From 71f736e0a26e343e3ed1bf20f488ae9b641b33bc Mon Sep 17 00:00:00 2001
From: Max Melentiev <melentievm@gmail.com>
Date: Thu, 19 May 2016 16:29:01 +0300
Subject: [PATCH] Async requests with ActiveJob

---
 README.md                                     |  15 ++
 lib/telegram/bot.rb                           |   1 +
 lib/telegram/bot/async.rb                     | 138 ++++++++++++++++++
 lib/telegram/bot/botan.rb                     |  20 ++-
 lib/telegram/bot/botan/client_helpers.rb      |   2 +-
 lib/telegram/bot/client.rb                    |   5 +
 lib/telegram/bot/config_methods.rb            |  20 ++-
 lib/telegram/bot/updates_poller.rb            |   2 +-
 spec/support/examples/async.rb                |  89 +++++++++++
 spec/telegram/bot/async_spec.rb               |  28 ++++
 .../telegram/bot/botan/client_helpers_spec.rb |   8 +
 spec/telegram/bot/botan_spec.rb               |   7 +
 spec/telegram/bot/client_spec.rb              |   7 +
 spec/telegram/bot/config_methods_spec.rb      |  94 ++++++++++++
 14 files changed, 421 insertions(+), 15 deletions(-)
 create mode 100644 lib/telegram/bot/async.rb
 create mode 100644 spec/support/examples/async.rb
 create mode 100644 spec/telegram/bot/async_spec.rb
 create mode 100644 spec/telegram/bot/config_methods_spec.rb

diff --git a/README.md b/README.md
index 7cf7d36..277e9e2 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,7 @@ Package contains:
 - Middleware and routes helpers for production env.
 - Poller with automatic source-reloader for development env.
 - Rake tasks to update webhook urls.
+- Async requests for Telegram and/or Botan API. Let the queue adapter handle errors!
 
 Here is sample [telegram_bot_app](https://github.com/telegram-bot-rb/telegram_bot_app)
 with session, keyboards and inline queries.
@@ -374,6 +375,20 @@ end
 
 There is no stubbing for botan clients, so don't set botan token in tests.
 
+### Async mode
+
+There is built in support for async requests using ActiveJob. Without Rails
+you can implement your own worker class to handle such requests. This allows:
+
+- Process updates very fast, without waiting for telegram and botan responses.
+- Handle and retry network and other errors with queue adapter.
+- ???
+
+To enable this mode add `async: true` to bot's and botan's config.
+For more information and custom configuration check out
+[docs](http://www.rubydoc.info/github/telegram-bot-rb/telegram-bot/master/Telegram/Bot/Async) or
+[source](https://github.com/telegram-bot-rb/telegram-bot/blob/master/lib/telegram/bot/async.rb).
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies.
diff --git a/lib/telegram/bot.rb b/lib/telegram/bot.rb
index a51694d..72f2400 100644
--- a/lib/telegram/bot.rb
+++ b/lib/telegram/bot.rb
@@ -27,6 +27,7 @@ module Telegram
       end
     end
 
