discourse-chat-integration/lib/discourse_chat/provider/telegram/telegram_provider.rb

module DiscourseChat
  module Provider
    module TelegramProvider
      PROVIDER_NAME = "telegram".freeze
      PROVIDER_ENABLED_SETTING = :chat_integration_telegram_enabled
      CHANNEL_PARAMETERS = [
                        {key: "name", regex: '^\S+'},
                        {key: "chat_id", regex: '^(-?[0-9]+|@\S+)$'}
                       ]

      def self.setup_webhook 
        newSecret = SecureRandom.hex
        SiteSetting.chat_integration_telegram_secret = newSecret

        message = {
          url: Discourse.base_url+'/chat-integration/telegram/command/'+newSecret,
        }

        response = self.do_api_request('setWebhook', message)

        if not response['ok'] == true
          # If setting up webhook failed, disable provider
          SiteSetting.chat_integration_telegram_enabled = false
          Rails.logger.error("Failed to setup telegram webhook. Message data= "+message.to_json+ " response="+response.to_json)
        end

      end

      def self.sendMessage(message)
        return self.do_api_request('sendMessage', message)
      end

      def self.do_api_request(methodName, message)
        http = Net::HTTP.new("api.telegram.org", 443)
        http.use_ssl = true

        access_token = SiteSetting.chat_integration_telegram_access_token

        uri = URI("https://api.telegram.org/bot#{access_token}/#{methodName}")

        req = Net::HTTP::Post.new(uri, 'Content-Type' =>'application/json')
        req.body = message.to_json
        response = http.request(req)

        responseData = JSON.parse(response.body)

        return responseData
      end

      def self.message_text(post)
        display_name = "@#{post.user.username}"
        full_name = post.user.name || ""

        if !(full_name.strip.empty?) && (full_name.strip.gsub(' ', '_').casecmp(post.user.username) != 0) && (full_name.strip.gsub(' ', '').casecmp(post.user.username) != 0)
          display_name = "#{full_name} @#{post.user.username}"
        end

        topic = post.topic

        category = ''
        if topic.category
          category = (topic.category.parent_category) ? "[#{topic.category.parent_category.name}/#{topic.category.name}]": "[#{topic.category.name}]"
        end

        tags = ''
        if topic.tags.present?
          tags = topic.tags.map(&:name).join(', ')
        end

        return I18n.t(
            "chat_integration.provider.telegram.message",
            user: display_name,
            post_url: post.full_url,
            title: CGI::escapeHTML(topic.title),
            post_excerpt: post.excerpt(SiteSetting.chat_integration_telegram_excerpt_length, text_entities: true, strip_links: true, remap_emoji: true),
          )

      end

      def self.trigger_notification(post, channel)
        chat_id = channel.data['chat_id']

        message = {
          chat_id: chat_id,
          text: message_text(post),
          parse_mode: "html",
          disable_web_page_preview: true,
        }

        response = sendMessage(message)

        if not response['ok'] == true
          error_key = nil
          if response['description'].include? 'chat not found'
            error_key = 'chat_integration.provider.telegram.channel_not_found'
          elsif response['description'].include? 'Forbidden'
            error_key = 'chat_integration.provider.telegram.forbidden'
          end
          raise ::DiscourseChat::ProviderError.new info: {error_key: error_key, message: message, response_body:response}  
        end

      end

    end
  end
end

require_relative "telegram_command_controller.rb"
require_relative "telegram_initializer.rb"