From ac93af60281d6c7a1cf394adaf213978ccceb5ae Mon Sep 17 00:00:00 2001
From: Sojan Jose <sojan@pepalo.com>
Date: Thu, 2 May 2024 14:05:14 -0700
Subject: [PATCH] feat: Support document file uploads on telegram channel
 (#9266)

---
 app/models/channel/telegram.rb                |  75 +++-------
 .../telegram/send_attachments_service.rb      | 138 ++++++++++++++++++
 spec/models/channel/telegram_spec.rb          |  58 +-------
 .../telegram/send_attachments_service_spec.rb | 114 +++++++++++++++
 4 files changed, 277 insertions(+), 108 deletions(-)
 create mode 100644 app/services/telegram/send_attachments_service.rb
 create mode 100644 spec/services/telegram/send_attachments_service_spec.rb

diff --git a/app/models/channel/telegram.rb b/app/models/channel/telegram.rb
index f6b97f2d2..7c09fe284 100644
--- a/app/models/channel/telegram.rb
+++ b/app/models/channel/telegram.rb
@@ -33,9 +33,9 @@ class Channel::Telegram < ApplicationRecord
   end
 
   def send_message_on_telegram(message)
-    return send_message(message) if message.attachments.empty?
-
-    send_attachments(message)
+    message_id = send_message(message) if message.content.present?
+    message_id = Telegram::SendAttachmentsService.new(message: message).perform if message.attachments.present?
+    message_id
   end
 
   def get_telegram_profile_image(user_id)
@@ -56,6 +56,23 @@ class Channel::Telegram < ApplicationRecord
     "https://api.telegram.org/file/bot#{bot_token}/#{response.parsed_response['result']['file_path']}"
   end
 
+  def process_error(message, response)
+    return unless response.parsed_response['ok'] == false
+
+    # https://github.com/TelegramBotAPI/errors/tree/master/json
+    message.external_error = "#{response.parsed_response['error_code']}, #{response.parsed_response['description']}"
+    message.status = :failed
+    message.save!
+  end
+
+  def chat_id(message)
+    message.conversation[:additional_attributes]['chat_id']
+  end
+
+  def reply_to_message_id(message)
+    message.content_attributes['in_reply_to_external_id']
+  end
+
   private
 
   def ensure_valid_bot_token
@@ -77,29 +94,12 @@ class Channel::Telegram < ApplicationRecord
     errors.add(:bot_token, 'error setting up the webook') unless response.success?
   end
 
-  def chat_id(message)
-    message.conversation[:additional_attributes]['chat_id']
-  end
-
-  def reply_to_message_id(message)
-    message.content_attributes['in_reply_to_external_id']
-  end
-
   def send_message(message)
     response = message_request(chat_id(message), message.content, reply_markup(message), reply_to_message_id(message))
     process_error(message, response)
     response.parsed_response['result']['message_id'] if response.success?
   end
 
-  def process_error(message, response)
-    return unless response.parsed_response['ok'] == false
-
-    # https://github.com/TelegramBotAPI/errors/tree/master/json
-    message.external_error = "#{response.parsed_response['error_code']}, #{response.parsed_response['description']}"
-    message.status = :failed
-    message.save!
-  end
-
   def reply_markup(message)
     return unless message.content_type == 'input_select'
 
@@ -114,41 +114,6 @@ class Channel::Telegram < ApplicationRecord
     }.to_json
   end
 
