Added lookup support for foreign language names. #15
[zzz-pokedex.git] / pokedex / lookup.py
index 2b38a1a..0bf1c18 100644 (file)
@@ -1,5 +1,7 @@
 # encoding: utf8
+from collections import namedtuple
 import os, os.path
+import pkg_resources
 import re
 
 from sqlalchemy.sql import func
@@ -10,7 +12,9 @@ import whoosh.index
 from whoosh.qparser import QueryParser
 import whoosh.spelling
 
+from pokedex.db import connect
 import pokedex.db.tables as tables
+from pokedex.roomaji import romanize
 
 # Dictionary of table name => table class.
 # Need the table name so we can get the class from the table name after we
@@ -36,32 +40,58 @@ extra_keys = {
     ],
 }
 
-index_bits = {}
-def get_index(session):
-    """Returns (index, speller).
+def open_index(directory=None, session=None, recreate=False):
+    """Opens the whoosh index stored in the named directory and returns (index,
+    speller).  If the index doesn't already exist, it will be created.
 
-    Creates an index if one does not exist.
+    `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.
     """
 
-    if index_bits:
-        return index_bits['index'], index_bits['speller']
+    # Defaults
+    if not directory:
+        directory = pkg_resources.resource_filename('pokedex',
+                                                    'data/whoosh_index')
+
+    if not session:
+        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!
+        try:
+            index = whoosh.index.open_dir(directory, indexname='MAIN')
+            spell_store = whoosh.filedb.filestore.FileStorage(directory)
+            speller = whoosh.spelling.SpellChecker(spell_store)
+            return index, speller
+        except whoosh.index.EmptyIndexError as e:
+            # Apparently not a real index.  Fall out of the if and create it
+            pass
+
+    if not directory_exists:
+        os.mkdir(directory)
+
 
-    store = whoosh.filedb.filestore.RamStorage()
+    # Create index
     schema = whoosh.fields.Schema(
         name=whoosh.fields.ID(stored=True),
         table=whoosh.fields.STORED,
         row_id=whoosh.fields.STORED,
         language=whoosh.fields.STORED,
-
-        # Whoosh 0.2 explodes when using a file-stored schema with no TEXT
-        # columns.  Appease it
-        dummy=whoosh.fields.TEXT,
     )
 
-    index_directory = '/var/tmp/pokedex'
-    if not os.path.exists(index_directory):
-        os.mkdir(index_directory)
-    index = whoosh.index.create_in(index_directory, schema=schema)
+    index = whoosh.index.create_in(directory, schema=schema, indexname='MAIN')
     writer = index.writer()
 
     # Index every name in all our tables of interest
@@ -76,77 +106,88 @@ def get_index(session):
         for row in q.yield_per(5):
             row_key = dict(table=cls.__tablename__, row_id=row.id)
 
-            # Spelling index only indexes strings of letters, alas, so we
-            # reduce every name to this to make the index work.  However, exact
-            # matches are not returned, so e.g. 'nidoran' would neither match
-            # exactly nor fuzzy-match.  Solution: add the spelling-munged name
-            # as a regular index row too.
             name = row.name.lower()
             writer.add_document(name=name, **row_key)
-
             speller_entries.append(name)
 
             for extra_key_func in extra_keys.get(cls, []):
                 extra_key = extra_key_func(row)
                 writer.add_document(name=extra_key, **row_key)
 
-    writer.commit()
+            # Pokemon also get other languages
+            if cls == tables.Pokemon:
+                for foreign_name in row.foreign_names:
+                    name = foreign_name.name.lower()
+                    writer.add_document(name=name,
+                                        language=foreign_name.language.name,
+                                        **row_key)
+                    speller_entries.append(name)
+
+                    if foreign_name.language.name == 'Japanese':
+                        # Add Roomaji too
+                        roomaji = romanize(foreign_name.name).lower()
+                        writer.add_document(name=roomaji,
+                                            language='Roomaji',
+                                            **row_key)
+                        speller_entries.append(roomaji)
+
 
