Convert an input BAM file into CNVkit expected output.

    Handles previous non-batch cases to avoid re-calculating,
    returning both new and old values:

def _bam_to_outbase(bam_file, work_dir, data):
    """Convert an input BAM file into CNVkit expected output.

    Handles previous non-batch cases to avoid re-calculating,
    returning both new and old values:
    """
    batch = dd.get_batch(data) or dd.get_sample_name(data)
    out_base = os.path.splitext(os.path.basename(bam_file))[0].split(".")[0]
    base = os.path.join(work_dir, out_base)
    return "%s-%s" % (base, batch), base