"""Utility functions for pylinac."""
import decimal
import inspect
import os.path as osp
from collections import Iterable

import numpy as np

from pylinac.core.decorators import type_accept
from pylinac.core.io import is_valid_file


def typed_property(name, expected_type_or_tuple_of_types):
    """Type-enforced property. Python Cookbook 9.21 (3rd ed)."""
    storage_name = '_' + name

    @property
    def prop(self):
        return getattr(self, storage_name, None)

    @prop.setter
    def prop(self, value):
        if not isinstance(value, expected_type_or_tuple_of_types):
            raise TypeError("{} must be a {}. Got: {}".format(name, expected_type_or_tuple_of_types, type(value)))
        setattr(self, storage_name, value)

    return prop

def is_dicom(file):
    """Boolean specifying if file is a proper DICOM file.

    This function is a pared down version of read_preamble meant for a fast return.
    The file is read for a proper preamble ('DICM'), returning True if so,
    and False otherwise. This is a conservative approach.

    Parameters
    ----------
    file : str
        The path to the file.

    See Also
    --------
    pydicom.filereader.read_preamble
    pydicom.filereader.read_partial
    """
    is_valid_file(file, raise_error=True)
    fp = open(file, 'rb')
    preamble = fp.read(0x80)
    prefix = fp.read(4)
    if prefix == b"DICM":
        return True
    else:
        return False

def isnumeric(object):
    """Check whether the passed object is numeric in any sense."""
    return isinstance(object, (int, float, decimal.Decimal, np.number))

def is_iterable(object):
    """Determine if an object is iterable."""
    if isinstance(object, Iterable):
        return True
    else:
        return False

@type_accept(array=np.ndarray)
def array2logical(array, threshold):
    """Return a 'logical' (binary) version of the input array based on a threshold.

    Parameters
    ----------
    array : numpy.ndarray
        numpy array to be analyzed for conversion.
    threshold : int, float
        Specifies the threshold value. If an array value is below the
        threshold value, it is converted to 0, otherwise to 1.
    """
    return np.where(array >= threshold, 1, 0)

def go_up_dirlevel(levels=0):
    """Go up directory levels from where the caller file is located.

    Parameters
    ----------
    levels : int
        Specifies how many levels to go up. 0 goes to the current directory.
    """
    calling_file = inspect.stack()[1][1]
    calling_dir = osp.dirname(calling_file)
    new_dir = calling_dir
    while levels > 0:
        old_dir = new_dir
        new_dir = osp.dirname(old_dir)
        levels -= 1
    return new_dir