-  def send_attachments(message)
-    send_message(message) unless message.content.nil?
-
-    telegram_attachments = []
-    message.attachments.each do |attachment|
-      telegram_attachment = {}
-      telegram_attachment[:type] = attachment_type(attachment[:file_type])
-      telegram_attachment[:media] = attachment.download_url
-      telegram_attachments << telegram_attachment
-    end
-
-    response = attachments_request(chat_id(message), telegram_attachments, reply_to_message_id(message))
-    process_error(message, response)
-    response.parsed_response['result'].first['message_id'] if response.success?
-  end
-
-  def attachment_type(file_type)
-    file_type_mappings = {
-      'audio' => 'audio',
-      'image' => 'photo',
-      'file' => 'document',
-      'video' => 'video'
-    }
-    file_type_mappings[file_type]
-  end
-
-  def attachments_request(chat_id, attachments, reply_to_message_id)
-    HTTParty.post("#{telegram_api_url}/sendMediaGroup",
-                  body: {
-                    chat_id: chat_id,
-                    media: attachments.to_json,
-                    reply_to_message_id: reply_to_message_id
-                  })
-  end
-
   def convert_markdown_to_telegram_html(text)
     # ref: https://core.telegram.org/bots/api#html-style
 
diff --git a/app/services/telegram/send_attachments_service.rb b/app/services/telegram/send_attachments_service.rb
new file mode 100644
index 000000000..2f69026b2
--- /dev/null
+++ b/app/services/telegram/send_attachments_service.rb
@@ -0,0 +1,138 @@
+# Telegram Attachment APIs: ref: https://core.telegram.org/bots/api#inputfile
+
+# Media attachments like photos, videos can be clubbed together and sent as a media group
+# Audio can be clubbed together and send as a media group, but can't be mixed with other types
+# Documents are sent individually
+
+# We are using `HTTP URL` to send media attachments, telegram will directly download the media from the URL and send it to the user.
+# But for documents, we need to send the file as a multipart request. as telegram only support pdf and zip for the download from the URL option.
+
+# ref: `In sendDocument, sending by URL will currently only work for GIF, PDF and ZIP files.`
+# ref: `https://core.telegram.org/bots/api#senddocument`
+# ref: `https://core.telegram.org/bots/api#sendmediaGroup
+
+# The service will terminate if any of the attachment requests fail when the message has multiple attachments
+# We will create multiple messages in telegram if the message has multiple attachments (if its documents or mixed media).
+class Telegram::SendAttachmentsService
+  pattr_initialize [:message!]
+
+  def perform
+    attachment_message_id = nil
+
+    group_attachments_by_type.each do |type, attachments|
+      attachment_message_id = process_attachments_by_type(type, attachments)
+      break if attachment_message_id.nil?
+    end
+
+    attachment_message_id
+  end
+
+  private
+
+  def process_attachments_by_type(type, attachments)
+    response = send_attachments(type, attachments)
+    return extract_attachment_message_id(response) if handle_response(response)
+
+    nil
+  end
+
+  def send_attachments(type, attachments)
+    if [:media, :audio].include?(type)
+      media_group_request(channel.chat_id(message), attachments, channel.reply_to_message_id(message))
+    else
+      send_individual_attachments(attachments)
+    end
+  end
+
+  def group_attachments_by_type
+    attachments_by_type = { media: [], audio: [], document: [] }
