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

# file:tablesMetadata.py.py
# author:Nathan
# datetime:2021年8月26日 14:56
# software: PyCharm

"""
 Get metadata of all tables
"""
import json


class TableMetadata(object):
 with open('config/default_table_config.json', 'r', encoding='utf-8') as f:
 DEFAULT_CONFIG = f.read()

 with open('config/datatype_map.json', 'r', encoding='utf-8') as f:
 TYPE_MAPPING = json.load(f)

 @classmethod
 def get_tables_metadata(cls, metadata, reflection_views, table_config=DEFAULT_CONFIG) -> dict:
 """
 获取数据库数据
 :param metadata: sqlalchemy元数据
 :param reflection_views: 需要反射的视图名称列表
 :param table_config: 表配置
 """

 table_config = table_config if isinstance(table_config, dict) else json.loads(table_config)

 # Get all tables object
 table_objs = metadata.tables.values()
 table_dict = {}

 # Traverse each table object to get corresponding attributes to form an attribute dictionary
 for table in table_objs:

 table_name = str(table)
 table_dict[table_name] = {}
 table_dict[table_name]['table_name'] = table_name

 # 如果该表是一个视图
 if table_name in reflection_views:
 table_dict[table_name]['is_view'] = True
 table_dict[table_name]['filter_field'] = []

 # 遍历所有的视图配置
 for view in table_config['view']:
 if table_name == view['view']:
 # 遍历配置中的字段
 for field in view['filter_field']:
 # 如果字段被勾选,则将字段名称和类型添加进字典中
 if field['ischecked']:
 table_dict[table_name]['filter_field'].append({
 "field_name": field['field_name'],
 "field_type": field['field_type']
 })

 table_dict[table_name]['columns'] = []
 for column in table.columns.values():
 temp_column_dict = {
 "field_name": str(column.name),
 }

 for type_ in cls.TYPE_MAPPING:
 if str(metadata.bind.url).split('+')[0] != type_['database']:
 continue
 for python_type, sql_type_list in type_['data_map'].items():
 if str(column.type).lower() in sql_type_list:
 temp_column_dict['field_type'] = python_type
 break

 temp_column_dict.setdefault('field_type', 'str')
 table_dict[table_name]['columns'].append(temp_column_dict)

 continue

 table_dict[table_name]['is_view'] = False
 table_dict[table_name]['logical_delete_mark'] = ""
 table_dict[table_name]['business_key'] = {}

 # Check if the business key exists and check record deletion method
 for config in table_config['table']:
 if config['table'] == table_name and config['logicaldeletemark'] != '':
 table_dict[table_name]['logical_delete_mark'] = config['logicaldeletemark']

 if config['table'] == table_name and config['businesskeyname'] != '':
 table_dict[table_name]['business_key']['column'] = config['businesskeyname']
 table_dict[table_name]['business_key']['rule'] = config['businesskeyrule']

 # 需要RSA加密的字段
 table_dict[table_name]['rsa_columns'] = []
 for rsa_table in table_config['table']:
 if rsa_table['table'] == table_name:
 for rsa_colume in rsa_table['field']:
 if rsa_colume['field_encrypt']:
 table_dict[table_name]['rsa_columns'].append(rsa_colume['field_name'])

 from sqlalchemy.engine import reflection
 insp = reflection.Inspector.from_engine(metadata.bind)
 # 初始化为空列表
 table_dict[table_name]['primaryKey'] = insp.get_pk_constraint(table_name)['constrained_columns']
 table_dict[table_name]['columns'] = {}

 # Traverse each columns to get corresponding attributes
 for column in table.columns.values():
 table_dict[table_name]['columns'][str(column.name)] = {}
 table_dict[table_name]['columns'][str(column.name)]['name'] = str(column.name)

 for type_ in cls.TYPE_MAPPING:
 if str(metadata.bind.url).split('+')[0] != type_['database']:
 continue
 for python_type, sql_type_list in type_['data_map'].items():
 if str(column.type).lower() in sql_type_list:
 table_dict[table_name]['columns'][str(column.name)]['type'] = python_type
 break
 table_dict[table_name]['columns'][str(column.name)].setdefault('type', 'str')

 # 是否自动递增
 table_dict[table_name]['columns'][str(column.name)][
 'is_autoincrement'] = True if column.autoincrement is True else False

 # 存在复合主键
 if len(table_dict[table_name]['primaryKey']) > 1:
 table_dict[table_name]['business_key'] = {}
 else:
 # 如果主键不是自增的,则将业务主键设置为主键
 if str(column.name) in table_dict[table_name]['primaryKey'] and not \
 table_dict[table_name]['columns'][str(column.name)]['is_autoincrement']:
 table_dict[table_name]['business_key']['column'] = str(column.name)

 # 是否可以为空
 table_dict[table_name]['columns'][str(column.name)]['nullable'] = column.nullable

 # 是否存在默认值
 table_dict[table_name]['columns'][str(column.name)][
 'is_exist_default'] = True if column.server_default is not None else False

 return table_dict