assets/HypertextPages/chat-members.nytl.html

@@ -34,11 +34,11 @@
             <a href="/list-rooms" id="go-to-chat-list" class="panel-thing">
                 <img alt="Go to list of chats" src="/assets/img/list-rooms.svg" width="32px">
             </a>
-            <a href="/user/{% WRITE userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
+            <a href="/user/{% W userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
                 <img alt="Go to my profile" src="/assets/img/user.svg" width="32px">
             </a>
-            <p class="panel-thing panel-header-txt"> Members list of {% WRITE openedchat.name %} ({% WRITE openedchat.nickname %})</p>
+            <p class="panel-thing panel-header-txt"> Members list of {% W openedchat.name %} ({% W openedchat.nickname %})</p>
-            <a href="/chat/{% WRITE openedchat.nickname %}" id="go-to-chat-settings" class="panel-thing">
+            <a href="/chat/{% W openedchat.nickname %}" id="go-to-chat-settings" class="panel-thing">
                 <img alt="Back to chat" src="/assets/img/return.svg" width="32px">
             </a>
         </div>

assets/HypertextPages/chat.nytl.html

@@ -36,11 +36,11 @@
             <a href="/list-rooms" id="go-to-chat-list" class="panel-thing">
                 <img alt="Go to list of chats" src="/assets/img/list-rooms.svg" width="32px">
             </a>
-            <a href="/user/{% WRITE userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
+            <a href="/user/{% W userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
                 <img alt="Go to my profile" src="/assets/img/user.svg" width="32px">
             </a>
-            <p class="panel-thing panel-header-txt"> {% WRITE openedchat.name %} ({% WRITE openedchat.nickname %})</p>
+            <p class="panel-thing panel-header-txt"> {% W openedchat.name %} ({% W openedchat.nickname %})</p>
-            <a href="/chat-members/{% WRITE openedchat.nickname %}" id="go-to-chat-settings" class="panel-thing">
+            <a href="/chat-members/{% W openedchat.nickname %}" id="go-to-chat-settings" class="panel-thing">
                 <img alt="Settings of chat. List of members" src="/assets/img/settings-iron.svg" width="32px">
             </a>
         </div>

assets/HypertextPages/edit-profile.nytl.html

@@ -16,28 +16,28 @@
             <a href="/list-rooms" id="go-to-chat-list" class="panel-thing">
                 <img alt="Go to list of chats" src="/assets/img/list-rooms.svg" width="32px">
             </a>
-            <a href="/user/{% WRITE userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
+            <a href="/user/{% W userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
                 <img alt="Go to my profile" src="/assets/img/user.svg" width="32px">
             </a>
         </div>
 
         {% FOR error IN errors %}
             <div class="server-notif-error-msg-box">
-                {% WRITE error.text %}
+                {% W error.text %}
             </div>
         {% ENDFOR %}
 
         <div class="profile-container">
-            <h2 class="profile-name-text">{% WRITE alienprofile.name %}</h2>
+            <h2 class="profile-name-text">{% W alienprofile.name %}</h2>
-            <h3 class="profile-nickname-text">Nickname: {% WRITE alienprofile.nickname %}</h3>
+            <h3 class="profile-nickname-text">Nickname: {% W alienprofile.nickname %}</h3>
             <p class="profile-bio-text">
-                {% WRITE alienprofile.bio %}
+                {% W alienprofile.bio %}
             </p>
         </div>
 
