1 files changed, 143 insertions, 0 deletions
diff --git a/searx/engines/duckduckgo.py b/searx/engines/duckduckgo.py
new file mode 100644
index 000000000..0d2c0af2d
--- /dev/null
+++ b/searx/engines/duckduckgo.py
@@ -0,0 +1,143 @@
+"""
+ DuckDuckGo (Web)
+
+ @website     https://duckduckgo.com/
+ @provide-api yes (https://duckduckgo.com/api),
+              but not all results from search-site
+
+ @using-api   no
+ @results     HTML (using search portal)
+ @stable      no (HTML can change)
+ @parse       url, title, content
+
+ @todo        rewrite to api
+"""
+
+from lxml.html import fromstring
+from json import loads
+from searx.engines.xpath import extract_text
+from searx.poolrequests import get
+from searx.url_utils import urlencode
+from searx.utils import match_language, eval_xpath
+
+# engine dependent config
+categories = ['general']
+paging = True
+language_support = True
+supported_languages_url = 'https://duckduckgo.com/util/u172.js'
+time_range_support = True
+
+language_aliases = {
+    'ar-SA': 'ar-XA',
+    'es-419': 'es-XL',
+    'ja': 'jp-JP',
+    'ko': 'kr-KR',
+    'sl-SI': 'sl-SL',
+    'zh-TW': 'tzh-TW',
+    'zh-HK': 'tzh-HK'
+}
+
+# search-url
+url = 'https://duckduckgo.com/html?{query}&s={offset}&dc={dc_param}'
+time_range_url = '&df={range}'
+
+time_range_dict = {'day': 'd',
+                   'week': 'w',
+                   'month': 'm'}
+
+# specific xpath variables
+result_xpath = '//div[@class="result results_links results_links_deep web-result "]'  # noqa
+url_xpath = './/a[@class="result__a"]/@href'
+title_xpath = './/a[@class="result__a"]'
+content_xpath = './/a[@class="result__snippet"]'
+
+
+# match query's language to a region code that duckduckgo will accept
+def get_region_code(lang, lang_list=[]):
+    if lang == 'all':
+        return None
+
+    lang_code = match_language(lang, lang_list, language_aliases, 'wt-WT')
+    lang_parts = lang_code.split('-')
+
+    # country code goes first
+    return lang_parts[1].lower() + '-' + lang_parts[0].lower()
+
+
+def request(query, params):
+    if params['time_range'] not in (None, 'None', '') and params['time_range'] not in time_range_dict:
+        return params
+
+    offset = (params['pageno'] - 1) * 30
+
+    region_code = get_region_code(params['language'], supported_languages)
+    params['url'] = 'https://duckduckgo.com/html/'
+    if params['pageno'] > 1:
+        params['method'] = 'POST'
+        params['data']['q'] = query
+        params['data']['s'] = offset
+        params['data']['dc'] = 30
+        params['data']['nextParams'] = ''
+        params['data']['v'] = 'l'
+        params['data']['o'] = 'json'
+        params['data']['api'] = '/d.js'
+        if params['time_range'] in time_range_dict:
+            params['data']['df'] = time_range_dict[params['time_range']]
+        if region_code:
+            params['data']['kl'] = region_code
+    else:
+        if region_code:
+            params['url'] = url.format(
+                query=urlencode({'q': query, 'kl': region_code}), offset=offset, dc_param=offset)
+        else:
+            params['url'] = url.format(
+                query=urlencode({'q': query}), offset=offset, dc_param=offset)
+
+        if params['time_range'] in time_range_dict:
+            params['url'] += time_range_url.format(range=time_range_dict[params['time_range']])
+
+    return params
+
+
+# get response from search-request
+def response(resp):
+    results = []
+
+    doc = fromstring(resp.text)
+
+    # parse results
+    for i, r in enumerate(eval_xpath(doc, result_xpath)):
+        if i >= 30:
+            break
+        try:
+            res_url = eval_xpath(r, url_xpath)[-1]
+        except:
+            continue
+
+        if not res_url:
+            continue
+
+        title = extract_text(eval_xpath(r, title_xpath))
+        content = extract_text(eval_xpath(r, content_xpath))
+
+        # append result
+        results.append({'title': title,
+                        'content': content,
+                        'url': res_url})
+
+    # return results
+    return results
+
+
+# get supported languages from their site
+def _fetch_supported_languages(resp):
+
+    # response is a js file with regions as an embedded object
+    response_page = resp.text
+    response_page = response_page[response_page.find('regions:{') + 8:]
+    response_page = response_page[:response_page.find('}') + 1]
+
+    regions_json = loads(response_page)
+    supported_languages = map((lambda x: x[3:] + '-' + x[:2].upper()), regions_json.keys())
+
+    return list(supported_languages)