+
+    message.attachments.each do |attachment|
+      type = attachment_type(attachment[:file_type])
+      attachment_data = { type: type, media: attachment.download_url, attachment: attachment }
+      case type
+      when 'document'
+        attachments_by_type[:document] << attachment_data
+      when 'audio'
+        attachments_by_type[:audio] << attachment_data
+      when 'photo', 'video'
+        attachments_by_type[:media] << attachment_data
+      end
+    end
+
+    attachments_by_type.reject { |_, v| v.empty? }
+  end
+
+  def attachment_type(file_type)
+    { 'audio' => 'audio', 'image' => 'photo', 'file' => 'document', 'video' => 'video' }[file_type] || 'document'
+  end
+
+  def media_group_request(chat_id, attachments, reply_to_message_id)
+    HTTParty.post("#{channel.telegram_api_url}/sendMediaGroup",
+                  body: {
+                    chat_id: chat_id,
+                    media: attachments.map { |hash| hash.except(:attachment) }.to_json,
+                    reply_to_message_id: reply_to_message_id
+                  })
+  end
+
+  def send_individual_attachments(attachments)
+    response = nil
+    attachments.map do |attachment|
+      response = document_request(channel.chat_id(message), attachment, channel.reply_to_message_id(message))
+      break unless handle_response(response)
+    end
+    response
+  end
+
+  def document_request(chat_id, attachment, reply_to_message_id)
+    temp_file_path = save_attachment_to_tempfile(attachment[:attachment])
+    response = send_file(chat_id, temp_file_path, reply_to_message_id)
+    File.delete(temp_file_path)
+    response
+  end
+
+  # Telegram picks up the file name from original field name, so we need to save the file with the original name.
+  # Hence not using Tempfile here.
+  def save_attachment_to_tempfile(attachment)
+    raw_data = attachment.file.download
+    temp_dir = Rails.root.join('tmp/uploads')
+    FileUtils.mkdir_p(temp_dir)
+    temp_file_path = File.join(temp_dir, attachment.file.filename.to_s)
+    File.write(temp_file_path, raw_data, mode: 'wb')
+    temp_file_path
+  end
+
+  def send_file(chat_id, file_path, reply_to_message_id)
+    File.open(file_path, 'rb') do |file|
+      HTTParty.post("#{channel.telegram_api_url}/sendDocument",
+                    body: {
+                      chat_id: chat_id,
+                      document: file,
+                      reply_to_message_id: reply_to_message_id
+                    },
+                    multipart: true)
+    end
+  end
+
+  def handle_response(response)
+    return true if response.success?
+
+    Rails.logger.error "Message Id: #{message.id}  - Error sending attachment to telegram:  #{response.parsed_response}"
+    channel.process_error(message, response)
+    false
+  end
+
+  def extract_attachment_message_id(response)
+    return unless response.success?
+
+    result = response.parsed_response['result']
+    # response will be an array if the request for media group
+    # response will be a hash if the request for document
+    result.is_a?(Array) ? result.first['message_id'] : result['message_id']
+  end
+
+  def channel
+    @channel ||= message.inbox.channel
+  end
+end
diff --git a/spec/models/channel/telegram_spec.rb b/spec/models/channel/telegram_spec.rb
index 2cc927977..17aa848f6 100644
--- a/spec/models/channel/telegram_spec.rb
+++ b/spec/models/channel/telegram_spec.rb
@@ -137,68 +137,20 @@ RSpec.describe Channel::Telegram do
     end
   end
 