         <div class="profile-container resp-container">
             <h1 class="wide-centered-header">Change user attributes</h1>
-            <form action = "/user/{% WRITE alienprofile.nickname %}" method="post" enctype="application/x-www-form-urlencoded">
+            <form action = "/user/{% W alienprofile.nickname %}" method="post" enctype="application/x-www-form-urlencoded">
                 <table class="logins-input-table">
                     <tr>
                         <td class="logins-input-td1">

assets/HypertextPages/list-rooms.nytl.html

@@ -1,6 +1,6 @@
 {% ELDEF main JSON pres JSON userinfo JSON initial_chatListUpdResp %}
 <!DOCTYPE html>
-<html lang="{% WRITE pres.lang %}">
+<html lang="{% W pres.lang %}">
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
@@ -51,7 +51,7 @@
 x
     <div class="document-container resp-container">
         <div id="navigation-panel" class="panel">
-            <a href="/user/{% WRITE userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
+            <a href="/user/{% W userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
                 <img alt="Go to my profile" src="/assets/img/user.svg" width="32px">
             </a>
             <p class="panel-thing panel-header-txt">

assets/HypertextPages/login.nytl.html

@@ -1,39 +1,41 @@
 {% ELDEF main JSON pres JSON userinfo JSON errors %}
 <!DOCTYPE html>
-<html lang="en">
+<html lang="{% W pres.lang %}">
 <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <link rel="icon" type="image/png" href="/assets/img/favicon.png">
     <link rel="stylesheet" href="/assets/css/common.css">
     <link rel="stylesheet" href="/assets/css/login.css">
-    <title>Login Page</title>
+    <title>{% W pres.loginP.header %}</title>
 </head>
 <body>
     {% FOR error IN errors %}
         <div class="server-notif-error-msg-box">
-            {% WRITE error.text %}
+            {% W error.text %}
         </div>
     {% ENDFOR %}
 
     <div class="form-container">
-        <h1 class="wide-centered-header">Login</h1>
+        <h1 class="wide-centered-header">{% W pres.loginP.header %}</h1>
         <form action="/login" method="post" enctype="application/x-www-form-urlencoded">
             <table class="logins-input-table">
                 <tr>
-                    <td class="logins-input-td1"><label for="input-nickname">Enter user nickname:</label></td>
+                    <td class="logins-input-td1"><label for="input-nickname">{% W pres.loginP.directive-nickname %}</label></td>
                     <td class="logins-input-td2">
-                        <input name="nickname" id="input-nickname" type="text" placeholder="Nickname" class="one-line-input" required>
+                        <input type="text" name="nickname" id="input-nickname"
+                               placeholder="{% W pres.loginP.placeholder-nickname %}" class="one-line-input" required>
                     </td>
                 </tr>
                 <tr>
-                    <td class="logins-input-td1"><label for="input-password">Enter password:</label></td>
+                    <td class="logins-input-td1"><label for="input-password">{% W pres.loginP.directive-password %}</label></td>
                     <td class="logins-input-td2">
-                        <input name="password" id="input-password" type="password" placeholder="Password" class="one-line-input" required>
+                        <input name="password" id="input-password" type="password"
+                               placeholder="{% W pres.loginP.placeholder-password %}" class="one-line-input" required>
                     </td>
                 </tr>
             </table>
-            <button class="action-button centered-block-el" type="submit">Login</button>
+            <button class="action-button centered-block-el" type="submit">{% W pres.loginP.act %}</button>
         </form>
     </div>
 

assets/HypertextPages/view-profile.nytl.html

@@ -16,16 +16,16 @@
             <a href="/list-rooms" id="go-to-chat-list" class="panel-thing">
                 <img alt="Go to list of chats" src="/assets/img/list-rooms.svg" width="32px">
             </a>
-            <a href="/user/{% WRITE userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
+            <a href="/user/{% W userinfo.nickname %}" id="go-to-my-profile" class="panel-thing">
                 <img alt="Go to my profile" src="/assets/img/user.svg" width="32px">
             </a>
         </div>
 
