module CProblemDifinition
    use CIActionReference
	implicit none    
	public 
    
    procedure (ActionInteger), pointer :: Nil => null()
    
    integer, parameter :: Time_ProblemType = 0
    integer, parameter :: PumpStrokes_ProblemType = 1
    integer, parameter :: VolumePumped_ProblemType = 2
    integer, parameter :: DistanceDrilled_ProblemType = 3
    
    integer, parameter :: Clear_StatusType = 0
    integer, parameter :: Now_StatusType = 1
    integer, parameter :: Later_StatusType = 2
    integer, parameter :: Executed_StatusType = 3
    
    type, bind(c), public :: CProblem
        integer :: ProblemType
        integer :: StatusType
        real(8) :: Value
        real(8) :: DueValue
    end type CProblem
    
    contains 
    
    subroutine Execute(problem, action)
        type(CProblem), intent(inout) :: problem
        procedure (ActionInteger), pointer, intent(in) :: action
        problem%StatusType = Executed_StatusType
        if(problem%StatusType == Executed_StatusType .and. associated(action)) call action(Executed_StatusType)
    end subroutine
    
    ! type(CProblem) function SetDue(problem, action)
    ! ! use CSimulationVariables
    
    !     implicit none
    !     type(CProblem), intent(in) :: problem
    !     procedure (ActionInteger), pointer, intent(in) :: action
    !     real(8) :: CurrentTime
    !     real(8) :: CurrentPumpStrokes
    !     real(8) :: CurrentVolumePumped
    !     real(8) :: CurrentDistanceDrilled
    !     real(8) :: Due
        
    !     CurrentTime = 0
    !     CurrentPumpStrokes = 0
    !     CurrentVolumePumped = 0
    !     CurrentDistanceDrilled = 0
        
    !     SetDue = problem
        
    !     if(problem%StatusType == Clear_StatusType .and. associated(action)) then
    !         call action(Clear_StatusType)
    !         SetDue%DueValue = 0
    !         return
    !     endif
        
    !     select case (problem%ProblemType)
    !     case(Time_ProblemType)
    !         select case (SimulationState)
    !         case(SimulationState_Stopped)
    !             CurrentTime = 0
    !         case(SimulationState_Started)
    !             CurrentTime = dble(SimulationTime)
    !         case(SimulationState_Paused)
    !             CurrentTime = dble(SimulationTime)
    !         end select
    !         Due = problem%Value + CurrentTime
    !     case(PumpStrokes_ProblemType)
    !         select case (SimulationState)
    !         case(SimulationState_Stopped)
    !             CurrentPumpStrokes = 0
    !         case(SimulationState_Started)
    !             CurrentPumpStrokes = TotalPumpStrokes
    !         case(SimulationState_Paused)
    !             CurrentPumpStrokes = TotalPumpStrokes
    !         end select
    !         Due = problem%Value + CurrentPumpStrokes
    !     case(VolumePumped_ProblemType)
    !         select case (SimulationState)
    !         case(SimulationState_Stopped)
    !             CurrentVolumePumped = 0
    !         case(SimulationState_Started)
    !             CurrentVolumePumped = TotalVolumePumped
    !         case(SimulationState_Paused)
    !             CurrentVolumePumped = TotalVolumePumped
    !         end select
    !         Due = problem%Value + CurrentVolumePumped
    !     case(DistanceDrilled_ProblemType)
    !         select case (SimulationState)
    !         case(SimulationState_Stopped)
    !             CurrentDistanceDrilled = 0
    !         case(SimulationState_Started)
    !             CurrentDistanceDrilled = DistanceDrilled
    !         case(SimulationState_Paused)
    !             CurrentDistanceDrilled = DistanceDrilled
    !         end select
    !         Due = problem%Value + CurrentDistanceDrilled
    !     end select
        
    !     SetDue%DueValue = Due
        
        
    ! end function SetDue
    
    
    subroutine ProcessDueTime(problem, action, time)
    ! use CSimulationVariables
        use CLog3
        implicit none
        type(CProblem) :: problem
        procedure (ActionInteger), pointer, intent(in) :: action
        integer :: time
        if(problem%ProblemType == Time_ProblemType .and. problem%StatusType /= Executed_StatusType .and. problem%StatusType /= Clear_StatusType) then 
            if(time >= int(problem%DueValue)) call Execute(problem, action)
        end if
    end subroutine
    
    subroutine ProcessDuePumpStrokes(problem, action, strokes)
    ! use CSimulationVariables
        implicit none
        type(CProblem) :: problem
        procedure (ActionInteger), pointer, intent(in) :: action
        integer :: strokes
        if(problem%ProblemType == PumpStrokes_ProblemType .and. problem%StatusType /= Executed_StatusType .and. problem%StatusType /= Clear_StatusType) then 
            if(strokes >= int(problem%DueValue)) call Execute(problem, action)
        end if
    end subroutine
    
    subroutine ProcessDueVolumePumped(problem, action, volume)
    ! use CSimulationVariables
        implicit none
        type(CProblem) :: problem
        procedure (ActionInteger), pointer, intent(in) :: action
        real(8) :: volume
        if(problem%ProblemType == VolumePumped_ProblemType .and. problem%StatusType /= Executed_StatusType .and. problem%StatusType /= Clear_StatusType) then 
            if(volume >= problem%DueValue) call Execute(problem, action)
        end if
    end subroutine
    
    subroutine ProcessDueDistanceDrilled(problem, action, distance)
    ! use CSimulationVariables
        implicit none
        type(CProblem) :: problem
        procedure (ActionInteger), pointer, intent(in) :: action
        real(8) :: distance
        if(problem%ProblemType == DistanceDrilled_ProblemType .and. problem%StatusType /= Executed_StatusType .and. problem%StatusType /= Clear_StatusType) then 
            if(distance >= problem%DueValue) call Execute(problem, action)
        end if
    end subroutine
    
    
end module CProblemDifinition