+    autoload :Async,              'telegram/bot/async'
     autoload :Botan,              'telegram/bot/botan'
     autoload :Client,             'telegram/bot/client'
     autoload :ClientStub,         'telegram/bot/client_stub'
diff --git a/lib/telegram/bot/async.rb b/lib/telegram/bot/async.rb
new file mode 100644
index 0000000..70ba221
--- /dev/null
+++ b/lib/telegram/bot/async.rb
@@ -0,0 +1,138 @@
+module Telegram
+  module Bot
+    # Telegram & Botan clients can perform requests in async way with
+    # any job adapter (ActiveJob by default). Using Rails you don't need any
+    # additional configuration. However you may want to enable async requests
+    # by default with `async: true` in `secrets.yml`. Botan client doesn't inherit
+    # async setting from client and must be configured separately.
+    #
+    #   telegram:
+    #     bots:
+    #       chat_async:
+    #         token: secret
+    #         async: true # enable async mode for client
+    #         botan: botan_token # in this way botan will not be async
+    #         botan: # in this way - it's in async mode
+    #           token: botan_token
+    #           async: true
+    #
+    # Without Rails To start using async requests
+    # initialize client with `id` kwarg and make sure the client is
+    # accessible via `Teletgram.bots[id]` in job worker. Or just use
+    # `Telegram.bots_config=` for configuration.
+    #
+    # Being in async mode `#request` enqueues job instead to perform
+    # http request instead of performing it directly.
+    # Async behavior is controlled with `#async=` writer
+    # and can be enabled/disabled for the block with `#async`:
+    #
+    #   client = Telegram::Bot::Client.new(**config, async: true)
+    #   client.send_message(message)
+    #   client.async(false) { client.send_message(other_one) }
+    #
+    # It can be set with custom job class or classname. By default it defines
+    # job classes for every client class, inherited from ApplicationRecord, which
+    # can be accessed via `.default_async_job`. You can integrate it with any
+    # other job provider by defining a class with `.perform_later(bot_id, *args)`
+    # method. See Async::Job for implemetation.
+    module Async
+      module Job
+        class << self
+          def included(base)
+            base.singleton_class.send :attr_accessor, :client_class
+          end
+        end
+
+        def perform(client_id, *args)
+          client = self.class.client_class.wrap(client_id.to_sym)
+          client.async(false) { client.request(*args) }
+        end
+      end
+
+      module ClassMethods
+        def default_async_job
+          @default_async_job ||= begin
+            begin
+              ApplicationJob
+            rescue NameError
+              raise 'Define ApplicationJob class or setup #async= with custom job class'
+            end
+            klass = Class.new(ApplicationJob) { include Job }
+            klass.client_class = self
+            const_set(:AsyncJob, klass)
+          end
+        end
+
+        # This is used in specs.
+        def default_async_job=(val)
+          @default_async_job = val
+          remove_const(:AsyncJob) if const_defined?(:AsyncJob, false)
+        end
+
+        # Prepares argments for async job. ActiveJob doesn't support
+        # Symbol in argumens. Also we can encode json bodies only once here,
+        # so it would not be unnecessarily serialized-deserialized.
+        #
+        # This is stub method, which returns input. Every client class
+        # must prepare args itself.
+        def prepare_async_args(*args)
+          args
+        end
+      end
+
+      class << self
+        def prepended(base)
+          base.extend(ClassMethods)
+        end
+
+        # Transforms symbols to strings in hash values.
+        def prepare_hash(hash)
+          return hash unless hash.is_a?(Hash)
+          hash = hash.dup
+          hash.each { |key, val| hash[key] = val.to_s if val.is_a?(Symbol) }
+        end
+      end
+
+      attr_reader :id
+
+      def initialize(*, id: nil, async: nil, **options)
+        @id = id
+        self.async = async
+        super
+      end
+
+      # Sets `@async` to `self.class.default_async_job` if `true` is given
+      # or uses given value.
+      # Pass custom job class to perform async calls with.
+      def async=(val)
+        @async =
+          case val
+          when true then self.class.default_async_job
+          when String then const_get(val)
+          else val
+          end
+      end
+
+      # Returns value of `@async` if no block is given. Otherwise sets this value
+      # for a block.
+      def async(val = true)
+        return @async unless block_given?
+        begin
+          old_val = @async
+          self.async = val
+          yield
+        ensure
+          @async = old_val
+        end
+      end
+
+      # Uses job if #async is set.
+      def request(*args)
+        job_class = async
+        return super unless job_class
+        raise 'Can not enqueue job without client id' unless id
+        job_class.perform_later(id.to_s, *self.class.prepare_async_args(*args))
+      end
+    end
+  end
+end
diff --git a/lib/telegram/bot/botan.rb b/lib/telegram/bot/botan.rb
index 34d53e9..75b3697 100644
--- a/lib/telegram/bot/botan.rb
+++ b/lib/telegram/bot/botan.rb
@@ -8,12 +8,17 @@ module Telegram
       class Error < Bot::Error; end
 
