module Admin

export all;

object  Roster is
   components: atd*: Attendance*;
   operations: AddStudent, EditStudent, RemoveStudent,ViewScreen,GrantAccess, GrantAllAccess;
   description: (* Roster is a dialogue with the collection of students names that are enrolled
                in the class. It contains operations for the instructor to add/edit/remove 
                students as well as loading a roster. It also has operation that grants
                students drawing access and view student screen.  
    
   *);
end InstructorRoster;

object Attendance is 
   components: sdb*: StudentDB*;
   description: (* Attendance is the component of Roster that stores information of students 
                that are enrolled in the class. The name component is the student database, 
                which contains a record of the student names, status, drawing status, and 
                log on time. 
   *);
end Attendance;

Object StudentDB is
   components: Name and Status and Draw and Time;
   description: (* A studentDB is the information stored about a registered student in e-Class
                roster. The Name component is the student's real name. The Status component is 
                a string of text determine whether the student is drawing or requesting to draw.
                The Draw component is a boolean variable showing whether the student is drawing 
                or not. The Time component is a string of text showing the studen't log on time.
   *);   

end StudentDB;

Object Name is string;
Object Status is string;
Object Time is string;
Object Draw is boolean;

operation AddStudent
   inputs: sdb:StudentDB, atd: Attendance;
   outputs: sdb': StudentDB, atd': Attendance;
   precondition:(* The student's name cannot be NULL and the student's ID has to be numerical values
                 The student's ID must be a unique 9 digit value.
   *)
   
   (sdb != nil) and (#(sdb.ID) == 9)  
   and (not (exists (sdb' in sdb) sdb'.id = sdb.id);
   
   postcondtion:(* A new student has been added to the database and the student's name will appear 
                on the roster attendance list *)
   forall (sdb': StudentDB)
       (sdb' in atd') iff ((sdb' = sdb) or (sdb' in atd));
   description:(* Adds a new student to the current roster *);
end;

operation EditStudent
   inputs: atd:Attendance, std: StudentDB, old_sdb:StudentDB, new_sdb: StudentDB;
   outputs: atd': Attendance, stb': StudentDB;
   precondition:(* The old and new student database cannot be the same *)
                
                (old_sdb != new_sdb)
 
                and 

                (* The old record is stored inside the Student database*)
                (old_sdb in sdb)
                 
                and
                
                (*There is no student record in the input studentDB with the same id as
                * the new record to be added
                *)
                 
                (not (exists (new_sdb' in atd) new_sdb'.id = new_sdb.id))
                 
                and

                (*The Id of the new student must not be emprt and have 9 integer values*)
                 
                (new_sdb.id != nil) and (#(new_sdb.id) == 9);

   postcondtion:(* The student's information has been edited and saved in the database. 
                 The new name will appear on the roster attendance *)
                 
                forall(sdb':StudentDB)
                    (sdb' in atd') iff (((sdb' = new_sdb) or (sdb' in atd)) and 
                                                              (sdb' != old_sdb))
                and

                (*If new ID is different than old id, then the old ID is replaced by the new 
                * ID 
                *)
                if (old_sdb.id != new_sdb.id)
                then (old_sdb.id = new_sdb.id);

   description:(* Change the Name and Id of the student *);
end;

Object Id is integer; 

operation RemoveStudent
   inputs: atd: Attendance, sdb: StudentDB;
   outputs: atd':Attendance, sdb': StudentDB;
   precondition:(* A name of the student on the roster list must be selected and the
                 * name is in the StudentDB 
                 *)
                sdb in atd; 
   postcondtion:(* Student has been removed from the attedance and the attedance list 
                 is updated *)
                
                (sdb' in atd');
                
   description:(* Removes a student from the roster *);
end;

operation ViewScreen
   inputs: old_Lec: LectureScreen;
   outputs: new_Lec: Lecturescreen;
   precondition:(*A name of the student on the roster list must be selected to be viewed*);

   postcondtion:(* The instructor screen displays the screen of that selected student *)
   
   (new_Lec = oldLec);

   description:(* views the screen of a selected student *);
end;

object LectureScreen;

operation GrantAccess
   inputs:  sdb: StudentDB, atd: Attedance, lec: LectureScreen;
   outputs: sdb': StudentDB, atd': Attendance, lec': LectureScreen;
   precondition:(* a student name on the attendance list must be selected 
                );
   

   postcondtion:(* The student must not have drawing access at the moment. The student's drawing 
                 will now appear on all screens *)
                
