from django.db import models

from teacher.models import Teacher
from Student.models import Student


# Create your models here.
class Course(models.Model):
    cid = models.AutoField(primary_key=True, verbose_name="课程编号", name="cid")
    name = models.CharField(max_length=255, verbose_name="课程名称", name="name", blank=True)
    type = models.CharField(max_length=128, verbose_name="课程类型", name="type", blank=True)
    credit = models.IntegerField(verbose_name="课程学分", name="credit")
    tid = models.ForeignKey(Teacher, to_field="tid", on_delete=models.CASCADE, name="tid")

    class Meta:
        db_table = "course"
        verbose_name = "课程"
        verbose_name_plural = verbose_name

    def to_dict(self):
        return {"cid": self.cid, "c_name": self.name, "type": self.type, "credit": self.credit,
                "tid": self.tid}


class SC(models.Model):
    sid = models.ForeignKey(Student, to_field="sid", on_delete=models.CASCADE, name="sid")
    cid = models.ForeignKey(Course, to_field="cid", on_delete=models.CASCADE, name="cid")
    middle_grade = models.IntegerField(name="middle_grade")
    end_grade = models.IntegerField(name="end_grade")

    def to_dict(self):
        return {"sid": self.sid, "cid": self.cid, "middle_grade": self.middle_grade, "end_grade": self.end_grade}

    class Meta:
        db_table = "sc"
        verbose_name = "选课"
        verbose_name_plural = verbose_name
        unique_together = ("sid", "cid")