const ExcelJS = require('exceljs');
const easypost = new (require('@easypost/api'))(process.env.EASYPOST_API_KEY);

module.exports = async function(users, coupons, items, filename) {
  const workbook = new ExcelJS.Workbook();
  workbook.creator = 'Ashe Erickson'
  workbook.lastModifiedBy = 'Ashe Erickson'
  workbook.created = new Date()
  workbook.modified = new Date()

  const usersSheet = workbook.addWorksheet('Users', {views:[{state: 'frozen', xSplit: 0, ySplit:1}]})
  const ordersSheet = workbook.addWorksheet('Orders', {views:[{state: 'frozen', xSplit: 0, ySplit:1}]})
  const couponsSheet = workbook.addWorksheet('Coupons', {views:[{state: 'frozen', xSplit: 0, ySplit:1}]})

  const couponCache = {};


  // Write coupons
  couponsSheet.columns = [
    {header: 'Coupon Code', width: 20},
    {header: 'Expires', width: 14},
    {header: 'Flat discount', key: 'flat', width: 12},
    {header: '% discount', key: 'percent', width: 10},
    {header: '# Socks free', width: 12},
    {header: 'Per sock discount', key: 'perSock', width: 18},
    {header: 'Free Shipping', width: 15},
    {header: '# Allowed Uses', width: 18},
    {header: '# Times Used', width: 18},
  ]

  for (const coupon of coupons) {
    const row = couponsSheet.addRow([
      coupon.code,
      new Date(coupon.expires * 1000),
      formatMoney(coupon.flatDiscount),
      coupon.percentDiscount ? coupon.percentDiscount / 100 : '',
      coupon.socksFree || '',
      formatMoney(coupon.perSockDiscount),
      coupon.freeShipping ? 'Yes' : 'No',
      coupon.numAllowedUses,
      coupon.uses.length
    ])

    row.eachCell(cell => {cell.alignment = {horizontal: 'left' }})

    couponCache[coupon._id.toString()] = {
      code: coupon.code,
      row: row.number
    }
  }

  // Write users + orders
  usersSheet.columns = [
    {header: 'Email', width: 40},
    {header: 'Email Confirmed', width: 10},
    {header: 'Registered', width: 20},
    {header: 'Last Login', width: 20},
    {header: 'Purchases', width: 20},
    {header: 'Admin', width: 20},
  ]

  ordersSheet.columns = [
    {header: 'User', width: 40},
    {header: 'Purchase Date', width: 14},
    {header: 'Shipment Date', width: 14},
    {header: 'Items', width: 60},
    {header: 'Item Subtotal', key: 'itemCost', width: 20},
    {header: 'Shipping Estimate', key: 'shippingEst', width: 20},
    {header: 'Shipping Actual', key: 'shippingCost', width: 20},
    {header: 'Total Paid', key: 'totalCost', width: 20},
    {header: 'Coupon', key: 'coupon', width: 20},
    {header: 'Tracking Code', width: 20},
    {header: 'Address', width: 20},
  ]

  const usersWithPurchases = users.filter(user => user.purchases?.length);
  usersWithPurchases.sort((a,b) => (a.email || 'zzzz').localeCompare(b.email || 'zzzz'))

  let userNum = 0;
  for(const user of usersWithPurchases) {
    if (user.purchases?.length < 1) continue;
    userNum++

    const creationDate = new Date(parseInt(user._id.toString().slice(0,8), 16)*1000)
    const userID = user.email || user._id.toString();
    const firstOrderRow = ordersSheet.rowCount + 1;
    const userRow = usersSheet.rowCount + 1;


    console.log(`  (${userNum}/${usersWithPurchases.length}) Retrieving shipment + address info for orders by user ${userID}`)

    for(const purchase of user.purchases) {
      const shipmentPromise = easypost.Shipment.retrieve(purchase.shipment);
      const addressPromise = easypost.Address.retrieve(purchase.address);

      try {
        purchase.shipment = await shipmentPromise;
        purchase.address = await addressPromise;
      } catch {
        console.warn(`    Unable to retrieve info for order ${purchase._id}`)
      }

      if (purchase.shipment?.tracker?.id) {
        easypost.Tracker.retrieve(purchase.shipment.tracker.id).then(tracker => {
          purchase.shipment.tracker = tracker
        }).catch(() => {})
      }

      const coupon = couponCache[purchase.coupon]
      const trackingCode = purchase.shipment?.tracking_code || purchase.trackingCode
      const trackingLink = purchase.shipment?.tracker?.public_url || `https://tools.usps.com/go/TrackConfirmAction_input?qtc_tLabels1=${trackingCode}`

      const row = ordersSheet.addRow([
        user.email ? {formula: `=HYPERLINK("#'Users'!A${userRow}", "${userID}")`} : userID,
        purchase.purchaseTime ? new Date(purchase.purchaseTime) : '',
        purchase.shippedOn ? new Date(purchase.shippedOn) : '',
        purchase.items.map(id => items.find(item => item._id.toString() === id.toString()).urlslug).join(', '),
        formatMoney(purchase.sockPrice),
        formatMoney(purchase.shippingEstimate),
        formatMoney(purchase.shipment?.selected_rate?.rate),
        formatMoney(purchase.totalPrice),
        coupon ? {formula: `=HYPERLINK("#'Coupons'!A${coupon.row}","${coupon.code}")`} : '',
        trackingCode ? {formula: `=HYPERLINK("${trackingLink}", "${trackingCode}")`} : "",
        formatAddress(purchase.address)
      ])

      row.eachCell(cell => {cell.alignment = {horizontal: 'left' }})
    }

    if (!user.email) continue;

    const row = usersSheet.addRow([
      userID,
      user.emailConfirmed ? 'Yes' : 'No',
      creationDate,
      user.lastLogin ? new Date(user.lastLogin) : '',
      {formula: `=HYPERLINK("#'Orders'!A${firstOrderRow}", "${user.purchases.length} purchase${user.purchases.length > 1 ? "s" : ""}")`},
      user.isAdmin ? 'Yes' : 'No'
    ])

    row.eachCell(cell => {cell.alignment = {horizontal: 'left' }})
  }

  ordersSheet.getColumn('itemCost').eachCell(cell => {cell.numFmt = '$0.00'})
  ordersSheet.getColumn('shippingEst').eachCell(cell => {cell.numFmt = '$0.00'})
  ordersSheet.getColumn('shippingCost').eachCell(cell => {cell.numFmt = '$0.00'})
  ordersSheet.getColumn('totalCost').eachCell(cell => {cell.numFmt = '$0.00'})

  couponsSheet.getColumn('flat').eachCell(cell => {cell.numFmt = '$0.00'})
  couponsSheet.getColumn('percent').eachCell(cell => {cell.numFmt = '0%'})
  couponsSheet.getColumn('perSock').eachCell(cell => {cell.numFmt = '$0.00'})

  await workbook.xlsx.writeFile(filename);
}

function formatMoney(value) {
  if(value === undefined) return ''
  if(value === '') return ''
  if(value === 0) return ''

  if(typeof value === 'string')
    return parseFloat(value);


  return value
}

function formatAddress(address) {
  if(typeof address !== 'object')
    return address

  return `${address.name || ""} | ${address.company ? address.company + "| " : ""}${address.street1} | ${address.street2 ? address.street2 + "| " : ""}${address.city} | ${address.state} | ${address.country} | ${address.zip}`
}