from __future__ import annotations

import pathlib
import subprocess
from itertools import product


def prepare_rw_parameter(parameter: dict) -> list:
    """
    Converts a dictionary of iterables to list of dictionaries

    Example:
    If Input is {'a': [1, 2, 3], 'b' = [4, 5]}, output is cartesian product of dictionary values, i.e.,
    [{'a': 1, 'b': 4}, {'a': 1, 'b': 5}, {'a': 2, 'b': 4}, {'a': 2, 'b': 5}, {'a': 3, 'b': 4}, {'a': 3, 'b': 5}]

    :param parameter: dictionary of list values
    :return: list of dictionaries
    """
    output = {}
    for k, v in parameter.items():
        if isinstance(v, (float, int)):
            v = [v]

        output[k] = v

    output = list(dict(zip(parameter.keys(), step)) for step in product(*output.values()))

    return output


def run_sims(
        motion: str,
        distribution: str,
        ste: bool = True,
        spectrum: bool = False,
        exec_file: str = './rwsim',
        config_file: str = './config.txt',
        **kwargs
) -> None:

    # set positional arguments
    arguments = [exec_file, config_file, motion, distribution]

    if ste:
        arguments += ['--ste']
    if spectrum:
        arguments += ['--spectrum']

    # add optional parameters that overwrite those given by config file
    for k, v in kwargs.items():
        arguments += [f'-{k.upper()}', f'{v}']

    subprocess.run(arguments)


def find_config_file(config_path: str | pathlib.Path, varied_params: dict[str, float]) -> dict[str, float]:
    parameter = read_parameter_file(config_path)
    parameter.update(varied_params)

    return parameter


def read_parameter_file(path: str | pathlib.Path) -> dict[str, float]:
    path = pathlib.Path(path)
    if not path.exists():
        raise ValueError(f"No parameter file found at {path}")

    parameter_dict = {}
    with path.open('r') as f:
        for line in f.readlines():
            if line.startswith('#'):
                continue
            k, v = line.split('=')
            parameter_dict[k] = float(v)

    return parameter_dict