       extend Initializers
+      prepend Async
       include DebugClient
 
       class << self
         def by_id(id)
           Telegram.botans[id]
         end
+
+        def prepare_async_args(method, uri, query = {}, body = nil)
+          [method.to_s, uri.to_s, Async.prepare_hash(query), body]
+        end
       end
 
       attr_reader :client, :token
@@ -24,12 +29,11 @@ module Telegram
       end
 
       def track(event, uid, payload = {})
-        res = http_request(
-          :post,
-          TRACK_URI,
-          {token: token, name: event, uid: uid},
-          payload.to_json,
-        )
+        request(:post, TRACK_URI, {name: event, uid: uid}, payload.to_json)
+      end
+
+      def request(method, uri, query = {}, body = nil)
+        res = http_request(method, uri, query.merge(token: token), body)
         status = res.status
         return JSON.parse(res.body) if 300 > status
         result = JSON.parse(res.body) rescue nil # rubocop:disable RescueModifier
@@ -40,6 +44,10 @@ module Telegram
       def http_request(method, uri, query, body)
         client.request(method, uri, query, body)
       end
+
+      def inspect
+        "#<#{self.class.name}##{object_id}(#{@id})>"
+      end
     end
   end
 end
diff --git a/lib/telegram/bot/botan/client_helpers.rb b/lib/telegram/bot/botan/client_helpers.rb
index c44ca8d..b88efa1 100644
--- a/lib/telegram/bot/botan/client_helpers.rb
+++ b/lib/telegram/bot/botan/client_helpers.rb
@@ -7,7 +7,7 @@ module Telegram
 
         def initialize(*, botan: nil, **)
           super
-          @botan = Botan.wrap(botan) if botan
+          @botan = Botan.wrap(botan, id: id) if botan
         end
       end
     end
diff --git a/lib/telegram/bot/client.rb b/lib/telegram/bot/client.rb
index b35d216..37a0812 100644
--- a/lib/telegram/bot/client.rb
+++ b/lib/telegram/bot/client.rb
@@ -10,6 +10,7 @@ module Telegram
 
       autoload :TypedResponse, 'telegram/bot/client/typed_response'
       extend Initializers
+      prepend Async
       prepend Botan::ClientHelpers
       include DebugClient
 
@@ -30,6 +31,10 @@ module Telegram
             body[k] = val.to_json if val.is_a?(Hash) || val.is_a?(Array)
           end
         end
+
+        def prepare_async_args(action, body = {})
+          [action.to_s, Async.prepare_hash(prepare_body(body))]
+        end
       end
 
       attr_reader :client, :token, :username, :base_uri
diff --git a/lib/telegram/bot/config_methods.rb b/lib/telegram/bot/config_methods.rb
index ea55ec1..6272e21 100644
--- a/lib/telegram/bot/config_methods.rb
+++ b/lib/telegram/bot/config_methods.rb
@@ -26,7 +26,9 @@ module Telegram
 
       # Hash of bots made with bots_config.
       def bots
-        @bots ||= bots_config.transform_values(&Client.method(:wrap))
+        @bots ||= bots_config.each_with_object({}) do |(id, config), h|
+          h[id] = Client.wrap(config, id: id)
+        end
       end
 
       # Default bot.
@@ -44,12 +46,16 @@ module Telegram
       #
       # Can be overwritten with .bots_config=
       def bots_config
-        return @bots_config if @bots_config
-        telegram_config = Rails.application.secrets[:telegram]
-        (telegram_config['bots'] || {}).symbolize_keys.tap do |config|
-          default = telegram_config['bot']
-          config[:default] = default if default
-        end
+        @bots_config ||=
+          if defined?(Rails)
+            telegram_config = Rails.application.secrets[:telegram] || {}
+            (telegram_config['bots'] || {}).symbolize_keys.tap do |config|
+              default = telegram_config['bot']
+              config[:default] = default if default
+            end
+          else
+            {}
+          end
       end
 
