Add ScanR structures search engine

In theory ScanR should also search for projects but the API is different,
so we'd need another engine.

searx/engines/scanr_structures.py

@@ -0,0 +1,78 @@
+"""
+ ScanR Structures (Science)
+
+ @website     https://scanr.enseignementsup-recherche.gouv.fr
+ @provide-api yes (https://scanr.enseignementsup-recherche.gouv.fr/api/swagger-ui.html)
+
+ @using-api   yes
+ @results     JSON
+ @stable      yes
+ @parse       url, title, content, img_src
+"""
+
+from urllib import urlencode
+from json import loads, dumps
+from dateutil import parser
+from searx.utils import html_to_text
+
+# engine dependent config
+categories = ['science']
+paging = True
+page_size = 20
+
+# search-url
+url = 'https://scanr.enseignementsup-recherche.gouv.fr/'
+search_url = url + 'api/structures/search'
+
+
+# do search-request
+def request(query, params):
+
+    params['url'] = search_url
+    params['method'] = 'POST'
+    params['headers']['Content-type'] = "application/json"
+    params['data'] = dumps({"query": query,
+                            "searchField": "ALL",
+                            "sortDirection": "ASC",
+                            "sortOrder": "RELEVANCY",
+                            "page": params['pageno'],
+                            "pageSize": page_size})
+
+    return params
+
+
+# get response from search-request
+def response(resp):
+    results = []
+
+    search_res = loads(resp.text)
+
+    # return empty array if there are no results
+    if search_res.get('total') < 1:
+        return []
+
+    # parse results
+    for result in search_res['results']:
+        if 'id' not in result:
+            continue
+
+        # is it thumbnail or img_src??
+        thumbnail = None
+        if 'logo' in result:
+            thumbnail = result['logo']
+            if thumbnail[0] == '/':
+                thumbnail = url + thumbnail
+
+        content = None
+        if 'highlights' in result:
+            content = result['highlights'][0]['value']
+
+        # append result
+        results.append({'url': url + 'structure/' + result['id'],
+                        'title': result['label'],
+                        # 'thumbnail': thumbnail,
+                        'img_src': thumbnail,
+                        'content': html_to_text(content)})
+
+    # return results
+    return results