"""Extend UserRole enum: add global_admin and tenant_admin.

Existing 'admin' users are backfilled to 'global_admin'.
The legacy 'admin' value is kept in the enum so existing tokens/sessions
remain valid during the transition period. It will be removed in a later
cleanup migration once all call sites are updated.

Revision ID: 049
Revises: 048
"""
from alembic import op
import sqlalchemy as sa

revision = "049"
down_revision = "048"
branch_labels = None
depends_on = None


def upgrade() -> None:
    # PostgreSQL requires ALTER TYPE ADD VALUE to be committed before the new value
    # can be referenced in the same session.  With asyncpg + alembic the connection
    # already has an open transaction (begin_transaction), so we cannot change
    # isolation level via execution_options.  Instead we manually COMMIT the outer
    # transaction, run the DDL, then open a new transaction for the DML backfill.
    conn = op.get_bind()

    # Commit the alembic-managed transaction so ALTER TYPE runs outside a tx block
    conn.execute(sa.text("COMMIT"))
    conn.execute(sa.text("ALTER TYPE userrole ADD VALUE IF NOT EXISTS 'global_admin'"))
    conn.execute(sa.text("ALTER TYPE userrole ADD VALUE IF NOT EXISTS 'tenant_admin'"))

    # Start a new transaction for the backfill DML
    conn.execute(sa.text("BEGIN"))
    conn.execute(
        sa.text("UPDATE users SET role = 'global_admin'::userrole WHERE role = 'admin'::userrole")
    )


def downgrade() -> None:
    # Restore global_admin/tenant_admin back to admin (for rollback)
    op.execute(
        "UPDATE users SET role = 'admin'::userrole WHERE role = 'global_admin'::userrole"
    )
    op.execute(
        "UPDATE users SET role = 'client'::userrole WHERE role = 'tenant_admin'::userrole"
    )
    # Note: cannot DROP enum values in PostgreSQL without recreating the type
    # The values will remain in the enum but unused after downgrade