6 files changed, 207 insertions, 18 deletions
diff --git a/searx/engines/elasticsearch.py b/searx/engines/elasticsearch.py
new file mode 100644
index 000000000..bad65fb27
--- /dev/null
+++ b/searx/engines/elasticsearch.py
@@ -0,0 +1,142 @@
+from json import loads, dumps
+from lxml import html
+from urllib.parse import quote, urljoin
+from requests.auth import HTTPBasicAuth
+from searx.utils import extract_text, get_torrent_size
+
+
+base_url = 'http://localhost:9200'
+username = ''
+password = ''
+index = ''
+search_url = base_url + '/' + index + '/_search'
+query_type = 'match'
+custom_query_json = {}
+show_metadata = False
+categories = ['general']
+
+
+def init(engine_settings):
+    if 'query_type' in engine_settings and engine_settings['query_type'] not in _available_query_types:
+        raise ValueError('unsupported query type', engine_settings['query_type'])
+
+    if index == '':
+        raise ValueError('index cannot be empty')
+
+
+def request(query, params):
+    if query_type not in _available_query_types:
+        return params
+
+    if username and password:
+        params['auth'] = HTTPBasicAuth(username, password)
+
+    params['url'] = search_url
+    params['method'] = 'GET'
+    params['data'] = dumps(_available_query_types[query_type](query))
+    params['headers']['Content-Type'] = 'application/json'
+
+    return params
+
+
+def _match_query(query):
+    """
+    The standard for full text queries.
+    searx format: "key:value" e.g. city:berlin
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-match-query.html
+    """
+
+    try:
+        key, value = query.split(':')
+    except:
+        raise ValueError('query format must be "key:value"')
+
+    return {"query": {"match": {key: {'query': value}}}}
+
+
+def _simple_query_string_query(query):
+    """
+    Accepts query strings, but it is less strict than query_string
+    The field used can be specified in index.query.default_field in Elasticsearch.
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-simple-query-string-query.html
+    """
+
+    return {'query': {'simple_query_string': {'query': query}}}
+
+
+def _term_query(query):
+    """
+    Accepts one term and the name of the field.
+    searx format: "key:value" e.g. city:berlin
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-term-query.html
+    """
+
+    try:
+        key, value = query.split(':')
+    except:
+        raise ValueError('query format must be key:value')
+
+    return {'query': {'term': {key: value}}}
+
+
+def _terms_query(query):
+    """
+    Accepts multiple terms and the name of the field.
+    searx format: "key:value1,value2" e.g. city:berlin,paris
+    REF: https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-terms-query.html
+    """
+
+    try:
+        key, values = query.split(':')
+    except:
+        raise ValueError('query format must be key:value1,value2')
+
+    return {'query': {'terms': {key: values.split(',')}}}
+
+
+def _custom_query(query):
+    key, value = query.split(':')
+    custom_query = custom_query_json
+    for query_key, query_value in custom_query.items():
+        if query_key == '{{KEY}}':
+            custom_query[key] = custom_query.pop(query_key)
+        if query_value == '{{VALUE}}':
+            custom_query[query_key] = value
+    return custom_query
+
+
+def response(resp):
+    results = []
+
+    resp_json = loads(resp.text)
+    if 'error' in resp_json:
+        raise Exception(resp_json['error'])
+
+    for result in resp_json['hits']['hits']:
+        r = {key: str(value) if not key.startswith('_') else value for key, value in result['_source'].items()}
+        r['template'] = 'key-value.html'
+
+        if show_metadata:
+            r['metadata'] = {'index': result['_index'],
+                             'id': result['_id'],
+                             'score': result['_score']}
+
+        results.append(r)
+
+    return results
+
+
+_available_query_types = {
+    # Full text queries
+    # https://www.elastic.co/guide/en/elasticsearch/reference/current/full-text-queries.html
+    'match': _match_query,
+    'simple_query_string': _simple_query_string_query,
+
+    # Term-level queries
+    # https://www.elastic.co/guide/en/elasticsearch/reference/current/term-level-queries.html
+    'term': _term_query,
+    'terms': _terms_query,
+
+    # Query JSON defined by the instance administrator.
+    'custom': _custom_query,
+}
diff --git a/searx/engines/qwant.py b/searx/engines/qwant.py
index 98460604c..c909ce11b 100644
--- a/searx/engines/qwant.py
+++ b/searx/engines/qwant.py
@@ -17,7 +17,7 @@ from searx.utils import html_to_text, match_language
 
 
 # engine dependent config
-categories = None
+categories = []
 paging = True
 language_support = True
 supported_languages_url = 'https://qwant.com/region'
diff --git a/searx/engines/xpath.py b/searx/engines/xpath.py
index 81c2747fb..a569d9160 100644
--- a/searx/engines/xpath.py
+++ b/searx/engines/xpath.py
@@ -7,6 +7,7 @@ url_xpath = None
 content_xpath = None
 title_xpath = None
 thumbnail_xpath = False
+categories = []
 paging = False
 suggestion_xpath = ''
 results_xpath = ''
diff --git a/searx/search.py b/searx/search.py
index cd195825a..1cb2a603b 100644
--- a/searx/search.py
+++ b/searx/search.py
@@ -57,8 +57,11 @@ class EngineRef:
         self.category = category
         self.from_bang = from_bang
 
-    def __str__(self):
-        return "(" + self.name + "," + self.category + "," + str(self.from_bang) + ")"
+    def __repr__(self):
+        return "EngineRef({!r}, {!r}, {!r})".format(self.name, self.category, self.from_bang)
+
+    def __eq__(self, other):
+        return self.name == other.name and self.category == other.category and self.from_bang == other.from_bang
 
 
 class SearchQuery:
@@ -87,8 +90,21 @@ class SearchQuery:
         self.timeout_limit = timeout_limit
         self.external_bang = external_bang
 
