#import logging
import time
import math
import datetime
import pymysql
import pymysql.cursors
import pymysql.connections
from dbutils.pooled_db import PooledDB
import logging


class DatabaseManager:
    def __init__(self, dbinfo):
        self.params = dbinfo

    def init_pool(self, dbinfo, maxcon=300, mincached=1):
        logging.info("Created a new connection pool.")

        self.params = dbinfo
        self.db = PooledDB(
            creator=pymysql,
            maxconnections=maxcon,
            mincached=mincached,
            blocking=True,
            host=self.params['host'],
            port=self.params['port'],
            user=self.params['user'],
            password=self.params['password'],
            database=self.params['db'],
            charset='utf8mb4',
            cursorclass=pymysql.cursors.DictCursor,
            autocommit=True)

    def close(self, conn, cursor):
        try:
            cursor.close()
            conn.close()
        except Exception as e:
            logging.error(f"Error closing connection: {str(e)}")

    def connect(self, db_name='tmnet'):
        sql = f"use {db_name}"
        conn = self.db.connection()
        cursor = conn.cursor()
        try:
            cursor.execute(sql)
            logging.info(f"Successfully change to MySQL database to {db_name}")
        except Exception as e:
            print(f"Error executing SQL: {str(e)}")
            return conn, cursor, e
        return conn, cursor, None

    def transaction_begin(self, db_name):
        conn, cursor, e = self.connect(db_name)
        conn.autocommit = False
        conn.begin()

    def transaction_commit(self, db_name):
        conn, cursor, e = self.connect(db_name)
        conn.commit()
        conn.autocommit = True

    def transaction_rollback(self, db_name):
        conn, cursor, e = self.connect(db_name)
        conn.rollback()
        conn.autocommit = True

    def show_tables(self, db_name):
        sql = "SHOW TABLES;"
        conn, cursor, e = self.connect(db_name)
        if e is not None:
            self.close(conn, cursor)
            return e
        try:
            cursor.execute(sql)
            results = cursor.fetchall()
            for item in results:
                print(item)
        except Exception as e:
            logging.error(f"Error executing SQL: {str(e)}")
        finally:
            self.close(conn, cursor)

    def do_select(self, sql_query, db_name):
        """
        Executes a SELECT SQL query and returns results as a list of dictionaries.
        """
        logging.debug(sql_query)
        conn, cursor, e = self.connect(db_name)
        if e is not None:
            self.close(conn, cursor)
            logging.error(f"Error executing SQL: {str(e)}")
            return []
        try:
            cursor.execute(sql_query)
            result_set = cursor.fetchall()
            data = [row for row in result_set]
        except Exception as e:
            logging.error(f"Error executing SQL: {str(e)}")
            data = []
        finally:
            self.close(conn, cursor)
        return data

    def connect2(self):
        return self.db.connection()