#!/usr/bin/env python
# -*- coding:utf-8 -*-

"""
 some common tools or fuctions your api project maybe need!
"""

from werkzeug.routing import BaseConverter
from datetime import datetime as cdatetime
from datetime import date, time
from flask_sqlalchemy import Model
from sqlalchemy import DateTime, Numeric, Date, Time
import json


# 定义正则转换器
class ReConverter(BaseConverter):
 """"""

 def __init__(self, url_map, regex):
 # 调用父类初始化方法
 super(ReConverter, self).__init__(url_map)

 # 保存正则表达式
 self.regex = regex


def put_remove_none(**args):
 """
 PUT方法更新时,如果参数不是必填,用reqparse检验参数会将数据转为空,
 数据库有的字段可能不允许为空,故用该方法解决
 :param args: 原始数据字典
 :return: 除去None数据的字典
 """
 for key in list(args.keys()):
 if args[key] is None or args[key] == '':
 del args[key]
 continue

 args = dict(args)
 return args


# flask-sqlachemy查询结果(对象)转换为字典,下面的所有方法为一个模块,使用时直接调用该方法即可
def query_to_dict(models):
 if isinstance(models, list):
 if not models:
 return []
 if isinstance(models[0], Model):
 lst = []
 for model in models:
 gen = model_to_dict(model)
 dit = dict((g[0], g[1]) for g in gen)
 lst.append(dit)
 return lst
 else:
 res = result_to_dict(models)
 return res
 else:
 if isinstance(models, Model):
 gen = model_to_dict(models)
 dit = dict((s[0], s[1]) for s in gen)
 return dit
 else:
 res = dict(zip(models.keys(), models))
 find_datetime(res)
 return res


# 当结果为result对象列表时,result有key()方法
def result_to_dict(results):
 res = [dict(zip(r.keys(), r)) for r in results]
 # 这里r为一个字典,对象传递直接改变字典属性
 for r in res:
 find_datetime(r)
 return res


def model_to_dict(model): # 这段来自于参考资源
 for col in model.__table__.columns:
 if isinstance(col.type, DateTime):
 value = convert_datetime(getattr(model, col.name))
 elif isinstance(col.type, Numeric):
 value = float(getattr(model, col.name))
 else:
 value = getattr(model, col.name)
 yield (col.name, value)


def find_datetime(value):
 for v in value:
 if isinstance(value[v], cdatetime):
 value[v] = convert_datetime(value[v]) # 这里原理类似,修改的字典对象,不用返回即可修改


def convert_datetime(value):
 """
 数据库datetime类型转时间字符串
 :param value:
 :return:
 """
 if value:
 if isinstance(value, (cdatetime, DateTime)):
 return value.strftime("%Y-%m-%d %H:%M:%S")
 elif isinstance(value, (date, Date)):
 return value.strftime("%Y-%m-%d")
 elif isinstance(value, (Time, time)):
 return value.strftime("%H:%M:%S")
 else:
 return ""


def is_json(json_str):
 """
 验证json字符串是否合法
 :param json_str:
 :return:
 """
 try:
 json.loads(json_str)
 except ValueError:
 return False
 return True


def list_to_tree(id, parent_id, data):
 """
 将列表结构数据转换为列表树状结构
 :param id: 主键id 字符串
 :param parentid: 父id 字符串
 :param data:要转换的列表结构数据
 :return:转换后的列表树状结构数据
 """
 res = {}
 for index, value in enumerate(data):
 data[index][id] = int(data[index][id])
 data[index][parent_id] = int(data[index][parent_id])
 for v in data:
 # 以id为key,存储当前元素数据
 res.setdefault(v[id], v)
 for v in data:
 res.setdefault(v[parent_id], {}).setdefault('Children', []).append(v)
 # 这里默认的关联关系,v的内存地址是一致的,所以后续修改只后,关联的结构也会变化。
 return res[0]['Children']


def tree(data, root, root_field, node_field):
 """
 解析list数据为树结构
 :param data: 被解析的数据
 :param root: 根节点值
 :param root_field: 根节点字段
 :param node_field: 节点字段
 :return: list
 """
 for index, value in enumerate(data):
 data[index][node_field] = int(data[index][node_field])
 data[index][root_field] = int(data[index][root_field])

 l = []
 for i in data:
 if i.get(root_field) == root:
 l.append(i)
 for i in data:
 node = i.get(node_field)
 children = []
 for j in data:
 parent = j.get(root_field)
 if node == parent:
 children.append(j)
 i['Children'] = children
 return l