.path.isfile(filepath):
raise FileNotFoundError(filepath)
image = PIL.Image.open(filepath)
(image, exif) = imagetools.rotate_by_exif(image)
(image_width, image_height) = image.size
(new_width, new_height) = imagetools.fit_into_bounds(
image_width=image_width,
image_height=image_height,
frame_width=width,
frame_height=height,
only_shrink=True,
)
if (new_width, new_height) != (image_width, image_height):
image = image.resize((new_width, new_height))
if image.mode == 'RGBA':
background = imagetools.checkerboard_image(
color_1=(256, 256, 256),
color_2=(128, 128, 128),
image_size=image.size,
checker_size=8,
)
# Thanks Yuji Tomita
# http://stackoverflow.com/a/9459208
background.paste(image, mask=image.split()[3])
image = background
image = image.convert('RGB')
return image
def generate_video_thumbnail(filepath, outfile, width, height, **special) -> PIL.Image:
if not os.path.isfile(filepath):
raise FileNotFoundError(filepath)
probe = constants.ffmpeg.probe(filepath)
if not probe or not probe.video:
return False
size = imagetools.fit_into_bounds(
image_width=probe.video.video_width,
image_height=probe.video.video_height,
frame_width=width,
frame_height=height,
)
size = '%dx%d' % size
duration = probe.video.duration
if 'timestamp' in special:
timestamp = special['timestamp']
elif duration < 3:
timestamp = 0
else:
timestamp = 2
constants.ffmpeg.thumbnail(
filepath,
outfile=outfile,
quality=2,
size=size,
time=timestamp,
)
return True
def get_mimetype(filepath) -> typing.Optional[str]:
'''
Extension to mimetypes.guess_type which uses my
constants.ADDITIONAL_MIMETYPES.
'''
extension = os.path.splitext(filepath)[1].replace('.', '')
mimetype = constants.ADDITIONAL_MIMETYPES.get(extension, None)
if mimetype is None:
mimetype = mimetypes.guess_type(filepath)[0]
return mimetype
def hash_photoset(photos) -> str:
'''
Given some photos, return a fingerprint string for that particular set.
'''
hasher = hashlib.md5()
photo_ids = sorted(set(p.id for p in photos))
for photo_id in photo_ids:
hasher.update(photo_id.encode('utf-8'))
return hasher.hexdigest()
def hyphen_range(s) -> tuple:
'''
Given a string like '1-3', return numbers (1, 3) representing lower
and upper bounds.
Supports bytestring.parsebytes and hh:mm:ss format, for example
'1k-2k', '10:00-20:00', '4gib-'
'''
s = s.strip()
s = s.replace(' ', '')
if not s:
return (None, None)
parts = s.split('-')
parts = [part.strip() or None for part in parts]
if len(parts) == 1:
(low, high) = (parts[0], None)
elif len(parts) == 2:
(low, high) = parts
else:
raise ValueError('Too many hyphens.')
low = parse_unit_string(low)
high = parse_unit_string(high)
if low is not None and high is not None and low > high:
raise exceptions.MinMaxOutOfOrder(range=s, min=low, max=high)
return (low, high)
def is_xor(*args) -> bool:
'''
Return True if and only if one arg is truthy.
'''
return [bool(a) for a in args].count(True) == 1
def now(timestamp=True):
'''
Return the current UTC timestamp or datetime object.
'''
n = datetime.datetime.now(datetime.timezone.utc)
if timestamp:
return n.timestamp()
return n
def parse_unit_string(s) -> typing.Union[int, float, None]:
'''
Try to parse the string as an int, float, or bytestring, or hms.
'''
if s is None:
return None
s = s.strip()
if ':' in s:
return hms.hms_to_seconds(s)
elif all(c in '0123456789' for c in s):
return int(s)
elif all(c in '0123456789.' for c in s):
return float(s)
else:
return bytestring.parsebytes(s)
def read_filebytes(
filepath,
range_min=0,
range_max=None,
chunk_size=bytestring.MIBIBYTE,
) -> typing.Iterable[bytes]:
'''
Yield chunks of bytes from the file between the endpoints.
