rent.rb

class RentDaysController < ApplicationController
  before_action :set_rent_day, only: [:show, :edit, :update, :destroy]
  before_action :authenticate_user!
  skip_before_action :verify_authenticity_token
  
  # GET /rent_days
  # GET /rent_days.json
  def index
    @rent_days = RentDay.all
  end

  # GET /rent_days/1
  # GET /rent_days/1.json
  def show
  end

  # GET /rent_days/new
  def new
    @rent_day = RentDay.new
  end

  # GET /rent_days/1/edit
  def edit
  end

  # POST /rent_days
  # POST /rent_days.json
  def create
    @rent_day = RentDay.new(rent_day_params)

    respond_to do |format|
      if @rent_day.save
        format.html { redirect_to @rent_day, notice: 'Rent day was successfully created.' }
        format.json { render :show, status: :created, location: @rent_day }
      else
        format.html { render :new }
        format.json { render json: @rent_day.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /rent_days/1
  # PATCH/PUT /rent_days/1.json
  def update
    respond_to do |format|
      if @rent_day.update(rent_day_params)
        format.html { redirect_to @rent_day, notice: 'Rent day was successfully updated.' }
        format.json { render :show, status: :ok, location: @rent_day }
      else
        format.html { render :edit }
        format.json { render json: @rent_day.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /rent_days/1
  # DELETE /rent_days/1.json
  def destroy
    @rent_day.destroy
    respond_to do |format|
      format.html { redirect_to rent_days_url, notice: 'Rent day was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  # CUSTOM METHODS

  # esta lógica de Business está misturada com responsabilidade do controller,
  # de capturar input e gerar output.
  # Seria melhor extrair para um Service.
  def availability

    # não informou o motivo da falha
    if params[:date].empty? && params[:days].empty?
      return render json: :fail
    end

    # não tratou data inválida
    start_date = Date.strptime(params[:date], '%Y-%m-%d')
    end_date = start_date + (params[:days].to_i).days

    days = params[:days].to_i
    
    # off by one error
    # (caso o cliente queira alugar por 1 dia,
    # 0..1 na verdade faz 2 loops, 1 para o zero e outro para o 1
    (0..days).each do |i|
      day_plus_one = start_date + i.days
      check_date = RentDay.find_by_start_date(day_plus_one)
      unless check_date.nil?
        return render json: :fail
        # break depois do return?
        break
      end
    end

    # ruby não precisa de return, qualquer editor com lint já pega isso
    return render json: :ok

  end

  # esta lógica de Business está misturada com responsabilidade do controller,
  # de capturar input e gerar output.
  # Seria melhor extrair para um Service.
  def make_reservation
    # não tratou data inválida
    start_date = Date.strptime(params[:date], '%Y-%m-%d')
    end_date = start_date + (params[:days].to_i).days
    days = params[:days].to_i
    # mesmo off-by-one error do método acima
    (0..days).each do |i|
      day_plus_one = start_date + i.days
      # não utilizou transaction da maneira correta,
      # ela deve estar fora do loop
      RentDay.transaction do
        RentDay.create(start_date: day_plus_one , end_date: end_date, days: days, user_id: current_user.id)
        # forçar rollback desfaz o create acima
        raise ActiveRecord::Rollback
      end

    end

    # porque não utilizar os ids dos registros criados acima?
    number = order_number 6
    # ruby não precisa de return
    return render json: {ok: :ok , order_number: number }
  end

  def order_number number
    # sugestão 1: rand(36**number).to_s(36)
    # sugestão 2: SecureRandom seria mais seguro
    charset = Array('A'..'Z') + Array('a'..'z')
    Array.new(number) { charset.sample }.join
  end

  def history
    @history = current_user.rent_days.order(:start_date)
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_rent_day
      @rent_day = RentDay.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def rent_day_params
      params.require(:rent_day).permit(:start_date, :end_date, :days)
    end
end