module Scrivito
  # @api public
  # The Scrivito::MembershipCollection includes all members of a given {Scrivito::Workspace}.
  # You can access it using the {Scrivito::Workspace#memberships} method.
  class MembershipCollection
    extend Forwardable
    include Enumerable

    attr_reader :workspace

    # @api public
    # @!method each
    # Iterate over all {Scrivito::Membership Memberships} of a specific {Scrivito::Workspace}.
    # Allows you to use all the methods defined by Ruby's Enumerable module.
    #
    # @yield [Scrivito::Membership]
    #
    # @return [Enumerator] if no block is given, an Enumerator is returned
    #
    # @example
    #   # Obtain all owners of a workspace.
    #   my_workspace.memberships.select do |membership|
    #     membership.role == "owner"
    #   end
    #
    #   # Get an array of all the members' user_ids.
    #   my_workspace.memberships.map { |membership| membership.user_id }
    #
    #   # Or use it directly to iterate over all items.
    #   my_workspace.memberships.each do |membership|
    #     puts "User #{membership.user_id} has the role #{membership.role}"
    #   end
    #
    # @note For a complete list of the provided methods, please refer to the
    #   documentation of the Enumerable module.
    def_delegator :memberships, :each

    def initialize(workspace)
      @workspace = workspace
    end

    # @api public
    # Returns a hash where the keys are +user_id+s and the values are Membership instances.
    # @return [Hash<String, Scrivito::Membership>]
    def to_h
      memberships.inject(HashWithIndifferentAccess.new) do |hash, membership|
        hash[membership.user_id] = membership
        hash
      end
    end

    # @api public
    # Returns the membership of a user or nil.
    #
    # @param  [Scrivito::User, String] id_or_user
    # @return [Scrivito::Membership, nil]
    def [](id_or_user)
      id = if id_or_user.respond_to?(:id)
        id_or_user.id
      else
        id_or_user
      end

      to_h[id]
    end

    def to_a
      memberships.sort_by(&:user_id)
    end

    private

    def memberships
      return [] if workspace.published?
      @memberships ||= begin
        workspace.data.memberships.map do |id, data|
          Membership.new(id, data)
        end
      end
    end

  end
end