"""Keep distinct legacy batches whose numbers differ by leading spaces."""
from alembic import op

revision = '0005'
down_revision = '0004'
branch_labels = None
depends_on = None


def upgrade():
    op.drop_index('ux_batch_number', table_name='fw_ProductBatch')
    op.execute('CREATE UNIQUE INDEX ux_batch_number ON "fw_ProductBatch" ("ProductId", lower(rtrim("Number")))')


def downgrade():
    # Downgrade refuses conflicting records rather than deleting or merging their inventory.
    op.drop_index('ux_batch_number', table_name='fw_ProductBatch')
    op.execute('CREATE UNIQUE INDEX ux_batch_number ON "fw_ProductBatch" ("ProductId", lower(trim("Number")))')