# -*- coding: utf-8 -*- # BSD 3-Clause License # # Apprise - Push Notification Library. # Copyright (c) 2023, Chris Caron <lead2gold@gmail.com> # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are met: # # 1. Redistributions of source code must retain the above copyright notice, # this list of conditions and the following disclaimer. # # 2. Redistributions in binary form must reproduce the above copyright notice, # this list of conditions and the following disclaimer in the documentation # and/or other materials provided with the distribution. # # 3. Neither the name of the copyright holder nor the names of its # contributors may be used to endorse or promote products derived from # this software without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE # POSSIBILITY OF SUCH DAMAGE. import os import time import mimetypes from ..URLBase import URLBase from ..utils import parse_bool from ..common import ContentLocation from ..AppriseLocale import gettext_lazy as _ class AttachBase(URLBase): """ This is the base class for all supported attachment types """ # For attachment type detection; this amount of data is read into memory # 128KB (131072B) max_detect_buffer_size = 131072 # Unknown mimetype unknown_mimetype = 'application/octet-stream' # Our filename when we can't otherwise determine one unknown_filename = 'apprise-attachment' # Our filename extension when we can't otherwise determine one unknown_filename_extension = '.obj' # The strict argument is a flag specifying whether the list of known MIME # types is limited to only the official types registered with IANA. When # strict is True, only the IANA types are supported; when strict is False # (the default), some additional non-standard but commonly used MIME types # are also recognized. strict = False # The maximum file-size we will accept for an attachment size. If this is # set to zero (0), then no check is performed # 1 MB = 1048576 bytes # 5 MB = 5242880 bytes max_file_size = 5242880 # By default all attachments types are inaccessible. # Developers of items identified in the attachment plugin directory # are requried to set a location location = ContentLocation.INACCESSIBLE # Here is where we define all of the arguments we accept on the url # such as: schema://whatever/?overflow=upstream&format=text # These act the same way as tokens except they are optional and/or # have default values set if mandatory. This rule must be followed template_args = { 'cache': { 'name': _('Cache Age'), 'type': 'int', # We default to (600) which means we cache for 10 minutes 'default': 600, }, 'mime': { 'name': _('Forced Mime Type'), 'type': 'string', }, 'name': { 'name': _('Forced File Name'), 'type': 'string', }, 'verify': { 'name': _('Verify SSL'), # SSL Certificate Authority Verification 'type': 'bool', # Provide a default 'default': True, }, } def __init__(self, name=None, mimetype=None, cache=None, **kwargs): """ Initialize some general logging and common server arguments that will keep things consistent when working with the configurations that inherit this class. Optionally provide a filename to over-ride name associated with the actual file retrieved (from where-ever). The mime-type is automatically detected, but you can over-ride this by explicitly stating what it should be. By default we cache our responses so that subsiquent calls does not cause the content to be retrieved again. For local file references this makes no difference at all. But for remote content, this does mean more then one call can be made to retrieve the (same) data. This method can be somewhat inefficient if disabled. Only disable caching if you understand the consequences. You can alternatively set the cache value to an int identifying the number of seconds the previously retrieved can exist for before it should be considered expired. """ super().__init__(**kwargs) if not mimetypes.inited: # Ensure mimetypes has been initialized mimetypes.init() # Attach Filename (does not have to be the same as path) self._name = name # The mime type of the attached content. This is detected if not # otherwise specified. self._mimetype = mimetype # The detected_mimetype, this is only used as a fallback if the # mimetype wasn't forced by the user self.detected_mimetype = None # The detected filename by calling child class. A detected filename # is always used if no force naming was specified. self.detected_name = None # Absolute path to attachment self.download_path = None # Set our cache flag; it can be True, False, None, or a (positive) # integer... nothing else if cache is not None: try: self.cache = cache if isinstance(cache, bool) else int(cache) except (TypeError, ValueError): err = 'An invalid cache value ({}) was specified.'.format( cache) self.logger.warning(err) raise TypeError(err) # Some simple error checking if self.cache < 0: err = 'A negative cache value ({}) was specified.'.format( cache) self.logger.warning(err) raise TypeError(err) else: self.cache = None # Validate mimetype if specified if self._mimetype: if next((t for t in mimetypes.types_map.values() if self._mimetype == t), None) is None: err = 'An invalid mime-type ({}) was specified.'