'''
filepath = pathclass.Path(filepath)
if not filepath.exists:
raise FileNotFoundError(filepath)
if range_max is None:
range_max = filepath.size
range_span = (range_max + 1) - range_min
f = filepath.open('rb')
sent_amount = 0
with f:
f.seek(range_min)
while sent_amount < range_span:
needed = range_span - sent_amount
chunk = f.read(min(needed, chunk_size))
if len(chunk) == 0:
break
yield chunk
sent_amount += len(chunk)
def remove_path_badchars(filepath, allowed='') -> str:
'''
Remove the bad characters seen in constants.FILENAME_BADCHARS, except
those which you explicitly permit.
'file*name' -> 'filename'
('D:\\file*name', allowed=':\\') -> 'D:\\filename'
'''
badchars = stringtools.remove_characters(constants.FILENAME_BADCHARS, allowed)
filepath = stringtools.remove_characters(filepath, badchars)
# Note: This is temporarily disabled until I can improve
# remove_control_characters. I want to avoid abusive / totally bogus names
# without breaking legitimate uses of control characters such as
# left-to-right marks which may appear in e.g. Arabic filenames.
# filepath = stringtools.remove_control_characters(filepath)
filepath = filepath.replace('/', os.sep)
filepath = filepath.replace('\\', os.sep)
return filepath
def slice_before(li, item):
index = li.index(item)
return li[:index]
def split_easybake_string(ebstring) -> tuple[str, str, str]:
'''
Given an easybake string, return (tagname, synonym, rename_to), where
tagname may be a full qualified name, and at least one of
synonym or rename_to will be None since both are not posible at once.
>>> split_easybake_string('languages.python')
('languages.python', None, None)
>>> split_easybake_string('languages.python+py')
('languages.python', 'py', None)
>>> split_easybake_string('languages.python=bestlang')
('languages.python', None, 'bestlang')
'''
ebstring = ebstring.strip()
ebstring = ebstring.strip('.+=')
if ebstring == '':
raise exceptions.EasyBakeError('No tag supplied.')
if '=' in ebstring and '+' in ebstring:
raise exceptions.EasyBakeError('Cannot rename and assign snynonym at once.')
rename_parts = ebstring.split('=')
if len(rename_parts) > 2:
raise exceptions.EasyBakeError('Too many equals signs.')
if len(rename_parts) == 2:
(ebstring, rename_to) = rename_parts
elif len(rename_parts) == 1:
(ebstring, rename_to) = (rename_parts[0], None)
synonym_parts = ebstring.split('+')
if len(synonym_parts) > 2:
raise exceptions.EasyBakeError('Too many plus signs.')
if len(synonym_parts) == 2:
(tagname, synonym) = synonym_parts
elif len(synonym_parts) == 1:
(tagname, synonym) = (synonym_parts[0], None)
if not tagname:
raise exceptions.EasyBakeError('No tag supplied.')
tagname = tagname.strip('.')
return (tagname, synonym, rename_to)
def zip_album(album, recursive=True) -> zipstream.ZipFile:
'''
Given an album, return a zipstream zipfile that contains the album's
photos (recursive = include children's photos) organized into folders
for each album. Each album folder also gets a text file containing
the album's name and description if applicable.
If an album is a child of multiple albums, only one instance is used.
If a photo appears in multiple albums, only one instance is used.
'''
zipfile = zipstream.ZipFile()
# Add the photos.
arcnames = album_photos_as_filename_map(album, once_each=True, recursive=recursive)
for (photo, arcname) in arcnames.items():
zipfile.write(filename=photo.real_path.absolute_path, arcname=arcname)
# Add the album metadata as an {id}.txt file within each directory.
directories = album_as_directory_map(album, once_each=True, recursive=recursive)
for (inner_album, directory) in directories.items():
metafile_text = []
if inner_album.title:
metafile_text.append(f'Title: {inner_album.title}')
if inner_album.description:
metafile_text.append(f'Description: {inner_album.description}')
if not metafile_text:
continue
metafile_text = '\r\n\r\n'.join(metafile_text)
metafile_text = metafile_text.encode('utf-8')
metafile_name = f'album {inner_album.id}.txt'
metafile_name = os.path.join(directory, metafile_name)
zipfile.writestr(
arcname=metafile_name,
data=metafile_text,
)
return zipfile
def zip_photos(photos) -> zipstream.ZipFile:
'''
Given some photos, return a zipstream zipfile that contains the files.
'''
zipfile = zipstream.ZipFile()
for photo in photos:
if not photo.real_path.is_file:
continue
arcname = os.path.join('photos', f'{photo.id} - {photo.basename}')
zipfile.write(filename=photo.real_path.absolute_path, arcname=arcname)
return zipfile