from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker

from tools.config_db import DB_CONFIG

"""
数据库操作工具类
"""


class sql_util:
    """
    Singleton class for managing MySQL database connection and operations
    """

    _instance = None

    def __new__(cls, *args, **kwargs):
        if not cls._instance:
            cls._instance = super(sql_util, cls).__new__(cls, *args, **kwargs)
        return cls._instance

    def __init__(self):
        self.engine = create_engine(
            f"mysql+mysqlconnector://{DB_CONFIG['user']}:{DB_CONFIG['password']}@{DB_CONFIG['host']}:{DB_CONFIG['port']}/{DB_CONFIG['db_name']}",
            max_overflow=0,
            pool_size=5,
            pool_timeout=30,
            pool_recycle=-1
        )
        self.SessionFactory = sessionmaker(bind=self.engine)
        self.session = self.SessionFactory()

    def execute_query(self, query, data=None):
        result = self.session.execute(text(query), data)
        return result

    def add_data(self, table_name, data):
        columns = ', '.join(data.keys())
        values = ', '.join([':%s' % key for key in data.keys()])
        query = f"INSERT INTO {table_name} ({columns}) VALUES ({values})"
        self.execute_query(query, data)
        self.session.commit()

    def delete_data(self, table_name, condition):
        query = f"DELETE FROM {table_name} WHERE {condition}"
        self.execute_query(query)
        self.session.commit()

    def update_data(self, table_name, condition, data):
        set_values = ', '.join([f"{key} = {data.get(key)}" for key in data.keys()])
        query = f"UPDATE {table_name} SET {set_values} WHERE {condition}"
        print(f'update sql: {query}')
        self.execute_query(query, data)
        self.session.commit()

    def search_data(self, table_name, columns=None, condition=None):
        column_str = '*' if columns is None else ', '.join(columns)
        query = f"SELECT {column_str} FROM {table_name}"
        if condition:
            query += f" WHERE {condition}"
        result = self.execute_query(query)
        return result.fetchall()

    def close_session(self):
        self.session.close()