         <div class="profile-container">
-            <h2 class="profile-name-text">{% WRITE alienprofile.name %}</h2>
+            <h2 class="profile-name-text">{% W alienprofile.name %}</h2>
-            <h3 class="profile-nickname-text">Nickname: {% WRITE alienprofile.nickname %}</h3>
+            <h3 class="profile-nickname-text">Nickname: {% W alienprofile.nickname %}</h3>
             <p class="profile-bio-text">
-                {% WRITE alienprofile.bio %}
+                {% W alienprofile.bio %}
             </p>
         </div>
     </div>

assets/lang/en-US.lang.json

@@ -0,0 +1,11 @@
+{
+  "lang": "en",
+  "loginP": {
+    "header": "Login",
+    "directive-nickname": "Enter your nickname:",
+    "placeholder-nickname": "Nickname",
+    "directive-password": "Enter password:",
+    "placeholder-password": "Password",
+    "act": "Login"
+  }
+}

assets/lang/ru-RU.lang.json

@@ -0,0 +1,11 @@
+{
+  "lang": "ru",
+  "loginP": {
+    "header": "Вход",
+    "directive-nickname": "Введите свой никнейм:",
+    "placeholder-nickname": "",
+    "directive-password": "Введите пароль:",
+    "placeholder-password": "",
+    "act": "Войти"
+  }
+}

building/main.cpp

@@ -78,6 +78,7 @@ struct CAWebChat {
                 "http_structures/client_request_parse.cpp",
                 "http_structures/response_gen.cpp",
                 "http_structures/cookies.cpp",
+                "http_structures/accept_language.cpp",
                 "connecting_assets/static_asset_manager.cpp",
                 "running_mainloop.cpp",
                 "form_data_structure/urlencoded_query.cpp",
@@ -97,6 +98,7 @@ struct CAWebChat {
                 "http_structures/client_request.h",
                 "http_structures/cookies.h",
                 "http_structures/response_gen.h",
+                "http_structures/accept_language.h",
                 "running_mainloop.h",
                 "form_data_structure/urlencoded_query.h",
                 "socket_address.h",
@@ -141,6 +143,7 @@ struct CAWebChat {
                 CTargetDependenceOnExternalLibrary{"sqlite3", {true, true}}
             };
             T.units = {
+                "localizator.cpp",
                 "initialize.cpp",
                 "run.cpp",
                 "str_fields.cpp",

example/config.json

@@ -1,33 +1,9 @@
 {
-  "presentation": {
+  "lang": {
-    "lang": "ru",
+    "whitelist": ["*"],
-    "instance-identity": {
+    "force-order": [
-      "top-title": "Вэб чат от ИУ9"
+      "ru"
-    },
+    ]
-    "phr": {
-      "decl": {
-        "enter": "Вход",
-        "nickname": "Никнейм",
-        "password": "Пароль",
-        "page-login": "Вход",
-        "list-of-chat-rooms": "Список Чат-Коsмнат",
-        "name-of-room": "Название комнаты",
-        "create-room": "Создать комнату",
-
-        "incorrect-nickname-or-password": "Неправильный никнейм или пароль",
-
-        "incorrect-profile-data": "Неправильно заполнены поля профиля"
-      },
-      "ask" : {
-        "select-chat-room": "Выберете чат комнату"
-      },
-      "act": {
-        "enter": "Войти",
-        "create-room": "Создать комнату",
-        "confirm": "Подтвердить",
-        "create": "Создать"
-      }
-    }
   },
   "assets": "./assets",
   "database": {
@@ -41,7 +17,7 @@
     "storage-size-limit": 100000000000
   },
   "server": {
-    "workers": 8,
+    "workers": 16,
     "http-listen": ["127.0.0.1:1025"],
     "admin-command-listen": ["[::1]:1026"]
   }

