"""run.idempotency_key

Submitting is a POST, so a client that retries one after a timeout cannot know
whether the first attempt landed. A key the caller mints per submission makes
the answer a lookup: the same key returns the run it already created.

Revision ID: f2c6a8d15e93
Revises: d1f7a3c8b204
Create Date: 2026-08-26

"""

import sqlalchemy as sa
import sqlmodel.sql.sqltypes
from alembic import op

# revision identifiers, used by Alembic.
revision = "f2c6a8d15e93"
down_revision = "d1f7a3c8b204"
branch_labels = None
depends_on = None


def upgrade():
    op.add_column(
        "run",
        sa.Column(
            "idempotency_key",
            sqlmodel.sql.sqltypes.AutoString(length=64),
            nullable=True,
        ),
    )
    # Nullable and unique: every run submitted without a key stays NULL, and
    # both SQLite and Postgres allow as many of those as there are runs.
    op.create_index("ix_run_idempotency_key", "run", ["idempotency_key"], unique=True)


def downgrade():
    op.drop_index("ix_run_idempotency_key", table_name="run")
    op.drop_column("run", "idempotency_key")