.format( mimetype) self.logger.warning(err) raise TypeError(err) return @property def path(self): """ Returns the absolute path to the filename. If this is not known or is know but has been considered expired (due to cache setting), then content is re-retrieved prior to returning. """ if not self.exists(): # we could not obtain our path return None return self.download_path @property def name(self): """ Returns the filename """ if self._name: # return our fixed content return self._name if not self.exists(): # we could not obtain our name return None if not self.detected_name: # If we get here, our download was successful but we don't have a # filename based on our content. extension = mimetypes.guess_extension(self.mimetype) self.detected_name = '{}{}'.format( self.unknown_filename, extension if extension else self.unknown_filename_extension) return self.detected_name @property def mimetype(self): """ Returns mime type (if one is present). Content is cached once determied to prevent overhead of future calls. """ if self._mimetype: # return our pre-calculated cached content return self._mimetype if not self.exists(): # we could not obtain our attachment return None if not self.detected_mimetype: # guess_type() returns: (type, encoding) and sets type to None # if it can't otherwise determine it. try: # Directly reference _name and detected_name to prevent # recursion loop (as self.name calls this function) self.detected_mimetype, _ = mimetypes.guess_type( self._name if self._name else self.detected_name, strict=self.strict) except TypeError: # Thrown if None was specified in filename section pass # Return our mime type return self.detected_mimetype \ if self.detected_mimetype else self.unknown_mimetype def exists(self): """ Simply returns true if the object has downloaded and stored the attachment AND the attachment has not expired. """ cache = self.template_args['cache']['default'] \ if self.cache is None else self.cache if self.download_path and os.path.isfile(self.download_path) \ and cache: # We have enough reason to look further into our cached content # and verify it has not expired. if cache is True: # return our fixed content as is; we will always cache it return True # Verify our cache time to determine whether we will get our # content again. try: age_in_sec = time.time() - os.stat(self.download_path).st_mtime if age_in_sec <= cache: return True except (OSError, IOError): # The file is not present pass return self.download() def invalidate(self): """ Release any temporary data that may be open by child classes. Externally fetched content should be automatically cleaned up when this function is called. This function should also reset the following entries to None: - detected_name : Should identify a human readable filename - download_path: Must contain a absolute path to content - detected_mimetype: Should identify mimetype of content """ self.detected_name = None self.download_path = None self.detected_mimetype = None return def download(self): """ This function must be over-ridden by inheriting classes. Inherited classes MUST populate: - detected_name: Should identify a human readable filename - download_path: Must contain a absolute path to content - detected_mimetype: Should identify mimetype of content If a download fails, you should ensure these values are set to None. """ raise NotImplementedError( "download() is implimented by the child class.") @staticmethod def parse_url(url, verify_host=True, mimetype_db=None): """Parses the URL and returns it broken apart into a dictionary. This is very specific and customized for Apprise. Args: url (str): The URL you want to fully parse. verify_host (:obj:`bool`, optional): a flag kept with the parsed URL which some child classes will later use to verify SSL keys (if SSL transactions take place). Unless under very specific circumstances, it is strongly recomended that you leave this default value set to True. Returns: A dictionary is returned containing the URL fully parsed if successful, otherwise None is returned. """ results = URLBase.parse_url(url, verify_host=verify_host) if not results: # We're done; we failed to parse our url return results # Allow overriding the default config mime type if 'mime' in results['qsd']: results['mimetype'] = results['qsd'].get('mime', '') \ .strip().lower() # Allow overriding the default file name if 'name' in results['qsd']: results['name'] = results['qsd'].get('name', '') \ .strip().lower() # Our cache value if 'cache' in results['qsd']: # First try to get it's integer value try: results['cache'] = int(results['qsd']['cache']) except (ValueError, TypeError): # No problem, it just isn't an integer; now treat it as a bool # instead: results['cache'] = parse_bool(results['qsd']['cache']) return results def __len__(self): """ Returns the filesize of the attachment. """ return os.path.getsize(self.path) if self.path else 0 def __bool__(self): """ Allows the Apprise object to be wrapped in an based 'if statement'. True is returned if our content was downloaded correctly. """ return True if self.path else False