#include <catch.hpp>
#include <libcron/Cron.h>
#include <thread>
#include <iostream>

using namespace libcron;
using namespace std::chrono;

std::string create_schedule_expiring_in(std::chrono::system_clock::time_point now, hours h, minutes m, seconds s)
{
    now = now + h + m + s;
    auto dt = CronSchedule::to_calendar_time(now);

    std::string res{};
    res += std::to_string(dt.sec) + " ";
    res += std::to_string(dt.min) + " ";
    res += std::to_string(dt.hour) + " * * ?";

    return res;
}

//SCENARIO("Adding a task")
//{
//    GIVEN("A Cron instance with no task")
//    {
//        Cron<> c;
//        auto expired = false;
//
//        THEN("Starts with no task")
//        {
//            REQUIRE(c.count() == 0);
//        }
//
//        WHEN("Adding a task that runs every second")
//        {
//            REQUIRE(c.add_schedule("A task", "* * * * * ?",
//                                   [&expired]()
//                                   {
//                                       expired = true;
//                                   })
//            );
//
//            THEN("Count is 1 and task was not expired two seconds ago")
//            {
//                REQUIRE(c.count() == 1);
//                c.tick(c.get_clock().now() - 2s);
//                REQUIRE_FALSE(expired);
//            }
//            AND_THEN("Task is expired when calculating based on current time")
//            {
//                c.tick();
//                THEN("Task is expired")
//                {
//                    REQUIRE(expired);
//                }
//            }
//        }
//    }
//}
//
//SCENARIO("Adding a task that expires in the future")
//{
//    GIVEN("A Cron instance with task expiring in 3 seconds")
//    {
//        auto expired = false;
//
//        Cron<> c;
//        REQUIRE(c.add_schedule("A task",
//                               create_schedule_expiring_in(c.get_clock().now(), hours{0}, minutes{0}, seconds{3}),
//                               [&expired]()
//                               {
//                                   expired = true;
//                               })
//        );
//
//        THEN("Not yet expired")
//        {
//            REQUIRE_FALSE(expired);
//        }
//        AND_WHEN("When waiting one second")
//        {
//            std::this_thread::sleep_for(1s);
//            c.tick();
//            THEN("Task has not yet expired")
//            {
//                REQUIRE_FALSE(expired);
//            }
//        }
//        AND_WHEN("When waiting three seconds")
//        {
//            std::this_thread::sleep_for(3s);
//            c.tick();
//            THEN("Task has expired")
//            {
//                REQUIRE(expired);
//            }
//        }
//    }
//}
//
//SCENARIO("Task priority")
//{
//    GIVEN("A Cron instance with two tasks expiring in 3 and 5 seconds, added in 'reverse' order")
//    {
//        auto _3_second_expired = 0;
//        auto _5_second_expired = 0;
//
//
//        Cron<> c;
//        REQUIRE(c.add_schedule("Five",
//                               create_schedule_expiring_in(c.get_clock().now(), hours{0}, minutes{0}, seconds{5}),
//                               [&_5_second_expired]()
//                               {
//                                   _5_second_expired++;
//                               })
//        );
//
//        REQUIRE(c.add_schedule("Three",
//                               create_schedule_expiring_in(c.get_clock().now(), hours{0}, minutes{0}, seconds{3}),
//                               [&_3_second_expired]()
//                               {
//                                   _3_second_expired++;
//                               })
//        );
//
//        THEN("Not yet expired")
//        {
//            REQUIRE_FALSE(_3_second_expired);
//            REQUIRE_FALSE(_5_second_expired);
//        }
//
//        WHEN("Waiting 1 seconds")
//        {
//            std::this_thread::sleep_for(1s);
//            c.tick();
//
//            THEN("Task has not yet expired")
//            {
//                REQUIRE(_3_second_expired == 0);
//                REQUIRE(_5_second_expired == 0);
//            }
//        }
//        AND_WHEN("Waiting 3 seconds")
//        {
//            std::this_thread::sleep_for(3s);
//            c.tick();
//
//            THEN("3 second task has expired")
//            {
//                REQUIRE(_3_second_expired == 1);
//                REQUIRE(_5_second_expired == 0);
//            }
//        }
//        AND_WHEN("Waiting 5 seconds")
//        {
//            std::this_thread::sleep_for(5s);
//            c.tick();
//
//            THEN("3 and 5 second task has expired")
//            {
//                REQUIRE(_3_second_expired == 1);
//                REQUIRE(_5_second_expired == 1);
//            }
//        }
//        AND_WHEN("Waiting based on the time given by the Cron instance")
//        {
//            std::this_thread::sleep_for(c.time_until_next());
//            c.tick();
//
//            THEN("3 second task has expired")
//            {
//                REQUIRE(_3_second_expired == 1);
//                REQUIRE(_5_second_expired == 0);
//            }
//        }
//        AND_WHEN("Waiting based on the time given by the Cron instance")
//        {
//            std::this_thread::sleep_for(c.time_until_next());
//            REQUIRE(c.tick() == 1);
//
//            std::this_thread::sleep_for(c.time_until_next());
//            REQUIRE(c.tick() == 1);
//
//            THEN("3 and 5 second task has each expired once")
//            {
//                REQUIRE(_3_second_expired == 1);
//                REQUIRE(_5_second_expired == 1);
//            }
//        }
//    }
//}
//
class TestClock
        : public ICronClock
{
    public:
        std::chrono::system_clock::time_point now() const override
        {
            return current_time;
        }

        std::chrono::seconds utc_offset(std::chrono::system_clock::time_point) const override
        {
            return 0s;
        }

        void add(system_clock::duration time)
        {
            current_time += time;
        }

        void set(system_clock::time_point new_time)
        {
            current_time = new_time;
        }

    private:
        system_clock::time_point current_time = system_clock::now();

};

SCENARIO("Clock changes")
{
    GIVEN("A Cron instance with a single task expiring in 4h")
    {
        Cron<TestClock> c{};
        auto& clock = c.get_clock();

        // Midnight
        clock.set(sys_days{2018_y / 05 / 05});

        // Every hour
        REQUIRE(c.add_schedule("Clock change task", "0 0 * * * ?", []()
        {
        })
        );

        // https://linux.die.net/man/8/cron

        WHEN("Clock changes <3h forward")
        {
            THEN("Task expires accordingly")
            {
                REQUIRE(c.tick() == 1);
                clock.add(minutes{30}); // 00:30
                REQUIRE(c.tick() == 0);
                clock.add(minutes{30}); // 01:00
                REQUIRE(c.tick() == 1);
                REQUIRE(c.tick() == 0);
                REQUIRE(c.tick() == 0);
                clock.add(minutes{30}); // 01:30
                REQUIRE(c.tick() == 0);
                clock.add(minutes{15}); // 01:45
                REQUIRE(c.tick() == 0);
                clock.add(minutes{15}); // 02:00
                REQUIRE(c.tick() == 1);
            }
        }
        AND_WHEN("Clock is moved forward >= 3h")
        {
            THEN("Task are rescheduled, not run")
            {
                REQUIRE(c.tick() == 1);
                std::cout << "0: " << c << std::endl;
                clock.add(hours{3}); // 03:00
                REQUIRE(c.tick() == 1); // Rescheduled
                std::cout << "1: " << c << std::endl;
                clock.add(minutes{15}); // 03:15
                REQUIRE(c.tick() == 0);
                std::cout << "2: " << c << std::endl;
                clock.add(minutes{45}); // 04:00
                REQUIRE(c.tick() == 1);
                std::cout << "3: " << c << std::endl;
            }
        }

    }
}