const router = module.exports = require('express-promise-router')()
const parseJSON = require('body-parser').json()
const db = require('../db')
const stripe = require('stripe')(process.env.STRIPE_PRIVATE_KEY);

const validate = require('./middleware/validators')

router.get('/', async (req, res) => {
  if(req.user)
    // TODO: Write this function
    return res.json(await db.order.findAllforUser(req.user.uuid))
  else
    return res.json(await db.order.findAllForSession(req.session.uuid))
})

router.use(require('./middleware/ensureCart'))

router.put('/', async (req, res) => {
  const order = await db.order.create(req.cart.uuid, req.sessionObj.uuid);
  res.json(order)
})

router.get('/current', async (req, res) => {
  const order = await db.order.findForCart(req.cart.uuid);
  res.json(order)
})

router.post('/current/address', parseJSON, validate.address, validate.handleApiError, async (req, res) => {
  const origOrder = await db.order.findForCart(req.cart.uuid);
  if(!origOrder) throw new Error("Unable to find current order");

  const currentTransaction = origOrder
    .transactions.find(transaction => (
      transaction.payment_state === 'started'
    ))

  const {name, street1, street2, city, state, zip, country} = req.body;

  // Create address, update order
  const address = await db.address.create(name, street1, street2, city, state, zip, country)
  const order = await db.order.addAddress(currentTransaction, address)

  res.json(order)
})

router.post('/current/coupon', parseJSON, validate.coupon, validate.handleApiError, async (req, res) => {
  const origOrder = await db.order.findForCart(req.cart.uuid);
  if(!origOrder) throw new Error("Unable to find current order");

  const coupon = await db.coupon.find(req.body.code)

  const currentTransaction = origOrder
    .transactions.find(transaction => (
      transaction.payment_state === 'started'
    ))

  const order = await db.order.addCoupon(currentTransaction, coupon)
  res.json(order)
})

router.post('/current/checkout/stripe', async (req, res) => {
  const order = await db.order.findForCart(req.cart.uuid);
  if(!order) throw new Error("Unable to find current order");

  const currentTransaction = order
    .transactions.find(transaction => (
      transaction.payment_state === 'started'
    ))

  const {item_total_price, shipping_price, tax_price, coupon_effective_discount} = currentTransaction
  const {free_shipping} = currentTransaction.coupon || {}

  const numberOfItems = currentTransaction.cart.items.map(i => i.count).reduce((a,b) => a+b)
  const itemPriceWithDiscount = item_total_price - (coupon_effective_discount || 0)
  const shippingPrice = (free_shipping ? 0 : shipping_price)

  const line_items = []

  if(itemPriceWithDiscount > 0)
    line_items.push({
      name: `Cart Total (${numberOfItems} item${numberOfItems > 1 ? 's' : ''})`,
      amount: itemPriceWithDiscount,
      currency: 'usd',
      quantity: 1
    })

  if(shippingPrice > 0)
    line_items.push({
      name: 'Shipping',
      amount: shippingPrice,
      currency: 'usd',
      quantity: 1
    })

  if(tax_price > 0)
    line_items.push({
      name: 'Sales Tax (Utah)',
      amount: tax_price,
      currency: 'usd',
      quantity: 1
    })

  // TODO: We need to handle this case, mark it paid or something?
  if(line_items.length < 1)
    res.json(null)

  const session = await stripe.checkout.sessions.create({
    client_reference_id: currentTransaction.uuid,
    customer_email: req.user ? req.user.email : undefined,
    payment_method_types: ['card'],
    line_items,
    success_url: `${process.env.EXTERNAL_URL}/store/checkout/verify?session_id={CHECKOUT_SESSION_ID}`,
    cancel_url: `${process.env.EXTERNAL_URL}/cancel`,
  });

  res.json(session.id)
})

router.post('/current/checkout/verify', parseJSON, async (req, res) => {
  const {session_id} = req.body
  if(!session_id) throw new Error("No session id given")

  let order = await db.order.findForCart(req.cart.uuid);
  if(!order) throw new Error("Unable to find current order");

  const currentTransaction = order
    .transactions.find(transaction => (
      transaction.payment_state === 'started'
    ))

  const {payment_intent} = await stripe.checkout.sessions.retrieve(session_id);
  const payment = await stripe.paymentIntents.retrieve(payment_intent)

  if(payment.status === "succeeded"){
    order = await db.order.addPayment(currentTransaction, payment)
    await db.session.clearCart(req.sessionObj.uuid)
  }

  // TODO: Save stockchange record for purchase

  res.json({status: payment.status, order})
})