Initial commit

services/data-repository/structures/collection.rb

@@ -0,0 +1,75 @@
+require 'ostruct'
+require 'set'
+require_relative '../repository'
+
+module DataRepository
+  class Collection
+    include Enumerable
+
+    INTERFACE  = %w{ signature add delete store fetch each to_json repository count } + Enumerable.instance_methods
+
+    attr_reader   :signature
+    attr_accessor :storage
+
+    def initialize(arguments={})
+      @storage      = Set.new
+      @member_class = arguments.fetch(:member_class, OpenStruct)
+      @repository   = arguments.fetch(:repository, Repository.new)
+      @signature    = arguments.fetch(:signature, @repository.next_id)
+    end #initialize
+
+    def add(member)
+      storage.add(member)
+      self
+    end #add
+
+    def delete(member)
+      storage.delete(member)
+      self
+    end #delete
+
+    def delete_if(&block)
+      storage.delete_if(&block)
+      self
+    end
+
+    def each(&block)
+      return storage.each(&block)
+      Enumerator.new(self, :each)
+    end #each
+
+    def fetch
+      self.storage = Set[*repository.fetch(signature)].map do |attributes|
+        puts attributes.inspect
+        member_class.new(attributes)
+      end
+        
+      self
+    rescue => exception
+      storage.clear
+      self
+    end #fetch
+
+    def store
+      repository.store(signature, storage.map(&:id).to_a)
+      self
+    end #store
+
+    def to_json(*args)
+      map { |member| member.to_hash }.to_json(*args)
+    end #to_json
+
+    def count
+      storage.count
+    end #count
+
+    private
+
+    attr_reader   :repository, :member_class
+
+    def members
+      storage.each { |member_id| yield member_class.new(id: member_id).fetch }
+    end #members
+  end # Collection
+end # DataRepository
+