from courses.models import Course, Lesson


class InApiTeacher:
    @staticmethod
    def add_teacher(slug: str, token: str) -> Course:
        course = Course.objects.get(slug=slug)
        course.teacher_tokens.append(token)
        course.save()
        return course

    @staticmethod
    def delete_teacher(slug: str, token: str) -> None:
        course = Course.objects.get(slug=slug)
        course.teacher_tokens.remove(token)
        course.save()

    @staticmethod
    def get_token_list(slug: str) -> list:
        return Course.objects.get(slug=slug).teacher_tokens


class CourseProgressApi:
    @staticmethod
    def get_topic_lesson(course_token: str):
        course = Course.objects.get(token=course_token)
        return [[lesson.token for lesson in topic.lesson_set.all()] for topic in course.topic_set.all()]

    @staticmethod
    def get_next(course_token: str, lesson_list: list):
        """
        :param course_token:
        :param lesson_list:
        :return: следующий урок для прохождения и требует ли он валидации
        """

        course = Course.objects.get(token=course_token)
        acc = []
        include_lesson = False
        reversed_list = course.get_lesson_list()[::-1]
        for lesson_idx, lesson in enumerate(reversed_list):
            prev_idx = lesson_idx - 1
            if include_lesson and not lesson.token in lesson_list:
                acc.append((lesson.token, lesson.is_hm))

            if lesson.token in lesson_list and not include_lesson:
                acc.append((reversed_list[prev_idx].token, reversed_list[prev_idx].is_hm))
                include_lesson = True

        return acc


class CourseParamsApi:

    def __init__(self, token):
        self.__course = Course.objects.get(token=token)

    def get_slug_and_title(self):
        return {"title": self.__course.title, "slug": self.__course.slug}

    def get_length(self):
        return self.__course.topic_set.count()

    def get_topic_by_lesson(self, lesson_token):
        for idx, topic in enumerate(self.__course.topic_set.all()):
            if topic.lesson_set.filter(token=lesson_token).exists():
                return {"title": topic.title, "idx": idx}