program esmftest
  use ESMF
  implicit none
  integer :: rc
  
  integer :: nx, ny, i, j, ubnd(2), lbnd(2)

  type(ESMF_Field) :: field1, field2
  type(ESMF_Grid) :: grid1, grid2
  type(ESMF_RouteHandle) :: routehandle
  real(ESMF_KIND_r8), pointer  :: coordX(:,:), coordY(:,:), arrayptr(:,:)

  ! Initialize ESMF
  call ESMF_Initialize(defaultCalKind=ESMF_CALKIND_GREGORIAN, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)

  ! Define 2 grids (4x5 and 5x4 with coordinates)
 
  nx = 4
  ny = 5
  ! Create the 2 grids
  grid1 = ESMF_GridCreateNoPeriDim(maxIndex=(/nx,ny/), &
       coordSys=ESMF_COORDSYS_CART, & ! Cartesian coordinates (x,y not lat,lon)
       coordDep1=(/1,2/), coordDep2=(/1,2/), & ! Use coordDep1=(/1,2/),coordDep2=(/1,2/) for curvilinear grids.
       indexflag=ESMF_INDEX_GLOBAL, & ! Needed for using XGrid
       name="Grid1", rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  call ESMF_GridAddCoord(grid1,  & 
       staggerloc=ESMF_STAGGERLOC_CENTER, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  
  ! Get the local grid coordinates for X
  call ESMF_GridGetCoord(grid1, coordDim=1, localDE=0, &
       staggerloc=ESMF_STAGGERLOC_CENTER, &
       computationalLBound=lbnd, computationalUBound=ubnd, &
       farrayPtr=coordX, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  do i=lbnd(1),ubnd(1)
     do j=lbnd(2),ubnd(2)
        coordX(i,:) = i 
     end do
  end do
  ! Get the local grid coordinates for X
  call ESMF_GridGetCoord(grid1, coordDim=2, localDE=0, &
       staggerloc=ESMF_STAGGERLOC_CENTER, &
       computationalLBound=lbnd, computationalUBound=ubnd, &
       farrayPtr=coordY, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  do i=lbnd(1),ubnd(1)
     do j=lbnd(2),ubnd(2)
        coordY(:,j) = j
     end do
  end do

  nx = 5
  ny = 4
  ! Create the 2 grids
  grid2 = ESMF_GridCreateNoPeriDim(maxIndex=(/nx,ny/), &
       coordSys=ESMF_COORDSYS_CART, & ! Cartesian coordinates (x,y not lat,lon)
       coordDep1=(/1,2/), coordDep2=(/1,2/), & ! Use coordDep1=(/1,2/),coordDep2=(/1,2/) for curvilinear grids.
       indexflag=ESMF_INDEX_GLOBAL, & ! Needed for using XGrid
       name="Grid2", rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  call ESMF_GridAddCoord(grid2,  & 
       staggerloc=ESMF_STAGGERLOC_CENTER, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  
  ! Get the local grid coordinates for X
  call ESMF_GridGetCoord(grid2, coordDim=1, localDE=0, &
       staggerloc=ESMF_STAGGERLOC_CENTER, &
       computationalLBound=lbnd, computationalUBound=ubnd, &
       farrayPtr=coordX, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  do i=lbnd(1),ubnd(1)
     do j=lbnd(2),ubnd(2)
        coordX(i,:) = i
     end do
  end do
  ! Get the local grid coordinates for X
  call ESMF_GridGetCoord(grid2, coordDim=2, localDE=0, &
       staggerloc=ESMF_STAGGERLOC_CENTER, &
       computationalLBound=lbnd, computationalUBound=ubnd, &
       farrayPtr=coordY, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  do i=lbnd(1),ubnd(1)
     do j=lbnd(2),ubnd(2)
        coordY(:,j) = j
     end do
  end do

  ! Create the 2 fields
  field1 = ESMF_FieldCreate(grid=grid1, &
       typekind=ESMF_TYPEKIND_r8, &
       staggerloc=ESMF_STAGGERLOC_CENTER, &
       indexflag=ESMF_INDEX_GLOBAL, &
       name="field1", rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  call ESMF_FieldGet(field1, farrayPtr=arrayptr, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  ! Set all the values to 0
  arrayptr = 0.0d0


  field2 = ESMF_FieldCreate(grid=grid2, &
       typekind=ESMF_TYPEKIND_r8, &
       staggerloc=ESMF_STAGGERLOC_CENTER, &
       indexflag=ESMF_INDEX_GLOBAL, &
       name="field1", rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  call ESMF_FieldGet(field2, farrayPtr=arrayptr, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  ! Set all the values to 0
  arrayptr = 0.0d0



  call ESMF_FieldRegridStore(field1, field2, &
       unmappedaction=ESMF_UNMAPPEDACTION_IGNORE, &
       routehandle=routehandle, rc=rc)        
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
  call ESMF_FieldRegrid(field1, field2, &
       routehandle, rc=rc)
  if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
       line=__LINE__, &
       file=__FILE__)) &
       call ESMF_Finalize(endflag=ESMF_END_ABORT)

  call ESMF_Finalize()


end program esmftest