feat: search tokenization, handling of quoted literal search, and pos…

…tgres fuzziness (#2351)

* Creating postgres migration script and starting to set up to detect database

* non-working placeholders for postgres pg_tgrm

* First draft of some indexes

* non-working commit of postgres indexing

* Further non-working edits to db-centric fuzzy search

* update alembic for extensions

* More non-working setup

* Move db type check to init_db

* fix typo in db name check

* Add sqlite token search and postgres full text search

* reorder search to hit exact matches faster

* Add settings and docs for POSTGRES_LANGUAGE (full text search)

* Use user-specified POSTGRES_LANGUAGE in search

* fix fuzzy search typo

* Remove full text search and instead order by trigram match

* cleaner adding of indices, remove fulltext

* Cleanup old import of getting app settings

* Fix typo in index

* Fix some alembic fuzzy typos

* Remove diagnostic printing from alembic migration

* Fix mixed up commutator for trigram operator and relax criteria

* forgot to remove query debug

* sort only on name

* token and fuzzy search tests

* Refactor recipe search test to avoid rare random string cross-matches.

* Add ability to quote parts of search for exact match

* Remove internal punctuation, unless it's quoted for literal search

* Add tests for special character removal and literal search

* Remove the outer double quotes from searches, but leave internal single quotes alone.

* Update tests to avoid intra-test name collisions

* Fixing leftovers highlighted by lint

* cleanup linting and mypy errors

* Fix test cross-matching on dirty db (leftovers from bulk import)

* forgot to cleanup something when debugging mypy errors

* re-order pg_trgm loading in postgres

* address comments

alembic/versions/2023-04-13-06.47.04_b3dbb554ba53_postgres_fuzzy_search.py

@@ -0,0 +1,89 @@
+"""postgres fuzzy search
+
+Revision ID: b3dbb554ba53
+Revises: 38514b39a824
+Create Date: 2023-04-13 06:47:04.617131
+
+"""
+import sqlalchemy as sa
+
+import mealie.db.migration_types
+from alembic import op
+import alembic.context as context
+from mealie.core.config import get_app_settings
+
+# revision identifiers, used by Alembic.
+revision = "b3dbb554ba53"
+down_revision = "38514b39a824"
+branch_labels = None
+depends_on = None
+
+
+def get_db_type():
+    return op.get_context().dialect.name
+
+
+def setup_postgres_trigrams():
+    op.execute("CREATE EXTENSION IF NOT EXISTS pg_trgm;")
+    op.create_index(
+        "ix_recipes_name_normalized_gin",
+        table_name="recipes",
+        columns=["name_normalized"],
+        unique=False,
+        postgresql_using="gin",
+        postgresql_ops={
+            "name_normalized": "gin_trgm_ops",
+        },
+    )
+    op.create_index(
+        "ix_recipes_description_normalized_gin",
+        table_name="recipes",
+        columns=["description_normalized"],
+        unique=False,
+        postgresql_using="gin",
+        postgresql_ops={
+            "description_normalized": "gin_trgm_ops",
+        },
+    )
+    op.create_index(
+        "ix_recipes_ingredients_note_normalized_gin",
+        table_name="recipes_ingredients",
+        columns=["note_normalized"],
+        unique=False,
+        postgresql_using="gin",
+        postgresql_ops={
+            "note_normalized": "gin_trgm_ops",
+        },
+    )
+    op.create_index(
+        "ix_recipes_ingredients_original_text_normalized_gin",
+        table_name="recipes_ingredients",
+        columns=["original_text_normalized"],
+        unique=False,
+        postgresql_using="gin",
+        postgresql_ops={
+            "original_text_normalized": "gin_trgm_ops",
+        },
+    )
+
+
+def remove_postgres_trigrams():
+    op.execute("DROP EXTENSION IF EXISTS pg_trgm;")
+    op.drop_index("ix_recipes_name_normalized_gin", table_name="recipe")
+    op.drop_index("ix_recipes_description_normalized_gin", table_name="recipe")
+    op.drop_index("ix_recipes_ingredients_note_normalized_gin", table_name="recipes_ingredients")
+    op.drop_index("ix_recipes_ingredients_original_text_normalized_gin", table_name="recipes_ingredients")
+
+
+def upgrade():
+    if get_db_type() == "postgresql":
+        setup_postgres_trigrams()
+    else:
+        pass
+
+
+def downgrade():
+    if get_db_type() == "postgres":
+        remove_postgres_trigrams()
+    else:
+        pass

docs/docs/documentation/getting-started/faq.md

@@ -68,6 +68,13 @@ Yes, you can install Mealie on your local machine. HOWEVER, it is recommended th
 
