Prefix lookup is now case-insensitive.
[zzz-pokedex.git] / pokedex / lookup.py
index 09c0a22..28dd4b2 100644 (file)
@@ -2,7 +2,9 @@
 from collections import namedtuple
 import os, os.path
 import pkg_resources
+import random
 import re
+import shutil
 
 from sqlalchemy.sql import func
 import whoosh
@@ -17,7 +19,10 @@ from pokedex.db import connect
 import pokedex.db.tables as tables
 from pokedex.roomaji import romanize
 
-__all__ = ['open_index', 'lookup']
+__all__ = ['open_index', 'lookup', 'random_lookup']
+
+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
@@ -71,6 +76,14 @@ def open_index(directory=None, session=None, recreate=False):
             # Apparently not a real index.  Fall out of the if 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)
 
@@ -104,15 +117,18 @@ def open_index(directory=None, session=None, recreate=False):
                            row_id=unicode(row.id),
                            forme_name=u'XXX')
 
+            def add(name, language, score):
+                writer.add_document(name=name.lower(), display_name=name,
+                                    language=language,
+                                    **row_key)
+                speller_entries.append((name.lower(), score))
+
             # If this is a form, mark it as such
             if getattr(row, 'forme_base_pokemon_id', None):
                 row_key['forme_name'] = row.forme_name
 
             name = row.name
-            writer.add_document(name=name.lower(),
-                                display_name=name,
-                                **row_key)
-            speller_entries.append((name.lower(), 1))
+            add(name, None, 1)
 
             # Pokemon also get other languages
             for foreign_name in getattr(row, 'foreign_names', []):
@@ -122,21 +138,12 @@ def open_index(directory=None, session=None, recreate=False):
                     # no point and it makes spell results confusing
                     continue
 
-                writer.add_document(name=moonspeak.lower(),
-                                    language=foreign_name.language.name,
-                                    display_name=moonspeak,
-                                    **row_key)
-                speller_entries.append((moonspeak.lower(), 3))
+                add(moonspeak, foreign_name.language.name, 3)
 
                 # Add Roomaji too
                 if foreign_name.language.name == 'Japanese':
                     roomaji = romanize(foreign_name.name)
-                    writer.add_document(name=roomaji.lower(),
-                                        language='Roomaji',
-                                        display_name=roomaji,
-                                        **row_key)
-                    speller_entries.append((roomaji.lower(), 8))
-
+                    add(roomaji, u'Roomaji', 8)
 
     writer.commit()
 
@@ -170,6 +177,49 @@ rx_is_number = re.compile('^\d+$')
 
 LookupResult = namedtuple('LookupResult',
                           ['object', 'name', 'language', 'exact'])
+
+def _parse_table_name(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 indexed_tables:
+        return name
+    elif name + 's' in indexed_tables:
+        return name + 's'
+    else:
+        # Bogus.  Be nice and return dummy
+        return None
+
+def _whoosh_records_to_results(records, session, 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 = indexed_tables[record['table']]
+        obj = session.query(cls).get(record['row_id'])
+
+        results.append(LookupResult(object=obj,
+                                    name=record['display_name'],
+                                    language=record['language'],
+                                    exact=exact))
+
+    return results
+
+
 def lookup(input, valid_types=[], session=None, indices=None, exact_only=False):
     """Attempts to find some sort of object, given a database session and name.
 
@@ -181,7 +231,10 @@ def lookup(input, valid_types=[], session=None, indices=None, exact_only=False):
     This function currently ONLY does fuzzy matching if there are no exact
     matches.
 
