Implement puzzle suggestion slackbot

Author: mateusdeap

app/controllers/slack/application_controller.rb

@@ -0,0 +1,47 @@
+class Slack::ApplicationController < ApplicationController
+  skip_before_action :verify_authenticity_token
+  before_action :valid_slack_request?
+
+  private
+
+  def valid_slack_request?
+    @verified ||= verify_slack_signature
+  end
+
+  def verify_slack_signature
+    timestamp = request.headers["X-Slack-Request-Timestamp"]
+    signature = request.headers["X-Slack-Signature"]
+
+    if Time.now.to_i - timestamp.to_i > 300
+      @verified = false
+      return
+    end
+
+    base_string = "v0:#{timestamp}:#{request.raw_post}"
+    my_signature = "v0=" + OpenSSL::HMAC.hexdigest(
+      "SHA256",
+      ENV["SLACK_SIGNING_SECRET"],
+      base_string
+    )
+
+    ActiveSupport::SecurityUtils.secure_compare(signature, my_signature)
+  end
+
+  def slack_client
+    @slack_client ||= SlackClient::Client.instance
+  end
+
+  def open_view(view, trigger_id:)
+    slack_client = SlackClient::Client.instance
+    slack_client.views_open view: view, trigger_id: trigger_id
+  rescue Slack::Web::Api::Errors::SlackError => e
+    Rails.logger.error "Failed to open Slack modal: #{e.message} #{e.response_metadata}"
+    head :unprocessable_entity
+  end
+
+  def send_message(message, channel_id:)
+    SlackClient::Client.instance.chat_postMessage(channel: channel_id, blocks: message)
+  rescue Slack::Web::Api::Errors::SlackError
+    head :unprocessable_entity
+  end
+end

app/controllers/slack/commands_controller.rb

@@ -0,0 +1,7 @@
+class Slack::CommandsController < Slack::ApplicationController
+  def new_puzzle
+    puts "I'm a new puzzle!"
+    view  = SlackClient::Views::PuzzleForm.new.create
+    open_view(view, trigger_id: params[:trigger_id])
+  end
+end

app/controllers/slack/puzzles_controller.rb

@@ -0,0 +1,20 @@
+class Slack::PuzzlesController < Slack::ApplicationController
+  def create
+    payload = JSON.parse(params[:payload])
+    user_id = payload["user"]["id"]
+    values = payload["view"]["state"]["values"]
+    question = values.dig("question", "question", "value")
+    answer = values.dig("answer", "answer", "selected_option", "value")
+    explanation = values.dig("explanation", "explanation", "value")
+    link = values.dig("link", "link", "value")
+    puzzle = Puzzle.new(question:, answer:, explanation:, link:, status: :pending)
+
+    view = if puzzle.save
+      SlackClient::Views::Success.new.create
+    else
+      SlackClient::Views::Failure.new.create
+    end
+
+    render json: { response_action: "update", view: view }, status: :ok
+  end
+end

app/lib/slack_client/client.rb

@@ -0,0 +1,36 @@
+require "singleton"
+
+module SlackClient
+  # This class is a wrapper around the Slack::Web::Client class that allows us to use the
+  # singleton pattern to create a single instance of the Slack client.
+  # This is useful because we can reuse the same client instance across the application,
+  # which can help reduce the number of connections to the Slack API.
+  #
+  # Example:
+  # slack_client = SlackClient::Client.instance
+  #
+  class Client
+    include Singleton
+
+    def initialize
+      @slack_client = Slack::Web::Client.new(token: ENV["SLACK_TOKEN"])
+    end
+
+    private
+
+    def method_missing(method, *args, &block)
+      if @slack_client.respond_to?(method)
+        @slack_client.send(method, *args, &block)
+      else
+        super
+      end
+    rescue Slack::Web::Api::Errors::SlackError => e
+      Rails.logger.error "Failed to complete Slack request: #{e.message} #{e.response_metadata}"
+      raise
+    end
+
+    def respond_to_missing?(method, include_private = false)
+      @slack_client.respond_to?(method) || super
+    end
+  end
+end

app/lib/slack_client/views/failure.rb

@@ -0,0 +1,16 @@
+module SlackClient
+  module Views
+    class Failure
+      def create
+        blocks = Slack::BlockKit.blocks do |block|
+          block.section do |section|
+            section.plain_text text: ":blob-no: Sorry, I could not register the puzzle suggestion."
+          end
+        end
+        Slack::BlockKit.modal blocks: blocks, title: "Uh oh..." do |modal|
+          modal.close text: "Close"
+        end.as_json
+      end
+    end
+  end
+end

app/lib/slack_client/views/puzzle_form.rb

@@ -0,0 +1,33 @@
+module SlackClient
+  module Views
+    class PuzzleForm
+      def create
+        blocks = Slack::BlockKit.blocks do |blocks|
+          blocks.input label: "What is the Puzzle question?", block_id: "question" do |input|
+            input.plain_text_input action_id: "question", multiline: true
+          end
+
+          blocks.input label: "Answer", block_id: "answer" do |input|
+            input.radio_buttons action_id: "answer" do |radio_button|
+              radio_button.option text: "Ruby", value: "ruby"
+              radio_button.option text: "Rails", value: "rails"
+            end
+          end
+
+          blocks.input label: "Explanation", block_id: "explanation" do |input|
+            input.plain_text_input action_id: "explanation", multiline: true
+          end
+
+          blocks.input label: "Link to documentation", block_id: "link", optional: true do |input|
+            input.plain_text_input action_id: "link"
+          end
+        end
+
+        Slack::BlockKit.modal blocks: blocks, external_id: "puzzle_form", title: "Suggest a Puzzle" do |modal|
+          modal.submit text: "Submit"
+          modal.close text: "Close"
+        end.as_json
+      end
+    end
+  end
+end

app/lib/slack_client/views/success.rb

@@ -0,0 +1,16 @@
+module SlackClient
+  module Views
+    class Success
+      def create
+        blocks = Slack::BlockKit.blocks do |block|
+          block.section do |section|
+            section.mrkdwn text: ":white_check_mark: All set! Puzzle submitted!"
+          end
+        end
+        Slack::BlockKit.modal blocks: blocks, title: "Thank you!" do |modal|
+          modal.close text: "Close"
+        end.as_json
+      end
+    end
+  end
+end

config/routes.rb

@@ -18,4 +18,9 @@
 
   # Defines the root path route ("/")
   root "puzzles#index"
+
+  namespace :slack do
+    post :new_puzzle, module: "slack", to: "commands#new_puzzle"
+    post :puzzle, module: "slack", to: "puzzles#create"
+  end
 end