CLI support for language switching

Author: danielpclark

language_cards.gemspec

@@ -4,26 +4,27 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'language_cards/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = "language_cards"
+  spec.name          = 'language_cards'
   spec.version       = LanguageCards::VERSION
-  spec.authors       = ["Daniel P. Clark"]
-  spec.email         = ["6ftdan@gmail.com"]
+  spec.authors       = ['Daniel P. Clark']
+  spec.email         = ['6ftdan@gmail.com']
 
   spec.summary       = %q{Flashcard game for language learning.}
   spec.description   = %q{Flashcard game for language learning. Make your own cards or translations as well.}
-  spec.homepage      = "http://github.com/danielpclark/language_cards"
-  spec.license       = "MIT"
+  spec.homepage      = 'http://github.com/danielpclark/language_cards'
+  spec.license       = 'MIT'
 
   spec.files         = `git ls-files -z`.split("\x0").reject do |f|
     f.match(%r{^(test|spec|features)/})
   end
 
   spec.executables   = ['language_cards']
-  spec.require_paths = ["lib","cards"]
+  spec.require_paths = ['lib','cards']
 
-  spec.add_dependency "highline", "~> 1.7"
-  spec.add_dependency "i18n", "~> 0.7"
-  spec.add_development_dependency "bundler", "~> 1.13"
-  spec.add_development_dependency "rake", "~> 12.3"
-  spec.add_development_dependency "minitest", "~> 5.10"
+  spec.add_dependency 'highline', '~> 1.7'
+  spec.add_dependency 'i18n', '~> 0.7'
+  spec.add_dependency 'slop', '~> 4.6'
+  spec.add_development_dependency 'bundler', '~> 1.13'
+  spec.add_development_dependency 'rake', '~> 12.3'
+  spec.add_development_dependency 'minitest', '~> 5.10'
 end

lib/language_cards.rb

@@ -2,6 +2,7 @@
 require 'language_cards/language_cards'
 require 'yaml'
 require 'i18n'
+require 'slop'
 require 'highline'
 
 ##
@@ -11,7 +12,11 @@
 #  * Weighted random for better learning
 
 module LanguageCards
-  CARD_LANGUAGE = 'en'
+  OPTS = Slop.parse do |args|
+    args.string '-l', '--language', 'language (default: en)', default: 'en'
+  end
+
+  CARD_LANGUAGE = OPTS[:language]
 
   module ESC
     CLEAR = (ERASE_SCOLLBACK = "\e[3J") + (CURSOR_HOME = "\e[H") + (ERASE_DISPLAY = "\e[2J")

lib/language_cards/controllers/application_controller.rb

@@ -3,16 +3,25 @@ module Controllers
     class ApplicationController
       include Helpers::ViewHelper
 
+      def initialize(opts = {})
+        @opts = opts
+      end
+
       def render(_binding)
         view = ERB.new IO.read File.expand_path("../view/#{snake name}.erb", __dir__)
 
         view.result(_binding)
       end
 
       private
+      attr_reader :opts
       def name
         self.class.name.split('::').last
       end
+
+      def errors
+        Array(opts[:errors])
+      end
     end
   end
 end

lib/language_cards/user_interface.rb

@@ -11,7 +11,7 @@ class UserInterface
     include Controllers
     def initialize cards
       @cards = cards
-      @courses = cards.flat_map {|i| i.label.join(' - ') }
+      @courses = process_courses(cards)
       @mode = [:translate, :typing_practice].cycle
     end
 
@@ -26,7 +26,7 @@ def start
         loop do
           clear
 
-          CLI.say MainMenu.new.render courses: courses, mode: mode
+          CLI.say MainMenu.new(opts).render courses: courses, mode: mode
 
           value = CLI.ask("")
 
@@ -40,7 +40,7 @@ def start
             title = "#{collection.title} (#{humanize mode.peek})"
             collection = collection.mode(mode.peek) # Mode<CardSet> < Game
 
-            game = Game.new
+            game = Game.new(opts)
             timer = Timer.new
             begin # Game Loop
               loop do
@@ -66,13 +66,27 @@ def start
 
     private
     attr_reader :mode, :cards, :correct, :incorrect, :courses
+    def opts
+      @opts ||= {}
+    end
+
     def correct!
       @correct = @correct.to_i + 1
     end
 
     def incorrect!
       @incorrect = @incorrect.to_i + 1
     end
+
+    def process_courses(cards)
+      courses = cards.flat_map {|i| i.label.join(' - ') }
+
+      if courses.empty?
+        opts[:errors] = ["No Flash Cards found for language: #{CARD_LANGUAGE}"]
+      end
+
+      courses
+    end
   end
 end
 

lib/language_cards/view/main_menu.erb

@@ -2,7 +2,7 @@
 <%= draw(_title, nil, 'v' + VERSION) %>
 <%= divider %>
 <%= draw(_select, nil, _mode) %>
-<% _courses.each do |course| %>
+<% (_courses.empty? ? errors : _courses).each do |course| %>
   <%= course.chomp %><% end %>
 
 <%= draw(_mexit, nil, _toggle) %>