# Copyright (c) [2024] [Daniel Pozsar]
#
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# of this software and associated documentation files (the "Software"), to deal
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# furnished to do so, subject to the following conditions:
#
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#
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# SOFTWARE.

from timeit import default_timer as timer

# runtime information
times = dict()
times["start_time"] = timer()


import warnings
from sys import getsizeof

import sisl
from mpi4py import MPI

from src.grogu_magn import *

# input output stuff
######################################################################
######################################################################
######################################################################

path = (
    "/Users/danielpozsar/Downloads/nojij/Fe3GeTe2/monolayer/soc/lat3_791/Fe3GeTe2.fdf"
)
outfile = "./Fe3GeTe2_notebook"

magnetic_entities = [
    dict(atom=3, l=2),
    dict(atom=4, l=2),
    dict(atom=5, l=2),
]
pairs = [
    dict(ai=0, aj=1, Ruc=np.array([0, 0, 0])),
    dict(ai=0, aj=2, Ruc=np.array([0, 0, 0])),
    dict(ai=1, aj=2, Ruc=np.array([0, 0, 0])),
    dict(ai=0, aj=2, Ruc=np.array([-1, -1, 0])),
    dict(ai=1, aj=2, Ruc=np.array([-1, -1, 0])),
    dict(ai=0, aj=2, Ruc=np.array([-1, 0, 0])),
    dict(ai=1, aj=2, Ruc=np.array([-1, 0, 0])),
    dict(ai=1, aj=2, Ruc=np.array([-2, 0, 0])),
    dict(ai=1, aj=2, Ruc=np.array([-3, 0, 0])),
]
simulation_parameters = default_args

######################################################################
######################################################################
######################################################################


# MPI parameters
comm = MPI.COMM_WORLD
size = comm.Get_size()
rank = comm.Get_rank()
root_node = 0

# check versions for debugging
if rank == root_node:
    try:
        print(sisl.__version__)
    except:
        print("sisl version unknown.")
    try:
        print(np.__version__)
    except:
        print("numpy version unknown.")

# rename outfile
if not simulation_parameters["outfile"].endswith(".pickle"):
    simulation_parameters["outfile"] += ".pickle"

# if ebot is not given put it 0.1 eV under the smallest energy
if simulation_parameters["ebot"] is None:
    try:
        eigfile = simulation_parameters["infile"][:-3] + "EIG"
        simulation_parameters["ebot"] = read_siesta_emin(eigfile) - 0.1
    except:
        print("Could not determine ebot.")
        print("Parameter was not given and .EIG file was not found.")

# read sile
fdf = sisl.get_sile(simulation_parameters["infile"])

# read in hamiltonian
dh = fdf.read_hamiltonian()

# read unit cell vectors
simulation_parameters["cell"] = fdf.read_geometry().cell

# unit cell index
uc_in_sc_idx = dh.lattice.sc_index([0, 0, 0])

if rank == root_node:
    print_parameters(simulation_parameters)
    times["setup_time"] = timer()
    print(f"Setup done. Elapsed time: {times['setup_time']} s")
    print(
        "================================================================================================================================================================"
    )


# reformat Hamltonian and Overlap matrix for manipulations
hh, ss, NO = build_hh_ss(dh)

# symmetrizing Hamiltonian and Overlap matrix to make them hermitian
for i in range(dh.lattice.sc_off.shape[0]):
    j = dh.lattice.sc_index(-dh.lattice.sc_off[i])
    h1, h1d = hh[i], hh[j]
    hh[i], hh[j] = (h1 + h1d.T.conj()) / 2, (h1d + h1.T.conj()) / 2
    s1, s1d = ss[i], ss[j]
    ss[i], ss[j] = (s1 + s1d.T.conj()) / 2, (s1d + s1.T.conj()) / 2

# identifying TRS and TRB parts of the Hamiltonian
TAUY = np.kron(np.eye(NO), tau_y)
hTR = np.array([TAUY @ hh[i].conj() @ TAUY for i in range(dh.lattice.nsc.prod())])
hTRS = (hh + hTR) / 2
hTRB = (hh - hTR) / 2

# extracting the exchange field
traced = [spin_tracer(hTRB[i]) for i in range(dh.lattice.nsc.prod())]  # equation 77
XCF = np.array(
    [
        np.array([f["x"] / 2 for f in traced]),
        np.array([f["y"] / 2 for f in traced]),
        np.array([f["z"] / 2 for f in traced]),
    ]
)

# check if exchange field has scalar part
max_xcfs = abs(np.array(np.array([f["c"] / 2 for f in traced]))).max()
if max_xcfs > 1e-12:
    warnings.warn(
        f"Exchange field has non negligible scalar part. Largest value is {max_xcfs}"
    )

if rank == root_node:
    times["H_and_XCF_time"] = timer()
    print(
        f"Hamiltonian and exchange field rotated. Elapsed time: {times['H_and_XCF_time']} s"
    )
    print(
        "================================================================================================================================================================"
    )

# initialize pairs and magnetic entities based on input information
pairs, magnetic_entities = setup_pairs_and_magnetic_entities(
    magnetic_entities, pairs, dh, simulation_parameters
)

if rank == root_node:
    times["site_and_pair_dictionaries_time"] = timer()
    print(
        f"Site and pair dictionaries created. Elapsed time: {times['site_and_pair_dictionaries_time']} s"
    )
    print(
        "================================================================================================================================================================"
    )

# generate k space sampling
kset = make_kset(
    dirs=simulation_parameters["kdirs"], NUMK=simulation_parameters["kset"]
)
wkset = np.ones(len(kset)) / len(kset)  # generate weights for k points
kpcs = np.array_split(kset, size)  # split the k points based on MPI size

if tqdm_imported:
    kpcs[root_node] = tqdm(kpcs[root_node], desc="k loop")

if rank == root_node:
    times["k_set_time"] = timer()
    print(f"k set created. Elapsed time: {times['k_set_time']} s")
    print(
        "================================================================================================================================================================"
    )