-    # XXX GIHWEGREHKG
-    old__schema = whoosh.spelling.SpellChecker._schema
-    def new__schema(self):
-        schema = old__schema(self)
-        schema.add('dummy', whoosh.fields.TEXT)
-        return schema
-    whoosh.spelling.SpellChecker._schema = new__schema
+    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
     speller = whoosh.spelling.SpellChecker(index.storage)
-    # WARNING: HERE BE DRAGONS
-    # whoosh.spelling refuses to index things that don't look like words.
-    # Unfortunately, this doesn't work so well for Pokémon (Mr. Mime,
-    # Porygon-Z, etc.), and attempts to work around it lead to further
-    # complications.
-    # The below is copied from SpellChecker.add_scored_words without the check
-    # for isalpha().  XXX get whoosh patched to make this unnecessary!
-    writer = speller.index(create=True).writer()
-    for word in speller_entries:
-        fields = {"word": word, "score": 1}
-        for size in xrange(speller.mingram, speller.maxgram + 1):
-            nga = whoosh.analysis.NgramAnalyzer(size)
-            gramlist = [t.text for t in nga(word)]
-            if len(gramlist) > 0:
-                fields["start%s" % size] = gramlist[0]
-                fields["end%s" % size] = gramlist[-1]
-                fields["gram%s" % size] = " ".join(gramlist)
-        writer.add_document(**fields)
-    writer.commit()
-    # end copy-pasta
+    speller.add_words(speller_entries)
+
+    return index, speller
 
-    index_bits['index'] = index
-    index_bits['speller'] = speller
-    index_bits['store'] = store
-    return index_bits['index'], index_bits['speller']
 
-def lookup(session, name, exact_only=False):
+LookupResult = namedtuple('LookupResult', ['object', 'language', 'exact'])
+def lookup(name, session=None, indices=None, exact_only=False):
     """Attempts to find some sort of object, given a database session and name.
 
-    Returns (objects, exact) where `objects` is a list of database objects, and
-    `exact` is True iff the given name matched the returned objects exactly.
+    Returns a list of named (object, language, exact) tuples.  `object` is a
+    database object, `language` is the name of the language in which the name
+    was found, and `exact` is True iff this was an exact match.
 
-    This function ONLY does fuzzy matching if there are no exact matches.
+    This function currently ONLY does fuzzy matching if there are no exact
+    matches.
 
     Formes are not returned; "Shaymin" will return only grass Shaymin.
 
-    Currently recognizes:
+    Recognizes:
     - Pokémon names: "Eevee"
+
+    `name`
+        Name of the thing to look for.
+
+    `session`
+        A database session to use for retrieving objects.  As with get_index,
+        if this is not provided, a connection to the default database will be
+        attempted.
+
+    `indices`
+        Tuple of index, speller as returned from `open_index()`.  Defaults to
+        a call to `open_index()`.
+
+    `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.
     """
 
-    exact = True
+    if not session:
+        session = connect()
+
+    if indices:
+        index, speller = indices
+    else:
+        index, speller = open_index()
 
-    index, speller = get_index(session)
+    name = unicode(name)
+
+    exact = True
 
     # Look for exact name.  A Term object does an exact match, so we don't have
     # to worry about a query parser tripping on weird characters in the input
@@ -154,17 +195,16 @@ def lookup(session, name, exact_only=False):
     query = whoosh.query.Term('name', name.lower())
     results = searcher.search(query)
 
-    if not exact_only:
-        # Look for some fuzzy matches
-        if not results:
-            exact = False
-            results = []
+    # Look for some fuzzy matches if necessary
+    if not exact_only and not results:
+        exact = False
+        results = []
 
-            for suggestion in speller.suggest(name, 3):
-                query = whoosh.query.Term('name', suggestion)
-                results.extend(searcher.search(query))
+        for suggestion in speller.suggest(name, 10):
+            query = whoosh.query.Term('name', suggestion)
+            results.extend(searcher.search(query))
 
-    # Convert results to db objects
+    ### Convert results to db objects
     objects = []
     seen = {}
     for result in results:
@@ -176,6 +216,6 @@ def lookup(session, name, exact_only=False):
 
         cls = indexed_tables[result['table']]
         obj = session.query(cls).get(result['row_id'])
-        objects.append(obj)
+        objects.append(LookupResult(obj, result['language'], exact))
 
-    return objects, exact
+    return objects