# Source code for searx.search.processors.online_currency

    # SPDX-License-Identifier: AGPL-3.0-or-later
    """Processors for engine-type: ``online_currency``

    """

    import unicodedata
    import re

    from searx.data import CURRENCIES
    from .online import OnlineProcessor

    parser_re = re.compile('.*?(\\d+(?:\\.\\d+)?) ([^.0-9]+) (?:in|to) ([^.0-9]+)', re.I)

    def normalize_name(name):
        name = name.lower().replace('-', ' ').rstrip('s')
        name = re.sub(' +', ' ', name)
        return unicodedata.normalize('NFKD', name).lower()

    def name_to_iso4217(name):
        name = normalize_name(name)
        currency = CURRENCIES['names'].get(name, [name])
        if isinstance(currency, str):
            return currency
        return currency[-1]

    def iso4217_to_name(iso4217, language):
        return CURRENCIES['iso4217'].get(iso4217, {}).get(language, iso4217)

    class OnlineCurrencyProcessor(OnlineProcessor):
        """Processor class used by ``online_currency`` engines."""

        engine_type = 'online_currency'

        def get_params(self, search_query, engine_category):
            """Returns a set of :ref:`request params <engine request online_currency>`
            or ``None`` if search query does not match to :py:obj:`parser_re`."""

            params = super().get_params(search_query, engine_category)
            if params is None:
                return None

            m = parser_re.match(search_query.query)
            if not m:
                return None

            amount_str, from_currency, to_currency = m.groups()
            try:
                amount = float(amount_str)
            except ValueError:
                return None
            from_currency = name_to_iso4217(from_currency.strip())
            to_currency = name_to_iso4217(to_currency.strip())

            params['amount'] = amount
            params['from'] = from_currency
            params['to'] = to_currency
            params['from_name'] = iso4217_to_name(from_currency, 'en')
            params['to_name'] = iso4217_to_name(to_currency, 'en')
            return params

        def get_default_tests(self):
            tests = {}

            tests['currency'] = {
                'matrix': {'query': '1337 usd in rmb'},
                'result_container': ['has_answer'],
            }

            return tests