!-----------------------------------------------------------------
!
!  This file is (or was) part of SPLASH, a visualisation tool
!  for Smoothed Particle Hydrodynamics written by Daniel Price:
!
!  http://users.monash.edu.au/~dprice/splash
!
!  SPLASH comes with ABSOLUTELY NO WARRANTY.
!  This is free software; and you are welcome to redistribute
!  it under the terms of the GNU General Public License
!  (see LICENSE file for details) and the provision that
!  this notice remains intact. If you modify this file, please
!  note section 2a) of the GPLv2 states that:
!
!  a) You must cause the modified files to carry prominent notices
!     stating that you changed the files and the date of any change.
!
!  Copyright (C) 2005-2014 Daniel Price. All rights reserved.
!  Contact: daniel.price@monash.edu
!
!-----------------------------------------------------------------

!-------------------------------------------------------------------------
! this subroutine reads from the data file(s)
! change this to change the format of data input
!
! the data is stored in the global array dat
!
! THIS VERSION FOR DAN'S SPMHD CODE (BINARY DUMPS)
! -> Now automatically handles single/double precision
!
! >> this subroutine must return values for the following: <<
!
! ncolumns    : number of data columns
! ndim, ndimV : number of spatial, velocity dimensions
! nstepsread  : number of steps read from this file
!
! maxplot,maxpart,maxstep      : dimensions of main data array
! dat(maxplot,maxpart,maxstep) : main data array
!
! npartoftype(maxstep) : number of particles of each type in each timestep
!
! time(maxstep)       : time at each step
! gamma(maxstep)      : gamma at each step
!
! most of these values are stored in global arrays
! in the module 'particle_data'
!-------------------------------------------------------------------------

subroutine read_data(rootname,indexstart,ipos,nstepsread)
 use exact,          only:hfact
 use particle_data,  only:npartoftype,time,gamma,headervals,dat,maxpart,maxstep,maxcol,iamtype
 use params
 use filenames,      only:nfiles
 use settings_data,  only:ndim,ndimV,ncolumns,ncalc,icoords,iformat, &
                          buffer_data,iverbose,debugmode
 use mem_allocation, only:alloc
 use geometry,       only:labelcoordsys
 use system_utils,   only:lenvironment
 use labels,         only:labeltype,print_types,headertags
 implicit none
 integer,          intent(in)  :: indexstart,ipos
 integer,          intent(out) :: nstepsread
 character(len=*), intent(in)  :: rootname
 character(len=len(rootname)+4) :: datfile
 integer :: i,icol,ierr,iunit,ilen,j,ilast
 integer :: ncol_max,ndim_max,npart_max,ndimV_max,nstep_max
 integer :: npartin,ntotin,ncolstep,nparti,ntoti
 integer, dimension(3) :: ibound
 logical :: reallocate, singleprecision

 real, dimension(3) :: xmin, xmax
 integer, parameter :: max_header_vars = 9
 real(doub_prec) :: header_dp(max_header_vars)
 real(sing_prec) :: header_sp(max_header_vars)
 real :: header(max_header_vars)
 real(doub_prec), dimension(:), allocatable :: dattempd
 real(sing_prec), dimension(:), allocatable :: dattemp
 integer, dimension(:), allocatable :: itype
 character(len=20) :: geomfile

 iunit = 11 ! file unit number
 ndim_max = 1
 ndimV_max = 1
 nstepsread = 0
 if (rootname(1:1) /= ' ') then
    datfile = trim(rootname)
    !print*,'rootname = ',rootname
 else
    print*,' **** no data read **** '
    return
 endif

 if (iverbose >= 1) print "(1x,a)",'reading ndspmhd format'
 write(*,"(23('-'),1x,a,1x,23('-'))") trim(datfile)
 !
 !--open data file and read data
 !
 open(unit=iunit,iostat=ierr,file=datfile,status='old',form='unformatted')
 if (ierr /= 0) then
    print*,' *** Error opening '//trim(datfile)//' ***'
    return
 endif
!
!--read first header line
!
 singleprecision = .false.
 read(iunit,iostat=ierr,end=80) header_dp(1),npartin,ntotin,header_dp(2), &
     header_dp(3),ndim_max,ndimV_max,ncol_max,iformat
!  print*,'time = ',timeind,' hfact = ',hfactind,' ndim=',ndim_max,'ncol=',ncol_max
!  print*,'npart = ',npartin,ntotin,geomfile
 if (ierr /= 0 .or. ndim_max <= 0 .or. ndim_max > 3 &
     .or. ndimV_max <= 0 .or. ndimV_max > 3 &
     .or. ncol_max <= 0 .or. ncol_max > 100 &
     .or. npartin <= 0 .or. npartin > 1e7 .or. ntotin <= 0 .or. ntotin > 1e7 &
     .or. iformat < 0 .or. iformat > 10) then
    !
    !--try single precision
    !
    rewind(iunit)
    read(iunit,iostat=ierr,end=80) header_sp(1),npartin,ntotin,header_sp(2), &
         header_sp(3),ndim_max,ndimV_max,ncol_max,iformat
    singleprecision = .true.
    if (ierr /= 0 .or. ndim_max <= 0 .or. ndim_max > 3 &
        .or. ndimV_max <= 0 .or. ndimV_max > 3 &
        .or. ncol_max <= 0 .or. ncol_max > 100 &
        .or. npartin <= 0 .or. npartin > 1e7 .or. ntotin <= 0 .or. ntotin > 1e7 &
        .or. iformat < 0 .or. iformat > 10) then