 - [Advanced Installation](../installation/advanced/)
 
+## What is fuzzy search and how do I use it?
+Mealie can use fuzzy search, which is robust to minor typos. For example, searching for "brocolli" will still find your recipe for "broccoli soup". But fuzzy search is only functional on a Postgres database backend. To enable fuzzy search you will need to migrate to Postgres:
+
+1. Backup your database and download the .zip file (same as when [migrating](./migrating-to-mealie-v1.md))
+2. Set up a [Postgres](./installation/postgres.md) instance of Mealie
+3. Upload the backup .zip and click to apply it (as as migration)
+
 ## How i can attach an image or video to a Recipe?
 
 Yes. Mealie's Recipe Steps and other fields support the markdown syntax and therefor supports images and videos. To attach an image to the recipe, you can upload it as an asset and use the provided copy button to generate the html image tag required to render the image. For videos, Mealie provides no way to host videos. You'll need to host your videos with another provider and embed them in your recipe. Generally, the video provider will provide a link to the video and the html tag required to render the video. For example, youtube provides the following link that works inside a step. You can adjust the width and height attributes as necessary to ensure a fit.

mealie/db/init_db.py

@@ -92,6 +92,9 @@ def main():
             logger.info("Migration needed. Performing migration...")
             command.upgrade(alembic_cfg, "head")
 
+        if session.get_bind().name == "postgresql":  # needed for fuzzy search and fast GIN text indices
+            session.execute(text("CREATE EXTENSION IF NOT EXISTS pg_trgm;"))
+
         db = get_repositories(session)
 
         if db.users.get_all():

mealie/db/models/recipe/ingredient.py

@@ -1,7 +1,9 @@
 from typing import TYPE_CHECKING
 
+import sqlalchemy as sa
 from sqlalchemy import Boolean, Float, ForeignKey, Integer, String, event, orm
 from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.orm.session import Session
 from text_unidecode import unidecode
 
 from mealie.db.models._model_base import BaseMixins, SqlAlchemyBase
@@ -87,21 +89,59 @@ class RecipeIngredientModel(SqlAlchemyBase, BaseMixins):
     original_text_normalized: Mapped[str | None] = mapped_column(String, index=True)
 
     @auto_init()
-    def __init__(self, note: str | None = None, orginal_text: str | None = None, **_) -> None:
+    def __init__(self, session: Session, note: str | None = None, orginal_text: str | None = None, **_) -> None:
         # SQLAlchemy events do not seem to register things that are set during auto_init
         if note is not None:
             self.note_normalized = unidecode(note).lower().strip()
 
         if orginal_text is not None:
             self.orginal_text = unidecode(orginal_text).lower().strip()
 
+        tableargs = [  # base set of indices
+            sa.Index(
+                "ix_recipes_ingredients_note_normalized",
+                "note_normalized",
+                unique=False,
+            ),
+            sa.Index(
+                "ix_recipes_ingredients_original_text_normalized",
+                "original_text_normalized",
+                unique=False,
+            ),
+        ]
+        if session.get_bind().name == "postgresql":
+            tableargs.extend(
+                [
+                    sa.Index(
+                        "ix_recipes_ingredients_note_normalized_gin",
+                        "note_normalized",
+                        unique=False,
+                        postgresql_using="gin",
+                        postgresql_ops={
+                            "note_normalized": "gin_trgm_ops",
+                        },
+                    ),
+                    sa.Index(
+                        "ix_recipes_ingredients_original_text_normalized_gin",
+                        "original_text",
+                        unique=False,
+                        postgresql_using="gin",
+                        postgresql_ops={
+                            "original_text_normalized": "gin_trgm_ops",
+                        },
+                    ),
+                ]
+            )
+        # add indices
+        self.__table_args__ = tuple(tableargs)
+
 
