fixin.me/app/controllers/measurements_controller.rb

class MeasurementsController < ApplicationController
  before_action :find_readout, only: [:destroy, :edit, :update]

  before_action except: :index do
    raise AccessForbidden unless current_user.at_least(:active)
  end

  def index
    load_measurements
  end

  def new
    @quantities = current_user.quantities.ordered
  end

  def create
    taken_at = params.permit(:taken_at)[:taken_at]
    readout_params = params.permit(readouts: Readout::ATTRIBUTES).fetch(:readouts, [])
    @readouts = readout_params.map { |rp| current_user.readouts.build(rp.merge(taken_at: taken_at)) }

    if @readouts.present? && @readouts.all?(&:valid?)
      ActiveRecord::Base.transaction { @readouts.each(&:save!) }
      load_measurements
      flash.now[:notice] = t('.success', count: @readouts.size)
    else
      errors = @readouts.flat_map { |r| r.errors.full_messages }
      flash.now[:alert] = errors.present? ? errors.first : t('.no_readouts')
    end
  end

  def edit
    @user_units = current_user.units.ordered
  end

  def update
    if @readout.update(params.require(:readout).permit(:value, :unit_id, :taken_at))
      load_measurements
      flash.now[:notice] = t('.success')
    else
      @user_units = current_user.units.ordered
      render :edit
    end
  end

  def destroy
    @readout.destroy!
    load_measurements
    flash.now[:notice] = t('.success')
  end

  private

  def find_readout
    @readout = current_user.readouts.find(params[:id])
  end

  def load_measurements
    @measurements = current_user.readouts.includes(:quantity, :unit).order(taken_at: :desc, id: :desc)
    @wide_groups = @measurements.group_by(&:taken_at)
    @wide_quantities = @measurements.map(&:quantity).uniq.sort_by(&:name)
  end
end