"""Add durable, single-route operational alert notification outbox."""

import sqlalchemy as sa

from alembic import op

revision = "20260923_0037"
down_revision = "20260923_0036"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_table(
        "alert_notification_deliveries",
        sa.Column("id", sa.Uuid(), nullable=False),
        sa.Column("alert_history_event_id", sa.Uuid(), nullable=True),
        sa.Column("route_key", sa.String(length=64), nullable=False),
        sa.Column("idempotency_key", sa.String(length=160), nullable=False),
        sa.Column("event_kind", sa.String(length=16), nullable=False),
        sa.Column("severity", sa.String(length=16), nullable=True),
        sa.Column("payload", sa.JSON(), nullable=False),
        sa.Column("status", sa.String(length=24), nullable=False),
        sa.Column("attempt_count", sa.Integer(), nullable=False),
        sa.Column("next_attempt_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("last_attempt_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("delivered_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("lease_expires_at", sa.DateTime(timezone=True), nullable=True),
        sa.Column("claim_token_hash", sa.String(length=64), nullable=True),
        sa.Column("last_http_status", sa.Integer(), nullable=True),
        sa.Column("last_error_code", sa.String(length=64), nullable=True),
        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.CheckConstraint(
            "event_kind IN ('FIRING', 'RESOLVED', 'TEST')",
            name="ck_alert_notification_event_kind",
        ),
        sa.CheckConstraint(
            "status IN ('PENDING', 'DISPATCHING', 'RETRY_WAIT', 'DELIVERED', 'FAILED', 'HELD_FOR_REVIEW')",
            name="ck_alert_notification_status",
        ),
        sa.CheckConstraint("attempt_count >= 0", name="ck_alert_notification_attempt_count"),
        sa.ForeignKeyConstraint(
            ["alert_history_event_id"], ["alert_history_events.id"], ondelete="RESTRICT"
        ),
        sa.PrimaryKeyConstraint("id"),
        sa.UniqueConstraint("idempotency_key", name="uq_alert_notification_idempotency"),
    )
    op.create_index(
        "ix_alert_notification_deliveries_alert_history_event_id",
        "alert_notification_deliveries",
        ["alert_history_event_id"],
    )
    op.create_index(
        "ix_alert_notification_deliveries_event_kind",
        "alert_notification_deliveries",
        ["event_kind"],
    )
    op.create_index(
        "ix_alert_notification_deliveries_severity",
        "alert_notification_deliveries",
        ["severity"],
    )
    op.create_index(
        "ix_alert_notification_deliveries_status",
        "alert_notification_deliveries",
        ["status"],
    )
    op.create_index(
        "ix_alert_notification_deliveries_next_attempt_at",
        "alert_notification_deliveries",
        ["next_attempt_at"],
    )
    op.create_index(
        "ix_alert_notification_deliveries_lease_expires_at",
        "alert_notification_deliveries",
        ["lease_expires_at"],
    )
    op.create_index(
        "ix_alert_notification_dispatch_due",
        "alert_notification_deliveries",
        ["status", "next_attempt_at", "created_at"],
    )


def downgrade() -> None:
    bind = op.get_bind()
    deliveries = sa.table("alert_notification_deliveries", sa.column("id"))
    if bind.scalar(sa.select(sa.func.count()).select_from(deliveries)):
        raise RuntimeError(
            "alert notification history exists; restore the pre-migration backup instead."
        )
    op.drop_index("ix_alert_notification_dispatch_due", table_name="alert_notification_deliveries")
    op.drop_index("ix_alert_notification_deliveries_lease_expires_at", table_name="alert_notification_deliveries")
    op.drop_index("ix_alert_notification_deliveries_next_attempt_at", table_name="alert_notification_deliveries")
    op.drop_index("ix_alert_notification_deliveries_status", table_name="alert_notification_deliveries")
    op.drop_index("ix_alert_notification_deliveries_severity", table_name="alert_notification_deliveries")
    op.drop_index("ix_alert_notification_deliveries_event_kind", table_name="alert_notification_deliveries")
    op.drop_index("ix_alert_notification_deliveries_alert_history_event_id", table_name="alert_notification_deliveries")
    op.drop_table("alert_notification_deliveries")