"""Composite indexes for the three list screens.

Each of these filters on one column and orders by another, and every index on
the table was single-column — so SQLite used one of them and sorted the rest by
hand. `engine_event` is the worst of the three: its filter is `type != 'audit'`,
which no index on `type` can serve at all.

Revision ID: e7d3b1a9c624
Revises: d4a71e9c2b58
Create Date: 2026-08-29

"""

from alembic import op

# revision identifiers, used by Alembic.
revision = "e7d3b1a9c624"
down_revision = "d4a71e9c2b58"
branch_labels = None
depends_on = None


def upgrade() -> None:
    # `GET /runs` filters flow and/or status, newest first.
    op.create_index("ix_run_flow_created", "run", ["flow", "created_at"])
    op.create_index("ix_run_status_created", "run", ["status", "created_at"])
    # `GET /observability/runs` does the same over the execution history.
    op.create_index("ix_flow_run_flow_started", "flow_run", ["flow", "started_at"])
    # `GET /observability/events` excludes audit rows, newest first.
    op.create_index("ix_engine_event_type_ts", "engine_event", ["type", "ts"])


def downgrade() -> None:
    op.drop_index("ix_engine_event_type_ts", table_name="engine_event")
    op.drop_index("ix_flow_run_flow_started", table_name="flow_run")
    op.drop_index("ix_run_status_created", table_name="run")
    op.drop_index("ix_run_flow_created", table_name="run")