import enum
import uuid
from datetime import datetime
from decimal import Decimal

from sqlalchemy import Boolean, ForeignKey, Numeric, String
from sqlalchemy.dialects.postgresql import ENUM as PgEnum, TIMESTAMP, UUID
from sqlalchemy.orm import Mapped, mapped_column

from app.db.base import Base


class KontrollStatus(str, enum.Enum):
    nicht_gestartet = "nicht_gestartet"
    in_bearbeitung = "in_bearbeitung"
    abgeschlossen = "abgeschlossen"
    abgebrochen = "abgebrochen"


kontroll_status_pg = PgEnum(KontrollStatus, name="kontroll_status", create_type=False)


class Kontrolle(Base):
    """Prompt 02: Kontrolle ändert NIEMALS Ist-Menge, ist reine Erfassung (Punkt 9,
    Vier-Kernbegriffe-Tabelle). Status='in_bearbeitung' IST die Objekt-Sperre
    (Punkt 8) – kein separates Sperr-Modell nötig."""

    __tablename__ = "kontrolle"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    erzeugt_von_server_id: Mapped[int] = mapped_column(ForeignKey("systemknoten.id"), nullable=False)
    objekt_id: Mapped[int] = mapped_column(ForeignKey("objekt.id"), nullable=False)
    benutzer_id: Mapped[int] = mapped_column(ForeignKey("benutzer.id"), nullable=False)
    status: Mapped[KontrollStatus] = mapped_column(
        kontroll_status_pg, nullable=False, default=KontrollStatus.in_bearbeitung
    )
    gestartet_am: Mapped[datetime] = mapped_column(TIMESTAMP(timezone=True), nullable=False)
    beendet_am: Mapped[datetime | None] = mapped_column(TIMESTAMP(timezone=True))
    abbruch_grund: Mapped[str | None] = mapped_column(String)
    signatur: Mapped[bytes | None] = mapped_column()


class Kontrollposition(Base):
    __tablename__ = "kontrollposition"

    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    kontrolle_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("kontrolle.id"), nullable=False
    )
    material_id: Mapped[int] = mapped_column(ForeignKey("material.id"), nullable=False)
    sollmenge_snapshot: Mapped[Decimal] = mapped_column(Numeric, nullable=False)
    istmenge_erfasst: Mapped[Decimal] = mapped_column(Numeric, nullable=False)
    abweichung: Mapped[bool] = mapped_column(Boolean, nullable=False)