"""Each hour of the metric rollup keeps the level it held, its 95th percentile,
beside its average and peak (#5738), so a learned normal can tell a brief
spike (a high peak, a low p95) from a level the metric stayed at.

Revision ID: 0044_hourly_p95
Revises: 0043_outbox_alert_words
Create Date: 2026-10-14
"""
from typing import Sequence, Union
from alembic import op
import sqlalchemy as sa

revision: str = "0044_hourly_p95"
down_revision: Union[str, None] = "0043_outbox_alert_words"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    # Hours rolled up before this have no p95 to recover (their raw samples
    # are gone), so they stay NULL and read as their average.
    op.add_column("plugin_metrics_hourly", sa.Column("value_p95", sa.Float, nullable=True))


def downgrade() -> None:
    op.drop_column("plugin_metrics_hourly", "value_p95")