 @event.listens_for(RecipeIngredientModel.note, "set")
 def receive_note(target: RecipeIngredientModel, value: str, oldvalue, initiator):
     if value is not None:
-        target.name_normalized = unidecode(value).lower().strip()
+        target.note_normalized = unidecode(value).lower().strip()
     else:
-        target.name_normalized = None
+        target.note_normalized = None
 
 
 @event.listens_for(RecipeIngredientModel.original_text, "set")

mealie/db/models/recipe/recipe.py

@@ -35,7 +35,9 @@
 
 class RecipeModel(SqlAlchemyBase, BaseMixins):
     __tablename__ = "recipes"
-    __table_args__ = (sa.UniqueConstraint("slug", "group_id", name="recipe_slug_group_id_key"),)
+    __table_args__: tuple[sa.UniqueConstraint, ...] = (
+        sa.UniqueConstraint("slug", "group_id", name="recipe_slug_group_id_key"),
+    )
 
     id: Mapped[GUID] = mapped_column(GUID, primary_key=True, default=GUID.generate)
     slug: Mapped[str | None] = mapped_column(sa.String, index=True)
@@ -192,6 +194,46 @@ def __init__(
         if description is not None:
             self.description_normalized = unidecode(description).lower().strip()
 
+        tableargs = [  # base set of indices
+            sa.UniqueConstraint("slug", "group_id", name="recipe_slug_group_id_key"),
+            sa.Index(
+                "ix_recipes_name_normalized",
+                "name_normalized",
+                unique=False,
+            ),
+            sa.Index(
+                "ix_recipes_description_normalized",
+                "description_normalized",
+                unique=False,
+            ),
+        ]
+
+        if session.get_bind().name == "postgresql":
+            tableargs.extend(
+                [
+                    sa.Index(
+                        "ix_recipes_name_normalized_gin",
+                        "name_normalized",
+                        unique=False,
+                        postgresql_using="gin",
+                        postgresql_ops={
+                            "name_normalized": "gin_trgm_ops",
+                        },
+                    ),
+                    sa.Index(
+                        "ix_recipes_description_normalized_gin",
+                        "description_normalized",
+                        unique=False,
+                        postgresql_using="gin",
+                        postgresql_ops={
+                            "description_normalized": "gin_trgm_ops",
+                        },
+                    ),
+                ]
+            )
+        # add indices
+        self.__table_args__ = tuple(tableargs)
+
 
 @event.listens_for(RecipeModel.name, "set")
 def receive_name(target: RecipeModel, value: str, oldvalue, initiator):

mealie/repos/repository_recipes.py

@@ -1,10 +1,11 @@
+import re as re
 from collections.abc import Sequence
 from random import randint
 from uuid import UUID
 
 from pydantic import UUID4
 from slugify import slugify
-from sqlalchemy import Select, and_, desc, func, or_, select
+from sqlalchemy import Select, and_, desc, func, or_, select, text
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.orm import joinedload
 from text_unidecode import unidecode
@@ -151,29 +152,94 @@ def _uuids_for_items(self, items: list[UUID | str] | None, model: type[SqlAlchem
         return ids + additional_ids
 
