(* This file defines objects and operation related to class scheduling. See Sections 2.4 and 2.6 of the Milestone 4 requirements. Module ScheduledClass defines the objects and operations related to scheduling Classes.
 *)

module ScheduledClass;

	from Time import all;
	from Database import all;
	from ScheduleM import all;
	export all;

    object ScheduledClass is   
        components: c:course and i:Instructor and r:Room and s:SectionNumber and startTime:TimePeriod and
            endTime:TimePeriod;    
        description: (*A scheduled class has a course, instructor, a room, a section 
                , a starting time, and an ending time.*);
     end ScheduledClass;

     
     
     operation ScheduleClass is
        inputs: sc:ScheduledClass, s:Schedule;
        outputs:s':Schedule;
	description: (*The Schedule Class operation takes all of the inputs in the manual scheduling of a class and adds it to the ScheduledClasses in the Schedule.*);
        precondition:(* The start time, is before the end time. Which means the starting
            * hour is before the ending hour. The hours are also, 0 - 23. The minutes are 
            *only 0 - 59. Instructor has to exist in the database. The course exists in the
            *database. The room exists in the database. There are no other classes
            *scheduled in the same room and in conflicting time periods.
            The instructor is not teaching another class at the same time. *)
            
            sc.c in s.cd and sc.i in s.id and sc.r in s.rd
            and
            (sc.startTime.h.i < 24 and sc.startTime.h.i > 0 and sc.startTime.m.i > 0 and
                 sc.startTime.m.i < 60 and sc.endTime.h.i > 0 and sc.endTime.h.i  <  24 
                 and sc.endTime.m.i > 0 and sc.endTime.m.i < 60)
             and
             (sc.startTime.h <  sc.endTime.h) or (sc.startTime.m < sc.endTime.m)
             and
            not (exists (sc' in s.scheduledClasses ) sc'.r = sc.r and ((sc'.endTime.h.i <= sc.startTime.h.i) or (sc'.startTime.h.i >= sc.endTime.h.i)))
            and
            not (exists (sc' in s.scheduledClasses) sc'.i = sc.i and (sc'.endTime.h.i <= sc.startTime.h.i or
                sc'.startTime.h.i >= sc.endTime.h.i));
            postcondition: (* The Scheduled Class is in the ScheduledClassList and
                nothing else is changed.*)
                forall (sc':ScheduledClass)
                    (sc' in s'.scheduledClasses) iff ((sc' = sc) or (sc' in s.scheduledClasses));
                

      end ScheduleClass;
    
 
end ScheduledClass;