Retrieve fastq files for the given lane, ready to process.

def get_fastq_files(data):
    """Retrieve fastq files for the given lane, ready to process.
    """
    assert "files" in data, "Did not find `files` in input; nothing to process"
    ready_files = []
    should_gzip = True

    # Bowtie does not accept gzipped fastq
    if 'bowtie' in data['reference'].keys():
        should_gzip = False
    for fname in data["files"]:
        if fname.endswith(".bam"):
            if _pipeline_needs_fastq(data["config"], data):
                ready_files = convert_bam_to_fastq(fname, data["dirs"]["work"],
                                                   data, data["dirs"], data["config"])
            else:
                ready_files = [fname]
        elif objectstore.is_remote(fname):
            ready_files.append(fname)
        # Trimming does quality conversion, so if not doing that, do an explicit conversion
        elif not(dd.get_trim_reads(data)) and dd.get_quality_format(data) != "standard":
            out_dir = utils.safe_makedir(os.path.join(dd.get_work_dir(data), "fastq_convert"))
            ready_files.append(fastq.groom(fname, data, out_dir=out_dir))
        else:
            ready_files.append(fname)
    ready_files = [x for x in ready_files if x is not None]
    if should_gzip:
        out_dir = utils.safe_makedir(os.path.join(dd.get_work_dir(data), "fastq"))
        ready_files = [_gzip_fastq(x, out_dir) for x in ready_files]
    for in_file in ready_files:
        if not objectstore.is_remote(in_file):
            assert os.path.exists(in_file), "%s does not exist." % in_file
    return ready_files