"""Represent an all-empty intelligence snapshot without a false fresh cutoff.

Revision ID: 475
Revises: 474
"""
import sqlalchemy as sa

from alembic import op

revision = "475"
down_revision = "474"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.alter_column(
        "intelligence_snapshots",
        "data_as_of",
        existing_type=sa.DateTime(),
        nullable=True,
    )


def downgrade() -> None:
    op.execute(
        sa.text(
            "UPDATE intelligence_snapshots SET data_as_of = created_at "
            "WHERE data_as_of IS NULL"
        )
    )
    op.alter_column(
        "intelligence_snapshots",
        "data_as_of",
        existing_type=sa.DateTime(),
        nullable=False,
    )