refactor(tgbot-front): moved the navigation handler to a separate file

modules/bot/front/src/handleNavigation.cpp

@@ -0,0 +1,147 @@
+#include "handlers.hpp"
+#include "KeyboardFactory.hpp"
+#include "structs.hpp"
+#include "constants.hpp"
+
+void BotHandlers::handleNavigation(TgBot::CallbackQuery::Ptr query, UserContext& ctx) {
+    const auto& current = ctx.history.back(); // текущий экран
+    const std::string& data = query->data;
+
+    // Пагинация (в списках)
+    if ((data == BotConstants::Callback::LIST_PREV || data == BotConstants::Callback::LIST_NEXT)
+        && (current.state == UserState::VIEWING_MY_TITLES || current.state == UserState::VIEWING_REVIEW_LIST || 
+            current.state == UserState::VIEWING_FOUND_TITLES)) {
+
+        int64_t newPayload = current.payload;
+        if (data == BotConstants::Callback::LIST_PREV && newPayload > 0) {
+            reducePayload(newPayload, current.state);
+        } else if (data == BotConstants::Callback::LIST_NEXT) {
+            increasePayload(newPayload, current.state);
+        } else {
+            if (data == BotConstants::Callback::LIST_PREV) {
+                std::cout << "Error: navigation:prev callback for 1st page" << std::endl;
+                return;
+            }
+            // TODO: log
+            std::cout << "Error: navigation:prev unknown error" << std::endl;
+        }
+
+        ctx.history.back().payload = newPayload;
+
+        auto result = renderCurrent(query, ctx);
+        if(result.message == "meow") return; // TODO: убрать
+        editMessage(query, result);
+        return;
+    }
+
+    // Обработка back по интерфейсу
+    if (data == BotConstants::Callback::NAV_BACK) {
+        if (!popState(ctx)) {
+            sendError(query, BotConstants::Text::SAD_ERROR);
+            return;
+        }
+        auto result = renderCurrent(query, ctx);
+        if(result.message == "meow") return; // TODO: убрать
+        editMessage(query, result);
+        return;
+    }
+
+    // Переходы вперёд (push)
+    auto newStepOpt = computeNextStep(query, current);
+    if (!newStepOpt.has_value()) {
+        sendError(query, BotConstants::Text::SAD_ERROR);
+        return;
+    }
+
+    ctx.history.push_back(*newStepOpt);
+    auto result = renderCurrent(query, ctx);
+    if(result.message == "meow") return; // TODO: убрать
+    editMessage(query, result);
+}
+
+HandlerResult BotHandlers::renderCurrent(TgBot::CallbackQuery::Ptr query, const UserContext& ctx) {
+    const auto& step = ctx.history.back();
+    int64_t userId = query->from->id;
+    switch (step.state) {
+        case UserState::MAIN_MENU:
+            return showMainMenu();
+        case UserState::VIEWING_MY_TITLES:
+            server_.fetchUserTitlesAsync(std::to_string(2)) // ALARM: тестовое значение вместо userId
+                .then([this, query](pplx::task<std::vector<BotStructs::Title>> t) {
+                    try {
+                        auto titles = t.get();
+
+                        std::string message = formatTitlesList(titles);
+                        auto keyboard = KeyboardFactory::createMyTitles(titles);
+
+                        editMessage(query, {message, keyboard});
+
+                    } catch (const std::exception& e) {
+                        sendError(query, BotConstants::Text::SERVER_ERROR);
+                        // Логирование ошибки (например, в cerr)
+                    }
+                });
+
+            return {"meow", nullptr};
+        /*
+        case UserState::VIEWING_TITLE_PAGE:
+            return returnTitlePage(step.payload); // payload = titleId
+        case UserState::VIEWING_REVIEW:
+            return returnReview(step.payload); // payload = reviewId
+        case UserState::AWAITING_REVIEW:
+            return HandlerResult{"Пришлите текст отзыва:", nullptr};
+        // ...
+        */
+        default:
+            return HandlerResult{BotConstants::Text::SAD_ERROR, nullptr};
+    }
+}
+
+std::optional<NavigationStep> BotHandlers::computeNextStep(
+    const TgBot::CallbackQuery::Ptr& query,
+    const NavigationStep& current
+) {
+    const std::string& data = query->data;
+
+    switch (current.state) {
+        case UserState::MAIN_MENU:
+            if (data == BotConstants::Callback::MY_TITLES) {
+                return NavigationStep{UserState::VIEWING_MY_TITLES, 0};
+            }
+            break;
+        /*
+        case UserState::VIEWING_MY_TITLES:
+            if (data.starts_with("title_")) {
+                int64_t titleId = parseId(data);
+                return NavigationStep{UserState::VIEWING_TITLE_PAGE, titleId};
+            }
+            break;
+
+        case UserState::VIEWING_TITLE_PAGE:
+            if (data == BotConstants::Callback::ACTION_ADD_REVIEW) {
+                return NavigationStep{UserState::AWAITING_REVIEW, current.payload};
+            }
+            if (data.starts_with("review_")) {
+                int64_t reviewId = parseId(data);
+                return NavigationStep{UserState::VIEWING_REVIEW, reviewId};
+            }
+            break;
+        */
+        default:
+            break;
+    }
+    return std::nullopt;
+}
+
+std::string BotHandlers::formatTitlesList(const std::vector<BotStructs::Title>& titles) {
+    if (titles.empty()) {
+        return "У вас пока нет тайтлов.";
+    }
+
+    std::string msg;
+    for (size_t i = 0; i < titles.size(); ++i) {
+        // num — 0-based, но в сообщении показываем 1-based
+        msg += std::to_string(i + 1) + ". " + titles[i].name + "\n";
+    }
+    return msg;
+}