       print "(a)",' *** Error reading first header ***'
       print*,' time = ',header_sp(1),' hfact = ',header_sp(3),' ndim=',ndim_max,'ncol=',ncol_max
       close(iunit)
       return
    endif
 endif
!
!--allocate memory for data arrays
!
 if (buffer_data) then
    nstep_max = max(nfiles,maxstep,indexstart)
 else
    nstep_max = max(1,maxstep,indexstart)
 endif
 npart_max = max(int(1.5*ntotin),maxpart)
 if (.not.allocated(dat) .or. ntotin > maxpart  &
       .or. nstep_max > maxstep .or. ncol_max > maxcol) then
    call alloc(npart_max,nstep_max,ncol_max+ncalc,mixedtypes=.true.)
 endif
!
!--rewind file
!
 rewind(iunit)

 i = indexstart
 nstepsread = 0

 reallocate = .false.
 npart_max = maxpart
 nstep_max = maxstep
 geomfile = ' '
 !
 !--read header line for this timestep
 !
 if (singleprecision) then
    if (debugmode) print "(a)",'DEBUG: single precision dump'
    read(iunit,iostat=ierr) header_sp(1),nparti,ntoti,header_sp(2), &
          header_sp(3),ndim,ndimV,ncolstep,iformat,ibound(1:ndim), &
          header_sp(4:3+2*ndim),ilen,geomfile(1:ilen)
    header = real(header_sp)
 else
    if (debugmode) print "(a)",'DEBUG: double precision dump'
    read(iunit,iostat=ierr) header_dp(1),nparti,ntoti,header_dp(2), &
          header_dp(3),ndim,ndimV,ncolstep,iformat,ibound(1:ndim), &
          header_dp(4:3+2*ndim),ilen,geomfile(1:ilen)
    header = real(header_dp)
 endif
 if (ierr /= 0) then
    print*,'*** error reading timestep header ***'
    close(iunit)
    return
 else ! count this as a successfully read timestep, even if data is partial
    nstepsread = nstepsread + 1
 endif

 time(i) = header(1)
 gamma(i) = header(2)
 hfact = header(3)
 xmin(1:ndim) = header(4:3+ndim)
 xmax(1:ndim) = header(4+ndim:4+2*ndim-1)
 headertags(1:7) = (/'time ','npart','ntot ','gamma','hfact','ndim ','ndimV'/)
 headervals(1:7,i) = (/time(i),real(nparti),real(ntoti),gamma(i),hfact,real(ndim),real(ndimV)/)
 npartoftype(1,i) = nparti
 npartoftype(3,i) = ntoti - nparti
 if (iverbose >= 1) then
    print "(a14,':',es10.3,a6,':',i8,a8,':',i8)",' time',time(i),'npart',nparti,'ntotal',ntoti
    print "(a14,':',i8,a8,':',f8.4,a8,':',f8.4)",' ncolumns',ncolstep,'gamma',gamma(i),'hfact',hfact
    print "(a14,':',i8,a8,':',i8)",'ndim',ndim,'ndimV',ndimV
 else
    print "(1x,a,':',es10.3,a8,':',i8,a8,':',i8)",'time',time(i),'npart',nparti,'ntotal',ntoti
 endif
 select case(geomfile(1:6))
 case('cylrpz')
    icoords = 2
 case('sphrpt')
    icoords = 3
 case default
    icoords = 1
 end select
 if (icoords /= 1) print "(a14,a)",' geometry: ',trim(geomfile)//' ('//trim(labelcoordsys(icoords))//')'
 if (iverbose >= 1 .and. any(ibound(1:ndim) /= 0)) then
    print "(a14,':',a15,' =',3(f8.4))",'boundaries','xmin',xmin(1:ndim)
    print "(15x,a15,' =',3(f8.4))",'xmax',xmax(1:ndim)
 endif
 !
 !--check for errors in timestep header
 !
 if (ndim > 3 .or. ndimV > 3) then
    print*,'*** error in header: ndim or ndimV in file> 3'
    nstepsread = nstepsread - 1
    ndim = ndim_max
    ndimV = ndimV_max
    close(iunit)
    return
 endif
 if (ndim > ndim_max) ndim_max = ndim
 if (ndimV > ndimV_max) ndimV_max = ndimV