-    Formes are not returned; "Shaymin" will return only grass Shaymin.
+    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.
@@ -226,23 +279,34 @@ def lookup(input, valid_types=[], session=None, indices=None, exact_only=False):
     else:
         index, speller = open_index()
 
-    name = unicode(input).lower()
+    name = unicode(input).strip().lower()
     exact = True
     form = None
 
     # Remove any type prefix (pokemon:133) before constructing a query
     if ':' in name:
-        prefix_chunk, name = name.split(':', 2)
-        prefixes = prefix_chunk.split(',')
+        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
-            valid_types = prefixes
-
-    # If the input provided is a number, match it as an id.  Otherwise, name.
-    # 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 rx_is_number.match(name):
+            prefixes = prefix_chunk.split(',')
+            valid_types = [_.strip() for _ in prefixes]
+
+    # Random lookup
+    if name == 'random':
+        return random_lookup(indices=(index, speller),
+                             session=session,
+                             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)
@@ -253,7 +317,7 @@ def lookup(input, valid_types=[], session=None, indices=None, exact_only=False):
 
         # If there's a space in the input, this might be a form
         if ' ' in name:
-            form, formless_name = name.split(' ', 2)
+            form, formless_name = name.split(' ', 1)
             form_query = whoosh.query.Term(u'name', formless_name) \
                        & whoosh.query.Term(u'forme_name', form)
             query = query | form_query
@@ -261,16 +325,7 @@ def lookup(input, valid_types=[], session=None, indices=None, exact_only=False):
     ### Filter by type of object
     type_terms = []
     for valid_type in valid_types:
-        if hasattr(valid_type, '__tablename__'):
-            table_name = getattr(valid_type, '__tablename__')
-        elif valid_type in indexed_tables:
-            table_name = valid_type
-        elif valid_type + 's' in indexed_tables:
-            table_name = valid_type + 's'
-        else:
-            # Bogus.  Be nice and ignore it
-            continue
-
+        table_name = _parse_table_name(valid_type)
         type_terms.append(whoosh.query.Term(u'table', table_name))
 
     if type_terms:
@@ -282,38 +337,81 @@ def lookup(input, valid_types=[], session=None, indices=None, exact_only=False):
     searcher.weighting = LanguageWeighting()  # XXX kosher?  docs say search()
                                               # takes a weighting kw but it
                                               # certainly does not
-    results = searcher.search(query)
+    results = searcher.search(query, limit=INTERMEDIATE_LOOKUP_RESULTS)
 
     # Look for some fuzzy matches if necessary
     if not exact_only and not results:
         exact = False
         results = []
 
-        for suggestion in speller.suggest(name, 25):
+        for suggestion in speller.suggest(name, INTERMEDIATE_LOOKUP_RESULTS):
             query = whoosh.query.Term('name', suggestion)
             results.extend(searcher.search(query))
 
     ### Convert results to db objects
-    objects = []
-    seen = {}
-    for result in results:
-        # Skip dupe results
-        seen_key = result['table'], result['row_id']
-        if seen_key in seen:
-            continue
-        seen[seen_key] = True
-
-        cls = indexed_tables[result['table']]
-        obj = session.query(cls).get(result['row_id'])
-
-        objects.append(LookupResult(object=obj,
-                                    name=result['display_name'],
-                                    language=result['language'],
-                                    exact=exact))
+    objects = _whoosh_records_to_results(results, session, 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[:10]
+    return objects[:MAX_LOOKUP_RESULTS]
+
+
+def random_lookup(valid_types=[], session=None, indices=None):
+    """Takes similar arguments as `lookup()`, but returns a random lookup
+    result from one of the provided `valid_types`.
+    """
+
+    tables = []
+    for valid_type in valid_types:
+        table_name = _parse_table_name(valid_type)
+        if table_name:
+            tables.append(indexed_tables[table_name])
+
+    if not tables:
+        tables = 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
+    total = 0
+    partitions = []
+    for table in tables:
+        count = 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 lookup(unicode(n), valid_types=[ partitions[0][0] ],
+                  indices=indices, session=session)
+
+def prefix_lookup(prefix, session=None, indices=None):
+    """Returns terms starting with the given exact prefix.
+
+    No special magic is currently done with the name; type prefixes are not
+    recognized.
+
+    `session` and `indices` are treated as with `lookup()`.
+    """
+
+    if not session:
+        session = connect()
+
+    if indices:
+        index, speller = indices
+    else:
+        index, speller = open_index()
+
+    query = whoosh.query.Prefix(u'name', prefix.lower())
+
+    searcher = index.searcher()
+    searcher.weighting = LanguageWeighting()
+    results = searcher.search(query)  # XXX , limit=MAX_LOOKUP_RESULTS)
+
+    return _whoosh_records_to_results(results, session)