from __future__ import annotations

import uuid
from typing import Any

from sqlalchemy import JSON, ForeignKey, String, Text
from sqlalchemy.orm import Mapped, mapped_column

from app.db.base import Base, TimestampMixin, UUIDPrimaryKeyMixin


class Snapshot(Base, UUIDPrimaryKeyMixin, TimestampMixin):
    """A structured, comparable summary of a source's state at a point in
    time - what change detection (Phase 6) diffs against the prior snapshot
    for the same source."""

    __tablename__ = "snapshots"

    company_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("companies.id", ondelete="CASCADE"), index=True
    )
    source_id: Mapped[uuid.UUID] = mapped_column(
        ForeignKey("sources.id", ondelete="CASCADE"), index=True
    )
    snapshot_type: Mapped[str] = mapped_column(String(50))
    hash: Mapped[str] = mapped_column(String(64), index=True)
    structured_summary: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict)
    text_summary: Mapped[str | None] = mapped_column(Text, nullable=True)
    monitoring_run_id: Mapped[uuid.UUID | None] = mapped_column(
        ForeignKey("monitoring_runs.id", ondelete="SET NULL"), nullable=True, index=True
    )