       # Resets all cached bots and their configs.
diff --git a/lib/telegram/bot/updates_poller.rb b/lib/telegram/bot/updates_poller.rb
index 825dcdb..05e2b15 100644
--- a/lib/telegram/bot/updates_poller.rb
+++ b/lib/telegram/bot/updates_poller.rb
@@ -64,7 +64,7 @@ module Telegram
       end
 
       def fetch_updates
-        response = bot.get_updates(offset: offset, timeout: timeout)
+        response = bot.async(false) { bot.get_updates(offset: offset, timeout: timeout) }
         return unless response['ok'] && response['result'].any?
         reload! do
           response['result'].each do |update|
diff --git a/spec/support/examples/async.rb b/spec/support/examples/async.rb
new file mode 100644
index 0000000..795b72c
--- /dev/null
+++ b/spec/support/examples/async.rb
@@ -0,0 +1,89 @@
+RSpec.shared_examples 'async' do |request_args: -> {}|
+  let(:instance) { described_class.new(token: token, id: id, async: async) }
+  let(:id) { :default_bot }
+  let(:async) { true }
+  let!(:application_job_class) do
+    klass = Class.new do
+      def self.perform_later(*)
+      end
+    end
+    klass.tap { |x| stub_const('ApplicationJob', x) }
+  end
+  after { described_class.default_async_job = nil }
+
+  describe '#async' do
+    subject { ->(*args, &block) { instance.async(*args, &block) } }
+    its(:call) { should eq described_class.default_async_job }
+
+    context 'when async is disabled' do
+      let(:async) { false }
+      its(:call) { should eq false }
+    end
+
+    context 'when using with block' do
+      it 'sets value inside block' do
+        expect do
+          expect do
+            subject.call(false) do
+              expect do
+                subject.call(nil) { expect(subject[]).to eq nil }
+              end.to_not change(&subject).from false
+              raise 'TestError'
+            end
+          end.to raise_error(/TestError/)
+        end.to_not change(instance, :async).from(described_class.default_async_job)
+      end
+    end
+  end
+
+  describe '.default_async_job' do
+    subject { described_class.default_async_job }
+    its(:superclass) { should eq application_job_class }
+    it { should include Telegram::Bot::Async::Job }
+    its(:client_class) { should eq described_class }
+
+    context 'when ApplicationJob is not defined' do
+      let(:application_job_class) {}
+      it { expect { subject }.to raise_error(/Define ApplicationJob/) }
+    end
+  end
+
+  describe '#request' do
+    subject { ->(*args) { instance.request(*(args.empty? ? self.args : args)) } }
+    let(:args, &request_args)
+    let(:result) { double(:result) }
+
+    shared_examples 'enqueues job' do
+      it 'enqueues job' do
+        expect(instance).to_not receive(:http_request)
+        expect(described_class).to receive(:prepare_async_args).with(*args) { args }
+        expect(instance.async).to receive(:perform_later).with(id.to_s, *args) { result }
+        expect(subject.call).to eq result
+      end
+    end
+
+    include_examples 'enqueues job'
+
+    context 'with custom job class' do
+      let(:async) { double(:job_class) }
+      include_examples 'enqueues job'
+    end
+
+    context 'when id is not set' do
+      let(:id) {}
+      it { should raise_error(/Can not enqueue/) }
+    end
+
+    context 'when async is disabled' do
+      let(:async) { false }
+      let(:result) { double(status: 200, body: '{"test":"ok"}') }
+      let(:args, &request_args)
+
+      it 'performs request immediately' do
+        expect(instance).to receive(:request).with(*args).and_call_original
+        expect(instance).to receive(:http_request) { result }
+        expect(subject[]).to eq 'test' => 'ok'
+      end
+    end
+  end
+end
diff --git a/spec/telegram/bot/async_spec.rb b/spec/telegram/bot/async_spec.rb
new file mode 100644
index 0000000..ce13e43
--- /dev/null
+++ b/spec/telegram/bot/async_spec.rb
@@ -0,0 +1,28 @@
+RSpec.describe Telegram::Bot::Async::Job do
+  let(:job_class) do
+    described_class = self.described_class
+    client_class = self.client_class
+    Class.new do
+      include described_class
+      self.client_class = client_class
+    end
+  end
+  let(:client_class) { Telegram::Bot::Client }
+  let(:instance) { job_class.new }
+
+  describe '#perform' do
+    subject { instance.perform(id, *args) }
+    let(:id) { 'bot_id' }
+    let(:args) { [double(:action), {body: :content}] }
+    let(:client) { Telegram::Bot::Client.new(async: custom_job_class) }
+    let(:custom_job_class) { Class.new }
+    let(:result) { double(status: 200, body: '{"test":"ok"}') }
+
+    it 'finds client and performs request' do
+      expect(client_class).to receive(:wrap).with(id.to_sym) { client }
+      expect(client).to receive(:request).with(*args).and_call_original
+      expect(client).to receive(:http_request) { result }
+      should eq 'test' => 'ok'
+    end
+  end
+end
diff --git a/spec/telegram/bot/botan/client_helpers_spec.rb b/spec/telegram/bot/botan/client_helpers_spec.rb
index a2e3cb5..69945f4 100644
--- a/spec/telegram/bot/botan/client_helpers_spec.rb
+++ b/spec/telegram/bot/botan/client_helpers_spec.rb
@@ -13,6 +13,12 @@ RSpec.describe Telegram::Bot::Client do
       let(:client_args) { [token, id: client_id, async: Class.new, botan: botan_token] }
       it { should be_instance_of Telegram::Bot::Botan }
       its(:token) { should eq botan_token }
+      its(:id) { should eq client_id }
+
+      it 'doesnt inherit async from client' do
+        expect(instance.async).to be
+        expect(subject.async).to_not be
+      end
     end
 
