add duckduckgo images engine

searx/engines/duckduckgo_images.py

@@ -0,0 +1,91 @@
+"""
+ DuckDuckGo (Images)
+
+ @website     https://duckduckgo.com/
+ @provide-api yes (https://duckduckgo.com/api),
+              but images are not supported
+
+ @using-api   no
+ @results     JSON (site requires js to get images)
+ @stable      no (JSON can change)
+ @parse       url, title, img_src
+
+ @todo        avoid extra request
+"""
+
+from requests import get
+from json import loads
+from searx.engines.xpath import extract_text
+from searx.engines.duckduckgo import _fetch_supported_languages, supported_languages_url, get_region_code
+from searx.url_utils import urlencode
+
+# engine dependent config
+categories = ['images']
+paging = True
+language_support = True
+safesearch = True
+
+# search-url
+images_url = 'https://duckduckgo.com/i.js?{query}&s={offset}&p={safesearch}&o=json&vqd={vqd}'
+site_url = 'https://duckduckgo.com/?{query}&iar=images&iax=1&ia=images'
+
+
+# run query in site to get vqd number needed for requesting images
+# TODO: find a way to get this number without an extra request (is it a hash of the query?)
+def get_vqd(query):
+    res = get(site_url.format(query=urlencode({'q': query})))
+    content = res.text
+    vqd = content[content.find('vqd=\'') + 5:]
+    vqd = vqd[:vqd.find('\'')]
+    return vqd
+
+
+# do search-request
+def request(query, params):
+    # to avoid running actual external requests when testing
+    if 'is_test' not in params:
+        vqd = get_vqd(query)
+    else:
+        vqd = '12345'
+
+    offset = (params['pageno'] - 1) * 50
+
+    safesearch = params['safesearch'] - 1
+
+    region_code = get_region_code(params['language'])
+    if region_code:
+        params['url'] = images_url.format(
+            query=urlencode({'q': query, 'l': region_code}), offset=offset, safesearch=safesearch, vqd=vqd)
+    else:
+        params['url'] = images_url.format(
+            query=urlencode({'q': query}), offset=offset, safesearch=safesearch, vqd=vqd)
+
+    return params
+
+
+# get response from search-request
+def response(resp):
+    results = []
+
+    content = resp.text
+    try:
+        res_json = loads(content)
+    except:
+        return []
+
+    # parse results
+    for result in res_json['results']:
+        title = result['title']
+        url = result['url']
+        thumbnail = result['thumbnail']
+        image = result['image']
+
+        # append result
+        results.append({'template': 'images.html',
+                        'title': title,
+                        'content': '',
+                        'thumbnail_src': thumbnail,
+                        'img_src': image,
+                        'url': url})
+
+    return results