1# frozen_string_literal: true
2
3require "forwardable"
4
5require_relative "em"
6require_relative "plan"
7
8class CustomerPlan
9 extend Forwardable
10
11 attr_reader :expires_at, :auto_top_up_amount, :monthly_overage_limit
12
13 def_delegator :@plan, :name, :plan_name
14 def_delegators :@plan, :currency, :merchant_account, :monthly_price,
15 :minute_limit, :message_limit
16
17 def self.for(customer_id, plan_name: nil, **kwargs)
18 new(customer_id, plan: plan_name&.then(&Plan.method(:for)), **kwargs)
19 end
20
21 def self.extract(customer_id, **kwargs)
22 self.for(
23 customer_id,
24 **kwargs.slice(
25 :plan_name, :expires_at,
26 :auto_top_up_amount, :monthly_overage_limit
27 )
28 )
29 end
30
31 def initialize(
32 customer_id,
33 plan: nil,
34 expires_at: Time.now,
35 auto_top_up_amount: 0,
36 monthly_overage_limit: 0
37 )
38 @customer_id = customer_id
39 @plan = plan || OpenStruct.new
40 @expires_at = expires_at
41 @auto_top_up_amount = auto_top_up_amount || 0
42 @monthly_overage_limit = monthly_overage_limit || 0
43 end
44
45 def active?
46 plan_name && @expires_at > Time.now
47 end
48
49 def with_plan_name(plan_name)
50 self.class.new(
51 @customer_id,
52 plan: Plan.for(plan_name),
53 expires_at: @expires_at
54 )
55 end
56
57 def save_plan!
58 DB.exec_defer(<<~SQL, [@customer_id, plan_name])
59 INSERT INTO plan_log
60 (customer_id, plan_name, date_range)
61 VALUES (
62 $1,
63 $2,
64 tsrange(
65 LOCALTIMESTAMP - '2 seconds'::interval,
66 LOCALTIMESTAMP - '1 second'::interval
67 )
68 )
69 SQL
70 end
71
72 def bill_plan(note: nil)
73 EMPromise.resolve(nil).then do
74 DB.transaction do |db|
75 next false unless !block_given? || yield(db)
76
77 charge_for_plan(note)
78 add_one_month_to_current_plan unless activate_plan_starting_now
79 true
80 end
81 end
82 end
83
84 def activate_plan_starting_now
85 activated = DB.exec(<<~SQL, [@customer_id, plan_name]).cmd_tuples.positive?
86 INSERT INTO plan_log (customer_id, plan_name, date_range)
87 VALUES ($1, $2, tsrange(LOCALTIMESTAMP, LOCALTIMESTAMP + '1 month'))
88 ON CONFLICT DO NOTHING
89 SQL
90 return false unless activated
91
92 DB.exec(<<~SQL, [@customer_id])
93 DELETE FROM plan_log WHERE customer_id=$1 AND date_range << '[now,now]'
94 AND upper(date_range) - lower(date_range) < '2 seconds'
95 SQL
96 end
97
98 def activation_date
99 DB.query_one(<<~SQL, @customer_id).then { |r| r[:start_date] }
100 SELECT
101 MIN(LOWER(date_range)) AS start_date
102 FROM plan_log WHERE customer_id = $1;
103 SQL
104 end
105
106protected
107
108 def charge_for_plan(note)
109 params = [
110 @customer_id,
111 "#{@customer_id}-bill-#{plan_name}-at-#{Time.now.to_i}",
112 -@plan.monthly_price,
113 note
114 ]
115 DB.exec(<<~SQL, params)
116 INSERT INTO transactions
117 (customer_id, transaction_id, created_at, settled_after, amount, note)
118 VALUES ($1, $2, LOCALTIMESTAMP, LOCALTIMESTAMP, $3, $4)
119 SQL
120 end
121
122 def add_one_month_to_current_plan
123 DB.exec(<<~SQL, [@customer_id])
124 UPDATE plan_log SET date_range=range_merge(
125 date_range,
126 tsrange(
127 LOCALTIMESTAMP,
128 GREATEST(upper(date_range), LOCALTIMESTAMP) + '1 month'
129 )
130 )
131 WHERE
132 customer_id=$1 AND
133 date_range && tsrange(LOCALTIMESTAMP, LOCALTIMESTAMP + '1 month')
134 SQL
135 end
136end