const pg = require('../pg')
const joinjs = require('join-js').default;
const debug = require('debug')('sos:db:order')
const mappings = require('../mappings')
const dbUtil = require('../util')

const {DateTime} = require('luxon')
const easypost = new (require('@easypost/api'))(process.env.EASYPOST_API_KEY);

const order = module.exports = {}

order.create = async function(cart_uuid){
  const query = {
    text: 'select * from sos.create_order($1)',
    values: [cart_uuid]
  }

  debug(query);

  const {rows} = await pg.query(query)
  return joinjs.map(rows, mappings, 'orderMap', 'order_')[0];
}

order.findForCart = async function(cart_uuid) {
  const query = {
    text: 'select * from sos.find_order_for_cart($1)',
    values: [cart_uuid]
  }

  debug(query)

  const {rows} = await pg.query(query)
  return joinjs.map(rows, mappings, 'orderMap', 'order_')[0];
}

order.addAddress = async function (transaction, address){
  // Get parcel size
  const parcel = {
    weight: .2 * transaction.cart.items.length,
    width: 10,
    length: transaction.cart.items.length,
    height: 3
  }

  // Create shipment
  const epShipment = new easypost.Shipment({
    to_address: address.easypost_id,
    from_address: {
      street1: '11381 N. Sampson Drive',
      city: 'Highland',
      state: 'UT',
      zip: '84003',
      country: 'US'
    },
    parcel
  })

  await epShipment.save()

  // Get shipping price (as cents)
  const lowestRate = epShipment.lowestRate(['USPS'])
  const price = parseFloat(lowestRate && lowestRate.retail_rate) * 100
  if(!price)
    throw new Error("Unable to estimate price");

  // TODO: Update with real tax rate
  const tax = epShipment.to_address.state === 'UT'
    ? 200
    : null

  // Update database
  const query = {
    text: 'select * from sos.add_address_to_order($1, $2, $3, $4)',
    values: [transaction.uuid, address.uuid, price, tax]
  }

  debug(query)
  const {rows} = await pg.query(query)

  return joinjs.map(rows, mappings, 'orderMap', 'order_')[0];
}

order.addCoupon = function(transaction, coupon) {
  // Check coupon validity
  const couponExpireTime = DateTime.fromJSDate(coupon.valid_until)
  if(couponExpireTime.diffNow().as('seconds') < 0)
    throw new Error("Coupon has expired");

  const {item_total_price} = transaction
  let discount = 0;

  if(coupon.flat_discount_cents)
    discount = coupon.flat_discount_cents;

  if(coupon.percent_discount)
    discount = Math.ceil(item_total_price * coupon.percent_discount / 100)

  if(coupon.per_sock_discount_cents)
    discount = transaction.cart.items
      // For each item type, create an array of length n (number of items of that type in cart)
      // where each index is initialized to the item price
      .map(({item, count}) => new Array(count).fill(item.price_cents))
      // Flatten to just be all prices
      .flat()
      // For each price, convert it to the per-item discount (max of item price)
      .map(price => Math.min(price, coupon.per_sock_discount_cents))
      // Sum all the discounts
      .reduce((a,c) => (a+c))

  if(coupon.number_of_socks_free)
    discount = transaction.cart.items
      // For each item type, create an array of length n (number of items of that type in cart)
      // where each index is initialized to the item price
      .map(({item, count}) => new Array(count).fill(item.price_cents))
      // Flatten to just be all prices
      .flat()
      // Order so the most expensive are at the front
      .sort((a,b) => (b-a))
      // Keep only first n items
      .slice(0, coupon.number_of_socks_free)
      // Sum the item costs for total discount
      .reduce((a,c) => (a+c))

  return dbUtil.executeFunction({
    name: 'add_coupon_to_transaction',
    params: [
      transaction.uuid,
      coupon.uuid,
      discount
    ],
    returnType: 'order',
    single: true
  })
}