"""UItility functions facilitate making unit testing easier and less brittle."""

import factory
import faker
import random
import re
import string
import unicodedata
from io import BytesIO
from email.message import Message
from email.mime.text import MIMEText
from numpy.random import randint
from PIL import Image
from typing import Tuple, Any


def strip_accents(text):
    """
    Strip accents from input String. (only works on Pythin 3

    :param text: The input string.
    :type text: String.

    :returns: The processed String.
    :rtype: String.
    """
    text = unicodedata.normalize('NFD', text)
    text = text.encode('ascii', 'ignore')
    text = text.decode("utf-8")
    return str(text)


def text_to_id(text):
    """
    Convert input text to id.

    :param text: The input string.
    :type text: String.

    :returns: The processed String.
    :rtype: String.
    """
    text = strip_accents(text.lower())
    text = re.sub('[ ]+', '_', text)
    text = re.sub('[^0-9a-zA-Z_-]', '', text)
    return text


def get_random_string(length: int=16) -> str:
    return "".join(
        [random.choice(string.ascii_letters + string.digits) for n in range(length)]
    )


def generate_random_image(image_format, array_dims):
    """
    Creates an image from a random array.
    
    :param image_format: An image format (PNG or JPEG).
    :param array_dims: A tuple with array dimensions.
    
    :returns: A byte string with encoded image
    :rtype: bytes
    """
    image_bytes = randint(low=0, high=255, size=array_dims, dtype='uint8')
    io = BytesIO()
    image_pil = Image.fromarray(image_bytes)
    image_pil.save(io, image_format, subsampling=0, quality=100)
    return io.getvalue()


def get_random_image(image_format: str="PNG", size: int=5):
    """
    Returns a random image.
    
    Args:
      image_format: An image format (PNG or JPEG).
    
    Returns:
      A string with encoded image
    """
    return generate_random_image(image_format, (size, size, 3))


def get_fake(provider: str, locale: str = "en_US", min_length: int = 5) -> Any:
    """
    Generates a random string, float, integer etc based on provider
    Provider can be "text', 'sentence',  
      e.g. `get_fake('name')` ==> 'Buzz Aldrin' 
    """
    return factory.Faker(provider).evaluate({}, None, {'locale': locale,})


def generate_email_address(locale: str="en_US") -> Tuple[str, str, str]:
    """
    Generate an email address making sure that the email address itself contains only ascii
    """
    fake = faker.Faker(locale=locale)
    first_name = fake.first_name()
    last_name = fake.last_name()
    first_name.replace(' ', '').encode("ascii", "ignore").lower()
    email_address = "{}.{}@{}".format(
        first_name.replace(' ', '').encode("ascii", "ignore").lower().decode(),
        last_name.replace(' ', '').encode("ascii", "ignore").lower().decode(),
        get_random_string(5) + fake.domain_name()
    )
    return email_address, first_name, last_name


def generate_email(locale: str="en_US", content_type: str="text/html", use_short_email: bool=False) -> Message:
    """
    Generates an email includng headers
    """
    to_meta = generate_email_address(locale)
    from_meta = generate_email_address(locale)
    body = get_fake("text", locale=locale)
    
    msg = MIMEText(body)
    msg['Subject'] = get_fake("sentence", locale=locale)
    msg['From'] = from_meta[0] if use_short_email else "{} {}<{}>".format(from_meta[1], from_meta[2], from_meta[0])
    msg['To'] = to_meta[0] if use_short_email else "{} {}<{}>".format(to_meta[1], to_meta[2], to_meta[0])
    return msg.as_string()