From b404a29e10b79deb67c75dafa7db2fa0d218a0e5 Mon Sep 17 00:00:00 2001
From: Igor Chubin <igor@chub.in>
Date: Thu, 31 Jan 2019 00:36:14 +0000
Subject: [PATCH] added initial support for multilingual answers

---
 bin/srv.py               | 50 ++++++++++++++++++++++++++++++++++++++++
 lib/adapter_learnxiny.py |  2 +-
 lib/get_answer.py        | 13 +++++++++++
 3 files changed, 64 insertions(+), 1 deletion(-)

diff --git a/bin/srv.py b/bin/srv.py
index 2c8499b..40270d0 100644
--- a/bin/srv.py
+++ b/bin/srv.py
@@ -107,6 +107,52 @@ def get_request_ip(req):
 
     return ip_addr
 
+def get_answer_language(request):
+    """
+    Return preferred answer language based on
+    domain name, query arguments and headers
+    """
+
+    def _parse_accept_language(accept_language):
+        languages = accept_language.split(",")
+        locale_q_pairs = []
+
+        for language in languages:
+            try:
+                if language.split(";")[0] == language:
+                    # no q => q = 1
+                    locale_q_pairs.append((language.strip(), "1"))
+                else:
+                    locale = language.split(";")[0].strip()
+                    weight = language.split(";")[1].split("=")[1]
+                    locale_q_pairs.append((locale, weight))
+            except IndexError:
+                pass
+
+        return locale_q_pairs
+
+    def _find_supported_language(accepted_languages):
+        for lang_tuple in accepted_languages:
+            lang = lang_tuple[0]
+            if '-' in lang:
+                lang = lang.split('-', 1)[0]
+            return lang
+        return None
+
+    lang = None
+    hostname = request.headers['Host']
+    if hostname.endswith('.cheat.sh'):
+        lang = hostname[:-9]
+
+    if 'lang' in request.args:
+        lang = request.args.get('lang')
+
+    header_accept_language = request.headers.get('Accept-Language', '')
+    if lang is None and header_accept_language:
+        lang = _find_supported_language(
+            _parse_accept_language(header_accept_language))
+
+    return lang
 
 def _proxy(*args, **kwargs):
     # print "method=", request.method,
@@ -190,6 +236,10 @@ def answer(topic=None):
         return _proxy()
         #return requests.get('http://127.0.0.1:3000'+topic[8:]).text
 
+    lang = get_answer_language(request)
+    if lang:
+        options['lang'] = lang
+
     ip_address = get_request_ip(request)
     if '+' in topic:
         not_allowed = LIMITS.check_ip(ip_address)
diff --git a/lib/adapter_learnxiny.py b/lib/adapter_learnxiny.py
index 180b997..5094fc5 100644
--- a/lib/adapter_learnxiny.py
+++ b/lib/adapter_learnxiny.py
@@ -788,7 +788,7 @@ class LearnVisualBasicAdapter(LearnXYAdapter):
 
 ADAPTERS = {cls.prefix: cls() for cls in vars()['LearnXYAdapter'].__subclasses__()}
 
-def get_learnxiny(topic):
+def get_learnxiny(topic, request_options=None):
     """
     Return cheat sheet for `topic`
     or empty string if nothing found
diff --git a/lib/get_answer.py b/lib/get_answer.py
index fb4c1df..b4529f7 100644
--- a/lib/get_answer.py
+++ b/lib/get_answer.py
@@ -423,7 +423,20 @@ def get_answer(topic, keyword, options="", request_options=None): # pylint: disa
             return query
 
         section_name, rest = query.split('/', 1)
+
+        if ':' in section_name:
+            # if ':' is in section_name, it means, that we want to
+            # translate the answer in the specified human language
+            # (experimental)
+            language, section_name = section_name.split(':', 1)
+        else:
+            language = ""
+
         section_name = LANGUAGE_ALIAS.get(section_name, section_name)
+
+        if language:
+            section_name = language + ":" + section_name
+
         return "%s/%s" % (section_name, rest)
 
     def _rewrite_section_name_for_q(query):