const mysql = require('koa-mysql')
const config = require('../config.js')
const pool = mysql.createPool(config.mysql_config)
const pool_remote = mysql.createPool(config.db_remote)
const pool_remote_server = mysql.createPool(config.db_remote_server)
const pool_map = {'master':pool,'remserver':pool_remote_server, 'remote':pool_remote}

let query = function(sql, values) {
  console.log(sql,"sql")
  return new Promise((resolve, reject) => {
    pool.getConnection(function(err, connection) {
      if (err) {
        reject(err)
      } else {
        connection.query(sql, values, (err, rows) => {
          if (err) {
            reject(err)
          } else {
            resolve(rows)
          }
          connection.release()
        })
      }
    })
  })
}

/**
 * 执行并返回LAST_INSERT_ID， 用于插入后返回自增id => new_id
 * @param {*} sql
 * @param {*} values
 */
let queryNewId = function(sql, values) {
  console.log(sql)
  return new Promise((resolve, reject) => {
    pool.getConnection(function(err, connection) {
      if (err) {
        reject(err)
      } else {
        connection.query(sql, values, (err, rows) => {
          if (err) {
            reject(err)
          } else {
            connection.query(
              `select LAST_INSERT_ID() as new_id;`,
              values,
              (err, rows) => {
                resolve(rows)
              }
            )
          }
          connection.release()
        })
      }
    })
  })
}

let queryproc = function(sql, values) {
  console.log(sql)
  return new Promise((resolve, reject) => {
    pool.getConnection(function(err, connection) {
      if (err) {
        reject(err)
      } else {
        connection.query(sql, function(err, results) {
          if (err) {
             throw err;
          }
          console.log('********************************************')
          console.log(results)
          resolve(results)
          connection.release()
        })
      }
    })
  })
}

let query_data = function(sql, remote_db, values) {
  console.log(sql)
  return new Promise((resolve, reject) => {
    pool_map[remote_db].getConnection(function(err, connection) {
      if (err) {
        reject(err)
      } else {
        connection.query(sql, values, (err, rows) => {
          if (err) {
            reject(err)
          } else {
            resolve(rows)
          }
          connection.release()
        })
      }
    })
  })
}

module.exports = {
  query,
  queryNewId,
  queryproc,
  query_data
}