#  Copyright (c) 2020. BioPro. Scientific.

import inspect
from functools import wraps
from pathlib import Path
from typing import Callable, Any, Union, Tuple, Optional


def para_validator_build(para: Union[str, Tuple[str, ...]],
                         validator: Callable[..., Any],
                         write_back: bool = False):
    """validating decorator builder.

    :param para: parameter names
    :param validator: argument validator
    :param write_back: write the result of **validator** back to arguments list
    :return: instance method decorator
    """

    def _return(f):
        signature = inspect.signature(f)

        @wraps(f)
        def _validator(self, *args, **kwargs):
            bind = signature.bind(self, *args, **kwargs)

            if isinstance(para, str):
                p = bind.arguments[para]
                p = validator(self, p)

                if write_back:
                    bind.arguments[para] = p
            else:
                p = [bind.arguments[q] for q in para]
                validator(self, *p)

            return f(*bind.args, **bind.kwargs)

        return _validator

    return _return


def path_validator_build(path: str,
                         validator: Callable[[Any, Path], Optional[Path]],
                         write_back: bool = False,
                         imply_path: bool = True):
    """path validating decorator builder.

    :param path: path parameter name
    :param validator: path validator
    :param write_back: write the result of **validator** back to arguments list
    :param imply_path: allow path like argument.
    :return: instance method decorator
    """

    def _return(f):
        signature = inspect.signature(f)

        @wraps(f)
        def _validator(self, *args, **kwargs):
            bind = signature.bind(self, *args, **kwargs)

            p = bind.arguments[path]

            if imply_path and isinstance(p, str):
                p = Path(p)
                bind.arguments[path] = p

            p = validator(self, p)

            if write_back:
                bind.arguments[path] = p

            return f(*bind.args, **bind.kwargs)

        return _validator

    return _return