Add matrix support

config/locales/client.en.yml

@@ -111,3 +111,19 @@ en:
               help: "e.g. #channel, @username."
           errors:
             channel_not_found: "The specified channel does not exist on Mattermost"
+
+        #######################################
+        ############ MATRIX STRINGS ###########
+        #######################################
+        matrix:
+          title: "Matrix"
+          param:
+            name:
+              title: "Name"
+              help: "A name to describe the channel. It is not used for the connection to Matrix."
+            room_id:
+              title: "Room ID"
+              help: "The 'private identifier' for the room. It should look something like !abcdefg:matrix.org"
+          errors:
+            unknown_token: "Access token is invalid"
+            unknown_room: "Room ID is invalid"

config/locales/server.en.yml

@@ -48,6 +48,14 @@ en:
     chat_integration_mattermost_icon_url: "Icon for posts to mattermost (defaults to forum logo)"
     chat_integration_mattermost_excerpt_length: "Mattermost post excerpt length"
 
+    #######################################
+    ############ MATRIX SETTINGS ##########
+    #######################################
+    chat_integration_matrix_enabled: "Enable the Matrix chat integration provider"
+    chat_integration_matrix_homeserver: "Homeserver to connect to. Make sure to include the protocol"
+    chat_integration_matrix_access_token: "Access token for the bot's matrix account"
+    chat_integration_matrix_excerpt_length: "Matrix post excerpt length"
+
   chat_integration:
     
     all_categories: "(all categories)"
@@ -182,3 +190,15 @@ en:
           *List rules:* `/discourse status`
           
           *Help:* `/discourse help`
+
+      #######################################
+      ############ MATRIX STRINGS ###########
+      #######################################
+      matrix:
+        text_message: "%{user} posted in %{title} - %{post_url}"
+        formatted_message: |
+                    <b>%{user}</b> posted in <b><a href='%{post_url}'>%{title}</a></b>
+                    <blockquote>
+                    %{excerpt}
+                    </blockquote>
+

config/settings.yml

@@ -72,3 +72,15 @@ plugins:
     default: ''
   chat_integration_mattermost_excerpt_length:
     default: 400
+
+#######################################
+########## MATRIX SETTINGS ############
+#######################################
+  chat_integration_matrix_enabled:
+    default: false
+  chat_integration_matrix_homeserver:
+    default: 'https://matrix.org'
+  chat_integration_matrix_access_token:
+    default: ''
+  chat_integration_matrix_excerpt_length:
+    default: 400

lib/discourse_chat/provider.rb

@@ -94,3 +94,4 @@ require_relative "provider/telegram/telegram_provider.rb"
 require_relative "provider/discord/discord_provider.rb"
 require_relative "provider/hipchat/hipchat_provider.rb"
 require_relative "provider/mattermost/mattermost_provider.rb"
+require_relative "provider/matrix/matrix_provider.rb"

lib/discourse_chat/provider/matrix/matrix_provider.rb

@@ -0,0 +1,86 @@
+module DiscourseChat
+  module Provider
+    module MatrixProvider
+      PROVIDER_NAME = "matrix".freeze
+      PROVIDER_ENABLED_SETTING = :chat_integration_matrix_enabled
+      CHANNEL_PARAMETERS = [
+                        {key: "name", regex: '^\S+'},
+                        {key: "room_id", regex: '^\!\S+:\S+$'}
+                       ]
+
+      def self.send_message(room_id, message)
+        homeserver = SiteSetting.chat_integration_matrix_homeserver
+        event_type = 'm.room.message'
+        uid = Time.now.to_i
+
+        url_params = URI.encode_www_form({
+          access_token: SiteSetting.chat_integration_matrix_access_token
+        })
+
+        url = "#{homeserver}/_matrix/client/r0/rooms/#{CGI::escape(room_id)}/send/#{event_type}/#{uid}"
+
+        uri = URI([url,url_params].join('?'))
+
+        http = Net::HTTP.new(uri.host, uri.port)
+        http.use_ssl = true
+
+        req = Net::HTTP::Put.new(uri, 'Content-Type' =>'application/json')
+        req.body = message.to_json
+        response = http.request(req)
+
+        return response
+      end
+
+      def self.generate_matrix_message(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
+
+        message = {
+          msgtype: 'm.notice',
+          body: I18n.t('chat_integration.provider.matrix.text_message', {
+                          user: display_name,
+                          post_url: post.full_url,
+                          title: post.topic.title
+            }),
+          format: 'org.matrix.custom.html',
+          formatted_body: I18n.t('chat_integration.provider.matrix.formatted_message', {
+                          user: display_name,
+                          post_url: post.full_url,
+                          title: post.topic.title,
+                          excerpt: post.excerpt(SiteSetting.chat_integration_discord_excerpt_length, text_entities: true, strip_links: true, remap_emoji: true),
+            })
+
+        }
+
+        return message
+      end
+
+      def self.trigger_notification(post, channel)
+        message = generate_matrix_message(post)
+
+        response = send_message(channel.data['room_id'], message)
+
+        if not response.kind_of? Net::HTTPSuccess
+          error_key = nil
+          begin
+            responseData = JSON.parse(response.body)
+            if responseData['errcode'] == "M_UNKNOWN_TOKEN"
+              error_key = 'chat_integration.provider.matrix.errors.unknown_token'
+            elsif responseData['errcode'] == "M_UNKNOWN"
+              error_key = 'chat_integration.provider.matrix.errors.unknown_room'
+            end
+          ensure
+            raise ::DiscourseChat::ProviderError.new info: {error_key: error_key, message: message, response_body:response.body}  
+          end
+        end
+
+      end
+
+    end
+  end
+end

spec/lib/discourse_chat/provider/matrix/matrix_provider_spec.rb

@@ -0,0 +1,29 @@
+require 'rails_helper'
+
+RSpec.describe DiscourseChat::Provider::MatrixProvider do
+  let(:post) { Fabricate(:post) }
+
+  describe '.trigger_notifications' do
+    before do
+      SiteSetting.chat_integration_matrix_enabled = true
+      SiteSetting.chat_integration_matrix_access_token = 'abcd'
+    end
+
+    let(:chan1){DiscourseChat::Channel.create!(provider:'matrix', data:{name: "Awesome Channel", room_id: '!blah:matrix.org'})}
+
+    it 'sends the message' do
+      stub1 = stub_request(:put, %r{https://matrix.org/_matrix/client/r0/rooms/!blah:matrix.org/send/m.room.message/*}).to_return(status: 200)
+      described_class.trigger_notification(post, chan1)
+      expect(stub1).to have_been_requested.once
+    end
+
+    it 'handles errors correctly' do 
+      stub1 = stub_request(:put, %r{https://matrix.org/_matrix/client/r0/rooms/!blah:matrix.org/send/m.room.message/*}).to_return(status: 400, body:'{"errmsg":"M_UNKNOWN"}')
+      expect(stub1).to have_been_requested.times(0)
+      expect{described_class.trigger_notification(post, chan1)}.to raise_exception(::DiscourseChat::ProviderError)
+      expect(stub1).to have_been_requested.once
+    end
+
+  end
+
+end