# encoding: utf8 from collections import namedtuple import os, os.path import pkg_resources import random import re import shutil import unicodedata from sqlalchemy.sql import func import whoosh import whoosh.filedb.filestore import whoosh.filedb.fileindex import whoosh.index from whoosh.qparser import QueryParser import whoosh.scoring import whoosh.spelling from pokedex.db import connect import pokedex.db.tables as tables from pokedex.roomaji import romanize __all__ = ['PokedexLookup'] rx_is_number = re.compile('^\d+$') LookupResult = namedtuple('LookupResult', ['object', 'indexed_name', 'name', 'language', 'iso3166', 'exact']) class LanguageWeighting(whoosh.scoring.Weighting): """A scoring class that forces otherwise-equal English results to come before foreign results. """ def score(self, searcher, fieldnum, text, docnum, weight, QTF=1): doc = searcher.stored_fields(docnum) if doc['language'] == None: # English (well, "default"); leave it at 1 return weight elif doc['language'] == u'Roomaji': # Give Roomaji a little boost; it's most likely to be searched return weight * 0.95 else: # Everything else can drop down the totem pole return weight * 0.9 class PokedexLookup(object): INTERMEDIATE_LOOKUP_RESULTS = 25 MAX_LOOKUP_RESULTS = 10 # Dictionary of table name => table class. # Need the table name so we can get the class from the table name after we # retrieve something from the index indexed_tables = dict( (cls.__tablename__, cls) for cls in ( tables.Ability, tables.Item, tables.Location, tables.Move, tables.Pokemon, tables.Type, ) ) def __init__(self, directory=None, session=None, recreate=False): """Opens the whoosh index stored in the named directory. If the index doesn't already exist, it will be created. `directory` Directory containing the index. Defaults to a location within the `pokedex` egg directory. `session` If the index needs to be created, this database session will be used. Defaults to an attempt to connect to the default SQLite database installed by `pokedex setup`. `recreate` If set to True, the whoosh index will be created even if it already exists. """ # By the time this returns, self.index, self.speller, and self.session # must be set # Defaults if not directory: directory = pkg_resources.resource_filename('pokedex', 'data/whoosh-index') if session: self.session = session else: self.session = connect() # Attempt to open or create the index directory_exists = os.path.exists(directory) if directory_exists and not recreate: # Already exists; should be an index! Bam, done. try: self.index = whoosh.index.open_dir(directory, indexname='MAIN') spell_store = whoosh.filedb.filestore.FileStorage(directory) self.speller = whoosh.spelling.SpellChecker(spell_store) return except whoosh.index.EmptyIndexError as e: # Apparently not a real index. Fall out and create it pass # Delete and start over if we're going to bail anyway. if directory_exists and recreate: # Be safe and only delete if it looks like a whoosh index, i.e., # everything starts with _ if all(f[0] == '_' for f in os.listdir(directory)): shutil.rmtree(directory) directory_exists = False if not directory_exists: os.mkdir(directory) ### Create index schema = whoosh.fields.Schema( name=whoosh.fields.ID(stored=True), table=whoosh.fields.ID(stored=True), row_id=whoosh.fields.ID(stored=True), language=whoosh.fields.STORED, iso3166=whoosh.fields.STORED, display_name=whoosh.fields.STORED, # non-lowercased name ) self.index = whoosh.index.create_in(directory, schema=schema, indexname='MAIN') writer = self.index.writer() # Index every name in all our tables of interest # speller_entries becomes a list of (word, score) tuples; the score is # 2 for English names, 1.5 for Roomaji, and 1 for everything else. I # think this biases the results in the direction most people expect, # especially when e.g. German names are very similar to English names speller_entries = [] for cls in self.indexed_tables.values(): q = self.session.query(cls) for row in q.yield_per(5): row_key = dict(table=unicode(cls.