[Scheduler] Event scheduler implementation (#1257)

* Event scheduler implementation

* Create 2021_02_17_server_scheduled_events.sql

* Tweak

* Remove unused event [skip ci]

* Cleanup [skip ci]

* PR adjustments

* Database manifest

common/server_event_scheduler.h

@@ -0,0 +1,57 @@
+#ifndef EQEMU_SERVER_EVENT_SCHEDULER_H
+#define EQEMU_SERVER_EVENT_SCHEDULER_H
+
+#include "../common/repositories/server_scheduled_events_repository.h"
+#include <time.h>
+#include <chrono>
+
+namespace ServerEvents {
+	static const std::string EVENT_TYPE_HOT_ZONE_ACTIVE     = "hot_zone_activate";
+	static const std::string EVENT_TYPE_BROADCAST           = "broadcast";
+	static const std::string EVENT_TYPE_RELOAD_WORLD        = "reload_world";
+	static const std::string EVENT_TYPE_RULE_CHANGE         = "rule_change";
+	static const std::string EVENT_TYPE_CONTENT_FLAG_CHANGE = "content_flag_change";
+}
+
+class ServerEventScheduler {
+public:
+	virtual ~ServerEventScheduler();
+	ServerEventScheduler();
+	ServerEventScheduler *SetDatabase(Database *db);
+	void LoadScheduledEvents();
+	bool CheckIfEventsChanged();
+
+protected:
+
+	// events directly from the database
+	std::vector<ServerScheduledEventsRepository::ServerScheduledEvents> m_events;
+
+	// used to track only when it is convenient to undo an action from an active event
+	// typically there should be two separate events to turn something on / off
+	// hotzones use this right now simply to keep us from toggling off the hotzone
+	// every minute we trigger and then immediately turning it right back on
+	std::vector<ServerScheduledEventsRepository::ServerScheduledEvents> m_active_events;
+
+	// simple ticker used to determine when the last polled minute was so that when the minute
+	// changes we fire checking the scheduler
+	int m_last_polled_minute;
+
+	// validates an event is currently active or not
+	bool ValidateEventReadyToActivate(ServerScheduledEventsRepository::ServerScheduledEvents &e);
+
+	// is event active
+	bool IsEventActive(ServerScheduledEventsRepository::ServerScheduledEvents &e);
+
+	// remove active event
+	bool RemoveActiveEvent(ServerScheduledEventsRepository::ServerScheduledEvents &e);
+
+	// build time object from event
+	std::tm BuildStartTimeFromEvent(ServerScheduledEventsRepository::ServerScheduledEvents &e, tm *now);
+	std::tm BuildEndTimeFromEvent(ServerScheduledEventsRepository::ServerScheduledEvents &e, tm *now);
+
+	// reference to database
+	Database *m_database;
+	bool ValidateDatabaseConnection();
+};
+
+#endif //EQEMU_SERVER_EVENT_SCHEDULER_H