[feat]: engines: add astrophysical data system

AUTHORS.rst

@@ -174,3 +174,4 @@ features or generally made searx better:
 - @micsthepick
 - Daniel Kukula `<https://github.com/dkuku>`
 - Patrick Evans `https://github.com/holysoles`
+- Daniel Mowitz `<https://daniel.mowitz.rocks>`

searx/engines/astrophysics_data_system.py

@@ -0,0 +1,93 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+""".. sidebar:: info
+
+The Astrophysics Data System (ADS) is a digital library portal for researchers in astronomy and physics,
+operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant.
+The engine is adapted from the solr engine.
+
+"""
+
+# pylint: disable=global-statement
+
+from datetime import datetime
+from json import loads
+from urllib.parse import urlencode
+from searx.exceptions import SearxEngineAPIException
+
+about = {
+    "website": 'https://ui.adsabs.harvard.edu/',
+    "wikidata_id": 'Q752099',
+    "official_api_documentation": 'https://ui.adsabs.harvard.edu/help/api/api-docs.html',
+    "use_official_api": True,
+    "require_api_key": True,
+    "results": 'JSON',
+}
+
+base_url = 'https://api.adsabs.harvard.edu/v1/search'
+result_base_url = 'https://ui.adsabs.harvard.edu/abs/'
+rows = 10
+sort = ''  # sorting: asc or desc
+field_list = ['bibcode', 'author', 'title', 'abstract', 'doi', 'date']  # list of field names to display on the UI
+default_fields = ''  # default field to query
+query_fields = ''  # query fields
+paging = True
+api_key = 'unset'
+
+
+def init(_):
+    if api_key == 'unset':
+        raise SearxEngineAPIException('missing ADS API key')
+
+
+def request(query, params):
+    query_params = {'q': query, 'rows': rows}
+    if field_list:
+        query_params['fl'] = ','.join(field_list)
+    if query_fields:
+        query_params['qf'] = ','.join(query_fields)
+    if default_fields:
+        query_params['df'] = default_fields
+    if sort:
+        query_params['sort'] = sort
+
+    query_params['start'] = rows * (params['pageno'] - 1)
+
+    params['headers']['Authorization'] = f'Bearer {api_key}'
+    params['url'] = f"{base_url}/query?{urlencode(query_params)}"
+
+    return params
+
+
+def response(resp):
+    try:
+        resp_json = loads(resp.text)
+    except Exception as e:
+        raise SearxEngineAPIException("failed to parse response") from e
+
+    if 'error' in resp_json:
+        raise SearxEngineAPIException(resp_json['error']['msg'])
+
+    resp_json = resp_json["response"]
+    result_len = resp_json["numFound"]
+    results = []
+
+    for res in resp_json["docs"]:
+        author = res.get("author")
+
+        if author:
+            author = author[0] + ' et al.'
+
+        results.append(
+            {
+                'url': result_base_url + res.get("bibcode") + "/",
+                'title': res.get("title")[0],
+                'author': author,
+                'content': res.get("abstract"),
+                'doi': res.get("doi"),
+                'publishedDate': datetime.fromisoformat(res.get("date")),
+            }
+        )
+
+    results.append({'number_of_results': result_len})
+
+    return results

searx/settings.yml

@@ -380,6 +380,14 @@ engines:
       require_api_key: false
       results: JSON
 
+  # - name: astrophysics data system
+  #   engine: astrophysics_data_system
+  #   sort: asc
+  #   weight: 5
+  #   categories: [science]
+  #   api_key: your-new-key
+  #   shortcut: ads
+
   - name: alpine linux packages
     engine: alpinelinux
     disabled: true