Renamed to Spoolman

Spoolson just didn't sound that good after all

spoolman/database/spool.py

@@ -0,0 +1,120 @@
+"""Helper functions for interacting with spool database objects."""
+
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from spoolman.database import filament, models
+from spoolman.exceptions import ItemCreateError, ItemNotFoundError
+from spoolman.math import weight_from_length
+
+
+async def create(
+    *,
+    db: AsyncSession,
+    filament_id: int,
+    weight: Optional[float] = None,
+    first_used: Optional[datetime] = None,
+    last_used: Optional[datetime] = None,
+    location: Optional[str] = None,
+    lot_nr: Optional[str] = None,
+    comment: Optional[str] = None,
+) -> models.Spool:
+    """Add a new spool to the database. Leave weight empty to assume full spool."""
+    filament_item = await filament.get_by_id(db, filament_id)
+    if weight is None:
+        if filament_item.weight is None:
+            raise ItemCreateError("The weight for neither the spool nor its filament type is set.")
+        weight = filament_item.weight
+
+    db_item = models.Spool(
+        filament=filament_item,
+        weight=weight,
+        first_used=first_used,
+        last_used=last_used,
+        location=location,
+        lot_nr=lot_nr,
+        comment=comment,
+    )
+    db.add(db_item)
+    await db.flush()
+    return db_item
+
+
+async def get_by_id(db: AsyncSession, spool_id: int, with_for_update: Optional[bool] = None) -> models.Spool:
+    """Get a spool object from the database by the unique ID."""
+    spool = await db.get(models.Spool, spool_id, with_for_update=with_for_update)  # type: ignore  # noqa: PGH003
+    if spool is None:
+        raise ItemNotFoundError(f"No spool with ID {spool_id} found.")
+    return spool
+
+
+async def update(
+    *,
+    db: AsyncSession,
+    spool_id: int,
+    data: dict,
+) -> models.Spool:
+    """Update the fields of a spool object."""
+    spool = await get_by_id(db, spool_id)
+    for k, v in data.items():
+        if k == "filament_id":
+            spool.filament = await filament.get_by_id(db, v)
+        else:
+            setattr(spool, k, v)
+    await db.flush()
+    return spool
+
+
+async def delete(db: AsyncSession, spool_id: int) -> None:
+    """Delete a spool object."""
+    spool = await get_by_id(db, spool_id)
+    await db.delete(spool)
+
+
+# TODO: Make unit tests for race conditions on these
+async def use_weight(db: AsyncSession, spool_id: int, weight: float) -> models.Spool:
+    """Reduce the weight of a spool.
+
+    Does nothing if the spool is empty.
+
+    Args:
+        db (AsyncSession): Database session
+        spool_id (int): Spool ID
+        weight (float): Weight loss in grams
+
+    Returns:
+        models.Spool: Updated spool object
+    """
+    spool = await get_by_id(db, spool_id, with_for_update=True)
+    spool.weight -= min(spool.weight, weight)
+    await db.flush()
+    return spool
+
+
+async def use_length(db: AsyncSession, spool_id: int, length: float) -> models.Spool:
+    """Reduce the weight of a spool by using a length of filament.
+
+    Does nothing if the spool is empty.
+
+    Args:
+        db (AsyncSession): Database session
+        spool_id (int): Spool ID
+        length (float): Length of filament to reduce by
+
+    Returns:
+        models.Spool: Updated spool object
+    """
+    spool = await get_by_id(db, spool_id, with_for_update=True)
+
+    filament = spool.filament
+
+    weight = weight_from_length(
+        length=length,
+        radius=filament.diameter / 2,
+        density=filament.density,
+    )
+    spool.weight -= min(spool.weight, weight)
+    await db.flush()
+    return spool