instagram_clone.rb

class PicturesController < ApplicationController

  def index
    if confirm_params_or_redirect(params)
      redirect_to root_path(:view => @view, :filter => @filter) and return
    end
    
    Picture.find(@view, @filter)
  end

  private

  def confirm_params_or_redirect(params)
    redirect = false

    if !current_user and params[:view] != "all"
      @view = session[:view] = params[:view] = "all"
      redirect = true
    end

    if params[:view] and %w(all followed).include? params[:view]
      @view = session[:view] = params[:view]
    elsif session[:view]
      @view = session[:view]
      redirect = true
    else
      @view = "all"
      redirect = true
    end

    if params[:filter] and %w(hot popular recent liked).include? params[:filter][0]
      if %w(popular liked).include? params[:filter][0]
        if %w(day hour month all).include? params[:filter][1]
          @filter = session[:filter] = params[:filter]
        else
          @filter = session[:filter]
          redirect = true
        end
      else
        @filter = session[:filter] = params[:filter]
      end
    elsif session[:filter]
      @filter = session[:filter]
      redirect = true
    else
      @filter = ["hot"]
      redirect = true
    end

    return redirect

  end
end