GoogleAnalyticsに登録してるサイト全ての昨日のPV数出すやつ

Gemfile

source "https://rubygems.org"

gem "google-api-client", "0.8.6"
gem "pry"
gem "oauth2"

prev_page_view.rb

#!/usr/bin/env ruby
# -*- encoding: utf-8 -*-

# 参考
# http://qiita.com/kazuph/items/2cf81a84985e894e9682
# http://bekkou68.hatenablog.com/entry/2014/08/20/222032
#
# api試すページ
# https://developers.google.com/apis-explorer/#s/analytics/v3/

require 'pp'
require 'json'
require 'pry'

require 'google/api_client'
require 'google/api_client/client_secrets'
require 'google/api_client/auth/installed_app'
require 'google/api_client/auth/file_storage'

Encoding.default_external='utf-8'

class PrevPageView
  CREDENTIAL_STORE_FILE = "#{$0}-oauth2.json"

  def initialize
    client
    authorize!
  end

  def client
    @client ||= Google::APIClient.new(:application_name => 'TestProject', :application_version => '0.0.1')
  end

  def authorize!
    authfile = Google::APIClient::FileStorage.new(CREDENTIAL_STORE_FILE)

    unless authfile.authorization.nil?
      @client.authorization = authfile.authorization
    else
      # ここでDLしたJSONを読み込んでいるので同じディレクトリにclient_secrets.jsonを置いておくこと
      client_secrets = Google::APIClient::ClientSecrets.load

      flow = Google::APIClient::InstalledAppFlow.new(
        :client_id     => client_secrets.client_id,
        :client_secret => client_secrets.client_secret,
        :scope         => ['https://www.googleapis.com/auth/analytics.readonly']
      )

      @client.authorization = flow.authorize
      authfile.write_credentials(@client.authorization.dup) # 認証情報をファイルに保存
    end
    @client
  end

  def analytics
    @analytics ||= client.discovered_api('analytics', 'v3')
  end

  def date
    DateTime.now.prev_day.strftime("%Y-%m-%d")
  end

  def page_view(profile_id)
    result = client.execute(
      :api_method => analytics.data.ga.get,
      :parameters => {
        'ids'        => "ga:" + profile_id,
        'start-date' => date,
        'end-date'   => date,
        'metrics'    => 'ga:pageviews',
      }
    )

    body = JSON.parse(result.response.body)
    return body['error']['message'] if body['error']
    body['totalsForAllResults']['ga:pageviews'].to_i
  end

  def profiles_list
    result = client.execute(
      :api_method => analytics.management.profiles.list,
      :parameters => {
        'accountId'     => "~all",
        'webPropertyId' => "~all",
      }
    )
    body = JSON.parse(result.response.body)
    return body['error']['message'] if body['error']
    body['items'].map{|i|[page_view(i['id']),i['websiteUrl']]}.sort {|(k1, v1), (k2, v2)| k2 <=> k1 }
  end
end

prev_page_view = PrevPageView.new
pp prev_page_view.date
pp prev_page_view.profiles_list