From 55aac0fe46c3704b356d2a03dd51344bb1599c89 Mon Sep 17 00:00:00 2001
From: Stephen Paul Weber <singpolyma@singpolyma.net>
Date: Tue, 18 Jan 2022 12:24:32 -0500
Subject: [PATCH] Represent plan limit details as a useful object

---
 lib/customer.rb      |  4 ++--
 lib/customer_plan.rb |  3 ++-
 lib/plan.rb          | 40 ++++++++++++++++++++++++++++++++++++++++
 test/test_helper.rb  |  4 +++-
 test/test_plan.rb    | 11 +++++++++++
 5 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/lib/customer.rb b/lib/customer.rb
index 70a22172cd59121df56b09bc119d8494bda42a45..dce3a07e025aab95e4f97463b49970c13eded0ed 100644
--- a/lib/customer.rb
+++ b/lib/customer.rb
@@ -22,8 +22,8 @@ class Customer
 	attr_reader :customer_id, :balance, :jid, :tndetails
 
 	def_delegators :@plan, :active?, :activate_plan_starting_now, :bill_plan,
-	               :currency, :merchant_account, :plan_name,
-	               :auto_top_up_amount, :monthly_overage_limit
+	               :currency, :merchant_account, :plan_name, :minute_limit,
+	               :message_limit, :auto_top_up_amount, :monthly_overage_limit
 	def_delegators :@sgx, :register!, :registered?, :set_ogm_url,
 	               :fwd, :transcription_enabled
 	def_delegators :@usage, :usage_report, :message_usage, :incr_message_usage
diff --git a/lib/customer_plan.rb b/lib/customer_plan.rb
index 870b5d30f9e0c93386ef42d14e97c539bf77a566..86fd8e2a1cdd04abbb793c94b423c666a53d1bfd 100644
--- a/lib/customer_plan.rb
+++ b/lib/customer_plan.rb
@@ -11,7 +11,8 @@ class CustomerPlan
 	attr_reader :expires_at, :auto_top_up_amount, :monthly_overage_limit
 
 	def_delegator :@plan, :name, :plan_name
-	def_delegators :@plan, :currency, :merchant_account, :monthly_price
+	def_delegators :@plan, :currency, :merchant_account, :monthly_price,
+	               :minute_limit, :message_limit
 
 	def self.for(customer_id, plan_name: nil, **kwargs)
 		new(customer_id, plan: plan_name&.then(&Plan.method(:for)), **kwargs)
diff --git a/lib/plan.rb b/lib/plan.rb
index eb1507bb5a50639b044a0fb9f1ec4317dae44067..37c0ba394d9350716ade6d7e4dafe0355eb67e18 100644
--- a/lib/plan.rb
+++ b/lib/plan.rb
@@ -29,4 +29,44 @@ class Plan
 			raise "No merchant account for this currency"
 		end
 	end
+
+	def minute_limit
+		Limit.for("minute", @plan[:minutes])
+	end
+
+	def message_limit
+		Limit.for("message", @plan[:messages])
+	end
+
+	class Limit
+		def self.for(unit, from_config)
+			case from_config
+			when :unlimited
+				Unlimited.new(unit)
+			else
+				new(unit: unit, **from_config)
+			end
+		end
+
+		value_semantics do
+			unit String
+			included Integer
+			price Integer
+		end
+
+		def to_s
+			"#{included} #{unit}s " \
+			"(overage $#{'%.4f' % (price.to_d / 10000)} / #{unit})"
+		end
+
+		class Unlimited
+			def initialize(unit)
+				@unit = unit
+			end
+
+			def to_s
+				"unlimited #{@unit}s"
+			end
+		end
+	end
 end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index c8f0acdec0c820f4b87d52d6578c308d7196c59f..be280445eaee7318d6b6ad0ff58d32814f3d306e 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -71,7 +71,9 @@ CONFIG = {
 		{
 			name: "test_usd",
 			currency: :USD,
-			monthly_price: 10000
+			monthly_price: 10000,
+			messages: :unlimited,
+			minutes: { included: 120, price: 87 }
 		},
 		{
 			name: "test_bad_currency",
diff --git a/test/test_plan.rb b/test/test_plan.rb
index acbbd52be57d0580fa41996eb8d36361d03fbc20..908d73b85e87299264dfc1dde572192da6362e1e 100644
--- a/test/test_plan.rb
+++ b/test/test_plan.rb
@@ -23,4 +23,15 @@ class PlanTest < Minitest::Test
 			Plan.for("test_bad_currency").merchant_account
 		end
 	end
+
+	def test_message_limit
+		assert_equal "unlimited messages", Plan.for("test_usd").message_limit.to_s
+	end
+
+	def test_minute_limit
+		assert_equal(
+			"120 minutes (overage $0.0087 / minute)",
+			Plan.for("test_usd").minute_limit.to_s
+		)
+	end
 end