# frozen_string_literal: true

# Helpers and utilities for interactions with the Stripe payment gateway
class StripeService
  class << self

    # Create the provided PaymentSchedule on Stripe, using the Subscription API
    def create_stripe_subscription(payment_schedule, setup_intent_id)
      stripe_key = Setting.get('stripe_secret_key')
      first_item = payment_schedule.ordered_items.first

      case payment_schedule.scheduled_type
      when Reservation.name
        subscription = payment_schedule.scheduled.subscription
        reservable_stp_id = payment_schedule.scheduled.reservable&.stp_product_id
      when Subscription.name
        subscription = payment_schedule.scheduled
        reservable_stp_id = nil
      else
        raise InvalidSubscriptionError
      end

      handle_wallet_transaction(payment_schedule)

      # setup intent (associates the customer and the payment method)
      intent = Stripe::SetupIntent.retrieve(setup_intent_id, api_key: stripe_key)
      # subscription (recurring price)
      price = create_price(first_item.details['recurring'],
                           subscription.plan.stp_product_id,
                           nil, monthly: true)
      # other items (not recurring)
      items = subscription_invoice_items(payment_schedule, subscription, first_item, reservable_stp_id)

      stp_subscription = Stripe::Subscription.create({
                                                       customer: payment_schedule.invoicing_profile.user.stp_customer_id,
                                                       cancel_at: (payment_schedule.ordered_items.last.due_date + 3.day).to_i,
                                                       add_invoice_items: items,
                                                       coupon: payment_schedule.coupon&.code,
                                                       items: [
                                                         { price: price[:id] }
                                                       ],
                                                       default_payment_method: intent[:payment_method]
                                                     }, { api_key: stripe_key })
      payment_schedule.update_attributes(stp_subscription_id: stp_subscription.id)
    end

    def create_stripe_coupon(coupon_id)
      coupon = Coupon.find(coupon_id)
      stp_coupon = { id: coupon.code }
      if coupon.type == 'percent_off'
        stp_coupon[:percent_off] = coupon.percent_off
      elsif coupon.type == 'amount_off'
        stp_coupon[:amount_off] = coupon.amount_off
        stp_coupon[:currency] = Setting.get('stripe_currency')
      end

      stp_coupon[:duration] = coupon.validity_per_user == 'always' ? 'forever' : 'once'
      stp_coupon[:redeem_by] = coupon.valid_until.to_i unless coupon.valid_until.nil?
      stp_coupon[:max_redemptions] = coupon.max_usages unless coupon.max_usages.nil?

      Stripe::Coupon.create(stp_coupon, api_key: Setting.get('stripe_secret_key'))
    end

    private

    def subscription_invoice_items(payment_schedule, subscription, first_item, reservable_stp_id)
      second_item = payment_schedule.ordered_items[1]

      items = []
      if first_item.amount != second_item.amount
        unless first_item.details['adjustment']&.zero?
          # adjustment: when dividing the price of the plan / months, sometimes it forces us to round the amount per month.
          # The difference is invoiced here
          p1 = create_price(first_item.details['adjustment'],
                            subscription.plan.stp_product_id,
                            "Price adjustment for payment schedule #{payment_schedule.id}")
          items.push(price: p1[:id])
        end
        unless first_item.details['other_items']&.zero?
          # when taking a subscription at the same time of a reservation (space, machine or training), the amount of the
          # reservation is invoiced here.
          p2 = create_price(first_item.details['other_items'],
                            reservable_stp_id,
                            "Reservations for payment schedule #{payment_schedule.id}")
          items.push(price: p2[:id])
        end
      end

      items
    end

    def create_price(amount, stp_product_id, name, monthly: false)
      params = {
        unit_amount: amount,
        currency: Setting.get('stripe_currency'),
        product: stp_product_id,
        nickname: name
      }
      params[:recurring] = { interval: 'month', interval_count: 1 } if monthly

      Stripe::Price.create(params, api_key: Setting.get('stripe_secret_key'))
    end

    def handle_wallet_transaction(payment_schedule)
      return unless payment_schedule.wallet_amount

      customer_id = payment_schedule.invoicing_profile.user.stp_customer_id
      Stripe::Customer.update(customer_id, { balance: -payment_schedule.wallet_amount }, { api_key: Setting.get('stripe_secret_key') })
    end
  end
end