 if (ncolstep /= ncol_max) then
    print*,'*** Warning number of columns not equal for timesteps'
    ncolumns = ncolstep
    if (iverbose >= 1) print*,'ncolumns = ',ncolumns,ncol_max
    if (ncolumns > ncol_max) ncol_max = ncolumns
 endif
 if (ncolstep > maxcol) then
    reallocate = .true.
    ncolumns = ncolstep
    ncol_max = ncolumns
 else
    ncolumns = ncolstep
 endif

 if (ntoti > maxpart) then
    !print*, 'ntot greater than array limits!!'
    reallocate = .true.
    npart_max = int(1.5*ntoti)
 endif
 if (i > maxstep) then
    nstep_max = i + max(10,INT(0.1*nstep_max))
    reallocate = .true.
 endif
 !
 !--reallocate memory for main data array
 !
 if (reallocate) then
    call alloc(npart_max,nstep_max,ncol_max+ncalc,mixedtypes=.true.)
 endif


 if (ntoti > 0) then
    if (singleprecision) then
       allocate(dattemp(ntoti))
    else
       allocate(dattempd(ntoti))
    endif
    do icol=1,ncolstep
       if (singleprecision) then
          read (iunit,iostat=ierr) dattemp(1:ntoti)
          dat(1:ntoti,icol,i) = real(dattemp(1:ntoti))
       else
          read (iunit,iostat=ierr) dattempd(1:ntoti)
          dat(1:ntoti,icol,i) = real(dattempd(1:ntoti))
       endif
       if (ierr /= 0) print "(a,i2,a)",'*** error reading column ',icol,' ***'
    enddo
    if (allocated(dattempd)) deallocate(dattempd)
    if (allocated(dattemp)) deallocate(dattemp)

    allocate(itype(ntoti))
    read(iunit,iostat=ierr) itype(1:ntoti)
    if (ierr /= 0) then
       if (debugmode) print "(a)",'DEBUG: itype not found in dump file'
       iamtype(1:nparti,i) = 1
       iamtype(nparti+1:ntoti,i) = 3
    else
       !
       !--assign SPLASH types from ndspmhd types
       !
       npartoftype(:,i) = 0
       do j=1,ntoti
          if (j > nparti) then
             if (itype(j)==12) then
                iamtype(j,i) = 4
                npartoftype(4,i) = npartoftype(4,i) + 1
             else
                iamtype(j,i) = 3
                npartoftype(3,i) = npartoftype(3,i) + 1
             endif
          elseif (itype(j)==2) then
             iamtype(j,i) = 2
             npartoftype(2,i) = npartoftype(2,i) + 1
          else
             iamtype(j,i) = 1
             npartoftype(1,i) = npartoftype(1,i) + 1
          endif
       enddo
    endif
    if (allocated(itype)) deallocate(itype)
 else
    npartoftype(:,i) = 0
    npartoftype(1,i) = 1
    dat(:,:,i) = 0.
 endif
 !
 !--close data file and return
 !
 close(unit=11)

 ilast = i
!
!--ONE FLUID DUST: FAKE IT AS IF IT IS TWO FLUIDS
!  (copy the particles, then copy gas properties onto first lot, then dust properties onto second lot)
!
 ncolumns = ncol_max
 ndim = ndim_max
 ndimV = ndimV_max

 call set_labels

!if (iformat==5 .and. .not.lenvironment('NSPLASH_BARYCENTRIC')) then
!   call fake_twofluids
!   iformat = 1
!endif

 if (any(npartoftype(2:,ilast) > 0)) call print_types(npartoftype(:,ilast),labeltype)

 if (debugmode) print*,'DEBUG> Read steps ',indexstart,'->',indexstart + nstepsread - 1, &
       ' last step ntot = ',sum(npartoftype(:,indexstart+nstepsread-1))
 return

