1# frozen_string_literal: true
 2
 3require "bigdecimal"
 4require "time"
 5require "value_semantics/monkey_patched"
 6
 7class Transaction
 8	value_semantics do
 9		customer_id String
10		transaction_id String
11		created_at Time, coerce: ->(x) { Time.parse(x.to_s) }
12		settled_after Time, coerce: ->(x) { Time.parse(x.to_s) }
13		amount BigDecimal, coerce: ->(x) { BigDecimal(x, 4) }
14		note String
15	end
16
17	def insert
18		EM.promise_fiber do
19			DB.transaction do
20				insert_tx
21				insert_bonus
22			end
23		end
24	end
25
26	def total
27		amount + bonus
28	end
29
30	def bonus
31		return BigDecimal(0) if amount <= 15
32
33		amount *
34			case amount
35			when (15..29.99)
36				0.01
37			when (30..139.99)
38				0.03
39			else
40				0.05
41			end
42	end
43
44	def to_s
45		plus = " + #{'%.4f' % bonus} bonus"
46		"$#{'%.2f' % amount}#{plus if bonus.positive?}"
47	end
48
49protected
50
51	def insert_tx
52		params = [
53			@customer_id, @transaction_id, @created_at, @settled_after, @amount, @note
54		]
55		DB.exec(<<~SQL, params)
56			INSERT INTO transactions
57				(customer_id, transaction_id, created_at, settled_after, amount, note)
58			VALUES
59				($1, $2, $3, $4, $5, $6)
60		SQL
61	end
62
63	def insert_bonus
64		return if bonus <= 0
65
66		params = [
67			@customer_id, "bonus_for_#{@transaction_id}", @created_at,
68			@settled_after, bonus, "#{@note} bonus"
69		]
70		DB.exec(<<~SQL, params)
71			INSERT INTO transactions
72				(customer_id, transaction_id, created_at, settled_after, amount, note)
73			VALUES
74				($1, $2, $3, $4, $5, $6)
75		SQL
76	end
77end