src/http_server/engine_engine_number_9/http_structures/accept_language.cpp

@@ -0,0 +1,72 @@
+#include "accept_language.h"
+#include <algorithm>
+#include "grammar.h"
+#include "../baza_inter.h"
+
+namespace een9 {
+    bool AcceptLanguageSpec(char ch) {
+        return ch == ',' || ch == ';' || ch == '=';
+    }
+
+    /* todo: This is one of many places in een9, where bad alloc does not interrupt request,
+     * todo:  completely changing response instead. (see cookies and login cookies lol)
+     * todo: I have to do something about it. Maybe add more exception types */
+    std::vector<std::string> parse_header_Accept_Language(const std::string &AcceptLanguage) {
+        size_t n = AcceptLanguage.size();
+        struct LR {
+            std::string lr;
+            float q = 1;
+        };
+        size_t i = 0;
+        auto skipOWS = [&]() {
+            while (i < n && isSPACE(AcceptLanguage[i]))
+                i++;
+        };
+        auto isThis = [&](char ch) {
+            skipOWS();
+            return i >= n ? false : AcceptLanguage[i] == ch;
+        };
+        auto readTkn = [&]() -> std::string {
+            skipOWS();
+            if (i >= n)
+                return "";
+            size_t bg = i;
+            while (i < n && !AcceptLanguageSpec(AcceptLanguage[i]) && !isSPACE(AcceptLanguage[i]))
+                i++;
+            return AcceptLanguage.substr(bg, i - bg);
+        };
+        std::vector<LR> lrs;
+#define myMsg "Bad Accept-Language"
+        while (i < n) {
+            skipOWS();
+            if (i >= n)
+                break;
+            if (!lrs.empty()) {
+                if (isThis(','))
+                    i++;
+                else
+                    break;
+            }
+            lrs.emplace_back();
+            lrs.back().lr = readTkn();
+            LR lr{readTkn(), 0};
+            if (isThis(';')) {
+                i++;
+                if (readTkn() != "q")
+                    THROW(myMsg);
+                if (!isThis('='))
+                    THROW(myMsg);
+                i++;
+                lrs.back().q = std::stof(readTkn());
+            }
+        }
+        std::sort(lrs.begin(), lrs.end(), [](const LR& A, const LR& B) {
+            return A.q > B.q;
+        });
+        std::vector<std::string> result;
+        result.reserve(lrs.size());
+        for (const LR& lr: lrs)
+            result.push_back(lr.lr == "*" ? "" : lr.lr);
+        return result;
+    }
+}

src/http_server/engine_engine_number_9/http_structures/accept_language.h

@@ -0,0 +1,13 @@
+#ifndef ENGINE_ENGINE_NUMBER_9_HTTP_STRUCTURES_ACCEPT_LANGUAGE_H
+#define ENGINE_ENGINE_NUMBER_9_HTTP_STRUCTURES_ACCEPT_LANGUAGE_H
+
+#include <vector>
+#include <string>
+
+namespace een9 {
+    /* Returns language ranges, sorted by priority (reverse)
+     * throws std::exception if header is incorrect! But it is not guaranteed. Maybe it won't */
+    std::vector<std::string> parse_header_Accept_Language(const std::string& AcceptLanguage);
+}
+
+#endif

src/http_server/engine_engine_number_9/http_structures/cookies.cpp

@@ -1,14 +1,20 @@
 #include "cookies.h"
 #include "../baza_inter.h"
 
+#include "grammar.h"
+
 namespace een9 {
     bool isSPACE(char ch) {
         return ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n';
     }
 
+    bool isALPHANUM(char ch) {
+        return ('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ('0' <= ch && ch <= '9');
+    }
+
     bool isToken(const std::string &str) {
         for (char ch : str) {
-            if (!(('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z') || ('0' <= ch && ch <= '9')
+            if (!(isALPHANUM(ch)
                 || ch == '!' || ch == '#' || ch == '$' || ch == '%' || ch == '&' || ch == '\'' || ch == '*'
                 || ch == '+' || ch == '-' || ch == '.' || ch == '^' || ch == '_' || ch == '`' || ch == '|'
                 || ch == '~' ))

src/http_server/engine_engine_number_9/http_structures/grammar.h

@@ -0,0 +1,11 @@
+#ifndef ENGINE_ENGINE_NUMBER_9_HTTP_STRUCTURES_GRAMMAR_H
+#define ENGINE_ENGINE_NUMBER_9_HTTP_STRUCTURES_GRAMMAR_H
+
+#include <string>
+
+namespace een9 {
+    bool isSPACE(char ch);
+    bool isALPHANUM(char ch);
+}
+
+#endif

