from django.db import models
import os, errno
from datetime import datetime
from random import randint

from api.utils import *
graphForAlgo = [
    ('optimize', 'optimize'),
    ('group', 'group'),
    ('predict', 'predict'),
]


class GraphManager(models.Manager):
    def checkDuplicate(self, token):
        try:
            self.get(tokne=token)
            return True
        except GraphToken.DoesNotExist:
            return False
        return True


class GraphToken(models.Model):
    # 用于访问图的验证码
    create_time = models.DateTimeField(auto_now_add=True)

    graph = models.ForeignKey(to="api.Graph", on_delete=models.CASCADE, related_name="own_tokens")
    token = models.CharField(max_length=8)

    objects = GraphManager()

    def checkExpire(self):
        now = datetime.now()
        diff = now - self.create_time
        if diff.days != 0 or diff.hours != 0 or diff.mins > 5:
            # 5分钟凭证过期
            return False
        else:
            return True

class GraphManager(models.Manager):
    def statistic(self, user):
      graphs = user.own_graphs.all()
      return {
          'amount': len(graphs),
      }

class Graph(models.Model):
    create_time = models.DateTimeField(auto_now_add=True)
    update_time = models.DateTimeField(auto_now=True)

    type = models.CharField(choices=graphForAlgo, default='optimize', max_length=16)
    # 根据算法不同，生成的图数据结构不同
    nodesMap = models.JSONField()
    edgeMap = models.JSONField()

    result = models.ForeignKey(to="api.Results", on_delete=models.CASCADE, related_name="own_graphs")
    user = models.ForeignKey(to="api.User", on_delete=models.CASCADE, related_name="own_graphs")


    objects = GraphManager()

    def generateToken(self):
        # 生成验证码
        token = GraphToken()
        token.graph = self
        token.token = ''.join([str(randint(0,9)) for n in range(6)])
        while(GraphToken.objects.checkDuplicate(token.token)){
            token.token = ''.join([str(randint(0,9)) for n in range(6)])
        }

    class Meta:
        app_label = 'api'