User language control via userlang cookie

src/server/request_context.cpp

@@ -97,6 +97,7 @@ RequestContext::RequestContext(struct MHD_Connection* connection,
 {
   MHD_get_connection_values(connection, MHD_HEADER_KIND, &RequestContext::fill_header, this);
   MHD_get_connection_values(connection, MHD_GET_ARGUMENT_KIND, &RequestContext::fill_argument, this);
+  MHD_get_connection_values(connection, MHD_COOKIE_KIND, &RequestContext::fill_cookie, this);
 
   try {
     acceptEncodingGzip =
@@ -106,6 +107,8 @@ RequestContext::RequestContext(struct MHD_Connection* connection,
   try {
     byteRange_ = ByteRange::parse(get_header(MHD_HTTP_HEADER_RANGE));
   } catch (const std::out_of_range&) {}
+
+  userlang = determine_user_language();
 }
 
 RequestContext::~RequestContext()
@@ -135,6 +138,14 @@ MHD_Result RequestContext::fill_argument(void *__this, enum MHD_ValueKind kind,
   return MHD_YES;
 }
 
+MHD_Result RequestContext::fill_cookie(void *__this, enum MHD_ValueKind kind,
+                                         const char *key, const char* value)
+{
+  RequestContext *_this = static_cast<RequestContext*>(__this);
+  _this->cookies[key] = value == nullptr ? "" : value;
+  return MHD_YES;
+}
+
 void RequestContext::print_debug_info() const {
   printf("method    : %s (%d)\n", method==RequestMethod::GET ? "GET" :
                                   method==RequestMethod::POST ? "POST" :
@@ -215,11 +226,20 @@ std::string RequestContext::get_header(const std::string& name) const {
 }
 
 std::string RequestContext::get_user_language() const
+{
+  return userlang;
+}
+
+std::string RequestContext::determine_user_language() const
 {
   try {
     return get_argument("userlang");
   } catch(const std::out_of_range&) {}
 
+  try {
+     return cookies.at("userlang");
+  } catch(const std::out_of_range&) {}
+
   try {
     return parseAcceptLanguageHeader(get_header("Accept-Language"));
   } catch(const std::out_of_range&) {}

src/server/request_context.h

@@ -130,10 +130,15 @@ class RequestContext {
     ByteRange byteRange_;
     std::map<std::string, std::string> headers;
     std::map<std::string, std::vector<std::string>> arguments;
+    std::map<std::string, std::string> cookies;
     std::string queryString;
+    std::string userlang;
 
   private: // functions
+    std::string determine_user_language() const;
+
     static MHD_Result fill_header(void *, enum MHD_ValueKind, const char*, const char*);
+    static MHD_Result fill_cookie(void *, enum MHD_ValueKind, const char*, const char*);
     static MHD_Result fill_argument(void *, enum MHD_ValueKind, const char*, const char*);
 };
 

test/server.cpp

@@ -1042,6 +1042,46 @@ TEST_F(ServerTest, UserLanguageControl)
       /*Response Set-Cookie:*/  "userlang=test",
       /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
     },
+    {
+      "userlang cookie is respected",
+      /*url*/ "/ROOT/content/zimfile/invalid-article",
+      /*Accept-Language:*/ "",
+      /*Request Cookie:*/       "userlang=test",
+      /*Response Set-Cookie:*/  "userlang=test",
+      /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
+    },
+    {
+      "userlang cookie is correctly parsed",
+      /*url*/ "/ROOT/content/zimfile/invalid-article",
+      /*Accept-Language:*/ "",
+      /*Request Cookie:*/       "anothercookie=123; userlang=test",
+      /*Response Set-Cookie:*/  "userlang=test",
+      /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
+    },
+    {
+      "userlang cookie is correctly parsed",
+      /*url*/ "/ROOT/content/zimfile/invalid-article",
+      /*Accept-Language:*/ "",
+      /*Request Cookie:*/       "userlang=test; anothercookie=abc",
+      /*Response Set-Cookie:*/  "userlang=test",
+      /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
+    },
+    {
+      "userlang cookie is correctly parsed",
+      /*url*/ "/ROOT/content/zimfile/invalid-article",
+      /*Accept-Language:*/ "",
+      /*Request Cookie:*/       "cookie1=abc; userlang=test; cookie2=xyz",
+      /*Response Set-Cookie:*/  "userlang=test",
+      /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
+    },
+    {
+      "Multiple userlang cookies are not a problem",
+      /*url*/ "/ROOT/content/zimfile/invalid-article",
+      /*Accept-Language:*/ "",
+      /*Request Cookie:*/       "cookie1=abc; userlang=en; userlang=test; cookie2=xyz",
+      /*Response Set-Cookie:*/  "userlang=test",
+      /* expected <h1> */ "[I18N TESTING] Content not found, but at least the server is alive"
+    },
     {
       "userlang query parameter takes precedence over Accept-Language",
       /*url*/ "/ROOT/content/zimfile/invalid-article?userlang=en",
@@ -1050,6 +1090,22 @@ TEST_F(ServerTest, UserLanguageControl)
       /*Response Set-Cookie:*/  "userlang=en",
       /* expected <h1> */ "Not Found"
     },
+    {
+      "userlang query parameter takes precedence over its cookie counterpart",
+      /*url*/ "/ROOT/content/zimfile/invalid-article?userlang=en",
+      /*Accept-Language:*/ "",
+      /*Request Cookie:*/       "userlang=test",
+      /*Response Set-Cookie:*/  "userlang=en",
+      /* expected <h1> */ "Not Found"
+    },
+    {
+      "userlang in cookies takes precedence over Accept-Language",
+      /*url*/ "/ROOT/content/zimfile/invalid-article",
+      /*Accept-Language:*/ "test",
+      /*Request Cookie:*/       "userlang=en",
+      /*Response Set-Cookie:*/  "userlang=en",
+      /* expected <h1> */ "Not Found"
+    },
     {
       "The value of the Accept-Language header is not currently parsed.",
       // In case of a comma separated list of languages (optionally weighted