day 109结算中心.

from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey,GenericRelation
from django.contrib.contenttypes.models import ContentType
# Create your models here.

from django.db import models
__all__ =["User","Usertoken","Course","CourseDetail","Chapter","CourseSection","OftenAskedQuestion","PricePolicy"]

##认证模型
class User(models.Model):
    user=models.CharField(max_length=32)
    pwd =models.CharField(max_length=32)

class Usertoken(models.Model):
    user =models.OneToOneField("User")
    token=models.CharField(max_length=128)

#1.课程表
class  Course(models.Model):
    """
    课程表
    """
    title =models.CharField(verbose_name="课程名称",max_length=32)
    course_img =models.CharField(verbose_name="课程图片",max_length=64)
    level_choices=(
        (1,"初级"),
        (2,"中级"),
        (3,"高级"),
    )
    level =models.IntegerField(verbose_name="课程难易程度",choices=level_choices,default=1)

    #用GenericForeignKey反向查询，不会生成表字段,切勿删除.
    price_policy =GenericRelation("PricePolicy")
    asked_question =GenericRelation("OftenAskedQuestion")
    def __str__(self):
        return self.title

#2.课程详情表
class CourseDetail(models.Model):
    """
    课程详情
    """
    course =models.OneToOneField(to="Course")
    slogon=models.CharField(verbose_name="口号",max_length=255)
    recommend_courses =models.ManyToManyField(verbose_name="推荐课程",to="Course",related_name="rc",null=True,blank=True)

    def __str__(self):
        return "课程详情："+self.course.title

#3.章节表
class Chapter(models.Model):
    """
    章节
    """
    num= models.IntegerField(verbose_name="章节")
    name= models.CharField(verbose_name="章节名称",max_length=32)
    course =models.ForeignKey(verbose_name="所属课程",to= "Course")

    def __str__(self):
        return self.name

#4.课时表
class CourseSection(models.Model):
    """
    课时目录
    """
    chapter =models.ForeignKey("Chapter",related_name="course_sections")
    name =models.CharField(max_length=128)

    class Meta:
        verbose_name_plural="11.课时"

#5.常见问题表.#用到content-type
class OftenAskedQuestion(models.Model):
    """
    常见问题
    """
    content_type =models.ForeignKey(ContentType,
                                    limit_choices_to={"model__contains":"course"}) #关联 course or degree_course
    object_id =models.PositiveIntegerField()
    content_object =GenericForeignKey("content_type","object_id")

    question =models.CharField(max_length=255)
    answer =models.TextField(max_length=1024)

    def __str__(self):
        return "%s-%s"%(self.content_object,self.question)

    class Meta:
        unique_together=("content_type","object_id","question")
        verbose_name_plural="08.常见问题"

#6.价格课程表.#用到content-type
class PricePolicy(models.Model):
    """
    价格与课程的有效期表
    """
    content_type =models.ForeignKey(ContentType) #关联 course or degree_course
    object_id =models.PositiveIntegerField()
    content_object =GenericForeignKey("content_type","object_id")

    valid_period_choices= ((1,"1天"),(3,"3天"),
                           (7,"1周"),(14,"2周"),
                           (30,"1个月"),
                           (60,"2个月"),
                           (90,"3个月"),
                           (180,"6个月"),(210,"12个月"),
                           (540,"18个月"),(720,"24个月"),
                            )

    valid_period =models.SmallIntegerField(choices=valid_period_choices)
    price =models.FloatField()

    def __str__(self):
        return str(self.content_object)+ "====>"+str(self.price)


#优惠券表
class Coupon(models.Model):
    "优惠券生成规则 "
    name =models.CharField(max_length=64,verbose_name="活动名称")
    brief = models.TextField(blank=True,null=True,verbose_name="优惠券介绍")
    coupon_type_choice =((0,"立减劵"),(1,"满减券"),(2,"折扣卷"))
    coupon_type =models.SmallIntegerField(choices=coupon_type_choice,default=0,verbose_name="券类型")

    """
    通用：
        money_equivalent_value=300
        off_percent =null 
        minimum_consume =0 
        
    满减：
        money_equivalent_value =100
        off_percent=null
        minimum_consume =1000
    折扣：
        money_equivalent_value =0
        off_percent =79
        minimum_consume =0 
    """
    money_equivalent_value =models.IntegerField(verbose_name="等值货币",blank=True,null=True)
    off_percent= models.PositiveIntegerField("折扣百分比",help_text="只针对折扣卷，例7.9，写成79",blank=True,null=True)
    minimum_consume =models.PositiveIntegerField("最低消费",default=0,help_text="仅在满减卷时填写此字段")

    content_type =models.ForeignKey(ContentType,blank=True,null=True)
    object_id =models.PositiveIntegerField("绑定课程",blank=True,null=True,help_text="可以把优惠券和课程绑定")
    content_object =GenericForeignKey("content_type","object_id")

    quantity =models.PositiveIntegerField("数量（张）",default=1)
    open_date = models.DateField("优惠券领取开始时间")
    close_date =models.DateField("优惠券结束时间")
    valid_begin_date =models.DateField(verbose_name="有效期开始时间",blank= True,null=True)
    valid_end_date =models.PositiveIntegerField(verbose_name="有效期结束时间",blank=True,null=True)
    coupon_valid_days= models.PositiveIntegerField(verbose_name="优惠券有效期（天）",blank=True,null=True,
                                                   help_text="自优惠券被领开始算起")
    date =models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name_plural="31.优惠券生成记录"

    def __str__(self):
        return "%s(%s)"%(self.get_coupon_type_display(),self.name)

    def save(self,*args,**kwargs):
        if not self.coupon_valid_days or (self.valid_begin_date and self.valid_end_date):
            if self.valid_begin_date and self.valid_end_date:
                raise  ValueError("valid_end_date 有效期结束日期必须晚于 valid_begin_date")
            if self.coupon_valid_days ==0:
                raise ValueError("coupon_valid_days 有效期不能为0")
        if self.coupon_valid_days ==0:
            raise  ValueError("coupon_valid_days 有效期不能为0 ")
        if self.close_date <self.open_date:
            raise ValueError("close_date 优惠券领取结束时间必须晚于open_date优惠券领取开始时间")
        super(Coupon, self).save(*args,**kwargs)


class CouponRecord(models.Model):
    """优惠券发放，消费记录"""
    coupon =models.ForeignKey("Coupon")
    number =models.CharField(max_length=64,unique=True)
    user =models.ForeignKey("User",verbose_name="拥有者")
    status_choices =((0,"未使用"),(1,"已使用"),(2,"已过期"))
    status= models.SmallIntegerField(choices=status_choices,default=0)
    get_time =models.DateTimeField(verbose_name="领取时间",help_text="用户领取时间")
    used_time =models.DateTimeField(blank=True,null=True,verbose_name="使用时间")

    class Meta:
        verbose_name_plural ="32.用户优惠券"

    def __str__(self):
        return "%s-%s-%s"%(self.user,self.number,self.status)