from django.contrib.contenttypes.fields import GenericRelation
from django.db import models
from django.utils import timezone

from django.core.files.storage import FileSystemStorage
from django.conf import settings
from django.utils.html import format_html

from django.urls import reverse

from django.utils.translation import ugettext_lazy as _

from sortedm2m.fields import SortedManyToManyField

from generic.models import ExamBase, QuestionNote

import reversion

class Category(models.Model):
    category = models.CharField(max_length=200)

    def __str__(self):
        return self.category

class Question(models.Model):
    stem = models.TextField(
        blank=False,
        help_text="Stem of the question",
    )

    answer_help_text = "Answer (check for true, uncheck for false)"

    a = models.TextField(
        blank=False,
        help_text="The question text",
    )
    a_answer = models.BooleanField(
        help_text=answer_help_text, default=True
    )
    a_feedback = models.TextField(
        blank=True,
        help_text="Feedback for answer",
    )

    b = models.TextField(
        blank=False,
        help_text="The question text",
    )
    b_answer = models.BooleanField(
        help_text=answer_help_text, default=True
    )
    b_feedback = models.TextField(
        blank=True,
        help_text="Feedback for answer",
    )

    c = models.TextField(
        blank=False,
        help_text="The question text",
    )
    c_answer = models.BooleanField(
        help_text=answer_help_text, default=True
    )
    c_feedback = models.TextField(
        blank=True,
        help_text="Feedback for answer",
    )

    d = models.TextField(
        blank=False,
        help_text="The question text",
    )
    d_answer = models.BooleanField(
        help_text=answer_help_text, default=True
    )
    d_feedback = models.TextField(
        blank=True,
        help_text="Feedback for answer",
    )

    e = models.TextField(
        blank=False,
        help_text="The question text",
    )
    e_answer = models.BooleanField(
        help_text=answer_help_text, default=True
    )
    e_feedback = models.TextField(
        blank=True,
        help_text="Feedback for answer",
    )

    created_date = models.DateTimeField(default=timezone.now)

    author = models.ManyToManyField(
        settings.AUTH_USER_MODEL,
        blank=True,
        help_text="Author(s) of question",
        related_name="physics_authored_questions",
    )

    category = models.ForeignKey(
        Category, on_delete=models.SET_NULL, null=True, blank=True
    )

    notes = GenericRelation(QuestionNote)

    def __str__(self):
        return self.stem

    def clean(self):
        if self.a:
            self.a = self.a.strip()
        if self.b:
            self.b = self.b.strip()
        if self.c:
            self.c = self.c.strip()
        if self.d:
            self.d = self.d.strip()
        if self.e:
            self.e = self.e.strip()

    def get_absolute_url(self):
        return reverse("physics:question_detail", kwargs={"pk": self.pk})

    def get_answers(self):
        return (self.a_answer, self.b_answer, self.c_answer, self.d_answer, self.e_answer)

    def get_questions(self):
        return (self.a, self.b, self.c, self.d, self.e)


@reversion.register
class Exam(ExamBase):
    app_name = "rapids"
    
    exam_questions = SortedManyToManyField(
        Question, related_name="exams", blank="true"
    )

    time_limit = models.IntegerField(
        help_text="Exam time limit (in seconds)",
        blank=True,
        null=True,
    )

    recreate_json = None

    author = models.ManyToManyField(settings.AUTH_USER_MODEL,
                                    blank=True,
                                    help_text='Author of exam',
                                    related_name="physics_exam_author")



@reversion.register
class CidUserAnswer(models.Model):
    """User answers by candidate"""

    question = models.ForeignKey(
        Question, related_name="cid_user_answers", on_delete=models.CASCADE
    )
    a = models.BooleanField(blank=False)
    b = models.BooleanField(blank=False)
    c = models.BooleanField(blank=False)
    d = models.BooleanField(blank=False)
    e = models.BooleanField(blank=False)

    cid = models.IntegerField(blank=True, null=True)

    # Each user answer is associated with a particular exam
    exam = models.ForeignKey(
        Exam, related_name="cid_user_answers", on_delete=models.CASCADE, null=True
    )

    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)

    def __str__(self):
        return "{}/{}/{}".format(self.cid, self.exam, self.question.pk)

    def get_answers(self):
        return (self.a, self.b, self.c, self.d, self.e)

    def get_answer_scores(self):
        q = self.question

        if self.a == q.a_answer:
            score_a = 1
        else:
            score_a = 0

        if self.b == q.b_answer:
            score_b = 1
        else:
            score_b = 0

        if self.c == q.c_answer:
            score_c = 1
        else:
            score_c = 0

        if self.d == q.d_answer:
            score_d = 1
        else:
            score_d = 0

        if self.e == q.e_answer:
            score_e = 1
        else:
            score_e = 0

        return (score_a, score_b, score_c, score_d, score_e)