Feat: Support for Microsoft Oauth in Email Channel (#6227)

- Adds the backend APIs required for Microsoft Email Channels

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>
Co-authored-by: Sojan <sojan@pepalo.com>

app/controllers/microsoft/callbacks_controller.rb

@@ -0,0 +1,72 @@
+class Microsoft::CallbacksController < ApplicationController
+  include MicrosoftConcern
+
+  def show
+    @response = microsoft_client.auth_code.get_token(
+      oauth_code,
+      redirect_uri: "#{base_url}/microsoft/callback"
+    )
+
+    inbox = find_or_create_inbox
+    ::Redis::Alfred.delete(users_data['email'])
+    redirect_to app_microsoft_inbox_agents_url(account_id: account.id, inbox_id: inbox.id)
+  rescue StandardError => e
+    ChatwootExceptionTracker.new(e).capture_exception
+    redirect_to '/'
+  end
+
+  private
+
+  def oauth_code
+    params[:code]
+  end
+
+  def users_data
+    decoded_token = JWT.decode parsed_body[:id_token], nil, false
+    decoded_token[0]
+  end
+
+  def parsed_body
+    @parsed_body ||= @response.response.parsed
+  end
+
+  def account_id
+    ::Redis::Alfred.get(users_data['email'])
+  end
+
+  def account
+    @account ||= Account.find(account_id)
+  end
+
+  def find_or_create_inbox
+    channel_email = Channel::Email.find_by(email: users_data['email'], account: account)
+    channel_email ||= create_microsoft_channel_with_inbox
+    update_microsoft_channel(channel_email)
+    channel_email.inbox
+  end
+
+  def create_microsoft_channel_with_inbox
+    ActiveRecord::Base.transaction do
+      channel_email = Channel::Email.create!(email: users_data['email'], account: account)
+      account.inboxes.create!(
+        account: account,
+        channel: channel_email,
+        name: users_data['name']
+      )
+      channel_email
+    end
+  end
+
+  def update_microsoft_channel(channel_email)
+    channel_email.update!({
+                            imap_login: users_data['email'], imap_address: 'outlook.office365.com',
+                            imap_port: '993', imap_enabled: true,
+                            provider: 'microsoft',
+                            provider_config: {
+                              access_token: parsed_body['access_token'],
+                              refresh_token: parsed_body['refresh_token'],
+                              expires_on: (Time.current.utc + 1.hour).to_s
+                            }
+                          })
+  end
+end