# frozen_string_literal: true

require "bigdecimal"

class Transaction
	def self.sale(customer, amount:, payment_method: nil)
		resolve_payment_method(customer, payment_method).then do |selected_method|
			BRAINTREE.transaction.sale(selected_method.transaction_details.merge(
				amount: amount,
				merchant_account_id: customer.merchant_account,
				options: { submit_for_settlement: true }
			)).then do |response|
				new(decline_guard(customer, response))
			end
		end
	end

	def self.resolve_payment_method(customer, payment_method)
		EMPromise.all([
			customer.declines,
			payment_method || customer.payment_methods.then(&:default_payment_method)
		]).then do |(declines, selected_method)|
			raise "Declined" if declines >= 2
			raise "No valid payment method on file" unless selected_method

			selected_method
		end
	end

	def self.decline_guard(customer, response)
		return response.transaction if response.success?

		customer.mark_decline
		raise response.message
	end

	attr_reader :amount

	def initialize(braintree_transaction)
		@customer_id = braintree_transaction.customer_details.id
		@transaction_id = braintree_transaction.id
		@created_at = braintree_transaction.created_at
		@amount = BigDecimal(braintree_transaction.amount, 4)
	end

	def insert
		EM.promise_fiber do
			DB.transaction do
				insert_tx
				insert_bonus
			end
		end
	end

	def total
		amount + bonus
	end

	def bonus
		return BigDecimal(0) if amount <= 15

		amount *
			case amount
			when (15..29.99)
				0.01
			when (30..139.99)
				0.03
			else
				0.05
			end
	end

	def to_s
		plus = " + #{'%.4f' % bonus} bonus"
		"$#{'%.2f' % amount}#{plus if bonus.positive?}"
	end

	def settled_after
		@created_at + (90 * 24 * 60 * 60)
	end

protected

	def insert_tx
		params = [
			@customer_id, @transaction_id, @created_at, settled_after, @amount
		]
		DB.exec(<<~SQL, params)
			INSERT INTO transactions
				(customer_id, transaction_id, created_at, settled_after, amount, note)
			VALUES
				($1, $2, $3, $4, $5, 'Credit card payment')
		SQL
	end

	def insert_bonus
		return if bonus <= 0

		params = [
			@customer_id, "bonus_for_#{@transaction_id}", @created_at,
			settled_after, bonus
		]
		DB.exec(<<~SQL, params)
			INSERT INTO transactions
				(customer_id, transaction_id, created_at, settled_after, amount, note)
			VALUES
				($1, $2, $3, $4, $5, 'Credit card payment bonus')
		SQL
	end
end