__tablename__), row_id=unicode(row.id)) def add(name, language, iso3166, score): normalized_name = self.normalize_name(name) writer.add_document( name=normalized_name, display_name=name, language=language, iso3166=iso3166, **row_key ) speller_entries.append((normalized_name, score)) # Add the basic English name to the index if cls == tables.Pokemon: # Pokémon need their form name added # XXX kinda kludgy add(row.full_name, None, u'us', 1) # If this is a default form, ALSO add the unadorned name, # so 'Deoxys' alone will still do the right thing if row.forme_name and not row.forme_base_pokemon_id: add(row.name, None, u'us', 1) else: add(row.name, None, u'us', 1) # Some things also have other languages' names # XXX other language form names..? for foreign_name in getattr(row, 'foreign_names', []): moonspeak = foreign_name.name if row.name == moonspeak: # Don't add the English name again as a different # language; no point and it makes spell results # confusing continue add(moonspeak, foreign_name.language.name, foreign_name.language.iso3166, 3) # Add Roomaji too if foreign_name.language.name == 'Japanese': roomaji = romanize(foreign_name.name) add(roomaji, u'Roomaji', u'jp', 8) writer.commit() # Construct and populate a spell-checker index. Quicker to do it all # at once, as every call to add_* does a commit(), and those seem to be # expensive self.speller = whoosh.spelling.SpellChecker(self.index.storage) self.speller.add_scored_words(speller_entries) def normalize_name(self, name): """Strips irrelevant formatting junk from name input. Specifically: everything is lowercased, and accents are removed. """ # http://stackoverflow.com/questions/517923/what-is-the-best-way-to-remove-accents-in-a-python-unicode-string # Makes sense to me. Decompose by Unicode rules, then remove combining # characters, then recombine. I'm explicitly doing it this way instead # of testing combining() because Korean characters apparently # decompose! But the results are considered letters, not combining # characters, so testing for Mn works well, and combining them again # makes them look right. nkfd_form = unicodedata.normalize('NFKD', unicode(name)) name = u"".join(c for c in nkfd_form if unicodedata.category(c) != 'Mn') name = unicodedata.normalize('NFC', name) name = name.strip() name = name.lower() return name def _parse_table_name(self, name): """Takes a singular table name, table name, or table object and returns the table name. Returns None for a bogus name. """ if hasattr(name, '__tablename__'): return getattr(name, '__tablename__') elif name in self.indexed_tables: return name elif name + 's' in self.indexed_tables: return name + 's' else: # Bogus. Be nice and return dummy return None def _whoosh_records_to_results(self, records, exact=True): """Converts a list of whoosh's indexed records to LookupResult tuples containing database objects. """ # XXX this 'exact' thing is getting kinda leaky. would like a better # way to handle it, since only lookup() cares about fuzzy results seen = {} results = [] for record in records: # Skip dupes seen_key = record['table'], record['row_id'] if seen_key in seen: continue seen[seen_key] = True cls = self.indexed_tables[record['table']] obj = self.session.query(cls).get(record['row_id']) results.append(LookupResult(object=obj, indexed_name=record['name'], name=record['display_name'], language=record['language'], iso3166=record['iso3166'], exact=exact)) return results def lookup(self, input, valid_types=[], exact_only=False): """Attempts to find some sort of object, given a name. Returns a list of named (object, name, language, iso3166, exact) tuples. `object` is a database object, `name` is the name under which the object was found, `language` and `iso3166` are the name and country code of the language in which the name was found, and `exact` is True iff this was an exact match. This function currently ONLY does fuzzy matching if there are no exact matches. Formes are not returned unless requested; "Shaymin" will return only grass Shaymin. Extraneous whitespace is removed with extreme prejudice. Recognizes: - Names: "Eevee", "Surf", "Run Away", "Payapa Berry", etc. - Foreign names: "Iibui", "Eivui" - Fuzzy names in whatever language: "Evee", "Ibui" - IDs: "133", "192", "250" Also: - Type restrictions. "type:psychic" will only return the type. This is how to make ID lookup useful. Multiple type specs can be entered with commas, as "move,item:1". If `valid_types` are provided, any type prefix will be ignored. - Alternate formes can be specified merely