from pywarpx import picmi
#from warp import picmi

constants = picmi.constants

nx = 64
ny = 64
nz = 64

xmin = -200.e-6
xmax = +200.e-6
ymin = -200.e-6
ymax = +200.e-6
zmin = -200.e-6
zmax = +200.e-6

moving_window_velocity = [0., 0., constants.c]

number_per_cell_each_dim = [2, 2, 1]

max_steps = 10

grid = picmi.Cartesian3DGrid(number_of_cells = [nx, ny, nz],
                             lower_bound = [xmin, ymin, zmin],
                             upper_bound = [xmax, ymax, zmax],
                             lower_boundary_conditions = ['periodic', 'periodic', 'open'],
                             upper_boundary_conditions = ['periodic', 'periodic', 'open'],
                             lower_boundary_conditions_particles = ['periodic', 'periodic', 'absorbing'],
                             upper_boundary_conditions_particles = ['periodic', 'periodic', 'absorbing'],
                             moving_window_velocity = moving_window_velocity,
                             warpx_max_grid_size=32)

solver = picmi.ElectromagneticSolver(grid=grid, cfl=1)

beam_distribution = picmi.UniformDistribution(density = 1.e23,
                                              lower_bound = [-20.e-6, -20.e-6, -150.e-6],
                                              upper_bound = [+20.e-6, +20.e-6, -100.e-6],
                                              directed_velocity = [0., 0., 1.e9])

plasma_distribution = picmi.UniformDistribution(density = 1.e22,
                                                lower_bound = [-200.e-6, -200.e-6, 0.],
                                                upper_bound = [+200.e-6, +200.e-6, None],
                                                fill_in = True)

beam = picmi.Species(particle_type='electron', name='beam', initial_distribution=beam_distribution)
plasma = picmi.Species(particle_type='electron', name='plasma', initial_distribution=plasma_distribution)

sim = picmi.Simulation(solver = solver,
                       max_steps = max_steps,
                       verbose = 1,
                       warpx_current_deposition_algo = 'esirkepov',
                       warpx_use_filter = 0)

sim.add_species(beam, layout=picmi.GriddedLayout(grid=grid, n_macroparticle_per_cell=number_per_cell_each_dim))
sim.add_species(plasma, layout=picmi.GriddedLayout(grid=grid, n_macroparticle_per_cell=number_per_cell_each_dim))

field_diag = picmi.FieldDiagnostic(name = 'diag1',
                                   grid = grid,
                                   period = max_steps,
                                   data_list = ['Ex', 'Ey', 'Ez', 'Jx', 'Jy', 'Jz', 'part_per_cell'],
                                   write_dir = '.',
                                   warpx_file_prefix = 'Python_PlasmaAcceleration_plt')

part_diag = picmi.ParticleDiagnostic(name = 'diag1',
                                     period = max_steps,
                                     species = [beam, plasma],
                                     data_list = ['ux', 'uy', 'uz', 'weighting'])

sim.add_diagnostic(field_diag)
sim.add_diagnostic(part_diag)

# write_inputs will create an inputs file that can be used to run
# with the compiled version.
#sim.write_input_file(file_name = 'inputs_from_PICMI')

# Alternatively, sim.step will run WarpX, controlling it from Python
sim.step()