module moduleTableBC
  use constantParameters, only: dp

  type:: tableBC
    real(dp):: t_min, t_max
    real(dp):: n_min, n_max
    real(dp):: u_min, u_max
    real(dp):: Temp_min, Temp_max
    real(dp), allocatable, dimension(:):: t
    real(dp), allocatable, dimension(:):: n, u, Temp
    real(dp), allocatable, dimension(:):: n_k, u_k, Temp_k
    contains
      procedure, pass:: init    => initTableBC
      procedure, pass:: get     => getValueTableBC

  end type tableBC

  contains
    subroutine initTableBC(self, tableFile)
      use constantParameters, only: eV_to_K
      use referenceValues, only: t_ref, n_ref, u_ref, Temp_ref
      implicit none

      class(tableBC), intent(inout):: self
      character(:), allocatable, intent(in):: tableFile
      character(100):: dummy
      integer:: amount
      integer:: i
      integer:: stat
      integer:: id = 20

      open(id, file = tableFile)
      amount = -1 ! Remove header
      do
        read(id, '(A)', iostat = stat) dummy
        !If EOF or error, exit file
        if (stat /= 0) EXIT
        ! !Skip comment
        ! if (index(dummy,'#') /= 0) CYCLE
        !Add row
        amount = amount + 1

      end do

      !Go bback to initial point
      rewind(id)

      !Allocate table arrays
      allocate(self%t(1:amount))
      allocate(  self%n(1:amount),   self%u(1:amount),   self%Temp(1:amount))
      allocate(self%n_k(1:amount), self%u_k(1:amount), self%Temp_k(1:amount))
      self%t      = 0.0_dp
      self%n      = 0.0_dp
      self%u      = 0.0_dp
      self%Temp   = 0.0_dp
      self%n_k    = 0.0_dp
      self%u_k    = 0.0_dp
      self%Temp_k = 0.0_dp

      i = 0
      read(id, *) ! Skip header
      do 
        read(id, '(A)', iostat = stat) dummy
        !TOdo: Make this a function
        if (stat /= 0) EXIT
        !Add data
        !TODO: substitute with extracting information from dummy
        backspace(id)
        i = i + 1
        read(id, *) self%t(i), self%n(i), self%u(i), self%Temp(i)

      end do

      self%t    =    self%t / t_ref
      self%n    =    self%n / n_ref
      self%u    =    self%u / u_ref
      self%Temp = self%Temp * eV_to_K / Temp_ref

      close(id)

      self%t_min    = self%t(1)
      self%t_max    = self%t(amount)
      self%n_min    = self%n(1)
      self%n_max    = self%n(amount)
      self%u_min    = self%u(1)
      self%u_max    = self%u(amount)
      self%Temp_min = self%Temp(1)
      self%Temp_max = self%Temp(amount)

      do i = 1, amount - 1
        self%n_k(i)    = (   self%n(i+1) -    self%n(i))/(self%t(i+1) - self%t(i))
        self%u_k(i)    = (   self%u(i+1) -    self%u(i))/(self%t(i+1) - self%t(i))
        self%Temp_k(i) = (self%Temp(i+1) - self%Temp(i))/(self%t(i+1) - self%t(i))

      end do

    end subroutine initTableBC

    subroutine getValueTableBC(self, t, n, u, Temp)
      implicit none

      class(tableBC), intent(in):: self
      real(dp), intent(in):: t
      real(dp), intent(out):: n, u, Temp
      real(dp):: delta_t
      integer:: i

      if     (t <= self%t_min) THEN
        n    = self%n_min
        u    = self%u_min
        Temp = self%Temp_min

      elseif (t >= self%t_max) THEN
        n    = self%n_max
        u    = self%u_max
        Temp = self%Temp_max

      else
        i = minloc(abs(t - self%t), 1)
        delta_t = t - self%t(i)
        if (delta_t < 0 ) THEN 
          i = i - 1
          delta_t = t - self%t(i)
          
        end if

        n    =    self%n(i) +    self%n_k(i)*delta_t
        u    =    self%u(i) +    self%u_k(i)*delta_t
        Temp = self%Temp(i) + self%Temp_k(i)*delta_t

      end if

    end subroutine getValueTableBC

end module moduleTableBC