import json
import os

from random import choices
from typing import List

from src.common import data_dir


class TestGenerator:
    """
    Wrapper to hold testing questions and serve up examples
    """
    questions: List[str] = None

    @classmethod
    def load_questions(cls, reload=False) -> None:
        """
        Load the available questions from the json file.
        Default to not re-loading if already done, but allow for the option to do so
        """
        if cls.questions is not None and not reload:
            return
        question_file = os.path.join(data_dir, 'json', 'test_questions.json')
        with open(question_file, 'r') as f:
            question_json = json.load(f)
        cls.questions = question_json['questions']

    @classmethod
    def question_count(cls) -> int:
        cls.load_questions()
        return len(cls.questions)

    @classmethod
    def get_random_questions(cls, n: int):
        """
        Return n random questions
        """
        return choices(cls.questions, k=n)