Scaffold SQLAlchemy models, routers, and Alembic migrations

- app/models/: Printer, Filament, PrintJob, Todo, PricingConfig with full
  SQLAlchemy 2.x mapped columns and relationships
- app/routers/: list + get-by-id endpoints for all five resources
- app/db.py: SQLAlchemy engine + SessionLocal + get_db dependency
- alembic/: env.py reads MYSQL_* env vars; 0001_initial_schema mirrors db.sql
- alembic.ini: script_location configured, URL injected at runtime

Since db.sql already created the tables, stamp the DB before running future
migrations:  alembic stamp head

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/models/__init__.py

@@ -0,0 +1,8 @@
+from app.models.base import Base
+from app.models.filament import Filament
+from app.models.pricing import PricingConfig
+from app.models.print_job import PrintJob
+from app.models.printer import Printer
+from app.models.todo import Todo
+
+__all__ = ["Base", "Printer", "Filament", "PrintJob", "Todo", "PricingConfig"]

app/models/base.py

@@ -0,0 +1,6 @@
+from sqlalchemy.orm import DeclarativeBase
+
+
+class Base(DeclarativeBase):
+    def to_dict(self) -> dict:
+        return {c.name: getattr(self, c.name) for c in self.__table__.columns}

app/models/filament.py

@@ -0,0 +1,38 @@
+import enum
+from datetime import datetime
+from decimal import Decimal
+
+from sqlalchemy import DateTime, Enum, Numeric, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class Material(enum.Enum):
+    PLA = "PLA"
+    PETG = "PETG"
+    ABS = "ABS"
+    ASA = "ASA"
+    TPU = "TPU"
+    Nylon = "Nylon"
+    PC = "PC"
+    Other = "Other"
+
+
+class Filament(Base):
+    __tablename__ = "filaments"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    brand: Mapped[str | None] = mapped_column(String(100))
+    material: Mapped[Material] = mapped_column(Enum(Material), default=Material.PLA)
+    color: Mapped[str | None] = mapped_column(String(100))
+    color_hex: Mapped[str | None] = mapped_column(String(7))
+    weight_total_g: Mapped[Decimal] = mapped_column(Numeric(8, 2))
+    weight_remaining_g: Mapped[Decimal] = mapped_column(Numeric(8, 2))
+    price_per_kg_eur: Mapped[Decimal | None] = mapped_column(Numeric(8, 2))
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    jobs: Mapped[list["PrintJob"]] = relationship(back_populates="filament")

app/models/pricing.py

@@ -0,0 +1,20 @@
+from datetime import date, datetime
+from decimal import Decimal
+
+from sqlalchemy import Date, DateTime, Numeric, String, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.models.base import Base
+
+
+class PricingConfig(Base):
+    __tablename__ = "pricing_config"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(100), default="default")
+    electricity_kwh_eur: Mapped[Decimal] = mapped_column(Numeric(6, 4), default=Decimal("0.30"))
+    printer_watt: Mapped[Decimal] = mapped_column(Numeric(8, 2), default=Decimal("200.00"))
+    hourly_rate_eur: Mapped[Decimal] = mapped_column(Numeric(8, 2), default=Decimal("0.00"))
+    markup_percent: Mapped[Decimal] = mapped_column(Numeric(5, 2), default=Decimal("20.00"))
+    valid_from: Mapped[date] = mapped_column(Date, server_default=func.current_date())
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())

app/models/print_job.py

@@ -0,0 +1,41 @@
+import enum
+from datetime import datetime
+from decimal import Decimal
+
+from sqlalchemy import DateTime, Enum, ForeignKey, Integer, Numeric, String, Text, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class JobStatus(enum.Enum):
+    queued = "queued"
+    printing = "printing"
+    done = "done"
+    failed = "failed"
+    cancelled = "cancelled"
+
+
+class PrintJob(Base):
+    __tablename__ = "print_jobs"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    printer_id: Mapped[int] = mapped_column(ForeignKey("printers.id"))
+    filament_id: Mapped[int | None] = mapped_column(ForeignKey("filaments.id"))
+    name: Mapped[str] = mapped_column(String(200))
+    file_name: Mapped[str | None] = mapped_column(String(255))
+    status: Mapped[JobStatus] = mapped_column(Enum(JobStatus), default=JobStatus.queued)
+    queue_position: Mapped[int | None] = mapped_column(Integer)
+    started_at: Mapped[datetime | None] = mapped_column(DateTime)
+    finished_at: Mapped[datetime | None] = mapped_column(DateTime)
+    duration_minutes: Mapped[int | None] = mapped_column(Integer)
+    filament_used_g: Mapped[Decimal | None] = mapped_column(Numeric(8, 2))
+    cost_eur: Mapped[Decimal | None] = mapped_column(Numeric(8, 2))
+    notes: Mapped[str | None] = mapped_column(Text)
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    printer: Mapped["Printer"] = relationship(back_populates="jobs")
+    filament: Mapped["Filament | None"] = relationship(back_populates="jobs")

app/models/printer.py

@@ -0,0 +1,33 @@
+import enum
+from datetime import datetime
+
+from sqlalchemy import DateTime, Enum, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class PrinterStatus(enum.Enum):
+    idle = "idle"
+    printing = "printing"
+    error = "error"
+    offline = "offline"
+
+
+class Printer(Base):
+    __tablename__ = "printers"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(100))
+    model: Mapped[str | None] = mapped_column(String(100))
+    location: Mapped[str | None] = mapped_column(String(100))
+    status: Mapped[PrinterStatus] = mapped_column(
+        Enum(PrinterStatus), default=PrinterStatus.offline
+    )
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    jobs: Mapped[list["PrintJob"]] = relationship(back_populates="printer")
+    todos: Mapped[list["Todo"]] = relationship(back_populates="printer")

app/models/todo.py

@@ -0,0 +1,21 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.models.base import Base
+
+
+class Todo(Base):
+    __tablename__ = "todos"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    title: Mapped[str] = mapped_column(String(255))
+    done: Mapped[bool] = mapped_column(Boolean, default=False)
+    printer_id: Mapped[int | None] = mapped_column(ForeignKey("printers.id"))
+    created_at: Mapped[datetime] = mapped_column(DateTime, server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime, server_default=func.now(), onupdate=func.now()
+    )
+
+    printer: Mapped["Printer | None"] = relationship(back_populates="todos")