src/http_server/misc_tests/accept_language_test.cpp

@@ -0,0 +1,35 @@
+#include <engine_engine_number_9/baza_inter.h>
+#include <engine_engine_number_9/http_structures/accept_language.h>
+
+using namespace een9;
+
+void test(const std::string& al, const std::vector<std::string>& rls) {
+    std::vector<std::string> got = parse_header_Accept_Language(al);
+    if (got != rls) {
+        printf("Test failed: wrong answer\n");
+        abort();
+    }
+    printf("Test passed\n");
+}
+
+void btest(const std::string& al) {
+    try {
+        parse_header_Accept_Language(al);
+    } catch (std::exception& e) {}
+    printf("...\n");
+}
+
+int main() {
+    test("RU-RU, uk-EN; q = 12.22", {"uk-EN", "RU-RU"});
+    test("   RU-RU   ,uk-EN; q = 12.22  ", {"uk-EN", "RU-RU"});
+    test(" AAA; q=0.1,  BBB-bb ; q=3, *; q=3", {"BBB-bb", "", "AAA"});
+    test(" AAA; q=0.1,  BBB-bb ; q=2.5, *; q=4.5", {"", "BBB-bb", "AAA"});
+    test("ABB, AAA; q=0.1,AAB,  BBB-bb ; q=2.5, *; q=4.5", {"", "BBB-bb", "ABB", "AAB", "AAA"});
+    test("", {});
+    test("   ", {});
+    btest(";;;;");
+    btest(";;==;;");
+    btest("-;");
+    btest("-==");
+    return 0;
+}

src/http_server/new_york_transit_line/parser.cpp

@@ -453,11 +453,11 @@ namespace nytl {
                 P.passed_arguments = {parse_expression(ctx, local_var_names)};
                 skip_magic_block_end(ctx, syntax);
             };
-            if (op == "WRITE") {
+            if (op == "WRITE" || op == "W") {
                 mediocre_operator("str2text");
                 goto ya_e_ya_h_i_ya_g_d_o;;
             }
-            if (op == "ROUGHINSERT") {
+            if (op == "ROUGHINSERT" || op == "RI") {
                 mediocre_operator("str2code");
                 goto ya_e_ya_h_i_ya_g_d_o;;
             }

src/web_chat/iu9_ca_web_chat_lib/backend_logic/client_server_interact.h

@@ -11,12 +11,14 @@
 #include <jsonincpp/jsonobj.h>
 #include <new_york_transit_line/templater.h>
 #include <memory>
+#include "../localizator.h"
 
 namespace iu9cawebchat {
     struct WorkerGuestData {
         /* Because templaters use libjsonincpp, they can't be READ by two thread simultaneously */
         std::unique_ptr<nytl::Templater> templater;
         std::unique_ptr<SqliteConnection> db;
+        std::unique_ptr<Localizator> locales;
     };
 
