const mysql = require("mysql");
const dbConfig = require("../config/db");
const query = sql => new Promise((resolve, reject) => {
  this.pool?.getConnection((err, conn) => {
    if (err) {
      console.log(err)
    } else {
      conn.query(sql, (err, result) => {
        if (err) {
          console.log(err)
          reject(err)
        } else {
          conn.release()
          resolve(result)
        }
      })
    }
  })
});
module.exports = {
  pool: null,
  init: () => {
    this.pool = mysql.createPool(dbConfig)
  },
  query,
  list: ({table, search, con}) => {
    let total = 0, records = []
    if (table) {
      const {current, size} = search, params = JSON.parse(JSON.stringify(search))
      delete params.current
      delete params.size
      const sqlCon = Object.keys(params).map(e => `and ${e}='${params[e]}'`).join(" ")
      return Promise.all([
        query(`select 1 from ${table} where name like '%${con}%' ${sqlCon}`).then(res => {
          return total = res.length
        }),
        query(`select * from ${table}  where name like '%${con}%' ${sqlCon} limit ${(current-1)*size},${size}`).then(res => {
          return records = res
        })
      ]).then(() => {
        return {records, total}
      })
    }
  },
  format: args => args.map(e => `${e.prop}`).join(" ")
}