     def _add_search_to_query(self, query: Select, search: str) -> Select:
+        """
+        0. fuzzy search (postgres only) and tokenized search are performed separately
+        1. take search string and do a little pre-normalization
+        2. look for internal quoted strings and keep them together as "literal" parts of the search
+        3. remove special characters from each non-literal search string
+        4. token search looks for any individual exact hit in name, description, and ingredients
+        5. fuzzy search looks for trigram hits in name, description, and ingredients
+        6. Sort order is determined by closeness to the recipe name
+        Should search also look at tags?
+        """
+
         normalized_search = unidecode(search).lower().strip()
+        punctuation = "!\#$%&()*+,-./:;<=>?@[\\]^_`{|}~"  # string.punctuation with ' & " removed
+        # keep quoted phrases together as literal portions of the search string
+        literal = False
+        quoted_regex = re.compile(r"""(["'])(?:(?=(\\?))\2.)*?\1""")  # thank you stack exchange!
+        removequotes_regex = re.compile(r"""['"](.*)['"]""")
+        if quoted_regex.search(normalized_search):
+            literal = True
+            temp = normalized_search
+            quoted_search_list = [match.group() for match in quoted_regex.finditer(temp)]  # all quoted strings
+            quoted_search_list = [removequotes_regex.sub("\\1", x) for x in quoted_search_list]  # remove outer quotes
+            temp = quoted_regex.sub("", temp)  # remove all quoted strings, leaving just non-quoted
+            temp = temp.translate(
+                str.maketrans(punctuation, " " * len(punctuation))
+            )  # punctuation->spaces for splitting, but only on unquoted strings
+            unquoted_search_list = temp.split()  # all unquoted strings
+            normalized_search_list = quoted_search_list + unquoted_search_list
+        else:
+            #
+            normalized_search = normalized_search.translate(str.maketrans(punctuation, " " * len(punctuation)))
+            normalized_search_list = normalized_search.split()
+        normalized_search_list = [x.strip() for x in normalized_search_list]  # remove padding whitespace inside quotes
         # I would prefer to just do this in the recipe_ingredient.any part of the main query, but it turns out
         # that at least sqlite wont use indexes for that correctly anymore and takes a big hit, so prefiltering it is
-        ingredient_ids = (
-            self.session.execute(
-                select(RecipeIngredientModel.id).filter(
-                    or_(
-                        RecipeIngredientModel.note_normalized.like(f"%{normalized_search}%"),
-                        RecipeIngredientModel.original_text_normalized.like(f"%{normalized_search}%"),
+        if (self.session.get_bind().name == "postgresql") & (literal is False):  # fuzzy search
+            ingredient_ids = (
+                self.session.execute(
+                    select(RecipeIngredientModel.id).filter(
+                        or_(
+                            RecipeIngredientModel.note_normalized.op("%>")(normalized_search),
+                            RecipeIngredientModel.original_text_normalized.op("%>")(normalized_search),
+                        )
                     )
                 )
+                .scalars()
+                .all()
+            )
+        else:  # exact token search
+            ingredient_ids = (
+                self.session.execute(
+                    select(RecipeIngredientModel.id).filter(
+                        or_(
+                            *[RecipeIngredientModel.note_normalized.like(f"%{ns}%") for ns in normalized_search_list],
+                            *[
+                                RecipeIngredientModel.original_text_normalized.like(f"%{ns}%")
+                                for ns in normalized_search_list
+                            ],
+                        )
+                    )
+                )
+                .scalars()
+                .all()
             )
-            .scalars()
-            .all()
-        )
 
-        q = query.filter(
-            or_(
-                RecipeModel.name_normalized.like(f"%{normalized_search}%"),
-                RecipeModel.description_normalized.like(f"%{normalized_search}%"),
-                RecipeModel.recipe_ingredient.any(RecipeIngredientModel.id.in_(ingredient_ids)),
+        if (self.session.get_bind().name == "postgresql") & (literal is False):  # fuzzy search
+            # default = 0.7 is too strict for effective fuzzing
+            self.session.execute(text("set pg_trgm.word_similarity_threshold = 0.5;"))
+            q = query.filter(
+                or_(
+                    RecipeModel.name_normalized.op("%>")(normalized_search),
+                    RecipeModel.description_normalized.op("%>")(normalized_search),
+                    RecipeModel.recipe_ingredient.any(RecipeIngredientModel.id.in_(ingredient_ids)),
+                )
+            ).order_by(  # trigram ordering could be too slow on million record db, but is fine with thousands.
+                func.least(
+                    RecipeModel.name_normalized.op("<->>")(normalized_search),
+                )
             )
-        ).order_by(desc(RecipeModel.name_normalized.like(f"%{normalized_search}%")))
+        else:  # exact token search
+            q = query.filter(
+                or_(
+                    *[RecipeModel.name_normalized.like(f"%{ns}%") for ns in normalized_search_list],
+                    *[RecipeModel.description_normalized.like(f"%{ns}%") for ns in normalized_search_list],
+                    RecipeModel.recipe_ingredient.any(RecipeIngredientModel.id.in_(ingredient_ids)),
+                )
+            ).order_by(desc(RecipeModel.name_normalized.like(f"%{normalized_search}%")))
+
         return q
 
     def page_all(