''' lsp.py: DIBS interface to LSPs. Copyright --------- Copyright (c) 2021-2022 by the California Institute of Technology. This code is open-source software released under a 3-clause BSD license. Please see the file "LICENSE" for more information. ''' from abc import ABC, abstractmethod from coif import cover_image from commonpy.network_utils import net from dataclasses import dataclass from os.path import join, exists import pokapi from pokapi import Folio import re from sidetrack import log from textwrap import wrap from topi import Tind from .settings import config, resolved_path # Classes for communicating exceptions. # ............................................................................. class LSPException(Exception): '''Base class for LSP exceptions.''' class LSPAccessError(LSPException): '''Encountered a problem with the LSP credentials or access permissions.''' class LSPRecordNotFoundError(LSPException): '''The requested record could not be found.''' class LSPBadRecordError(LSPException): '''The requested record is incomplete or otherwise unusable.''' # Classes implementing interface to specific LSPs. # ............................................................................. @dataclass class LSPRecord(): '''Common abstraction for records returned by different LSP's.''' item_id : str item_page : str title : str author : str publisher : str edition : str year : str isbn_issn : str class LSPInterface(ABC): '''Abstract interface class for getting a record from an LSP. All concrete implementations of this class are assumed to have at least a URL for the API of the server, and may have additional parameters on a per-class basis. ''' def __init__(self, url = None): '''Create an interface for the server at "url".''' self.url = url def __repr__(self): '''Return a string representing this interface object.''' return "<{} for {}>".format(self.__class__.__name__, self.url) @property @abstractmethod def name(self): '''Return the name of this LSP, for use in (e.g.) error messages.''' pass # noqa: PIE790 @abstractmethod def record(self, barcode = None): '''Return a record for the item identified by the "barcode".''' pass # noqa: PIE790 class TindInterface(LSPInterface): '''Interface layer for TIND hosted LSP servers.''' def __init__(self, url = None, thumbnails_dir = None): '''Create an interface for the server at "url".''' self.url = url self._thumbnails_dir = thumbnails_dir self._tind = Tind(url) @property def name(self): '''Return the name of this LSP, for use in (e.g.) error messages.''' return 'TIND' def record(self, barcode = None): '''Return a record for the item identified by the "barcode".''' try: rec = self._tind.item(barcode = barcode).parent title = rec.title if rec.subtitle: title += ': ' + rec.subtitle log(f'record for {barcode} has id {rec.tind_id} in {self.url}') thumbnail_file = join(self._thumbnails_dir, barcode + '.jpg') # Don't overwrite existing images. if not exists(thumbnail_file): if rec.thumbnail_url: save_thumbnail(thumbnail_file, url = rec.thumbnail_url) elif rec.isbn_issn: save_thumbnail(thumbnail_file, isbn = rec.isbn_issn) else: log(f"{barcode} lacks ISBN & thumbnail URL => no thumbnail") else: log(f'thumbnail image already exists in {thumbnail_file}') return LSPRecord(item_id = rec.tind_id, item_page = rec.tind_url, title = truncated_title(rec.title), author = rec.author, publisher = rec.publisher, year = rec.year, edition = rec.edition, isbn_issn = rec.isbn_issn) except Exception: log(f'could not find {barcode} in TIND') raise LSPRecordNotFoundError('Could not find {barcode} in {self.url}') class FolioInterface(LSPInterface): '''Interface layer for FOLIO hosted LSP servers.''' def __init__(self, url = None, token = None, tenant_id = None, an_prefix = None, page_template = None, thumbnails_dir = None): '''Create an interface for the server at "url".''' self.url = url self._token = token self._tenant_id = tenant_id self._an_prefix = an_prefix self._page_tmpl = page_template self._thumbnails_dir = thumbnails_dir self._folio = Folio(okapi_url = url, okapi_token = token, tenant_id = tenant_id, an_prefix = an_prefix) @property def name(self): '''Return the name of this LSP, for use in (e.g.) error messages.''' return 'FOLIO' def record(self, barcode = None): '''Return a record for the item identified by the "barcode". This will return None if no such entry can be found in FOLIO. It will raise a ValueError exception if an entry is found but lacks the 3 most basic metadata fields of title, author and year. ''' try: