"""Give importbatches.status room for a value longer than 'undone'.

7d37 sized the column String(16), which fitted the two statuses it shipped with.
'partially-undone' - the status an undo writes when some entries reverted and
others hit conflicts - is exactly 16 characters. It fits, with nothing to spare:
the next status anyone adds, or a rename of this one, silently truncates on
MySQL in non-strict mode and errors in strict.

Widened to 32 rather than left at the exact fit, because a column that happens
to be wide enough is not the same as a column that is wide enough.

Revision ID: 7d38_widen_importbatch_status
Revises: 7d37_import_batches_and_journal
"""
from alembic import op

import sqlalchemy as sa


revision = '7d38_widen_importbatch_status'
down_revision = '7d37_import_batches_and_journal'
branch_labels = None
depends_on = None


def _has_table(bind, name):
    return sa.inspect(bind).has_table(name)


def upgrade():
    bind = op.get_bind()
    if not _has_table(bind, 'importbatches'):
        return
    # SQLite cannot ALTER a column type; it also does not enforce VARCHAR
    # length, so there is nothing to widen there.
    if bind.dialect.name == 'sqlite':
        return
    op.alter_column('importbatches', 'status',
                    existing_type=sa.String(length=16),
                    type_=sa.String(length=32),
                    existing_nullable=False)


def downgrade():
    bind = op.get_bind()
    if not _has_table(bind, 'importbatches') or bind.dialect.name == 'sqlite':
        return
    op.alter_column('importbatches', 'status',
                    existing_type=sa.String(length=32),
                    type_=sa.String(length=16),
                    existing_nullable=False)