Assignments working

app/models/command/parser.rb

@@ -1,15 +1,41 @@
 class Command::Parser
-  attr_reader :user
+  attr_reader :context
 
-  def initialize(user)
-    @user = user
+  delegate :user, :cards, to: :context
+
+  def initialize(context)
+    @context = context
   end
 
   def parse(string)
-    if card = user.accessible_cards.find_by_id(string)
-      Command::GoToCard.new(card: card)
-    else
-      Command::Search.new(query: string)
+    command_name, *command_arguments = string.split(" ")
+
+    case command_name
+      when "/assign", "/assign_to"
+        Command::Assign.new(assignee_ids: assignees_from(command_arguments).collect(&:id), card_ids: cards.ids)
+      else
+        search(string)
     end
   end
+
+  private
+    def search(string)
+      if card = user.accessible_cards.find_by_id(string)
+        Command::GoToCard.new(card_id: card.id)
+      else
+        Command::Search.new(query: string)
+      end
+    end
+
+    def assignees_from(strings)
+      Array(strings).filter_map do |string|
+        assignee_from(string)
+      end
+    end
+
+    # TODO: This is temporary as it can be ambiguous. We should inject the user ID in the command
+    #   instead, as determined by the user picker.
+    def assignee_from(string)
+      User.all.find { |user| user.mentionable_handles.include?(string) }
+    end
 end