module SimpleAdmin
  class ResourcesController < BaseController
    def index
      model_klass  = params[:model_klass_name].constantize
      model_fields = params[:model_fields].map { |field_attributes| field_attributes[:field_name] }

      per_page = params[:per_page].to_i
      page     = params[:page].to_i if params[:page].present?
      total    = model_klass.count

      resources = model_klass.limit(per_page)

      if params[:query].present?
        search_result = search(params[:query], model_klass, params[:model_attributes])

        resources = search_result[:resources]
        total     = search_result[:total]
      end

      resources = resources.offset((per_page * page) - per_page) if page.present?

      if params[:sort].present?
        resources = resources.order(params[:sort][:column_name] => params[:sort][:order])
      else
        resources = resources.order(id: :asc)
      end

      resources = resources.map do |resource|
        _resource = {}

        resource.attributes.each do |attribute_name, attribute_value|
          next unless model_fields.include?(attribute_name)

          _resource[attribute_name] = attribute_value
        end

        _resource
      end

      render json: {
        resources: resources,
        total:     total
      }
    end

    def show
      model_klass = params[:model_klass_name].constantize
      model_fields = params[:model_fields].map { |model_field| model_field['field_name'] }

      resource = model_klass.find(params[:id]).attributes.slice(*model_fields)

      render json: resource
    end

    def create
      model_klass = params[:model_klass_name].constantize

      resource = model_klass.new(resource_params)

      if resource.save
        render json: resource
      else
        render json: resource.errors
      end
    end

    def update
      model_klass = params[:model_klass_name].constantize
      resource = model_klass.find(params[:id])

      if resource.update(resource_params)
        render json: resource
      else
        render json: resource.errors
      end
    end

    def destroy
      model_klass = params[:model_klass_name].constantize
      resource = model_klass.find(params[:id])

      resource.destroy
    end

    private

      def search(search_query, model_klass, model_attributes)
        return [] if model_attributes.empty?

        query = model_attributes.map { |model_attribute| "#{model_attribute} LIKE ?" }.join(' OR ')
        query_arguments = model_attributes.map { "%#{search_query}%" }

        {
          resources: model_klass.where(query, *query_arguments),
          total:     model_klass.where(query, *query_arguments).count
        }
      end

      def resource_params
        params.require(:resource).permit!
      end
  end
end