!Copyright (c) 2013 by tdem.org under guide of Xiu Li(lixiu@chd.edu.cn)
!written by Huaifeng Sun(sunhuaifeng@gmail.com) and Xushan Lu(luxushan@gmail.com)
!Code distribution @ tdem.org or sunhuaifeng.com
    
subroutine SubOpenRecFiles(Flag)
  use constantparameters
  implicit none
  integer ii,jj
  character*2 Flag
  character*30 string
  do ii=1,NumRecHeights,1
     write(Height(ii),'(i3.3)')FlightHeight(ii) !Convert real kind of variable to character so that it can be used in the filename distribution process
     Height(ii)=trim(adjustl(Height(ii)))       
  end do
  write(PostProcessFilePid,*)  (NumRecLines)*(1+NumRecHeights),RecPointMin,RecPointMax !The number of total recording files
  write(SplitFilePid,*)NumRecLines,NumRecPoints,NumRecHeights
  do ii=1,NumRecLines,1
     write(SplitFilePid,*)RecLine(ii)
  end do
  do ii=1,NumRecPoints,1
     write(SplitFilePid,*)RecPoint(ii)
  end do
  do ii=1,NumRecHeights,1
     write(SplitFilePid,*)FlightHeight(ii)
  end do
  close(SplitFilePid)
  ! -------------------------------------------------check for RecFilePid------------------------------------!
  ! if NumRecPoints is greater than 500, then the value of RecFilePid must be reset
  ! ----------------------------------------------------------------------------------------------------------------!
  if(NumRecLines.ge.2000)then
     print*,'NumRecLines is greater than 1000! Reset the value of RecFilePid in subroutine "OpenRecFiles"'
     ! This is because the distribution of file pid. You should modify the distribution part if your recording files number is greater than 1000.
     stop
  end if
  ! ----------------------------------------------------------------------------------------------------------------!
  ! -------------------------------------File Pid Distribution------------------------------------------------!
  ! Change it whenever you need to do so
  ! ----------------------------------------------------------------------------------------------------------------!
  if(Flag.eq.'Hz')then
     do jj=1,NumRecLines,1
        RecFilePid(1,jj)=20000+jj !For the ground plane. 
        do ii=1,NumRecHeights,1
           RecFilePid(ii+1,jj)=20000+ii*2000+jj !For the air plane, with multiple height
        end do
     enddo
     RecHzFilePid=RecFilePid    !Transfer the value of RecFilePid to RecHzFilePid if Flag.eq.'Hz'
  elseif(Flag.eq.'HE')then
     do jj=1,NumRecLines,1
        RecFilePid(1,jj)=20000+(NumRecHeights+1)*2000+jj
        do ii=1,NumRecHeights,1
           RecFilePid(ii+1,jj)=20000+(NumRecHeights+1+ii)*2000+jj
        end do
     enddo
     RecHEFilePid=RecFilePid
  end if
  ! --------------------------------------end of File Pid Distribution----------------------------------------------!
  !------------------------------------------File name Distribution-------------------------------------------------!
  do jj=1,NumRecLines,1
     write(string,'(I3.3)')RecLine(jj)
     RecFile(1,jj)='Ground-Line'//'='//trim(adjustl(string))//'.dat'
     write(PostProcessFilePid,*)RecFile(1,jj)
     do ii=1,NumRecHeights,1
        RecFile(ii+1,jj)='Air-Line='//trim(adjustl(string))//'-H='//Height(ii)//'.dat'
        write(PostProcessFilePid,*)RecFile(ii+1,jj)
     end do
  end do
  select case(Flag)
  case('Hz')
     RecHzFile=RecFile
  case('HE')
     RecHEFile=RecFile
  end select
  ! ------------------------------------end of File name Distribution---------------------------------------------!
  ! --------------------------------------open file code-------------------------------------------!
  ! if the compiler reports the error: 'Too Many Open FIles!', you can come to tdem.org website and find the solutions.
  ! -----------------------------------------------------------------------------------------------------!
  do ii=1,NumRecHeights+1,1
     do jj=1,NumRecLines,1
        open(RecFilePid(ii,jj),file=RecFile(ii,jj))
     end do
  end do
  ! -----------------------------------end of opening file----------------------------------------!
end subroutine SubOpenRecFiles