module E9Crm
  #
  # This module is included into all controllers and makes available the current +tracking_cookie+
  # and +tracking_campaign+ as controller and helper methods
  #
  module Controller
    extend ActiveSupport::Concern

    included do
      helper_method :tracking_cookie, :tracking_campaign

      #
      # monkey patch liquid_env to insert campaign
      #
      alias :liquid_env_without_crm :liquid_env
      def liquid_env
        liquid_env_without_crm.tap do |env|
          env[:campaign] = tracking_campaign
        end
      end
    end

    protected

    #
    # Attempts to get the Campaign associated with the loaded tracking cookie, and will
    # install a tracking cookie first if one is not found.
    #
    # Falls back the the default campaign (typically No Campaign) if the tracking cookie
    # is not associated with a campaign.
    #
    def tracking_campaign
      @_tracking_campaign ||= begin
        tracking_cookie.code.present? && ::Campaign.find_by_code(tracking_cookie.code) || ::Campaign.default
      end
    end

    def _user_from_params
      if user_id = params.delete(E9Crm.query_user_id)
        @_user_from_params = User.find_by_id(user_id)
      end

      @_user_from_params
    end

    #
    # Loads or installs the tracking cookie
    #
    def tracking_cookie
      @_tracking_cookie ||= begin
        E9Crm.log "Begin load or install cookie: cookie_name[#{E9Crm.cookie_name}] query_param[#{E9Crm.query_param}]"

        code    = params.delete(E9Crm.query_param)

        if hid = cookies[E9Crm.cookie_name]
          E9Crm.log("Installed cookie found: hid(#{hid})")
          @_tracking_cookie = ::TrackingCookie.find_by_hid(hid)

          unless @_tracking_cookie
            # This should only happen in developemnt, as it means the cookie has been
            # installed then removed from the database.
            E9Crm.log("Installed cookie's hash id does not match any stored cookies!")
          end
        end

        E9Crm.log(@_tracking_cookie ? "Cookie loaded: (#{E9Crm.cookie_name} : #{@_tracking_cookie.hid})" : "Cookie not found")

        if @_tracking_cookie
          if current_user && @_tracking_cookie.user_id? && @_tracking_cookie.user_id != current_user.id
            E9Crm.log "Tracking user_id not matched: found(#{@_tracking_cookie.user_id}), current(#{current_user.id}"
            @_tracking_cookie = nil
          else
            attrs = {}

            if @_tracking_cookie.user_id.nil?
              if current_user
                E9Crm.log("Cookie has no user, setting as current_user (#{current_user.id})")
                attrs[:user] = current_user
              elsif _user_from_params
                E9Crm.log("Cookie has no user, setting as user from params (#{_user_from_params.id})")
                attrs[:user] = _user_from_params
              end
            end

            if code.present? && code != @_tracking_cookie.code && ::Campaign.find_by_code(code)
              E9Crm.log "Code present and cookie code(#{@_tracking_cookie.code}) does not match (#{code}), changing..."
              attrs[:code] = code

              E9Crm.log "Cookie marked as new"
              session[:new_visit] = true
            end

            if attrs.blank?
              E9Crm.log "Cookie unchanged, no update"
            else
              E9Crm.log "Cookie changed, new attrs: #{attrs.inspect}"
              @_tracking_cookie.update_attributes(attrs)
            end
          end
        end

        @_tracking_cookie ||= begin
          session[:new_visit] = true

          ::TrackingCookie.create(:code => code, :user => current_user || _user_from_params).tap do |cookie|
            E9Crm.log "Installing new cookie (#{E9Crm.cookie_name} : #{cookie.hid})"
            cookies.permanent[E9Crm.cookie_name] = cookie.hid
          end
        end

        E9Crm.log("Final Cookie : #{@_tracking_cookie.inspect}")

        @_tracking_cookie
      end
    end
  end
end