"""Docker swarm service placement column

Adds docker_swarm_services.placement_json — the task→node placement of a
service's running replicas, captured from the agent's swarm payload (a manager
sees every task, so this records cross-node placement the local container rows
can't). Additive column; no DROP+recreate.

Revision ID: docker_005_swarm_placement
Revises: docker_004_events_swarm
Create Date: 2026-06-19
"""
from typing import Sequence, Union
from alembic import op
import sqlalchemy as sa

revision: str = "docker_005_swarm_placement"
down_revision: Union[str, None] = "docker_004_events_swarm"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.add_column("docker_swarm_services",
                  sa.Column("placement_json", sa.Text, nullable=False,
                            server_default="[]"))


def downgrade() -> None:
    op.drop_column("docker_swarm_services", "placement_json")