module SlackRubyBotServer
  module Api
    module Helpers
      module ErrorHelpers
        extend ActiveSupport::Concern

        included do
          rescue_from :all, backtrace: true do |e|
            backtrace = e.backtrace[0..5].join("\n  ")
            Middleware.logger.error "#{e.class.name}: #{e.message}\n  #{backtrace}"
            error = { type: 'other_error', message: e.message }
            error[:backtrace] = backtrace
            rack_response(error.to_json, 400)
          end
          # rescue document validation errors into detail json
          if SlackRubyBotServer::Config.mongoid?
            rescue_from Mongoid::Errors::Validations do |e|
              backtrace = e.backtrace[0..5].join("\n  ")
              Middleware.logger.warn "#{e.class.name}: #{e.message}\n  #{backtrace}"
              rack_response({
                type: 'param_error',
                message: e.document.errors.full_messages.uniq.join(', ') + '.',
                detail: e.document.errors.messages.each_with_object({}) do |(k, v), h|
                  h[k] = v.uniq
                end
              }.to_json, 400)
            end
          end
          rescue_from Grape::Exceptions::Validation do |e|
            backtrace = e.backtrace[0..5].join("\n  ")
            Middleware.logger.warn "#{e.class.name}: #{e.message}\n  #{backtrace}"
            rack_response({
              type: 'param_error',
              message: 'Invalid parameters.',
              detail: { e.params.join(', ') => [e.message] }
            }.to_json, 400)
          end
          rescue_from Grape::Exceptions::ValidationErrors do |e|
            backtrace = e.backtrace[0..5].join("\n  ")
            Middleware.logger.warn "#{e.class.name}: #{e.message}\n  #{backtrace}"
            rack_response({
              type: 'param_error',
              message: 'Invalid parameters.',
              detail: e.errors.each_with_object({}) do |(k, v), h|
                # JSON does not permit having a key of type Array
                h[k.count == 1 ? k.first : k.join(', ')] = v
              end
            }.to_json, 400)
          end
        end
      end
    end
  end
end