-  context 'when a empty message and valid attachments' do
+  context 'when message contains attachments' do
     let(:message) do
       create(:message, message_type: :outgoing, content: nil,
                        conversation: create(:conversation, inbox: telegram_channel.inbox, additional_attributes: { 'chat_id' => '123' }))
     end
 
-    it 'send image' do
-      telegram_attachment_response = double
+    it 'calls send attachment service' do
+      telegram_attachment_service = double
       attachment = message.attachments.new(account_id: message.account_id, file_type: :image)
       attachment.file.attach(io: Rails.root.join('spec/assets/avatar.png').open, filename: 'avatar.png', content_type: 'image/png')
 
-      allow(telegram_attachment_response).to receive(:success?).and_return(true)
-      allow(telegram_attachment_response).to receive(:parsed_response).and_return({ 'result' => [{ 'message_id' => 'telegram_456' }] })
-      allow(telegram_channel).to receive(:attachments_request).and_return(telegram_attachment_response)
+      allow(Telegram::SendAttachmentsService).to receive(:new).with(message: message).and_return(telegram_attachment_service)
+      allow(telegram_attachment_service).to receive(:perform).and_return('telegram_456')
       expect(telegram_channel.send_message_on_telegram(message)).to eq('telegram_456')
     end
-
-    it 'send document' do
-      telegram_attachment_response = double
-      attachment = message.attachments.new(account_id: message.account_id, file_type: :file)
-      attachment.file.attach(io: Rails.root.join('spec/assets/attachment.pdf').open, filename: 'attachment.pdf',
-                             content_type: 'application/pdf')
-
-      allow(telegram_attachment_response).to receive(:success?).and_return(true)
-      allow(telegram_attachment_response).to receive(:parsed_response).and_return({ 'result' => [{ 'message_id' => 'telegram_456' }] })
-      allow(telegram_channel).to receive(:attachments_request).and_return(telegram_attachment_response)
-      expect(telegram_channel.send_message_on_telegram(message)).to eq('telegram_456')
-    end
-
-    it 'send image failed' do
-      telegram_attachment_response = double
-      attachment = message.attachments.new(account_id: message.account_id, file_type: :image)
-      attachment.file.attach(io: Rails.root.join('spec/assets/avatar.png').open, filename: 'avatar.png', content_type: 'image/png')
-
-      allow(telegram_attachment_response).to receive(:success?).and_return(false)
-      allow(telegram_attachment_response).to receive(:parsed_response).and_return({ 'ok' => false, 'error_code' => '400',
-                                                                                    'description' => 'Bad Request: invalid file id' })
-      allow(telegram_channel).to receive(:attachments_request).and_return(telegram_attachment_response)
-      telegram_channel.send_message_on_telegram(message)
-      expect(message.reload.status).to eq('failed')
-      expect(message.reload.external_error).to eq('400, Bad Request: invalid file id')
-    end
-  end
-
-  context 'when a valid message and valid attachment' do
-    it 'send both message and attachment' do
-      message = create(:message, message_type: :outgoing, content: 'test',
-                                 conversation: create(:conversation, inbox: telegram_channel.inbox, additional_attributes: { 'chat_id' => '123' }))
-
-      telegram_message_response = double
-      telegram_attachment_response = double
-      attachment = message.attachments.new(account_id: message.account_id, file_type: :image)
-      attachment.file.attach(io: Rails.root.join('spec/assets/avatar.png').open, filename: 'avatar.png', content_type: 'image/png')
-
-      allow(telegram_message_response).to receive(:success?).and_return(true)
-      allow(telegram_message_response).to receive(:parsed_response).and_return({ 'result' => { 'message_id' => 'telegram_456' } })
-      allow(telegram_attachment_response).to receive(:success?).and_return(true)
-      allow(telegram_attachment_response).to receive(:parsed_response).and_return({ 'result' => [{ 'message_id' => 'telegram_789' }] })
-
-      allow(telegram_channel).to receive(:message_request).and_return(telegram_message_response)
-      allow(telegram_channel).to receive(:attachments_request).and_return(telegram_attachment_response)
-      expect(telegram_channel.send_message_on_telegram(message)).to eq('telegram_789')
-    end
   end
 end
diff --git a/spec/services/telegram/send_attachments_service_spec.rb b/spec/services/telegram/send_attachments_service_spec.rb
new file mode 100644
index 000000000..2159acddd
--- /dev/null
+++ b/spec/services/telegram/send_attachments_service_spec.rb
@@ -0,0 +1,114 @@
+require 'rails_helper'
+
+RSpec.describe Telegram::SendAttachmentsService do