like "wash rotom". `input` Name of the thing to look for. `valid_types` A list of table objects or names, e.g., `['pokemon', 'moves']`. If this is provided, only results in one of the given tables will be returned. `exact_only` If True, only exact matches are returned. If set to False (the default), and the provided `name` doesn't match anything exactly, spelling correction will be attempted. """ name = self.normalize_name(input) exact = True form = None # Remove any type prefix (pokemon:133) before constructing a query if ':' in name: prefix_chunk, name = name.split(':', 1) name = name.strip() if not valid_types: # Only use types from the query string if none were explicitly # provided prefixes = prefix_chunk.split(',') valid_types = [_.strip() for _ in prefixes] # Random lookup if name == 'random': return self.random_lookup(valid_types=valid_types) # Do different things depending what the query looks like # Note: Term objects do an exact match, so we don't have to worry about # a query parser tripping on weird characters in the input if '*' in name or '?' in name: exact_only = True query = whoosh.query.Wildcard(u'name', name) elif rx_is_number.match(name): # Don't spell-check numbers! exact_only = True query = whoosh.query.Term(u'row_id', name) else: # Not an integer query = whoosh.query.Term(u'name', name) ### Filter by type of object type_terms = [] for valid_type in valid_types: table_name = self._parse_table_name(valid_type) if table_name: # Quietly ignore bogus valid_types; more likely to DTRT type_terms.append(whoosh.query.Term(u'table', table_name)) if type_terms: query = query & whoosh.query.Or(type_terms) ### Actual searching searcher = self.index.searcher() # XXX is this kosher? docs say search() takes a weighting arg, but it # certainly does not searcher.weighting = LanguageWeighting() results = searcher.search(query, limit=self.INTERMEDIATE_LOOKUP_RESULTS) # Look for some fuzzy matches if necessary if not exact_only and not results: exact = False results = [] for suggestion in self.speller.suggest( name, self.INTERMEDIATE_LOOKUP_RESULTS): query = whoosh.query.Term('name', suggestion) results.extend(searcher.search(query)) ### Convert results to db objects objects = self._whoosh_records_to_results(results, exact=exact) # Only return up to 10 matches; beyond that, something is wrong. We # strip out duplicate entries above, so it's remotely possible that we # should have more than 10 here and lost a few. The speller returns 25 # to give us some padding, and should avoid that problem. Not a big # deal if we lose the 25th-most-likely match anyway. return objects[:self.MAX_LOOKUP_RESULTS] def random_lookup(self, valid_types=[]): """Returns a random lookup result from one of the provided `valid_types`. """ tables = [] for valid_type in valid_types: table_name = self._parse_table_name(valid_type) if table_name: tables.append(self.indexed_tables[table_name]) if not tables: # n.b.: It's possible we got a list of valid_types and none of them # were valid, but this function is guaranteed to return # *something*, so it politely selects from the entire index isntead tables = self.indexed_tables.values() # Rather than create an array of many hundred items and pick randomly # from it, just pick a number up to the total number of potential # items, then pick randomly from that, and partition the whole range # into chunks. This also avoids the slight problem that the index # contains more rows (for languages) for some items than others. # XXX ought to cache this (in the index?) if possible total = 0 partitions = [] for table in tables: count = self.session.query(table).count() total += count partitions.append((table, count)) n = random.randint(1, total) while n > partitions[0][1]: n -= partitions[0][1] partitions.pop(0) return self.lookup(unicode(n), valid_types=[ partitions[0][0] ]) def prefix_lookup(self, prefix): """Returns terms starting with the given exact prefix. No special magic is currently done with the name; type prefixes are not recognized. """ query = whoosh.query.Prefix(u'name', self.normalize_name(prefix)) searcher = self.index.searcher() searcher.weighting = LanguageWeighting() results = searcher.search(query) # XXX , limit=self.MAX_LOOKUP_RESULTS) return self._whoosh_records_to_results(results)