From 30eeb362d03f925da520cb9ab24f8516924ea9ce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Piotr=20Ta=C5=84ski?= <piotr.tanski@mudita.com>
Date: Wed, 13 Oct 2021 18:21:58 +0200
Subject: [PATCH] [EGD-7789] Sort timezones by their UTC offset

Currently, timezones are sorted alphabetlically.
---
 .../windows/system/ChangeTimeZone.cpp         | 26 +++++++++++++++++--
 .../windows/system/ChangeTimeZone.hpp         |  5 +++-
 module-utils/time/time/TimeZone.cpp           |  2 ++
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/module-apps/application-settings/windows/system/ChangeTimeZone.cpp b/module-apps/application-settings/windows/system/ChangeTimeZone.cpp
index f72a53cc57508efb35772e33ac7e69cfcbf685e7..d0af377c97dc8d0e4cbd0c410cc1a1a03032cf28 100644
--- a/module-apps/application-settings/windows/system/ChangeTimeZone.cpp
+++ b/module-apps/application-settings/windows/system/ChangeTimeZone.cpp
@@ -11,15 +11,37 @@
 #include <service-time/service-time/TimeMessage.hpp>
 #include <time/TimeZone.hpp>
 
+#include <algorithm>
+
 namespace gui
 {
+    namespace
+    {
+        constexpr auto NegativeOffsetPrefix = "UTC-";
+    } // namespace
+
     ChangeTimeZone::ChangeTimeZone(app::ApplicationCommon *app)
-        : BaseSettingsWindow(app, window::name::change_date_and_time),
-          timeZonesList(utils::time::getAvailableTimeZonesWithOffset())
+        : BaseSettingsWindow(app, window::name::change_date_and_time), timeZonesList(sortTimeZones(getTimeZones()))
     {
         setTitle(utils::translate("app_settings_date_and_time_time_zone"));
     }
 
+    auto ChangeTimeZone::getTimeZones() -> std::vector<std::string>
+    {
+        return utils::time::getAvailableTimeZonesWithOffset();
+    }
+
+    auto ChangeTimeZone::sortTimeZones(std::vector<std::string> &&timeZones) -> std::vector<std::string>
+    {
+        std::vector<std::string> zones = std::move(timeZones);
+        auto pivot                     = std::partition(zones.begin(), zones.end(), [](const auto &tz) {
+            return tz.rfind(NegativeOffsetPrefix, 0) == 0; // starts with NegativeOffsetPrefix
+        });
+        std::sort(zones.begin(), pivot, std::greater<std::string>{});
+        std::sort(pivot, zones.end());
+        return zones;
+    }
+
     void ChangeTimeZone::onBeforeShow(ShowMode mode, SwitchData *data)
     {
         selectedTimeZone = stm::api::getCurrentTimezoneName();
diff --git a/module-apps/application-settings/windows/system/ChangeTimeZone.hpp b/module-apps/application-settings/windows/system/ChangeTimeZone.hpp
index ae0e6083c3b33ab304088268df3452f84d4e6998..36d8fcb3d6a6465dad203312655db97a8799aa22 100644
--- a/module-apps/application-settings/windows/system/ChangeTimeZone.hpp
+++ b/module-apps/application-settings/windows/system/ChangeTimeZone.hpp
@@ -13,12 +13,15 @@ namespace gui
       public:
         explicit ChangeTimeZone(app::ApplicationCommon *app);
 
-      protected:
+      private:
         [[nodiscard]] auto buildOptionsList() -> std::list<Option> override;
         void onBeforeShow(ShowMode mode, SwitchData *data) override;
         [[nodiscard]] auto setTimeZoneIndex() -> unsigned int;
         [[nodiscard]] auto extractTimeZoneName(const std::string &name) const noexcept -> std::string;
 
+        [[nodiscard]] static auto getTimeZones() -> std::vector<std::string>;
+        [[nodiscard]] static auto sortTimeZones(std::vector<std::string> &&timeZones) -> std::vector<std::string>;
+
         const std::vector<std::string> timeZonesList;
         std::string selectedTimeZone;
     };
diff --git a/module-utils/time/time/TimeZone.cpp b/module-utils/time/time/TimeZone.cpp
index 99f1a5b803a1c07e2d2bee00eb54ce30eace9162..b22f54a002a20b70aec53d0a910bfffb2d548244 100644
--- a/module-utils/time/time/TimeZone.cpp
+++ b/module-utils/time/time/TimeZone.cpp
@@ -54,6 +54,8 @@ namespace utils::time
     [[nodiscard]] auto getAvailableTimeZonesWithOffset() -> std::vector<std::string>
     {
         std::vector<std::string> timeZonesNames;
+        timeZonesNames.reserve(NUM_ZONE_NAMES);
+
         char zoneToDisplay[maxZoneToDisplayLength];
         auto zonePointer = reinterpret_cast<const char *>(zone_names);
         uzone_t zoneOut;