import logging
import os

import pymysql
from dbutils.pooled_db import PooledDB
from pymysql.cursors import DictCursor

logger = logging.getLogger(__name__)

# 连接池公共参数（可自行调大 maxconnections 等）
_POOL_COMMON = {
    "maxconnections": 10,
    "mincached": 2,
    "maxcached": 5,
    "blocking": True,
    # 取出连接前 ping，避免服务端超时断开后仍使用死连接（pymysql 支持）
    "ping": 1,
}


def _env_port(name, default="3306"):
    """环境变量端口；空串/非数字时回退默认值，避免 int() 抛错导致池子无法创建。"""
    raw = os.environ.get(name)
    if raw is None or not str(raw).strip():
        return int(default)
    try:
        return int(raw)
    except ValueError:
        logger.warning("环境变量 %s=%r 不是合法端口，使用默认 %s", name, raw, default)
        return int(default)


def _create_pool(
        host,
        port,
        user,
        password,
        database,
):
    if not host or not str(host).strip():
        raise ValueError("MySQL host 不能为空")
    if not database or not str(database).strip():
        raise ValueError("MySQL database 不能为空")
    return PooledDB(
        creator=pymysql,
        cursorclass=DictCursor,
        charset="utf8mb4",
        host=host,
        port=int(port),
        user=user,
        password=password,
        database=database,
        **_POOL_COMMON,
    )


class _MySQLPoolBase:
    """共用的取连接、写库、读库逻辑，避免两套类复制粘贴。"""

    def __init__(self, pool):
        self.pool = pool

    def get_conn(self):
        return self.pool.connection()

    def _close(self, conn, cursor) -> None:
        try:
            if cursor:
                cursor.close()
        finally:
            if conn:
                conn.close()

    def _write(self, fn, *args, **kwargs):
        conn = self.get_conn()
        cursor = conn.cursor()
        try:
            result = fn(cursor, *args, **kwargs)
            conn.commit()
            return result
        except Exception as e:
            logger.error("SQL 执行错误: %s", e)
            conn.rollback()
            return None
        finally:
            self._close(conn, cursor)

    def execute_many(self, sql, data):
        rows = list(data)
        if not rows:
            return

        def _do(c, s, d):
            c.executemany(s, d)

        self._write(_do, sql, rows)

    def execute_one(self, sql, data):
        def _do(c, s, d):
            c.execute(s, d)

        self._write(_do, sql, data)

    def update_data(self, sql, data):
        self.execute_one(sql, data)

    def select_data(self, sql,data=None):
        """只读查询，不应 commit。"""
        conn = self.get_conn()
        cursor = conn.cursor()
        try:
            if data:
                cursor.execute(sql,data)
                return cursor.fetchall()
            else:
                cursor.execute(sql)
                return cursor.fetchall()
        except Exception as e:
            logger.error("SQL 查询错误: %s", e)
            return []
        finally:
            self._close(conn, cursor)

    def execute(self, sql, data=None):
        """通用写操作，返回受影响行数；失败返回 0。"""

        def _do(c, s, d):
            if d is not None:
                return c.execute(s, d)
            return c.execute(s)

        result = self._write(_do, sql, data)
        return result if isinstance(result, int) else 0


class MySQLPool(_MySQLPoolBase):
    """test2 库（可通过环境变量覆盖，便于部署；未设置则沿用原默认）。"""

    def __init__(self):
        pool = _create_pool(
            host=os.environ.get("MYSQL_TEST2_HOST", "47.119.164.65"),
            port=_env_port("MYSQL_TEST2_PORT", "3306"),
            user=os.environ.get("MYSQL_TEST2_USER", "test_c"),
            password=os.environ.get("MYSQL_TEST2_PASSWORD", "Dfwy@2025"),
            database=os.environ.get("MYSQL_TEST2_DB", "test2"),
        )
        super().__init__(pool)


class MySQLPool39(_MySQLPoolBase):
    """drug_retrieve 库。"""

    def __init__(self):
        pool = _create_pool(
            host=os.environ.get("MYSQL_DRUG_HOST", "39.108.116.125"),
            port=_env_port("MYSQL_DRUG_PORT", "3306"),
            user=os.environ.get("MYSQL_DRUG_USER", "drug_retrieve"),
            password=os.environ.get("MYSQL_DRUG_PASSWORD", "Pem287cwM58jNpe2"),
            database=os.environ.get("MYSQL_DRUG_DB", "drug_retrieve"),
        )
        super().__init__(pool)


class MySQLPoolOnline(_MySQLPoolBase):
    """drug_retrieve 库。"""

    def __init__(self):
        pool = _create_pool(
            host=os.environ.get("MYSQL_DRUG_HOST", "120.24.49.2"),
            port=_env_port("MYSQL_DRUG_PORT", "3306"),
            user=os.environ.get("MYSQL_DRUG_USER", "drug_retrieve"),
            password=os.environ.get("MYSQL_DRUG_PASSWORD", "ksCt3xm6chzdkafj"),
            database=os.environ.get("MYSQL_DRUG_DB", "drug_retrieve"),
        )
        super().__init__(pool)


if __name__ == "__main__":
    pool = MySQLPool()
    rows = pool.select_data("SELECT 1 AS one")
    print(rows)