"""Cumulative curation coverage marks and model fallback candidates."""

from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op

revision: str = "20260808_0014"
down_revision: str | Sequence[str] | None = "20260806_0013"
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None


def upgrade() -> None:
    with op.batch_alter_table("memory_references") as batch:
        batch.add_column(sa.Column("covered_reason", sa.String(length=16), nullable=True))
        batch.add_column(sa.Column("reviewed_revision", sa.Integer(), nullable=True))
        batch.add_column(sa.Column("reviewed_job_id", sa.String(length=36), nullable=True))

    with op.batch_alter_table("curation_model_configs") as batch:
        batch.add_column(
            sa.Column("candidates_json", sa.Text(), nullable=False, server_default="[]")
        )
        batch.add_column(
            sa.Column(
                "candidate_cooldown_seconds",
                sa.Integer(),
                nullable=False,
                server_default="600",
            )
        )

    op.create_table(
        "curation_model_candidate_states",
        sa.Column("model_name", sa.String(length=300), primary_key=True),
        sa.Column("cooling_until", sa.DateTime(timezone=True), nullable=True),
        sa.Column("last_error_code", sa.String(length=100), nullable=True),
        sa.Column("last_error_message", sa.Text(), nullable=True),
        sa.Column("last_success_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("last_failure_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False),
    )
    op.create_index(
        "ix_curation_model_candidate_states_cooling_until",
        "curation_model_candidate_states",
        ["cooling_until"],
    )

    # Existing covered memories were all covered through citation; backfill the reason so
    # the UI does not show them as unexplained.
    op.execute(
        "UPDATE memory_references SET covered_reason = 'cited' "
        "WHERE curation_status = 'covered' AND covered_reason IS NULL"
    )


def downgrade() -> None:
    op.drop_index(
        "ix_curation_model_candidate_states_cooling_until",
        table_name="curation_model_candidate_states",
    )
    op.drop_table("curation_model_candidate_states")

    with op.batch_alter_table("curation_model_configs") as batch:
        batch.drop_column("candidate_cooldown_seconds")
        batch.drop_column("candidates_json")

    with op.batch_alter_table("memory_references") as batch:
        batch.drop_column("reviewed_job_id")
        batch.drop_column("reviewed_revision")
        batch.drop_column("covered_reason")