from diceplayer.config import PlayerConfig
from diceplayer.environment import Atom, Molecule, System

from pathlib import Path


def read_system_from_phb(config: PlayerConfig) -> System:
    phb_file = Path(config.dice.ljname)
    if not phb_file.exists():
        raise FileNotFoundError

    ljc_data = phb_file.read_text(encoding="utf-8").splitlines()

    combrule = ljc_data.pop(0).strip()
    if combrule != config.dice.combrule:
        raise ValueError(
            f"Invalid combrule defined in {phb_file}. Expected the same value configured in the config file"
        )

    ntypes = ljc_data.pop(0).strip()
    if not ntypes.isdigit():
        raise ValueError(f"Invalid ntypes defined in {phb_file}")

    nmol = int(ntypes)
    if nmol != len(config.dice.nmol):
        raise ValueError(f"Invalid nmol defined in {phb_file}")

    sys = System()

    for i in range(nmol):
        nsites, molname = ljc_data.pop(0).split()

        if not nsites.isdigit():
            raise ValueError(f"Invalid nsites defined in {phb_file}")
        nsites = int(nsites)

        mol = Molecule(molname)

        for j in range(nsites):
            _fields = ljc_data.pop(0).split()
            mol.add_atom(Atom(*_fields))

        sys.add_type(mol)

    return sys


# def write_phb(phb_file: Path, state: StateModel) -> None:
#     if phb_file.exists():
#        raise RuntimeError(f"File {phb_file} already exists")
#
#     with open(phb_file, "w") as f:
#         f.write(f"{state.config.dice.combrule}\n")
#         f.write(f"{len(state.system.nmols)}\n")
#         f.write(f"{state.config.dice.nmol}\n")