-    def __str__(self):
-        return self.query + ";" + str(self.engineref_list)
+    def __repr__(self):
+        return "SearchQuery({!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r}, {!r})".\
+               format(self.query, self.engineref_list, self.categories, self.lang, self.safesearch,
+                      self.pageno, self.time_range, self.timeout_limit, self.external_bang)
+
+    def __eq__(self, other):
+        return self.query == other.query\
+            and self.engineref_list == other.engineref_list\
+            and self.categories == self.categories\
+            and self.lang == other.lang\
+            and self.safesearch == other.safesearch\
+            and self.pageno == other.pageno\
+            and self.time_range == other.time_range\
+            and self.timeout_limit == other.timeout_limit\
+            and self.external_bang == other.external_bang
 
 
 def send_http_request(engine, request_params):
@@ -110,7 +126,8 @@ def send_http_request(engine, request_params):
         req = requests_lib.get
     else:
         req = requests_lib.post
-        request_args['data'] = request_params['data']
+
+    request_args['data'] = request_params['data']
 
     # send the request
     return req(request_params['url'], **request_args)
diff --git a/searx/settings.yml b/searx/settings.yml
index 54352bbfc..78ae26b97 100644
--- a/searx/settings.yml
+++ b/searx/settings.yml
@@ -17,6 +17,12 @@ server:
     image_proxy : False # Proxying image results through searx
     http_protocol_version : "1.0"  # 1.0 and 1.1 are supported
     method: "POST" # POST queries are more secure as they don't show up in history but may cause problems when using Firefox containers
+    default_http_headers:
+        X-Content-Type-Options : nosniff
+        X-XSS-Protection : 1; mode=block
+        X-Download-Options : noopen
+        X-Robots-Tag : noindex, nofollow
+        Referrer-Policy : no-referrer
 
 ui:
     static_path : "" # Custom static path - leave it blank if you didn't change
@@ -225,6 +231,20 @@ engines:
     shortcut : ew
     disabled : True
 
+#  - name : elasticsearch
+#    shortcut : es
+#    engine : elasticsearch
+#    base_url : http://localhost:9200
+#    username : elastic
+#    password : changeme
+#    index : my-index
+#    # available options: match, simple_query_string, term, terms, custom
+#    query_type : match
+#    # if query_type is set to custom, provide your query here
+#    #custom_query_json: {"query":{"match_all": {}}}
+#    #show_metadata: False
+#    disabled : True
+
   - name : wikidata
     engine : wikidata
     shortcut : wd
diff --git a/searx/webapp.py b/searx/webapp.py
index 46d547d52..326200cec 100755
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -44,7 +44,7 @@ from urllib.parse import urlencode, urlparse, urljoin, urlsplit
 
 from pygments import highlight
 from pygments.lexers import get_lexer_by_name
-from pygments.formatters import HtmlFormatter
+from pygments.formatters import HtmlFormatter  # pylint: disable=no-name-in-module
 
 from werkzeug.middleware.proxy_fix import ProxyFix
 from flask import (
@@ -111,7 +111,7 @@ app = Flask(
 
 app.jinja_env.trim_blocks = True
 app.jinja_env.lstrip_blocks = True
-app.jinja_env.add_extension('jinja2.ext.loopcontrols')
+app.jinja_env.add_extension('jinja2.ext.loopcontrols')  # pylint: disable=no-member
 app.secret_key = settings['server']['secret_key']
 
 # see https://flask.palletsprojects.com/en/1.1.x/cli/
@@ -488,6 +488,16 @@ def pre_request():
 
 
 @app.after_request
+def add_default_headers(response):
+    # set default http headers
+    for header, value in settings['server'].get('default_http_headers', {}).items():
+        if header in response.headers:
+            continue
+        response.headers[header] = value
+    return response
+
+
+@app.after_request
 def post_request(response):
     total_time = time() - request.start_time
     timings_all = ['total;dur=' + str(round(total_time * 1000, 3))]
@@ -537,10 +547,12 @@ def index():
 
     # redirect to search if there's a query in the request
     if request.form.get('q'):
-        return redirect(url_for('search'), 308)
+        query = ('?' + request.query_string.decode()) if request.query_string else ''
+        return redirect(url_for('search') + query, 308)
 
     return render(
         'index.html',
+        selected_categories=get_selected_categories(request.preferences, request.form),
     )
 
 
@@ -556,8 +568,8 @@ def search():
     if output_format not in ['html', 'csv', 'json', 'rss']:
         output_format = 'html'
 
-    # check if there is query
-    if request.form.get('q') is None:
+    # check if there is query (not None and not an empty string)
+    if not request.form.get('q'):
         if output_format == 'html':
             return render(
                 'index.html',
@@ -577,15 +589,12 @@ def search():
 
         result_container = search.search()
 
+    except SearxParameterException as e:
+        logger.exception('search error: SearxParameterException')
+        return index_error(output_format, e.message), 400
     except Exception as e:
-        # log exception
         logger.exception('search error')
-
-        # is it an invalid input parameter or something else ?
-        if (issubclass(e.__class__, SearxParameterException)):
-            return index_error(output_format, e.message), 400
-        else:
-            return index_error(output_format, gettext('search error')), 500
+        return index_error(output_format, gettext('search error')), 500
 
     # results
     results = result_container.get_ordered_results()