"""Explicit selected-model upstream watches and deduplicated revision notices."""
import sqlalchemy as sa

from alembic import op

revision = "20260909_0030"
down_revision = "20260909_0029"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.create_table("model_update_watches",
        sa.Column("id", sa.Uuid(), primary_key=True),
        sa.Column("model_id", sa.Uuid(), sa.ForeignKey("models.id", ondelete="RESTRICT"), nullable=False),
        sa.Column("baseline_revision_id", sa.Uuid(), sa.ForeignKey("model_revisions.id", ondelete="RESTRICT"), nullable=False),
        sa.Column("baseline_commit_sha", sa.String(64), nullable=False),
        sa.Column("upstream_ref", sa.String(255), nullable=False),
        sa.Column("last_checked_at", sa.DateTime(timezone=True)),
        sa.Column("last_error_code", sa.String(64)),
        sa.Column("check_until", sa.DateTime(timezone=True)),
        sa.Column("check_token", sa.Uuid()),
        sa.UniqueConstraint("model_id", "upstream_ref", name="uq_model_watch_ref"))
    op.create_table("model_update_notices",
        sa.Column("id", sa.Uuid(), primary_key=True),
        sa.Column("watch_id", sa.Uuid(), sa.ForeignKey("model_update_watches.id", ondelete="RESTRICT"), nullable=False),
        sa.Column("model_id", sa.Uuid(), sa.ForeignKey("models.id", ondelete="RESTRICT"), nullable=False),
        sa.Column("baseline_commit_sha", sa.String(64), nullable=False),
        sa.Column("candidate_revision_id", sa.Uuid(), sa.ForeignKey("model_revisions.id", ondelete="RESTRICT"), nullable=False),
        sa.Column("candidate_commit_sha", sa.String(64), nullable=False),
        sa.Column("status", sa.String(16), nullable=False),
        sa.Column("discovered_at", sa.DateTime(timezone=True), server_default=sa.func.now(), nullable=False),
        sa.UniqueConstraint("watch_id", "candidate_commit_sha", name="uq_model_notice_commit"),
        sa.CheckConstraint("status IN ('new', 'dismissed')", name="ck_model_notice_status"))
    if op.get_bind().dialect.name == "postgresql":
        op.execute("GRANT SELECT, INSERT, UPDATE ON model_update_watches, model_update_notices TO modelforge_runtime")


def downgrade() -> None:
    if op.get_bind().scalar(sa.text("SELECT count(*) FROM model_update_watches")):
        raise RuntimeError("Model update history exists; restore the pre-migration backup instead.")
    op.drop_table("model_update_notices")
    op.drop_table("model_update_watches")