# python standard library
import random
from  datetime import datetime

# this project
import questions


# contains the kowledge state of each student.
class Knowledge(object):
    def __init__(self):
        self.factory = questions.QuestionFactory()
        self.factory.load_files(['questions.yaml'], 'demo') # FIXME
        self.current_question = None

    def get_current_question(self):
        return self.current_question

    # --- generates a new question given the current state
    def new_question(self):
        # FIXME
        if self.current_question is None or self.current_question.get('grade', 0.0) > 0.9999:
            questions = list(self.factory)
            self.current_question = self.factory.generate(random.choice(questions))
            self.current_question['start_time'] = datetime.now()

            return self.current_question

    # --- checks answer and updates knowledge state
    #     returns current question with correction, time and comments updated
    def check_answer(self, answer):
        question = self.current_question
        if question is not None:
            question['finish_time'] = datetime.now()
            question.correct(answer)
        return question