Added backend filament search by similar color

spoolman/database/filament.py

@@ -14,12 +14,14 @@ from spoolman.api.v1.models import EventType, Filament, FilamentEvent
 from spoolman.database import models, vendor
 from spoolman.database.utils import (
     SortOrder,
+    add_where_clause_int_in,
     add_where_clause_int_opt,
     add_where_clause_str,
     add_where_clause_str_opt,
     parse_nested_field,
 )
 from spoolman.exceptions import ItemDeleteError, ItemNotFoundError
+from spoolman.math import delta_e, hex_to_rgb, rgb_to_lab
 from spoolman.ws import websocket_manager
 
 
@@ -82,6 +84,7 @@ async def get_by_id(db: AsyncSession, filament_id: int) -> models.Filament:
 async def find(
     *,
     db: AsyncSession,
+    ids: Optional[list[int]] = None,
     vendor_name: Optional[str] = None,
     vendor_id: Optional[Union[int, Sequence[int]]] = None,
     name: Optional[str] = None,
@@ -104,6 +107,7 @@ async def find(
         .join(models.Filament.vendor, isouter=True)
     )
 
+    stmt = add_where_clause_int_in(stmt, models.Filament.id, ids)
     stmt = add_where_clause_int_opt(stmt, models.Filament.vendor_id, vendor_id)
     stmt = add_where_clause_str(stmt, models.Vendor.name, vendor_name)
     stmt = add_where_clause_str_opt(stmt, models.Filament.name, name)
@@ -190,6 +194,33 @@ async def find_article_numbers(
     return [row[0] for row in rows.all() if row[0] is not None]
 
 
+async def find_by_color(
+    *,
+    db: AsyncSession,
+    color_query_hex: str,
+    similarity_threshold: float = 25,
+) -> list[models.Filament]:
+    """Find a list of filament objects by similarity to a color.
+
+    This performs a server-side search, where all filaments are loaded into memory, making it not so efficient.
+    The similarity threshold is a value between 0 and 100, where 0 means the colors must be identical and 100 means
+    pretty much all colors are considered similar.
+    """
+    filaments, _ = await find(db=db)
+
+    color_query_lab = rgb_to_lab(hex_to_rgb(color_query_hex))
+
+    found_filaments: list[models.Filament] = []
+    for filament in filaments:
+        if filament.color_hex is None:
+            continue
+        color_lab = rgb_to_lab(hex_to_rgb(filament.color_hex))
+        if delta_e(color_query_lab, color_lab) <= similarity_threshold:
+            found_filaments.append(filament)
+
+    return found_filaments
+
+
 async def filament_changed(filament: models.Filament, typ: EventType) -> None:
     """Notify websocket clients that a filament has changed."""
     await websocket_manager.send(

spoolman/database/utils.py

@@ -2,7 +2,7 @@
 
 from collections.abc import Sequence
 from enum import Enum
-from typing import Any, Optional, Union
+from typing import Any, Optional, TypeVar, Union
 
 import sqlalchemy
 from sqlalchemy import Select
@@ -105,3 +105,17 @@ def add_where_clause_int_opt(
                 statements.append(field == value_part)
         stmt = stmt.where(sqlalchemy.or_(*statements))
     return stmt
+
+
+T = TypeVar("T")
+
+
+def add_where_clause_int_in(
+    stmt: Select,
+    field: attributes.InstrumentedAttribute[T],
+    value: Optional[Sequence[T]],
+) -> Select:
+    """Add a where clause to a select statement for a field."""
+    if value is not None and len(value) > 0:
+        stmt = stmt.where(field.in_(value))
+    return stmt