80 continue
 print*,' *** data file empty : no timesteps ***'
 return

end subroutine read_data

!!------------------------------------------------------------
!! set labels for each column of data
!!------------------------------------------------------------

subroutine set_labels
 use labels, only:ix,ivx,ih,irho,iutherm,ipmass,ipr,iBfirst, &
             idivB,iJfirst,iamvec,labelvec,label,labeltype, &
             irhorestframe,idustfrac,ideltav
 use params
 use settings_data, only:ndim,ndimV,iformat,ntypes, &
                    UseTypeInRenderings,ncolumns
 use geometry, only:labelcoord
 implicit none
 integer :: i,icol

 if (ndim <= 0 .or. ndim > 3) then
    print*,'*** ERROR: ndim = ',ndim,' in set_labels ***'
    return
 endif
 if (ndimV <= 0 .or. ndimV > 3) then
    print*,'*** ERROR: ndimV = ',ndimV,' in set_labels ***'
    return
 endif

 do i=1,ndim
    ix(i) = i
 enddo
 ivx = ndim + 1
 ih = ndim + ndimV + 1        !  smoothing length
 irho = ndim + ndimV + 2      ! location of rho in data array
 iutherm = ndim + ndimV + 3   !  thermal energy
 ipmass = ndim + ndimV + 4    !  particle mass

 label(ix(1:ndim)) = labelcoord(1:ndim,1)
 !
 !--label vector quantities (e.g. velocity) appropriately
 !
 iamvec(ivx:ivx+ndimV-1) = ivx
 labelvec(ivx:ivx+ndimV-1) = 'v'

 label(irho) = '\gr'
 label(iutherm) = 'u'
 label(ih) = 'h       '
 label(ipmass) = 'particle mass'
 label(ndim + ndimV+5) = '\ga'
 label(ndim + ndimV+6) = '\ga\du'
 icol = ndim+ndimV + 7
 if (iformat==2 .or. iformat==4) then
    !
    !--mag field (vector)
    !
    label(icol) = '\ga\dB'
    iBfirst = icol+1        ! location of Bx
    iamvec(iBfirst:iBfirst+ndimV-1) = iBfirst
    labelvec(iBfirst:iBfirst+ndimV-1) = 'B'
    icol = icol + ndimV
    !
    !--more scalars
    !
    icol = icol + 1
    label(icol) = 'psi'

    icol = icol + 1
    ipr = icol !  pressure
    label(ipr) = 'P'

    icol = icol + 1
    label(icol) = 'div v'

    icol = icol + 1
    idivB = icol
    label(idivB) = 'div B'
    !
    !--current density (vector)
    !
    iJfirst = icol + 1
    iamvec(icol+1:icol+ndimV) = icol + 1
    labelvec(icol+1:icol+ndimV) = 'J'
    icol = icol + ndimV

    icol = icol + 1
    label(icol) = 'grad h'

    iamvec(icol+1:icol+ndimV) = icol + 1
    labelvec(icol+1:icol+ndimV) = 'force'
    icol = icol + ndimV

    iamvec(icol+1:icol+ndimV) = icol + 1
    labelvec(icol+1:icol+ndimV) = 'A'
    icol = icol + ndimV

 else
    ipr = icol !  pressure
    label(ipr) = 'P'
    icol = icol + 1
    label(icol) = 'div v'
    icol = icol + 1
    label(icol) = 'grad h'

    iamvec(icol+1:icol+ndimV) = icol + 1
    labelvec(icol+1:icol+ndimV) = 'force'
    icol = icol + ndimV
    iBfirst = 0

    if (ncolumns > 20) then
       iamvec(icol+1:icol+ndimV) = icol + 1
       labelvec(icol+1:icol+ndimV) = 'del^{2} v'
       icol = icol + ndimV

       iamvec(icol+1:icol+ndimV) = icol + 1
       labelvec(icol+1:icol+ndimV) = 'grad (div {\bf v})'
       icol = icol + ndimV
    endif
 endif
 if (iformat==5) then
    icol = icol + 1
    label(icol) = 'Dust fraction'
    idustfrac = icol
    iamvec(icol+1:icol+ndimV) = icol + 1
    labelvec(icol+1:icol+ndimV) = '\Deltav'
    ideltav = icol + 1
    icol = icol + ndimV
 elseif (iformat > 2) then
    irhorestframe = irho
    icol = icol + 1
    irho = icol
    label(icol) = 'rho*'
    !irho = icol
    icol = icol + 1
    label(icol) = 'sqrt g'
    iamvec(icol+1:icol+ndimV) = icol + 1
    labelvec(icol+1:icol+ndimV) = 'pmom'
    icol = icol + ndimV
 endif
!
!--set labels for each type of particles
!
 ntypes = 4
 labeltype(1) = 'gas'
 labeltype(2) = 'dust'
 labeltype(3) = 'ghost'
 labeltype(4) = 'ghost (dust)'
 UseTypeInRenderings(:) = .true.

!-----------------------------------------------------------

 return
end subroutine set_labels
