program bmad_to_gpt

use gpt_interface_mod
use bmad_interface
use time_tracker_mod
use beam_mod

type (lat_struct), target :: lat
type (branch_struct), pointer :: branch
type (beam_init_struct) beam_init
type (beam_struct) beam
type (ele_struct), pointer :: ele0, ele1
type (coord_struct) :: orb0
type (coord_struct), allocatable :: closed_orb(:)
type (gpt_lattice_param_struct) :: gpt_lattice_param
integer :: ios, iu
integer :: namelist_file, n_char, gpt_file

character(100) :: lat_filename, lat2_filename, lat_path, base_name, in_file, gpt_filename
character(100) :: gpt_particle_filename, time_particle_filename
character(30), parameter :: r_name = 'bmad_to_gpt'

logical :: err
logical :: write_time_particles, write_gpt_particles

namelist / bmad_to_gpt_params / &
    lat_filename, lat2_filename, write_time_particles, write_gpt_particles, &
    gpt_lattice_param, beam_init, gpt_filename

!------------------------------------------
!Defaults for namelist
lat_filename = 'lat.bmad'
lat2_filename = ''
gpt_filename = ''
write_time_particles = .false.
write_gpt_particles = .false.
gpt_lattice_param%fieldmap_dimension = 3
beam_init%n_particle = 1
beam_init%n_bunch = 1

!Read namelist
in_file = 'bmad_to_gpt.in'
if (command_argument_count() > 0) call get_command_argument(1, in_file)

namelist_file = lunget()
print *, 'Opening: ', trim(in_file)
open (namelist_file, file = in_file, status = "old")
read (namelist_file, nml = bmad_to_gpt_params)
close (namelist_file)

!Trim filename
n_char= SplitFileName(lat_filename, lat_path, base_name) 

!Parse Lattice
call bmad_parser (lat_filename, lat)

!Parse additional settings
if (lat2_filename /= '') then
  print *, 'Parsing: '//trim(lat2_filename)
  call bmad_parser2 (lat2_filename, lat)
endif

!Trim filename
n_char= SplitFileName(lat_filename, lat_path, base_name) 

!Prepare gpt file
if (gpt_filename == '') then
  call file_suffixer (base_name, gpt_filename, 'gpt', .true.)
endif

gpt_file = lunget()	
open (gpt_file, file = gpt_filename, iostat = ios)
if (ios /= 0) then
  call out_io (s_error$, r_name, 'CANNOT OPEN FILE: ' // trim(gpt_filename))
  stop
endif



! 
print *, 'Field map dimension: ', gpt_lattice_param%fieldmap_dimension

call write_gpt_lattice_file(gpt_file, lat, gpt_lattice_param, err)

print *, 'Written: ', gpt_filename


! Stop if no particles are to be written
if ( (.not. write_time_particles) .and. (.not. write_gpt_particles) ) then
  stop
endif

!-------------------------------------------
!Particle distribution
!Write particle file if more than one particle is defined
if (beam_init%n_particle > 1 ) then
  !set ele1 to be the init_ele
  ele1 => lat%ele(0)

  !Initialize beam
  call init_beam_distribution (ele1, lat%param, beam_init, beam)
  beam%bunch(1)%particle(:)%p0c = ele1%value(p0c_start$)
  call out_io (s_info$, r_name, 'Initialized bunch with p0c = \es13.3\ ', ele1%value(p0c$) )
  
  if (write_gpt_particles) then
  call file_suffixer (base_name, gpt_particle_filename, 'gpt_particles', .true.)
    iu = lunget()	
    open (iu, file = gpt_particle_filename, iostat = ios)
    if (ios /= 0) then
	    call out_io (s_error$, r_name, 'CANNOT OPEN FILE: ' // trim(gpt_particle_filename))
  	    stop
    endif

    !Write the first bunch only
    !call write_opal_particle_distribution (iu, beam%bunch(1), mass_of(lat%param%particle),  err)
    call write_time_particle_distribution (iu, beam%bunch(1), style = 'GPT', branch = lat%branch(0))
    print *, "Written gpt particles: ", gpt_particle_filename
    close(iu)
  endif
  
  if (write_time_particles) then
    iu = lunget()
    call file_suffixer (base_name, time_particle_filename, 'time_particles', .true.)
    open (iu, file = time_particle_filename, iostat = ios)
    if (ios /= 0) then
	    call out_io (s_error$, r_name, 'CANNOT OPEN FILE: ' // trim(time_particle_filename))
  	    stop
    endif

    !Write the first bunch only
    call write_time_particle_distribution (iu, beam%bunch(1), 'BMAD')
    print *, "Written bmad particles: ", time_particle_filename
    close(iu)
    
    ! Track to the end, write to file for reference
    !call track_beam (lat, beam, err=err)
    !call file_suffixer (base_name, time_particle_filename, 'end_particles', .true.)
    !open (iu, file = time_particle_filename, iostat = ios)
    !call write_time_particle_distribution (iu, beam%bunch(1))
    !print *, "Written: ", time_particle_filename
    !close(iu)   
  endif

endif




end program