import mysql, {MysqlError, PoolConnection} from 'mysql'
import {MysqlConnectOptionType, PojoType} from '../../../../type/type'
import { exception } from '../../../../util'

export default class DataSource{
    private connectionOption: MysqlConnectOptionType
    private static pool: any

    constructor(option: MysqlConnectOptionType = {
        host: 'rm-2zec525s5ubhd120k4o.mysql.rds.aliyuncs.com',
        user: 'zhujin',
        password: 'HrGGSnsWK8jyG5I4YYCy',
        database: 'demo'
    }){
        this.connectionOption = option
        this.initDataPool()
    }

    private initDataPool(): void{
        try{
            DataSource.pool || (DataSource.pool = mysql.createPool(this.connectionOption))
        }catch(err){
            exception((<Error>err).message)
        }
    }

    public async getConnection(): Promise<PoolConnection>{
        return new Promise((resolve: Function, reject: Function) => {
            if(DataSource.pool){
                DataSource.pool.getConnection((err: MysqlError, conn: PoolConnection) => {
                    if(err){
                        const {message} = err
                        reject(message)
                    }else{
                        (<any>conn).counter = 1
                        resolve(conn)
                    }
                })
            }else{
                reject('数据源未初始化！')
            }
        })
    }
}