rec = self._folio.record(barcode = barcode) except pokapi.exceptions.NotFound: raise LSPRecordNotFoundError(f'Could not find {barcode}.') except pokapi.exceptions.FolioPermissionError: raise LSPAccessError(f'Cannot access {barcode} in FOLIO') except Exception as ex: log('got exception from FOLIO: ' + str(ex)) raise log(f'record for {barcode} has id {rec.id}') if not all([rec.title, rec.author, rec.year]): log(f'record for {barcode} in FOLIO lacks minimum metadata') raise LSPBadRecordError('{barcode} is incomplete in {self.url}') thumbnail_file = join(self._thumbnails_dir, barcode + '.jpg') if not exists(thumbnail_file): if rec.isbn_issn: try: save_thumbnail(thumbnail_file, isbn = rec.isbn_issn) except Exception as ex: # noqa PIE786 # Log it and go on; don't fail just because of this. log(f'failed to save thumbnail for {barcode}: ' + str(ex)) else: log(f"{rec.id} has no ISBN/ISSN => can't get a thumbnail") else: log(f'thumbnail image already exists in {thumbnail_file}') page = self._page_tmpl.format(accession_number = rec.accession_number) return LSPRecord(item_id = rec.id, item_page = page, title = truncated_title(rec.title), author = rec.author, year = rec.year, publisher = rec.publisher or '', edition = rec.edition or '', isbn_issn = rec.isbn_issn or '') class UnconfiguredInterface(LSPInterface): '''Dummy interface, for when no LSP is chosen.''' def __repr__(self): '''Return a string representing this interface object.''' return "<{}>".format(self.__class__.__name__) def record(self, barcode = None): '''Return a record for the item identified by the "barcode".''' return LSPRecord(item_id = 'LSP not configured', item_page = '', title = 'LSP not configured', author = 'LSP not configured', publisher = 'LSP not configured', year = 'LSP not configured', edition = 'LSP not configured', isbn_issn = '') # Primary exported class. # ............................................................................. class LSP(LSPInterface): '''LSP abstraction class.''' def __new__(cls, *args, **kwds): # This implements a Singleton pattern by storing the object we create # and returning the same one if the class constructor is called again. lsp = cls.__dict__.get("__lsp_interface__") if lsp is not None: log(f'Using previously-created LSP object {str(cls)}') return lsp # Read common configuration variables. thumbnails_dir = resolved_path(config('THUMBNAILS_DIR', section = 'dibs')) log(f'assuming thumbnails dir is {thumbnails_dir}') # Select the appropriate interface type and create the object. lsp_type = config('LSP_TYPE').lower() if lsp_type == 'folio': def folio_config(key): return config(key, section = 'folio') url = folio_config('FOLIO_OKAPI_URL') token = folio_config('FOLIO_OKAPI_TOKEN') tenant_id = folio_config('FOLIO_OKAPI_TENANT_ID') an_prefix = folio_config('FOLIO_ACCESSION_PREFIX') page_template = folio_config('EDS_PAGE_TEMPLATE') log(f'Using FOLIO URL {url} with tenant id {tenant_id}') lsp = FolioInterface(url = url, token = token, tenant_id = tenant_id, an_prefix = an_prefix, page_template = page_template, thumbnails_dir = thumbnails_dir) elif lsp_type == 'tind': url = config('TIND_SERVER_URL', section = 'tind') log(f'Using TIND URL {url}') lsp = TindInterface(url, thumbnails_dir = thumbnails_dir) else: lsp = UnconfiguredInterface() # Store the interface object (to implement the Singleton pattern). cls.__lsp_interface__ = lsp return lsp # Internal utilities. # ............................................................................. def save_thumbnail(dest_file, url = None, isbn = None): image = None cc_user = config('CC_USER', section = 'contentcafe', default = None) cc_password = config('CC_PASSWORD', section = 'contentcafe', default = None) cc_login = (cc_user, cc_password) if (cc_user and cc_password) else None if isbn: url, image = cover_image(isbn, size = 'L', cc_login = cc_login) log(f'cover_image returned image at {url}') # We were either given a url in the call, or we found one using the isbn. elif url: (response, error) = net('get', url) if not error and response.status_code == 200: log(f'got image from {url}') image = response.content if image: log(f'will save cover image in {dest_file}') with open(dest_file, 'wb') as file: file.write(image) else: log(f'no cover image found for {url}') def probable_issn(value): return len(value) < 10 and '-' in value def truncated_title(title): modified_title = re.split(r':|;|\.', title)[0].strip() if len(modified_title) > 60: return wrap(modified_title, 60)[0] + ' ...' else: return modified_title