     context 'when botan is configured with hash' do
@@ -20,6 +26,8 @@ RSpec.describe Telegram::Bot::Client do
       let(:botan_config) { {token: botan_token, async: Class.new} }
       it { should be_instance_of Telegram::Bot::Botan }
       its(:token) { should eq botan_token }
+      its(:id) { should eq client_id }
+      its(:async) { should eq botan_config[:async] }
     end
   end
 end
diff --git a/spec/telegram/bot/botan_spec.rb b/spec/telegram/bot/botan_spec.rb
index 809d69d..03a072b 100644
--- a/spec/telegram/bot/botan_spec.rb
+++ b/spec/telegram/bot/botan_spec.rb
@@ -3,6 +3,7 @@ RSpec.describe Telegram::Bot::Botan do
   let(:token) { 'token' }
 
   include_examples 'initializers', :botans
+  include_examples 'async', request_args: -> { [double(:method), double(:url)] }
 
   describe '.new' do
     subject { described_class.new(*args) }
@@ -17,4 +18,10 @@ RSpec.describe Telegram::Bot::Botan do
       its(:token) { should eq args[0][:token] }
     end
   end
+
+  describe '.prepare_async_args' do
+    subject { described_class.prepare_async_args(*input) }
+    let(:input) { [:post, :uri, {a: 1, b: :sym, 'd' => 'str'}, 'body'] }
+    it { should eq ['post', 'uri', {a: 1, b: 'sym', 'd' => 'str'}, 'body'] }
+  end
 end
diff --git a/spec/telegram/bot/client_spec.rb b/spec/telegram/bot/client_spec.rb
index 41f0b38..df4d1a8 100644
--- a/spec/telegram/bot/client_spec.rb
+++ b/spec/telegram/bot/client_spec.rb
@@ -4,6 +4,7 @@ RSpec.describe Telegram::Bot::Client do
   let(:botan_token) { double(:botan_token) }
 
   include_examples 'initializers'
+  include_examples 'async', request_args: -> { [double(:action), {body: :content}] }
 
   describe '.prepare_body' do
     subject { described_class.prepare_body(input) }
@@ -24,6 +25,12 @@ RSpec.describe Telegram::Bot::Client do
     end
   end
 
