#-- copyright
# OpenProject is a project management system.
# Copyright (C) 2012-2018 the OpenProject Foundation (OPF)
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License version 3.
#
# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
# Copyright (C) 2006-2017 Jean-Philippe Lang
# Copyright (C) 2010-2013 the ChiliProject Team
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# See docs/COPYRIGHT.rdoc for more details.
#++

module API
  module V3
    module Utilities
      module Endpoints
        class Show
          def default_instance_generator(model)
            ->(_params) do
              instance_variable_get("@#{model.name.demodulize.underscore}")
            end
          end

          def initialize(model:,
                         api_name: model.name.demodulize,
                         render_representer: nil,
                         instance_generator: default_instance_generator(model))

            self.model = model
            self.api_name = api_name
            self.instance_generator = instance_generator
            self.render_representer = render_representer || deduce_render_representer
          end

          def mount
            show = self

            -> do
              show.render(instance_exec(params, &show.instance_generator))
            end
          end

          def render(instance)
            render_representer
              .create(instance,
                      current_user: User.current,
                      embed_links: true)
          end

          def self_path
            api_name.underscore.pluralize
          end

          attr_accessor :model,
                        :api_name,
                        :instance_generator,
                        :render_representer

          private

          def deduce_render_representer
            "::API::V3::#{deduce_namespace}::#{api_name}Representer".constantize
          end

          def deduce_namespace
            api_name.pluralize
          end
        end
      end
    end
  end
end