     void initial_extraction_of_all_the_useful_info_from_cookies(

src/web_chat/iu9_ca_web_chat_lib/localizator.cpp

@@ -0,0 +1,154 @@
+#include "localizator.h"
+
+#include <jsonincpp/string_representation.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <engine_engine_number_9/os_utils.h>
+#include <engine_engine_number_9/baza_throw.h>
+#include <assert.h>
+
+namespace iu9cawebchat {
+    std::string languageRangeSimpler(const std::string& a) {
+        return a == "*" ? "" : a;
+    }
+
+    // I won't use iterators. c plus plus IS a scripting language and I do not want to mess with iterators
+    std::vector<std::string> languageRangeGetPrefixes(const std::string& lr) {
+        if (lr.empty())
+            return {""};
+        std::vector<std::string> result = {"", ""};
+        for (size_t i = 0; i < lr.size(); i++) {
+            if (lr[i] == '-')
+                result.push_back(result.back());
+            result.back() += lr[i];
+
+        }
+        return result;
+    }
+
+    bool isInWhitelist(const std::string& lr, const std::vector<std::string>& whitelist) {
+        for (const std::string& prefix : languageRangeGetPrefixes(lr))
+            for (const std::string& nicePrefix: whitelist)
+                if (prefix == nicePrefix)
+                    return true;
+        return false;
+    }
+
+    std::vector<LanguageFile> collect_lang_dir_content(const std::string& lang_dir,
+        const std::vector<std::string>& whitelist) {
+
+        std::vector<LanguageFile> result;
+        errno = 0;
+        DIR* D = opendir(lang_dir.c_str());
+        struct Guard1{ DIR*& D; ~Guard1(){ closedir(D); } } g1{D};
+        if (!D)
+            een9_THROW_on_errno("opendir (" + lang_dir + ")");
+        while (true) {
+            errno = 0;
+            struct dirent* Dent = readdir(D);
+            if (Dent == NULL) {
+                if (errno == 0)
+                    break;
+                een9_THROW_on_errno("dirent");
+            }
+            std::string entry = Dent->d_name;
+            if (entry == "." || entry == "..")
+                continue;
+            std::string filename = lang_dir + "/" + entry;
+            struct stat info;
+            int ret = stat(filename.c_str(), &info);
+            een9_ASSERT_on_iret(ret, "stat(" + filename + ")");
+            if (!S_ISREG(info.st_mode))
+                continue;
+            const std::string postfix = ".lang.json";
+            if (!een9::endsWith(entry, postfix))
+                continue;
+            std::string lang_antirange = entry.substr(0, entry.size() - postfix.size());
+            if (!isInWhitelist(lang_antirange, whitelist))
+                continue;
+            std::string content;
+            een9::readFile(filename, content);
+
+            result.emplace_back();
+            result.back().languagerange = languageRangeSimpler(lang_antirange);
+            result.back().content = json::parse_str_flawless(content);
+        }
+        return result;
+    }
+
+
+    Localizator::Localizator(const LocalizatorSettings &settings) : settings(settings) {
+        /* First - length of the longest prefix that was found so far (in force_order)
+         * Second - index in force_order that was assigned to this thingy
+         */
+
+        files = collect_lang_dir_content(settings.lang_dir, settings.whitelist);
+        size_t n = files.size();
+#define redundantFileMsg "Redundant localization file"
+        for (size_t i = 0; i < n; i++) {
+            for (size_t j = i + 1; j < n; j++) {
+                std::string A = files[i].languagerange;
+                std::string B = files[j].languagerange;
+                for (std::string& pa: languageRangeGetPrefixes(A))
+                    if (pa == B)
+                        een9_THROW(redundantFileMsg);
+                for (std::string& pb: languageRangeGetPrefixes(B))
+                    if (pb == A)
+                        een9_THROW(redundantFileMsg);
+            }
+        }
+        std::map<std::string, std::vector<std::size_t>> pref_to_files;
+        for (size_t k = 0; k < n; k++) {
+            for (const std::string& prefix: languageRangeGetPrefixes(files[k].languagerange)) {
+                pref_to_files[prefix].push_back(k);
+            }
+        }
+        std::vector<std::pair<size_t, size_t>> assignment;
+        constexpr size_t inf_bad_order = 999999999;
+        assignment.assign(n, {0, inf_bad_order});
+        if (settings.force_order.size() >= inf_bad_order - 2)
+            een9_THROW("o_O");
+        for (ssize_t i = 0; i < settings.force_order.size(); i++) {
+            const std::string& ip = settings.force_order[i];
+            if (pref_to_files.count(ip) != 1)
+                een9_THROW("force-order list contains entries that match no files (" + ip + ")");
+            for (size_t k: pref_to_files.at(ip)) {
+                if (assignment[k].first <= ip.size()) {
+                    assignment[k].first = ip.size();
+                    assignment[k].second = i;
+                }
+            }
+        }
+        for (auto& p: pref_to_files) {
+            const std::vector<size_t>& candidates = p.second;
+            assert(!candidates.empty());
+            size_t bestSoFar = candidates[0];
+            size_t f = inf_bad_order;
+            for (size_t k: candidates) {
+                if (assignment[k].second <= f) {
+                    f = assignment[k].second;
+                    bestSoFar = k;
+                }
+            }
+            prefix_to_file[p.first] = bestSoFar;
+        }
+        if (prefix_to_file.count("") != 1)
+            een9_THROW("No locales were provided");
+        // todo: remove DEBUG
+        // for (size_t k = 0; k < n; k++) {
+            // printf("%s has priority %lu\n", files[k].languagerange.c_str(), assignment[k].second);
+        // }
+        // printf("==============\n");
+        // for (const auto& p : prefix_to_file) {
+            // printf("%s  ->  %s\n", p.first.c_str(), files[p.second].languagerange.c_str());
+        // }
+    }
+
+    const LanguageFile& Localizator::get_right_locale(const std::vector<std::string> &preferred_langs) {
+        for (const std::string& lr: preferred_langs) {
+            if (prefix_to_file.count(lr) == 1)
+                return files[prefix_to_file.at(lr)];
+        }
+        return files[prefix_to_file.at("")];
+    }
+}

