import re

from sqlalchemy.engine.row import Row


class SnakeCaseUtil:
		"""
		小驼峰形式(camelCase)转下划线形式(snake_case)工具方法
		"""
		
		@classmethod
		def camel_to_snake(cls, camel_str):
				"""
				小驼峰形式字符串(camelCase)转换为下划线形式字符串(snake_case)

				:param camel_str: 小驼峰形式字符串
				:return: 下划线形式字符串
				"""
				# 在大写字母前添加一个下划线，然后将整个字符串转为小写
				words = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', camel_str)
				return re.sub('([a-z0-9])([A-Z])', r'\1_\2', words).lower()
		
		@classmethod
		def transform_result(cls, result):
				"""
				针对不同类型将下划线形式(snake_case)批量转换为小驼峰形式(camelCase)方法

				:param result: 输入数据
				:return: 小驼峰形式结果
				"""
				if result is None:
						return result
				# 如果是字典，直接转换键
				elif isinstance(result, dict):
						return {cls.camel_to_snake(k): v for k, v in result.items()}
				# 如果是一组字典或其他类型的列表，遍历列表进行转换
				elif isinstance(result, list):
						return [
								cls.transform_result(row)
								if isinstance(row, (dict, Row))
								else (
										cls.transform_result({c.name: getattr(row, c.name) for c in row.__table__.columns}) if row else row
								)
								for row in result
						]
				# 如果是sqlalchemy的Row实例，遍历Row进行转换
				elif isinstance(result, Row):
						return [
								cls.transform_result(row)
								if isinstance(row, dict)
								else (
										cls.transform_result({c.name: getattr(row, c.name) for c in row.__table__.columns}) if row else row
								)
								for row in result
						]
				# 如果是其他类型，如模型实例，先转换为字典
				else:
						return cls.transform_result({c.name: getattr(result, c.name) for c in result.__table__.columns})