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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def prepare_config(data: dict) -> dict: """Prepare the config data."""

        data_copy = deepcopy(data)
        # handle single sample cases with 'unknown' phenotype
        if len(data_copy['samples']) == 1:
            if data_copy['samples'][0]['phenotype'] == 'unknown':
                LOG.info("setting 'unknown' phenotype to 'unaffected'")
                data_copy['samples'][0]['phenotype'] = 'unaffected'
        # set the mother/father to '0' if they are not set for a sample
        for sample_data in data_copy['samples']:
            sample_data['mother'] = sample_data.get('mother') or '0'
            sample_data['father'] = sample_data.get('father') or '0'
            if sample_data['analysis_type'] == 'wgs' and sample_data.get('capture_kit') is None:
                sample_data['capture_kit'] = DEFAULT_CAPTURE_KIT
        return data_copy