Added UTC handling for Windows

libcron/CMakeLists.txt

@@ -2,7 +2,12 @@ cmake_minimum_required(VERSION 3.6)
 project(libcron)
 
 set(CMAKE_CXX_STANDARD 14)
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wpedantic")
+
+if( MSVC )
+	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+else()
+	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wpedantic")
+endif()
 
 include_directories(${CMAKE_CURRENT_LIST_DIR}/externals/date/include)
 
@@ -16,7 +21,8 @@ add_library(${PROJECT_NAME}
         CronSchedule.h
         DateTime.h
         Task.cpp
-        CronClock.h)
+        CronClock.h
+		CronClock.cpp)
 
 set_target_properties(${PROJECT_NAME} PROPERTIES
         ARCHIVE_OUTPUT_DIRECTORY "${OUTPUT_LOCATION}"

libcron/Cron.h

@@ -45,6 +45,8 @@ namespace libcron
                 return clock;
             }
 
+			void get_time_until_expiry_for_tasks(std::vector<std::tuple<std::string, std::chrono::system_clock::duration>>& status) const;
+
             friend std::ostream& operator<<<>(std::ostream& stream, const Cron<ClockType>& c);
 
         private:
@@ -78,7 +80,6 @@ namespace libcron
         bool res = cron.is_valid();
         if (res)
         {
-
             Task t{std::move(name), CronSchedule{cron}, std::move(work)};
             if (t.calculate_next(clock.now()))
             {
@@ -106,7 +107,7 @@ namespace libcron
     }
 
     template<typename ClockType>
-    size_t Cron<ClockType>::tick(system_clock::time_point now)
+    size_t Cron<ClockType>::tick(std::chrono::system_clock::time_point now)
     {
         size_t res = 0;
 
@@ -160,6 +161,19 @@ namespace libcron
         return res;
     }
 
+	template<typename ClockType>
+	void Cron<ClockType>::get_time_until_expiry_for_tasks(std::vector<std::tuple<std::string, std::chrono::system_clock::duration>>& status) const
+	{
+		auto now = clock.now();
+		status.clear();
+
+		std::for_each(tasks.get_tasks().cbegin(), tasks.get_tasks().cend(),
+			[&status, &now](const Task& t)
+		{
+			status.emplace_back(t.get_name(), t.time_until_expiry(now));
+		});
+	}
+
     template<typename ClockType>
     std::ostream& operator<<(std::ostream& stream, const Cron<ClockType>& c)
     {

libcron/CronClock.cpp

@@ -0,0 +1,39 @@
+#include "CronClock.h"
+
+#ifdef WIN32
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+#define WIN32_LEAN_AND_MEAN 
+#include <Windows.h>
+#endif
+
+using namespace std::chrono;
+
+namespace libcron
+{
+
+	std::chrono::seconds LocalClock::utc_offset(std::chrono::system_clock::time_point now) const
+	{
+#ifdef WIN32
+		(void)now;
+
+		TIME_ZONE_INFORMATION tz_info{};
+		seconds offset{ 0 };
+
+		auto res = GetTimeZoneInformation(&tz_info);
+		if (res != TIME_ZONE_ID_INVALID)
+		{
+			// https://msdn.microsoft.com/en-us/library/windows/desktop/ms725481(v=vs.85).aspx
+			// UTC = local time + bias => local_time = utc - bias, so UTC offset is -bias
+			offset = minutes{ -tz_info.Bias };
+		}
+#else
+		auto t = system_clock::to_time_t(now);
+		tm tm{};
+		localtime_r(&t, &tm);
+		seconds offset{ tm.tm_gmtoff };
+#endif
+		return offset;
+	}
+}

libcron/CronClock.h

@@ -2,9 +2,6 @@
 
 #include <chrono>
 
-using namespace std::chrono;
-using namespace date;
-
 namespace libcron
 {
     class ICronClock
@@ -25,6 +22,7 @@ namespace libcron
 
             std::chrono::seconds utc_offset(std::chrono::system_clock::time_point) const override
             {
+				using namespace std::chrono;
                 return 0s;
             }
     };
@@ -35,20 +33,10 @@ namespace libcron
         public:
             std::chrono::system_clock::time_point now() const override
             {
-                auto now = system_clock::now();
+                auto now = std::chrono::system_clock::now();
                 return now + utc_offset(now);
             }
 
-            std::chrono::seconds utc_offset(std::chrono::system_clock::time_point now) const override
+			std::chrono::seconds utc_offset(std::chrono::system_clock::time_point now) const override;
-            {
-                auto t = system_clock::to_time_t(now);
-                tm tm{};
-#ifdef __WIN32
-                localtime_s(&tm, &t);
-#else
-                localtime_r(&t, &tm);
-#endif
-                return seconds{tm.tm_gmtoff};
-            }
     };
 }

libcron/CronSchedule.cpp

@@ -1,4 +1,5 @@
 #include "CronSchedule.h"
+#include <tuple>
 
 using namespace std::chrono;
 using namespace date;

test/CMakeLists.txt

@@ -2,7 +2,12 @@ cmake_minimum_required(VERSION 3.6)
 project(cron_test)
 
 set(CMAKE_CXX_STANDARD 14)
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wpedantic -Wextra")
+
+if( MSVC )
+	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W4")
+else()
+	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wpedantic")
+endif()
 
 include_directories(
         ${CMAKE_CURRENT_LIST_DIR}/externals/Catch2/single_include/

test/CronTest.cpp

@@ -5,6 +5,7 @@
 
 using namespace libcron;
 using namespace std::chrono;
+using namespace date;
 
 std::string create_schedule_expiring_in(std::chrono::system_clock::time_point now, hours h, minutes m, seconds s)
 {
@@ -221,7 +222,7 @@ class TestClock
 
 SCENARIO("Clock changes")
 {
-    GIVEN("A Cron instance with a single task expiring in 4h")
+    GIVEN("A Cron instance with a single task expiring every hour")
     {
         Cron<TestClock> c{};
         auto& clock = c.get_clock();
@@ -239,11 +240,11 @@ SCENARIO("Clock changes")
 
         WHEN("Clock changes <3h forward")
         {
-            THEN("Task expires accordingly")
+			THEN("Task expires accordingly")
-            {
+			{
-                REQUIRE(c.tick() == 1);
+				REQUIRE(c.tick() == 1);
-                clock.add(minutes{30}); // 00:30
+				clock.add(minutes{ 30 }); // 00:30
-                REQUIRE(c.tick() == 0);
+				REQUIRE(c.tick() == 0);
                 clock.add(minutes{30}); // 01:00
                 REQUIRE(c.tick() == 1);
                 REQUIRE(c.tick() == 0);
@@ -294,6 +295,5 @@ SCENARIO("Clock changes")
                 REQUIRE(c.tick() == 1);
             }
         }
-
     }
 }