From 3e3672e0790266fc7f2482fdd854d7789a915d4d Mon Sep 17 00:00:00 2001
From: jibe-b <user701@orange.fr>
Date: Sat, 23 Sep 2017 14:16:06 +0200
Subject: [PATCH] [add] arxiv engine

---
 searx/engines/arxiv.py           | 73 ++++++++++++++++++++++++++++++++
 searx/settings.yml               |  6 +++
 tests/unit/engines/test_arxiv.py | 58 +++++++++++++++++++++++++
 3 files changed, 137 insertions(+)
 create mode 100644 searx/engines/arxiv.py
 create mode 100644 tests/unit/engines/test_arxiv.py

diff --git a/searx/engines/arxiv.py b/searx/engines/arxiv.py
new file mode 100644
index 00000000..cbeac008
--- /dev/null
+++ b/searx/engines/arxiv.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+
+"""
+ ArXiV (Scientific preprints)
+ @website     https://axiv.org
+ @provide-api yes (export.arxiv.org/api/query)
+ @using-api   yes
+ @results     XML-RSS
+ @stable      yes
+ @parse       url, title, publishedDate, content
+ More info on api: https://arxiv.org/help/api/user-manual
+"""
+
+from lxml import html
+from datetime import datetime
+from searx.url_utils import urlencode
+
+
+categories = ['science']
+
+base_url = 'http://export.arxiv.org/api/query?search_query=all:'\
+           + '{query}&start={offset}&max_results={number_of_results}'
+
+# engine dependent config
+number_of_results = 10
+
+
+def request(query, params):
+    # basic search
+    offset = (params['pageno'] - 1) * number_of_results
+
+    string_args = dict(query=query,
+                       offset=offset,
+                       number_of_results=number_of_results)
+
+    params['url'] = base_url.format(**string_args)
+
+    return params
+
+
+def response(resp):
+    results = []
+
+    search_results = html.fromstring(resp.text.encode('utf-8')).xpath('//entry')
+
+    for entry in search_results:
+        title = entry.xpath('.//title')[0].text
+
+        url = entry.xpath('.//id')[0].text
+
+        content = entry.xpath('.//summary')[0].text
+
+        #  If a doi is available, add it to the snipppet
+        try:
+            doi = entry.xpath('.//link[@title="doi"]')[0].text
+            content = 'DOI: ' + doi + ' Abstract: ' + content
+        except:
+            pass
+
+        if len(content) > 300:
+                    content = content[0:300] + "..."
+        # TODO: center snippet on query term
+
+        publishedDate = datetime.strptime(entry.xpath('.//published')[0].text, '%Y-%m-%dT%H:%M:%SZ')
+
+        res_dict = {'url': url,
+                    'title': title,
+                    'publishedDate': publishedDate,
+                    'content': content}
+
+        results.append(res_dict)
+
+    return results
diff --git a/searx/settings.yml b/searx/settings.yml
index 6f44a3b8..54b2b2e6 100644
--- a/searx/settings.yml
+++ b/searx/settings.yml
@@ -60,6 +60,12 @@ engines:
     disabled : True
     shortcut : ai
 
+  - name : arxiv
+    engine : arxiv
+    shortcut : arx
+    categories : science
+    timeout : 4.0
+
   - name : base
     engine : base
     shortcut : bs
diff --git a/tests/unit/engines/test_arxiv.py b/tests/unit/engines/test_arxiv.py
new file mode 100644
index 00000000..e51d0f48
--- /dev/null
+++ b/tests/unit/engines/test_arxiv.py
@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+from collections import defaultdict
+import mock
+from searx.engines import arxiv
+from searx.testing import SearxTestCase
+
+
+class TestBaseEngine(SearxTestCase):
+
+    def test_request(self):
+        query = 'test_query'
+        dicto = defaultdict(dict)
+        dicto['pageno'] = 1
+        params = arxiv.request(query, dicto)
+        self.assertIn('url', params)
+        self.assertIn('export.arxiv.org/api/', params['url'])
+
+    def test_response(self):
+        self.assertRaises(AttributeError, arxiv.response, None)
+        self.assertRaises(AttributeError, arxiv.response, [])
+        self.assertRaises(AttributeError, arxiv.response, '')
+        self.assertRaises(AttributeError, arxiv.response, '[]')
+
+        response = mock.Mock(text='''<?xml version="1.0" encoding="UTF-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom"></feed>''')
+        self.assertEqual(arxiv.response(response), [])
+
+        xml_mock = '''<?xml version="1.0" encoding="UTF-8"?>
+<feed xmlns="http://www.w3.org/2005/Atom">
+  <title type="html">ArXiv Query: search_query=all:test_query&amp;id_list=&amp;start=0&amp;max_results=1</title>
+  <id>http://arxiv.org/api/1</id>
+  <updated>2000-01-21T00:00:00-01:00</updated>
+  <opensearch:totalResults xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/">1</opensearch:totalResults>
+  <opensearch:startIndex xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/">0</opensearch:startIndex>
+  <opensearch:itemsPerPage xmlns:opensearch="http://a9.com/-/spec/opensearch/1.1/">1</opensearch:itemsPerPage>
+  <entry>
+    <id>http://arxiv.org/1</id>
+    <updated>2000-01-01T00:00:01Z</updated>
+    <published>2000-01-01T00:00:01Z</published>
+    <title>Mathematical proof.</title>
+    <summary>Mathematical formula.</summary>
+    <author>
+      <name>A. B.</name>
+    </author>
+    <link href="http://arxiv.org/1" rel="alternate" type="text/html"/>
+    <link title="pdf" href="http://arxiv.org/1" rel="related" type="application/pdf"/>
+    <category term="math.QA" scheme="http://arxiv.org/schemas/atom"/>
+    <category term="1" scheme="http://arxiv.org/schemas/atom"/>
+  </entry>
+</feed>
+'''
+
+        response = mock.Mock(text=xml_mock.encode('utf-8'))
+        results = arxiv.response(response)
+        self.assertEqual(type(results), list)
+        self.assertEqual(len(results), 1)
+        self.assertEqual(results[0]['title'], 'Mathematical proof.')
+        self.assertEqual(results[0]['content'], 'Mathematical formula.')