                (sdb' in atd') iff (sdb.draw == false)
              
                and 
                
                lec' = lec;  
             
   description:(* grats the selected student access to draw *);
end;

operation GrantAllAcess 
   inputs: stb: StudentDB, atd: Attendance, lec: LectureScreen;
   outputs: sdb': StudentDB, atd': Attendance, lec': LectureScreen;
   precondition:(* None at the moment *);
   postcondition:(* Every student in the list of Attedance contains drawing access*)
        
                  forall (sdb in atd) sdb.draw = true
                  
                  and 

                  (* Attendance list is updated with all the students' 'Draw' checkbox checked*)
 
                  atd' = atd
                  
                  and

                  (*Students workstation screen can see other students drawing*)
                 
                  lec' = lec; 

                                     
   description: (* The GrantAllAccess operation grants all students in the class roster access to draw lively and their drawings 
                 * are broadcasted to the entire network
                 *); 
end;

Object UserAccess is
   components: Mode*;
   description: (* UserAccess allows the instructor to set different accessing mode for the
                students. These modes determine how much access the students have over their
                workstations.
                *);
end UserAccess;

Object Mode is
   components: FreeAccess or LectureOnly or EnableProgram or Disable;
   description:(*The Mode object allows the intrucstor to select an access mode for the students. 
               The four modes are FreeAccess, LectureOnly, EnableProgram, and Disable *);
end Mode; 
   
Object FreeAccess is
   components: Access*;
   precondition:(* None yet *);
   postcondition:(* The useraccess mode is changed to free access*);
   description:(*This is a mode that grants the students all access to their workstation*); 
end FreeAccess;

Object LectureOnly is
   components: Access*;
   precondition:(* None yet *);
   postcondition:(* The useraccess mode is changed to lecture only*);
   description:(*This is a mode that only allows e-Class lecture application to run in the students workstation*); 
end LectureOnly;

Object EnableProgram is
   components: Access*;
   precondition:(* None yet*);
   postcondition:(* The useraccess mode is changed to Enable Program *);
   description:(*This is a mode that allows the instructor to allow selective applications
               for the students to use along with the lecture.
               *); 
end EnableProgram;

Object Disable is
   components: Keyboard and Mouse;
   precondition:(* None yet *);
   postcondition:(* The useraccess mode is changed to Disable Mode and the user must
                 select either Keyboards and/or Mouse to disable *);
   description:(*This is a mode that allows the instructor to disable either the Keyboards and/or mouse
                in the students workstations. 
              *); 
end Disable;

Object Access is
   component: AccessType;
   precondition: (* A type of mode must be selected *);
   postcondition:(* The access is changed to the access type contains in Mode *);
   description: (* The Access component contains that actual code that sets the actual mode *);
  
End Access;

Object AccessType is string;

Object Keyboard is 
   components: Access*;
   precondition( * The 'Disable' mode must be selected *);
   postcondition( * All keyboards in the students' workstations are now disabled*);
   description: (* The keyboard component disables all the students' keyboards access to their 
                workstations *);
End Keyboard;


Object Mouse is 
   components: Access*;
   precondition( *The 'Disable' mode must be selected *);
   postcondition( *All mouse in the students' workstations are now disabled*);
   description: (* The mouse component disables all the students' mouse access to their 
                workstations *);
End Mouse;

operation SaveSettings
   inputs: f:File, ros: Roster,ua: UserAccess; ;
   outputs: f':File;
   precondition:(* the fileName to be saved must not be nil and cannot be existed*)

                f != nil 
                and forall (f' in File) not(exists(f == f'));
 
   postcondtion:(* The roster information and the UserAccess settings are saved into a file *)
                 
                f = (ros and ua)
                and
                f' = f; 
   descriptiopn:(* The SaveSettings saves the current roster list in Roster and
                the current Mode and settings in UserAccess to a file with .adm extension *);
end;

operation LoadSettings
   inputs: f: File, ros: Roster, ua: UserAccess;
   outputs: f': File, ros': Roster, ua'= UserAccess;
   precondition:(* the file must exists *)
                f != nil
                and
                (* the file must have an extension of .adm *)
                (f' = f) iff (f.ext == ".adm");
   postcondtion:(* The new roster is loaded, replacing the current roster*)
                ros' = ros
                and
                (* The new useraccess settings replaced the current useracess settings*)
                ua' = ua; 
   descriptiopn:(* loads a roster and the UserAccess settings to this current settings*);
end;

Object File;

end Admin;