###############################################################################
# This file is part of SWIFT.
# Copyright (c) 2016 Matthieu Schaller (schaller@strw.leidenuniv.nl)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################

import h5py
from numpy import *

# Generates a swift IC file for the 2D Noh problem in a periodic box

# Parameters
gamma = 5.0 / 3.0  # Gas adiabatic index
gamma = 5.0 / 3.0  # Gas adiabatic index
rho0 = 1.0  # Background density
P0 = 1.0e-6  # Background pressure
fileName = "noh.hdf5"

# ---------------------------------------------------
glass = h5py.File("glassPlane_128.hdf5", "r")

vol = 4.0

pos = glass["/PartType0/Coordinates"][:, :] * sqrt(vol)
h = glass["/PartType0/SmoothingLength"][:] * sqrt(vol)
numPart = size(h)

# Generate extra arrays
v = zeros((numPart, 3))
ids = linspace(1, numPart, numPart)

m = zeros(numPart)
u = zeros(numPart)
m[:] = rho0 * vol / numPart
u[:] = P0 / (rho0 * (gamma - 1))

# Make radial velocities
# r = sqrt((pos[:,0]-1.)**2 + (pos[:,1]-1.)**2)
# theta = arctan2((pos[:,1]-1.), (pos[:,0]-1.))
v[:, 0] = -(pos[:, 0] - 1.0)
v[:, 1] = -(pos[:, 1] - 1.0)

norm_v = sqrt(v[:, 0] ** 2 + v[:, 1] ** 2)
v[:, 0] /= norm_v
v[:, 1] /= norm_v

# File
file = h5py.File(fileName, "w")

# Header
grp = file.create_group("/Header")
grp.attrs["BoxSize"] = [sqrt(vol), sqrt(vol), 1.0]
grp.attrs["NumPart_Total"] = [numPart, 0, 0, 0, 0, 0]
grp.attrs["NumPart_Total_HighWord"] = [0, 0, 0, 0, 0, 0]
grp.attrs["NumPart_ThisFile"] = [numPart, 0, 0, 0, 0, 0]
grp.attrs["Time"] = 0.0
grp.attrs["NumFilesPerSnapshot"] = 1
grp.attrs["MassTable"] = [0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
grp.attrs["Flag_Entropy_ICs"] = 0
grp.attrs["Dimension"] = 2

# Units
grp = file.create_group("/Units")
grp.attrs["Unit length in cgs (U_L)"] = 1.0
grp.attrs["Unit mass in cgs (U_M)"] = 1.0
grp.attrs["Unit time in cgs (U_t)"] = 1.0
grp.attrs["Unit current in cgs (U_I)"] = 1.0
grp.attrs["Unit temperature in cgs (U_T)"] = 1.0

# Particle group
grp = file.create_group("/PartType0")
grp.create_dataset("Coordinates", data=pos, dtype="d")
grp.create_dataset("Velocities", data=v, dtype="f")
grp.create_dataset("Masses", data=m, dtype="f")
grp.create_dataset("SmoothingLength", data=h, dtype="f")
grp.create_dataset("InternalEnergy", data=u, dtype="f")
grp.create_dataset("ParticleIDs", data=ids, dtype="L")


file.close()