"""Add dellupdatesjson to endpointstates.

Stores the pending Dell Command | Update summary reported by the
shopdb-dellupdates agent utility. MEDIUMTEXT for consistency with the other
snapshot columns on this table.

Nullable with no backfill. Null means the endpoint has never reported a Dell
scan result, which is deliberately distinct from a stored payload whose status
is 'ok' with an empty list (scanned, nothing pending). The status card renders
those two states differently, so defaulting this to an empty summary would
assert every pre-existing endpoint had been scanned and found clean.

Idempotent: the column-add checks the live schema first, so a re-run and a
db.create_all() site both stay clean on strict MySQL 8.
"""
from alembic import op

import sqlalchemy as sa


# revision identifiers, used by Alembic.
revision = 'endpoints0016dellupdates'
down_revision = 'endpoints0015systemtelemetry'
branch_labels = None
depends_on = None

TABLE_NAME = 'endpointstates'

COLUMN_NAME = 'dellupdatesjson'


def _has_column(table_name, column_name):
    from sqlalchemy import inspect

    inspector = inspect(op.get_bind())
    if not inspector.has_table(table_name):
        return False
    return any(col['name'] == column_name
               for col in inspector.get_columns(table_name))


def upgrade():
    if not _has_column(TABLE_NAME, COLUMN_NAME):
        op.add_column(
            TABLE_NAME,
            sa.Column(COLUMN_NAME, sa.Text(length=16777215), nullable=True))


def downgrade():
    if _has_column(TABLE_NAME, COLUMN_NAME):
        op.drop_column(TABLE_NAME, COLUMN_NAME)