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							from flask_babel import gettext
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							import re
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							from searx.url_utils import urlparse, parse_qsl
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							from searx import settings
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							regex = re.compile(r'10\.\d{4,9}/[^\s]+')
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							name = gettext('Open Access DOI rewrite')
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							description = gettext('Avoid paywalls by redirecting to open-access versions of publications when available')
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							default_on = False
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							preference_section = 'general'
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							doi_resolvers = settings['doi_resolvers']
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							def extract_doi(url):
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							    match = regex.search(url.path)
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							    if match:
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							        return match.group(0)
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							    for _, v in parse_qsl(url.query):
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							        match = regex.search(v)
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							        if match:
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							            return match.group(0)
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							    return None
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							def get_doi_resolver(args, preference_doi_resolver):
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							    doi_resolvers = settings['doi_resolvers']
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							    doi_resolver = args.get('doi_resolver', preference_doi_resolver)[0]
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							    if doi_resolver not in doi_resolvers:
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							        doi_resolvers = settings['default_doi_resolver']
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							    doi_resolver_url = doi_resolvers[doi_resolver]
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							    return doi_resolver_url
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							def on_result(request, search, result):
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							    if 'parsed_url' not in result:
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							        return True
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							    doi = extract_doi(result['parsed_url'])
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							    if doi and len(doi) < 50:
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							        for suffix in ('/', '.pdf', '/full', '/meta', '/abstract'):
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							            if doi.endswith(suffix):
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							                doi = doi[:-len(suffix)]
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							        result['url'] = get_doi_resolver(request.args, request.preferences.get_value('doi_resolver')) + doi
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							        result['parsed_url'] = urlparse(result['url'])
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							    return True
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