#-- 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 Schema
          def default_instance_generator(model)
            ->(_params) do
              model.new
            end
          end

          def initialize(model:,
                         api_name: model.name.demodulize,
                         render_representer: nil,
                         contract: nil,
                         instance_generator: default_instance_generator(model))
            self.model = model
            self.api_name = api_name
            self.instance_generator = instance_generator
            self.representer = render_representer || deduce_representer
            self.contract = contract || deduce_contract
          end

          def mount
            schema = self

            -> do
              self_path = api_v3_paths.send(schema.self_path)

              schema.render(instance_exec(params, &schema.instance_generator),
                            self_path)
            end
          end

          def render(instance,
                     self_path)
            contract_instance = contract.new(instance, User.current)

            representer
              .create(contract_instance,
                      self_path,
                      current_user: User.current)
          end

          def self_path
            "#{api_name.underscore}_schema"
          end

          attr_accessor :model,
                        :api_name,
                        :representer,
                        :contract,
                        :instance_generator

          private

          def deduce_representer
            "::API::V3::#{deduce_namespace}::Schemas::#{api_name}SchemaRepresenter".constantize
          end

          def deduce_contract
            "::#{deduce_namespace}::CreateContract".constantize
          end

          def deduce_namespace
            api_name.pluralize
          end
        end
      end
    end
  end
end