from __future__ import annotations

from datetime import datetime, timezone

from sqlalchemy import (
    Boolean,
    DateTime,
    Enum as SAEnum,
    Float,
    ForeignKey,
    Integer,
    String,
    func,
)
from sqlalchemy.orm import Mapped, mapped_column

from .base import Base, MatchStatus, SubjectType


class Match(Base):
    """A persisted candidate match for human review (spec §7.7)."""

    __tablename__ = "matches"

    id: Mapped[int] = mapped_column(primary_key=True)
    case_id: Mapped[int] = mapped_column(ForeignKey("cases.id"), index=True)
    candidate_type: Mapped[SubjectType] = mapped_column(
        SAEnum(SubjectType, native_enum=False)
    )
    candidate_id: Mapped[int] = mapped_column(Integer)  # the matched dog
    candidate_case_id: Mapped[int | None] = mapped_column(
        ForeignKey("cases.id"), nullable=True
    )
    similarity_score: Mapped[float] = mapped_column(Float)  # dog-level aggregate
    rank: Mapped[int] = mapped_column(Integer)  # 1 = best
    model_name: Mapped[str] = mapped_column(String(80))
    model_version: Mapped[str] = mapped_column(String(40))
    status: Mapped[MatchStatus] = mapped_column(
        SAEnum(MatchStatus, native_enum=False), default=MatchStatus.pending
    )
    reviewed: Mapped[bool] = mapped_column(Boolean, default=False)
    reviewed_by: Mapped[int | None] = mapped_column(
        ForeignKey("users.id"), nullable=True
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        server_default=func.now(),
    )