+  describe '.prepare_async_args' do
+    subject { described_class.prepare_async_args(*input) }
+    let(:input) { [:action, a: 1, b: :sym, c: [:other], 'd' => 'str'] }
+    it { should eq ['action', a: 1, b: 'sym', c: '["other"]', 'd' => 'str'] }
+  end
+
   describe '.new' do
     subject { described_class.new(*args) }
 
diff --git a/spec/telegram/bot/config_methods_spec.rb b/spec/telegram/bot/config_methods_spec.rb
new file mode 100644
index 0000000..f806896
--- /dev/null
+++ b/spec/telegram/bot/config_methods_spec.rb
@@ -0,0 +1,94 @@
+RSpec.describe Telegram::Bot::ConfigMethods do
+  let(:registry) do
+    Object.new.tap do |x|
+      x.extend described_class
+      x.bots_config = config
+    end
+  end
+  let(:config) do
+    {
+      default: 'default_token',
+      chat: {
+        token: 'chat_token',
+        username: 'Chat',
+        botan: 'chat_botan_token',
+      },
+      other_chat: {
+        'token' => 'other_chat_token',
+        'username' => 'OtherChat',
+        'botan' => 'other_chat_botan_token',
+      },
+    }
+  end
+
+  describe '#bot' do
+    subject { registry.bot }
+    it { should eq registry.bots[:default] }
+  end
+
+  describe '#bots' do
+    context 'configured by token' do
+      subject { registry.bots[:default] }
+      its(:id) { should eq :default }
+      its(:token) { should eq config[:default] }
+    end
+
+    context 'configured by hash' do
+      subject { registry.bots[:chat] }
+      its(:id) { should eq :chat }
+      its(:token) { should eq config[:chat][:token] }
+      its(:username) { should eq config[:chat][:username] }
+      its('botan.token') { should eq config[:chat][:botan] }
+    end
+
+    context 'configured by hash with stringified keys' do
+      subject { registry.bots[:other_chat] }
+      its(:id) { should eq :other_chat }
+      its(:token) { should eq config[:other_chat]['token'] }
+      its(:username) { should eq config[:other_chat]['username'] }
+      its('botan.token') { should eq config[:other_chat]['botan'] }
+    end
+  end
+
+  describe '#botans' do
+    subject { registry.botans }
+    it do
+      should eq(
+        default: nil,
+        chat: registry.bots[:chat].botan,
+        other_chat: registry.bots[:other_chat].botan,
+      )
+    end
+  end
+
+  describe '#bots_config' do
+    subject { registry.bots_config }
+    it { should eq config }
+
+    context 'when not configured' do
+      let(:registry) { Object.new.tap { |x| x.extend described_class } }
+      it { should eq({}) }
+
+      context 'in rails environment' do
+        before { stub_const('Rails', double(application: double(secrets: secrets))) }
+        let(:secrets) { {} }
+        it { should eq({}) }
+
+        context 'when there is telegram section in secrets' do
+          let(:secrets) { {telegram: config.stringify_keys} }
+          let(:config) do
+            {
+              bot: double(:bot_config),
+              bots: {
+                chat: double(:chat_config),
+                other_chat: double(:other_chat_config),
+              },
+            }
+          end
+          it { should include default: config[:bot] }
+          it { should include config[:bots] }
+        end
+      end
+    end
+  end
+end