from datetime import datetime

from sqlalchemy import Boolean, DateTime, ForeignKey, String, Text, func
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.core.database import Base
from app.models.associations import augmented_part_imported_parts
from app.models.imported_part import ImportedPart
from app.models.manufacturer import Manufacturer
from app.models.part_colour import PartColour
from app.models.part_type import PartType
from app.models.scope_model import ScopeModel
from app.models.sub_part_type import SubPartType


class AugmentedPart(Base):
    __tablename__ = "augmented_parts"

    id: Mapped[int] = mapped_column(primary_key=True)
    sku: Mapped[str | None] = mapped_column(
        String, nullable=True, unique=True, default=None
    )
    description: Mapped[str] = mapped_column(String, nullable=False)
    colour_id: Mapped[int] = mapped_column(
        ForeignKey("part_colours.id", ondelete="RESTRICT"), nullable=False
    )
    manufacturer_id: Mapped[int] = mapped_column(
        ForeignKey("manufacturers.id", ondelete="RESTRICT"), nullable=False
    )
    scope_model_id: Mapped[int | None] = mapped_column(
        ForeignKey("scope_models.id", ondelete="SET NULL"), nullable=True, default=None
    )
    part_type_id: Mapped[int] = mapped_column(
        ForeignKey("part_types.id", ondelete="RESTRICT"), nullable=False
    )
    sub_part_type_id: Mapped[int | None] = mapped_column(
        ForeignKey("sub_part_types.id", ondelete="SET NULL"),
        nullable=True,
        default=None,
    )
    # Set instead of deleting the row when the last backing ImportedPart is
    # removed, so fit/attachment-point history is preserved. Hidden from list
    # views by default.
    archived: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)

    # linked imported parts — not eagerly loaded; used by sync service only
    imported_parts: Mapped[list[ImportedPart]] = relationship(
        secondary=augmented_part_imported_parts, lazy="select"
    )

    colour: Mapped[PartColour] = relationship(lazy="selectin")
    manufacturer: Mapped[Manufacturer] = relationship(lazy="selectin")
    scope_model: Mapped[ScopeModel | None] = relationship(lazy="selectin")
    part_type: Mapped[PartType] = relationship(lazy="selectin")
    sub_part_type: Mapped[SubPartType | None] = relationship(lazy="selectin")
    notes: Mapped[list["AugmentedPartNote"]] = relationship(
        back_populates="augmented_part",
        lazy="selectin",
        order_by="AugmentedPartNote.created_at",
        cascade="all, delete-orphan",
    )


class AugmentedPartNote(Base):
    __tablename__ = "augmented_part_notes"

    id: Mapped[int] = mapped_column(primary_key=True)
    augmented_part_id: Mapped[int] = mapped_column(
        ForeignKey("augmented_parts.id", ondelete="CASCADE"), nullable=False
    )
    user_id: Mapped[int | None] = mapped_column(
        ForeignKey("users.id", ondelete="SET NULL"), nullable=True
    )
    # Denormalized snapshot of who wrote the note (mirrors FitNote.username), so
    # the note stays attributable even if the user is later deleted.
    username: Mapped[str] = mapped_column(String(255), nullable=False)
    body: Mapped[str] = mapped_column(Text, nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now()
    )

    augmented_part: Mapped[AugmentedPart] = relationship(back_populates="notes")