# frozen_string_literal: true

require "forwardable"

require_relative "./backend_sgx"
require_relative "./ibr"
require_relative "./payment_methods"
require_relative "./plan"

class Customer
	def self.for_jid(jid)
		REDIS.get("jmp_customer_id-#{jid}").then do |customer_id|
			raise "No customer id" unless customer_id
			for_customer_id(customer_id)
		end
	end

	def self.for_customer_id(customer_id)
		result = DB.query_defer(<<~SQL, [customer_id])
			SELECT COALESCE(balance,0) AS balance, plan_name, expires_at
			FROM customer_plans LEFT JOIN balances USING (customer_id)
			WHERE customer_id=$1 LIMIT 1
		SQL
		result.then do |rows|
			new(customer_id, **rows.first&.transform_keys(&:to_sym) || {})
		end
	end

	extend Forwardable

	attr_reader :customer_id, :balance
	def_delegator :@plan, :name, :plan_name
	def_delegators :@plan, :currency, :merchant_account
	def_delegators :@sgx, :register!, :registered?

	def initialize(
		customer_id,
		plan_name: nil,
		expires_at: Time.now,
		balance: BigDecimal.new(0),
		sgx: BackendSgx.new(customer_id)
	)
		@plan = plan_name && Plan.for(plan_name)
		@expires_at = expires_at
		@customer_id = customer_id
		@balance = balance
		@sgx = sgx
	end

	def with_plan(plan_name)
		self.class.new(
			@customer_id,
			balance: @balance,
			expires_at: @expires_at,
			plan_name: plan_name
		)
	end

	def bill_plan
		EM.promise_fiber do
			DB.transaction do
				charge_for_plan
				add_one_month_to_current_plan unless activate_plan_starting_now
			end
		end
	end

	def activate_plan_starting_now
		DB.exec(<<~SQL, [@customer_id, plan_name]).cmd_tuples.positive?
			INSERT INTO plan_log
				(customer_id, plan_name, date_range)
			VALUES ($1, $2, tsrange(LOCALTIMESTAMP, LOCALTIMESTAMP + '1 month'))
			ON CONFLICT DO NOTHING
		SQL
	end

	def payment_methods
		@payment_methods ||=
			BRAINTREE
			.customer
			.find(@customer_id)
			.then(PaymentMethods.method(:for_braintree_customer))
	end

	def active?
		@plan && @expires_at > Time.now
	end

protected

	def charge_for_plan
		params = [
			@customer_id,
			"#{@customer_id}-bill-#{plan_name}-at-#{Time.now.to_i}",
			-@plan.monthly_price
		]
		DB.exec(<<~SQL, params)
			INSERT INTO transactions
				(customer_id, transaction_id, created_at, amount)
			VALUES ($1, $2, LOCALTIMESTAMP, $3)
		SQL
	end

	def add_one_month_to_current_plan
		DB.exec(<<~SQL, [@customer_id])
			UPDATE plan_log SET date_range=range_merge(
				date_range,
				tsrange(
					LOCALTIMESTAMP,
					GREATEST(upper(date_range), LOCALTIMESTAMP) + '1 month'
				)
			)
			WHERE
				customer_id=$1 AND
				date_range && tsrange(LOCALTIMESTAMP, LOCALTIMESTAMP + '1 month')
		SQL
	end
end