1 files changed, 44 insertions, 0 deletions
diff --git a/searx/plugins/oa_doi_rewrite.py b/searx/plugins/oa_doi_rewrite.py
new file mode 100644
index 000000000..b62ef0b1e
--- /dev/null
+++ b/searx/plugins/oa_doi_rewrite.py
@@ -0,0 +1,44 @@
+from flask_babel import gettext
+import re
+from searx.url_utils import urlparse, parse_qsl
+from searx import settings
+
+
+regex = re.compile(r'10\.\d{4,9}/[^\s]+')
+
+name = gettext('Open Access DOI rewrite')
+description = gettext('Avoid paywalls by redirecting to open-access versions of publications when available')
+default_on = False
+preference_section = 'privacy'
+
+doi_resolvers = settings['doi_resolvers']
+
+
+def extract_doi(url):
+    match = regex.search(url.path)
+    if match:
+        return match.group(0)
+    for _, v in parse_qsl(url.query):
+        match = regex.search(v)
+        if match:
+            return match.group(0)
+    return None
+
+
+def get_doi_resolver(args, preference_doi_resolver):
+    doi_resolvers = settings['doi_resolvers']
+    doi_resolver = args.get('doi_resolver', preference_doi_resolver)[0]
+    if doi_resolver not in doi_resolvers:
+        doi_resolvers = settings['default_doi_resolver']
+    return doi_resolver
+
+
+def on_result(request, search, result):
+    doi = extract_doi(result['parsed_url'])
+    if doi and len(doi) < 50:
+        for suffix in ('/', '.pdf', '/full', '/meta', '/abstract'):
+            if doi.endswith(suffix):
+                doi = doi[:-len(suffix)]
+        result['url'] = get_doi_resolver(request.args, request.preferences.get_value('doi_resolver')) + doi
+        result['parsed_url'] = urlparse(result['url'])
+    return True