title Schedule Session

bottomparticipants

actor "Trainee" as A
boundary "Schedule Session" as B
control "Schedule Controller" as C
database "Database" as D

C->B:
B->A:Send email
A->B:Interact
B->C:
C->B:
B->A:Log in
A->B:Provide login\n      details
B->C:
C->D:get_id
D->C:
C->D:get_available_trainings
D->C:
C->B:
B->A:Display times\n    and roles
A->B:Choose time
B->C:
C->D:get_valid_roles
D->C:
note over A,D:If the trainee can only assume one role (due to having\ncompleted their allowed observations or practicals,\nor due to the slot already having an allocated practical\ntrainee), then the following round-trip is skipped\n(until the next note)
C->B:
B->A:Offer choice\n      of role
A->B:Choose role
B->C:
note over A,D:If the previous interaction was skipped, the user's choice\nis set automatically to the only available role
C->B:
B->A:Confirm time\n    and role
A->B:Confirm
B->C:
C->D:record_trainee_role