# Copyright (c) 2025 ByteDance Ltd. and/or its affiliates
# SPDX-License-Identifier: Apache-2.0 

import numpy as np
import pyscf
import pyscf.df

from dataset import MultipartLMDBDataset

BASIS = "def2-svp"
AUXBASIS = "def2-universal-jfit"


def get_rho_auxbasis_denfit(features):
    nums = features["atom_number"]
    coords = features["atom_coords"]
    charge = int(features["net_charge"])
    spin = int(features["spin"])
    dm = features["density_matrix"]

    mol = pyscf.M(
        atom=list(zip(nums.tolist(), coords.tolist())),
        unit="angstrom",
        basis=BASIS,
        charge=charge,
        spin=spin,
    )
    auxmol = pyscf.df.addons.make_auxmol(mol, auxbasis=AUXBASIS)

    ints_3c1e = pyscf.df.incore.aux_e2(mol, auxmol, intor="int3c1e")
    aux_vec = np.linalg.solve(
        auxmol.intor("int1e_ovlp"), np.einsum("ij,ijp->p", dm, ints_3c1e)
    )

    return {"aux_density_denfit": aux_vec}


def main():
    dataset = MultipartLMDBDataset("dataset/main", parts_to_load=["base", "dm"])
    d = dataset[0]
    density_coeffs_dict = get_rho_auxbasis_denfit(d)
    print(density_coeffs_dict["aux_density_denfit"])


if __name__ == "__main__":
    main()