src/web_chat/iu9_ca_web_chat_lib/localizator.h

@@ -0,0 +1,36 @@
+#ifndef IU9_CA_WEB_CHAT_LIB_LOCALIZATOR_H
+#define IU9_CA_WEB_CHAT_LIB_LOCALIZATOR_H
+
+#include <jsonincpp/jsonobj.h>
+
+namespace iu9cawebchat {
+    /* '*' -> ''; X -> X */
+    std::string languageRangeSimpler(const std::string& a);
+
+    struct LocalizatorSettings {
+        std::string lang_dir;
+        std::vector<std::string> whitelist;
+        std::vector<std::string> force_order;
+    };
+
+    /* There is no need to put http Content-Language response value into json file. When is is in the name */
+    struct LanguageFile {
+        std::string languagerange;
+        json::JSON content;
+    };
+
+    /* Localizator uses libjsonincpp internally, and thus can't be read by two treads simultaneously */
+    struct Localizator {
+        LocalizatorSettings settings;
+        std::vector<LanguageFile> files;
+        std::map<std::string, size_t> prefix_to_file;
+
+        /* Throws std::exception if something goes wrong */
+        explicit Localizator(const LocalizatorSettings& settings);
+
+        /* Returns a reference to object inside Localizator */
+        const LanguageFile& get_right_locale(const std::vector<std::string>& preferred_langs);
+    };
+}
+
+#endif

src/web_chat/iu9_ca_web_chat_lib/run.cpp

@@ -5,6 +5,7 @@
 #include <engine_engine_number_9/connecting_assets/static_asset_manager.h>
 #include "find_db.h"
 #include <engine_engine_number_9/running_mainloop.h>
+#include <engine_engine_number_9/http_structures/accept_language.h>
 #include <signal.h>
 #include "str_fields.h"
 #include "backend_logic/client_server_interact.h"
@@ -32,11 +33,23 @@ namespace iu9cawebchat {
         }
     };
 
+    LocalizatorSettings make_localizator_settings(const std::string& assets_dir, const json::JSON& config) {
+        std::vector<std::string> whitelist;
+        for (const json::JSON& entry: config["lang"]["whitelist"].asArray())
+            whitelist.push_back(languageRangeSimpler(entry.asString()));
+        std::vector<std::string> force_order;
+        for (const json::JSON& entry: config["lang"]["force-order"].asArray())
+            force_order.push_back(languageRangeSimpler(entry.asString()));
+        return LocalizatorSettings{assets_dir + "/lang", whitelist, force_order};
+    }
+
     void run_website(const json::JSON& config) {
         een9_ASSERT(config["assets"].isString(), "config[\"assets\"] is not string");
         const std::string& assets_dir = config["assets"].asString();
         een9_ASSERT(een9::isDirectory(assets_dir), "\"" + assets_dir + "\" is not a directory");
 
