"""The timeline: one row per thing that happened to the infrastructure.

Revision ID: 0047_timeline
Revises: 0046_metric_anomalies
Create Date: 2026-10-24
"""
from typing import Sequence, Union
from alembic import op
import sqlalchemy as sa
from sqlalchemy.dialects.postgresql import ARRAY

revision: str = "0047_timeline"
down_revision: Union[str, None] = "0046_metric_anomalies"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.create_table(
        "timeline_entries",
        sa.Column("id", sa.String(36), primary_key=True),
        sa.Column("at", sa.DateTime(timezone=True), nullable=False),
        sa.Column("until", sa.DateTime(timezone=True), nullable=True),
        sa.Column("type", sa.String(64), nullable=False),
        sa.Column("area", sa.String(32), nullable=False),
        sa.Column("hosts", ARRAY(sa.String(128)), nullable=False, server_default="{}"),
        sa.Column("subject", sa.String(255), nullable=True),
        sa.Column("summary", sa.Text, nullable=False),
        sa.Column("detail", sa.JSON, nullable=True),
        sa.Column("actor", sa.String(64), nullable=False, server_default="system"),
        sa.Column("ref_type", sa.String(32), nullable=True),
        sa.Column("ref_id", sa.String(64), nullable=True),
    )
    op.create_index("ix_timeline_entries_at", "timeline_entries", ["at", "id"])
    op.create_index("ix_timeline_entries_hosts", "timeline_entries", ["hosts"],
                    postgresql_using="gin")
    op.create_index("ix_timeline_entries_type", "timeline_entries", ["type"])
    op.create_index("uq_timeline_entries_ref", "timeline_entries", ["ref_type", "ref_id"],
                    unique=True, postgresql_where=sa.text("ref_id IS NOT NULL"))


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