import random
from typing import Optional
from openpyxl.reader.excel import load_workbook


class Question:
    def __init__(self, no: str, topic: str):
        self._no: str = no
        self._topic: str = topic

    def __str__(self):
        return f"Question<No: {self._no}, Topic: {self._topic}>"

    def __repr__(self):
        return self.__str__()

    @staticmethod
    def load_from_csv(path: Optional[str] = None) -> list['Question']:
        questions = []
        with open(path if path else '../files/questions.csv', encoding='gbk') as f:
            for line in f.readlines():
                questions.append(Question(*line.strip('\n').split(',')))
        return questions

    @property
    def no(self) -> str:
        return self._no

    @property
    def topic(self) -> str:
        return self._topic


class Student:
    def __init__(self, no: str, so: str, name: str, major: str, class_name: str):
        self._no: str = no
        self._so: str = so
        self._name: str = name
        self._major: str = major
        self._class_name: str = class_name
        self._picked_questions: list[Question] = []

    def __str__(self):
        return f"Student<No: {self._no}, SO: {self._so}, Name: {self._name}, Major: {self._major}, Class: {self._class_name}>"

    def __repr__(self):
        return self.__str__()

    @staticmethod
    def load_from_xls(path: str) -> list['Student']:
        wb = load_workbook(path, read_only=True)
        ws = wb.active
        students = []
        for row in ws.iter_rows(min_row=6, max_col=5, values_only=True):
            students.append(Student(*row))
        return [x for x in students if x.valid]

    @property
    def valid(self) -> bool:
        return bool(self._no and self._so and self._name and self._major and self._class_name)

    @property
    def picked_questions(self) -> list[Question]:
        return self._picked_questions

    @property
    def no(self) -> str:
        return self._no

    @property
    def so(self) -> str:
        return self._so

    @property
    def name(self) -> str:
        return self._name

    @property
    def major(self) -> str:
        return self._major

    @property
    def class_name(self) -> str:
        return self._class_name

    def pick_question(self, questions: list[Question], num: int = 3) -> None:
        if len(questions) < num:
            raise ValueError("Not enough questions to pick from.")
        self._picked_questions = random.sample(questions, num)


class Course:
    def __init__(self, name: str):
        self._name = name

    def __str__(self):
        return f"Course<Name: {self._name}>"

    def __repr__(self):
        return self.__str__()

    @staticmethod
    def load_from_xls(path: str) -> 'Course':
        wb = load_workbook(path, read_only=True)
        ws = wb.active
        name: str = ws['E3'].value
        return Course(name[5:])

    @property
    def name(self) -> str:
        return self._name


if __name__ == '__main__':
    ...