#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
数据库连接池模块
"""
import pymysql
from dbutils.pooled_db import PooledDB
from flask import current_app

# 全局连接池
_pool = None

def get_pool():
    """获取数据库连接池"""
    global _pool
    if _pool is None:
        _pool = PooledDB(
            creator=pymysql,
            maxconnections=20,
            mincached=2,
            maxcached=5,
            blocking=True,
            ping=1,
            host=current_app.config['DB_HOST'],
            port=current_app.config['DB_PORT'],
            user=current_app.config['DB_USER'],
            password=current_app.config['DB_PASSWORD'],
            database=current_app.config['DB_NAME'],
            charset='utf8mb4',
            cursorclass=pymysql.cursors.DictCursor
        )
    return _pool

def get_connection():
    """获取数据库连接"""
    return get_pool().connection()

def init_db(app):
    """初始化数据库连接池"""
    global _pool
    with app.app_context():
        _pool = PooledDB(
            creator=pymysql,
            maxconnections=20,
            mincached=2,
            maxcached=5,
            blocking=True,
            ping=1,
            host=app.config['DB_HOST'],
            port=app.config['DB_PORT'],
            user=app.config['DB_USER'],
            password=app.config['DB_PASSWORD'],
            database=app.config['DB_NAME'],
            charset='utf8mb4',
            cursorclass=pymysql.cursors.DictCursor
        )

def close_db():
    """关闭数据库连接池"""
    global _pool
    if _pool is not None:
        _pool.closeAll()
        _pool = None