"""service_seen — the learned roster that makes a stopped part observable.

Milestone 365. Nothing in FabledCurator knew what was SUPPOSED to be running:
`celery inspect` reports the workers that answer, so a dead worker was a
shorter list rather than a red light, and the only surface that could tell an
operator otherwise was Portainer. This table is the memory that turns an
absence into something the app can see.

Keyed on the queue set for a celery role and on agent_id for the GPU agent —
NOT on the celery worker name, which here is `celery@<container id>` and is
minted fresh on every deploy. See the model docstring for why that choice is
the whole design.

## First migration on the collapsed baseline

0089 is the single generated baseline that replaced revisions 0001..0089
(milestone 328). This is the first revision written on top of it, so it is
also the first evidence that the chain steps forward from the collapse rather
than merely reproducing the schema — which nothing had demonstrated yet.

An existing install is at 0089 because it ran the real 0089; a fresh one is at
0089 because it ran the baseline. Both arrive here identically, which was the
property the collapse was designed around.

Revision ID: 0090
Revises: 0089
Create Date: 2026-09-02

"""
from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op

revision: str = "0090"
down_revision: Union[str, None] = "0089"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        "service_seen",
        sa.Column("key", sa.String(length=128), nullable=False),
        sa.Column("kind", sa.String(length=16), nullable=False),
        sa.Column("display_name", sa.String(length=64), nullable=False),
        sa.Column(
            "first_seen_at", sa.DateTime(timezone=True),
            server_default=sa.text("now()"), nullable=False,
        ),
        sa.Column(
            "last_seen_at", sa.DateTime(timezone=True),
            server_default=sa.text("now()"), nullable=False,
        ),
        sa.Column("details", sa.JSON(), nullable=False),
        sa.PrimaryKeyConstraint("key", name=op.f("pk_service_seen")),
    )
    # No secondary indexes, deliberately: one row per moving part means every
    # read is a handful of rows and an index would be write cost buying
    # nothing (#3301 removed seven of exactly that shape).


def downgrade() -> None:
    op.drop_table("service_seen")