+  describe '#perform' do
+    let(:channel) { create(:channel_telegram) }
+    let(:message) { build(:message, conversation: create(:conversation, inbox: channel.inbox)) }
+    let(:service) { described_class.new(message: message) }
+    let(:telegram_api_url) { channel.telegram_api_url }
+
+    before do
+      allow(channel).to receive(:chat_id).and_return('chat123')
+
+      stub_request(:post, "#{telegram_api_url}/sendMediaGroup")
+        .to_return(status: 200, body: { ok: true, result: [{ message_id: 'media' }] }.to_json, headers: { 'Content-Type' => 'application/json' })
+
+      stub_request(:post, "#{telegram_api_url}/sendDocument")
+        .to_return(status: 200, body: { ok: true, result: { message_id: 'document' } }.to_json, headers: { 'Content-Type' => 'application/json' })
+    end
+
+    it 'sends all types of attachments in seperate groups and returns the last successful message ID from the batch' do
+      attach_files(message)
+      result = service.perform
+      expect(result).to eq('document')
+      # videos and images are sent in a media group
+      # audio is sent in another group
+      expect(a_request(:post, "#{telegram_api_url}/sendMediaGroup")).to have_been_made.times(2)
+      expect(a_request(:post, "#{telegram_api_url}/sendDocument")).to have_been_made.once
+    end
+
+    context 'when all attachments are documents' do
+      before do
+        2.times { attach_file_to_message(message, 'file', 'sample.pdf', 'application/pdf') }
+        message.save!
+      end
+
+      it 'sends documents individually and returns the message ID of the first successful document' do
+        result = service.perform
+        expect(result).to eq('document')
+        expect(a_request(:post, "#{telegram_api_url}/sendDocument")).to have_been_made.times(2)
+      end
+    end
+
+    context 'when all attachments are photo and video' do
+      before do
+        2.times { attach_file_to_message(message, 'image', 'sample.png', 'image/png') }
+        attach_file_to_message(message, 'video', 'sample.mp4', 'video/mp4')
+        message.save!
+      end
+
+      it 'sends in a single media group and returns the message ID' do
+        result = service.perform
+        expect(result).to eq('media')
+        expect(a_request(:post, "#{telegram_api_url}/sendMediaGroup")).to have_been_made.once
+      end
+    end
+
+    context 'when all attachments are audio' do
+      before do
+        2.times { attach_file_to_message(message, 'audio', 'sample.mp3', 'audio/mpeg') }
+        message.save!
+      end
+
+      it 'sends audio messages in single media group and returns the message ID' do
+        result = service.perform
+        expect(result).to eq('media')
+        expect(a_request(:post, "#{telegram_api_url}/sendMediaGroup")).to have_been_made.once
+      end
+    end
+
+    context 'when all attachments are photos, videos, and audio' do
+      before do
+        attach_file_to_message(message, 'image', 'sample.png', 'image/png')
+        attach_file_to_message(message, 'video', 'sample.mp4', 'video/mp4')
+        attach_file_to_message(message, 'audio', 'sample.mp3', 'audio/mpeg')
+        message.save!
+      end
+
+      it 'sends photos and videos in a media group and audio in a separate group' do
+        result = service.perform
+        expect(result).to eq('media')
+        expect(a_request(:post, "#{telegram_api_url}/sendMediaGroup")).to have_been_made.times(2)
+      end
+    end
+
+    context 'when an attachment fails to send' do
+      before do
+        stub_request(:post, "#{telegram_api_url}/sendDocument")
+          .to_return(status: 500, body: { ok: false,
+                                          description: 'Internal server error' }.to_json, headers: { 'Content-Type' => 'application/json' })
+      end
+
+      it 'logs an error, stops processing, and returns nil' do
+        attach_files(message)
+        expect(Rails.logger).to receive(:error).at_least(:once)
+        result = service.perform
+        expect(result).to be_nil
+        expect(a_request(:post, "#{telegram_api_url}/sendDocument")).to have_been_made.once
+      end
+    end
+
+    def attach_files(message)
+      attach_file_to_message(message, 'file', 'sample.pdf', 'application/pdf')
+      attach_file_to_message(message, 'image', 'sample.png', 'image/png')
+      attach_file_to_message(message, 'video', 'sample.mp4', 'video/mp4')
+      attach_file_to_message(message, 'audio', 'sample.mp3', 'audio/mpeg')
+      message.save!
+    end
+
+    def attach_file_to_message(message, type, filename, content_type)
+      attachment = message.attachments.new(account_id: message.account_id, file_type: type)
+      attachment.file.attach(io: Rails.root.join("spec/assets/#{filename}").open, filename: filename, content_type: content_type)
+    end
+  end
+end