+        LocalizatorSettings localizator_settings = make_localizator_settings(assets_dir, config);
+
         een9::StaticAssetManagerSlaveModule samI;
         samI.update({
             een9::StaticAssetManagerRule{assets_dir + "/css", "/assets/css", {{".css", "text/css"}} },
@@ -47,7 +60,6 @@ namespace iu9cawebchat {
             } },
         });
 
-        const json::JSON& config_presentation = config["presentation"];
         int64_t slave_number = config["server"]["workers"].asInteger().get_int();
         een9_ASSERT(slave_number > 0 && slave_number <= 200, "E");
 
@@ -61,15 +73,24 @@ namespace iu9cawebchat {
                 nytl::TemplaterSettings{nytl::TemplaterDetourRules{assets_dir + "/HypertextPages"}});
             worker_guest_data[i].templater->update();
             worker_guest_data[i].db = std::make_unique<SqliteConnection>(sqlite_db_path);
+            worker_guest_data[i].locales = std::make_unique<Localizator>(localizator_settings);
         }
 
         een9::MainloopParameters params;
-        params.guest_core = [&samI, &worker_guest_data, config_presentation]
+        params.guest_core = [&samI, &worker_guest_data]
         (const een9::SlaveTask& task, const een9::ClientRequest& req, een9::worker_id_t worker_id) -> std::string {
             een9_ASSERT_pl(0 <= worker_id && worker_id < worker_guest_data.size());
             WorkerGuestData& wgd = worker_guest_data[worker_id];
             een9::StaticAsset sa;
             ONE_SQLITE_TRANSACTION_GUARD conn_guard(*wgd.db);
+            std::string AcceptLanguage;
+            for (const std::pair<std::string, std::string>& p: req.headers) {
+                if (p.first == "Accept-Language")
+                    AcceptLanguage = p.second;
+            }
+            std::vector<std::string> AcceptLanguageB = een9::parse_header_Accept_Language(AcceptLanguage);
+            const LanguageFile& locale = wgd.locales->get_right_locale(AcceptLanguageB);
+            const json::JSON& pres = locale.content;
             try {
                 std::vector<std::pair<std::string, std::string>> cookies;
                 std::vector<LoginCookie> login_cookies;
@@ -78,17 +99,17 @@ namespace iu9cawebchat {
                 initial_extraction_of_all_the_useful_info_from_cookies(*wgd.db, req, cookies, login_cookies, userinfo, logged_in_user);
 
                 if (req.uri_path == "/" || req.uri_path == "/list-rooms") {
-                    return when_page_list_rooms(wgd, config_presentation, req, userinfo);
+                    return when_page_list_rooms(wgd, pres, req, userinfo);
                 }
                 if (req.uri_path == "/login") {
-                    return when_page_login(wgd, config_presentation, req, login_cookies, userinfo);
+                    return when_page_login(wgd, pres, req, login_cookies, userinfo);
                 }
                 // todo: split
                 if (een9::beginsWith(req.uri_path, "/chat/") || een9::beginsWith(req.uri_path, "/chat-members/")) {
-                    return when_page_chat(wgd, config_presentation, req, userinfo);
+                    return when_page_chat(wgd, pres, req, userinfo);
                 }
                 if (een9::beginsWith(req.uri_path, "/user/")) {
-                    return when_page_user(wgd, config_presentation, req, login_cookies, userinfo);
+                    return when_page_user(wgd, pres, req, login_cookies, userinfo);
                 }
                 if (req.uri_path == "/api/chatPollEvents") {
                     return when_internalapi_chatpollevents(wgd, req, logged_in_user);