from django.db import models
from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils.html import escape,mark_safe

class User(AbstractUser):
    is_student = models.BooleanField(default= False)
    is_teacher = models.BooleanField(default= False)

class Subject(models.Model):
    name = models.CharField(max_length=30)
    color = models.CharField(max_length=7,default='#007bff')

    def __str__(self):
        return self.name

    def get_html_badge(self):
        name = escape(self.name)
        color = escape(self.color)
        html = '<span class="badge badge-primary" style="background-color: %s">%s</span>'%(color,name)
        return mark_safe(html)

class Quiz(models.Model):
    owner = models.ForeignKey(User,related_name='quizzes',on_delete=models.CASCADE)
    name = models.CharField(max_length=255)
    subject = models.ForeignKey(Subject,related_name='quizzes',on_delete=models.CASCADE)

    def __str__(self):
        return self.name

class Question(models.Model):
    quiz = models.ForeignKey(Quiz,related_name='questions',on_delete=models.CASCADE)
    text = models.CharField('Question',max_length=255)

    def __str__(self):
        return self.text

class Answer(models.Model):
    question = models.ForeignKey(Question,on_delete=models.CASCADE,related_name='answers')
    text = models.CharField('Answer',max_length=255)
    is_correct = models.BooleanField('Correct answer',default=False)

    def __str__(self):
        self.text

class Student(models.Model):
    user = models.OneToOneField(User,on_delete=models.CASCADE, primary_key=True)
    quizzes = models.ManyToManyField(Subject,through='TakenQuiz')
    interests = models.ManyToManyField(Subject,related_name='interested_students')

    def get_unanswered_questions(self,quiz):
        answered_questions = self.quiz_answers.filter(answer__question__quiz = quiz).values_list('answer__question__pk',flat=True)
        questions = quiz.questions.exclude(pk=answered_questions).order_by('text')
        return questions

    def __str__(self):
        return self.user.username

class TakenQuiz(models.Model):
    student = models.ForeignKey(Student,related_name='taken_quizzes')
    quiz = models.ForeignKey(Quiz,related_name='taken_quizes',on_delete=models.CASCADE)
    score = models.FloatField()
    date = models.DateTimeField(auto_now_add=True)

class StudentAnswer(models.Model):
    student = models.ForeignKey(Student,related_name='quiz_answers')
    answer = models.ForeignKey(Answer,on_delete=models.CASCADE,related_name="+")