#!/usr/bin/env node
const path = require('path')
require('dotenv').config({path: path.join(__dirname, '../.env')})

const pg = require('../db/pg')
const newDB = require('../db')
const oldDB = require('./mongo')('mongodb://localhost/sos')

const createItems = require('./tasks/createItems')
const createUsers = require('./tasks/createUsers')
const uploadImages = require('./tasks/uploadImages')
const saveExcelDataFile = require('./tasks/writeExcelSheet')

async function doMigration() {
  const items = await oldDB.sock.find().lean().exec()
  const allUsers = await oldDB.user.find().populate('purchases').lean().exec()
  const carts = allUsers.map(u => u.purchases).flat()
  const coupons = await oldDB.coupon.find().lean().exec()

  const registeredUsers = allUsers.filter(user => user.email)

  console.log(`Loaded ${carts.length} purchases and ${registeredUsers.length} users`)

  console.log(`Inserting ${registeredUsers.length} users into the database`)
  const importAdmin = await createUsers(newDB, registeredUsers);
  console.log(`  Found user account ${importAdmin.uuid} (${importAdmin.email}) to attribute file uploads to`)

  console.log(`\nInserting ${items.length} items into database`)
  const itemImages = await createItems(newDB, items);

  const numImages = itemImages.map(({images}) => images.length).reduce((a,b) => b+a, 0)
  console.log(`\nImporting ${numImages} images into database`)
  await uploadImages(newDB, itemImages, importAdmin.uuid)

  console.log('\nWriting Excel data file')
  await saveExcelDataFile(allUsers, coupons, items, path.join(__dirname, './datafile.xlsx'))
}

doMigration()
  .catch(console.error)
  .finally(() => {
    pg.end()
    oldDB._connection.close()
  })