module Rico
  class Array
    include Rico::Object
    include Enumerable
    extend Forwardable

    def_delegators :members, :each, :[], :length, :count

    public

    # Adds the requested items to the array and stores the object
    #
    # items - items to be added to the array
    #
    # Returns the result of the store operation
    def add(*items)
      mutate build_map_add(items)
    end

    # Removes the requested items from the array and stores the object
    #
    # items - items to be removed from the array
    #
    # Returns the result of the store operation
    def remove(*items)
      mutate build_map_remove(items)
    end

    # Obtains the items in the array
    #
    # Returns the data in the object as an array
    def members
      Array((data || {})["_values"])
    end

    # Tests whether or not an item exists in the array
    #
    # item - item to test against
    #
    # Returns true or false
    def member?(item)
      members.include? item
    end

    # Resolve conflict between one or more RObject siblings
    #
    # robjects - array of RObjects to merge
    #
    # Returns a single RObject result or nil
    def self.resolve(robject)
      siblings = robject.siblings
      values = siblings.map {|r| Array(r.data["_values"]) }
      deletions = siblings.map {|r| Array(r.data["_deletes"]) }.flatten

      result = []
      values.each do |v|
        result += (v - result)
      end

      result -= deletions

      obj = robject.dup
      obj.siblings = [obj.siblings.first]
      obj.data = { "_values" => result, "_deletes" => deletions }
      obj
    end

    protected

    def build_map_add(items)
      { "_type" => type_key, "_values" => compute_add(items) }
    end

    def build_map_remove(items)
      { "_type" => type_key, "_values" => compute_remove(items), "_deletes" => items }
    end

    def compute_add(items)
      members + items
    end

    def compute_remove(items)
      members - items
    end
  end
end