post '/webhooks/paypal' do
  'ok'
end

def valid_paypal_webhook_source?
  return true if request.ip == '127.0.0.1'

  # Use DNS to resolve notify.paypal.com as PayPal recommends
  begin
    resolved_ips = Resolv.getaddresses 'notify.paypal.com'
    return resolved_ips.include?(request.ip)
  rescue Resolv::ResolvError
    return false
  end
end

post '/webhooks/paypal/tipping_notify' do
  return 403 unless valid_paypal_webhook_source?

  # Handle missing custom parameter (this seems to happen with recurring donations)
  if params[:custom].nil? || params[:custom].strip.empty?
    # Try to extract username from product_name like "Site Donation for Two-reeler (USERNAME_HERE)"
    if params[:product_name] && params[:product_name].match(/\((.+)\)$/)
      username = params[:product_name].match(/\((.+)\)$/)[1]
      site = Site.where(username: username).first
    end

    # If no site found by username, try to find by payer email
    if params[:payer_email]
      actioning_site = Site.where(email: params[:payer_email]).first
    end

    # Create payload structure for anonymous tip
    payload = {
      site_id: site.id,
      actioning_site_id: (actioning_site ? actioning_site : nil)
    }
  else
    payload = JSON.parse Base64.strict_decode64(params[:custom]), symbolize_names: true
    site = Site[payload[:site_id]]
  end

  @tip_hash = {
    message: (params[:memo] ? params[:memo] : nil),
    amount: params[:mc_gross],
    currency: params[:mc_currency],
    fee: params[:mc_fee],
    actioning_site: (payload[:actioning_site_id] ? Site[payload[:actioning_site_id]] : nil),
    paypal_payer_email: params[:payer_email],
    paypal_receiver_email: params[:receiver_email],
    paypal_txn_id: params[:txn_id],
    created_at: DateTime.strptime(params[:payment_date], "%H:%M:%S %b %e, %Y %Z").to_time
  }

  @tip = site.add_tip @tip_hash

  Event.create(
    site_id: @tip.site.id,
    actioning_site_id: (@tip.actioning_site ? @tip.actioning_site.id : nil),
    tip_id: @tip.id
  )

  if @tip.actioning_site
    subject = "You received a #{@tip.amount_string} tip from #{@tip.actioning_site.username}!"
  else
    subject = "You received a #{@tip.amount_string} tip!"
  end

  @tip.site.send_email(
    subject: subject,
    body: Tilt.new('./views/templates/email/tip_received.erb', pretty: true).render(self)
  )

  EmailWorker.perform_async({
    from: Site::FROM_EMAIL,
    to: params[:payer_email],
    subject: "You sent a #{@tip.amount_string} tip!",
    body: Tilt.new('./views/templates/email/tip_sent.erb', pretty: true).render(self)
  })
end

post '/webhooks/stripe' do
  event = JSON.parse request.body.read

  if event['type'] == 'charge.failed'
    site = stripe_get_site_from_event event

    EmailWorker.perform_async({
      from:    Site::FROM_EMAIL,
      to:      site.email,
      subject: "[Neocities] There was an issue charging your card",
      body:    Tilt.new('./views/templates/email/charge_failure.erb', pretty: true).render(self)
    })
  end

  if event['type'] == 'customer.subscription.deleted'
    site = stripe_get_site_from_event event
    site.stripe_subscription_id = nil
    site.plan_type = nil
    site.plan_ended = true
    site.save_changes validate: false

    EmailWorker.perform_async({
      from:    Site::FROM_EMAIL,
      to:      site.email,
      subject: "[Neocities] Supporter plan has ended",
      body:    Tilt.new('./views/templates/email/supporter_ended.erb', pretty: true).render(self)
    })
  end

  if event['type'] == 'invoice.payment_succeeded'
    site = stripe_get_site_from_event event

    if site.email_invoice && site.stripe_paying_supporter?
      invoice_obj = event['data']['object']

      EmailWorker.perform_async({
        from:    Site::FROM_EMAIL,
        to:      site.email,
        subject: "[Neocities] Invoice",
        body:    Tilt.new('./views/templates/email/invoice.erb', pretty: true).render(
          self,
          site: site,
          amount: invoice_obj['amount_due'],
          period_start: Time.at(invoice_obj['period_start']),
          period_end: Time.at(invoice_obj['period_end']),
          date: Time.at(invoice_obj['date'])
        )
      })
    end
  end

  'ok'
end

def stripe_get_site_from_event(event)
  customer_id = event['data']['object']['customer']
  halt 'ok' if customer_id.nil? # Likely a fraudulent card report

  retries = 0
  begin
    customer = Stripe::Customer.retrieve customer_id
  rescue Stripe::APIConnectionError, Stripe::RateLimitError => e
    retries += 1
    if retries <= 3
      sleep(2 ** retries) # exponential backoff: 2s, 4s, 8s
      retry
    else
      raise e
    end
  end

  # Some old accounts only have a username for the desc
  desc_split = customer.description.split(' - ')

  if desc_split.length == 1
    site_where = {username: desc_split.first}
  end

  if desc_split.last.not_an_integer?
    site_where = {username: desc_split.first}
  else
    site_where = {id: desc_split.last}
  end

  Site.where(site_where).first
end
