fix(whatsapp): resolve replies across scoped message ids

app/services/whatsapp/in_reply_to_message_finder.rb

@@ -0,0 +1,37 @@
+class Whatsapp::InReplyToMessageFinder
+  MESSAGE_TOKEN_PATTERN = /(?<![0-9a-f])(?:[0-9a-f]{32}|[0-9a-f]{20})(?![0-9a-f])/i
+
+  pattr_initialize [:conversation!, :source_id!]
+
+  def perform
+    exact_match || matching_scoped_message
+  end
+
+  private
+
+  def exact_match
+    conversation.messages.find_by(source_id: source_id)
+  end
+
+  def matching_scoped_message
+    token = message_token(source_id)
+    return if token.blank?
+
+    # Phone-scoped and BSUID-scoped WAMIDs can carry the same message token
+    # even when their complete source IDs differ.
+    matches = conversation.messages.where('source_id LIKE ?', 'wamid.%').select(:id, :source_id).select do |message|
+      message_token(message.source_id) == token
+    end
+
+    matches.one? ? matches.first : nil
+  end
+
+  def message_token(message_id)
+    return unless message_id.start_with?('wamid.')
+
+    tokens = Base64.strict_decode64(message_id.delete_prefix('wamid.')).scan(MESSAGE_TOKEN_PATTERN)
+    tokens.one? ? tokens.first.downcase : nil
+  rescue ArgumentError
+    nil
+  end
+end

app/services/whatsapp/incoming_message_base_service.rb

@@ -174,6 +174,7 @@ class Whatsapp::IncomingMessageBaseService
 
   def message_content_attributes(message)
     content_attrs = outgoing_echo ? { external_echo: true } : {}
+    content_attrs[:in_reply_to] = @in_reply_to_message_id if @in_reply_to_message_id.present?
     content_attrs[:in_reply_to_external_id] = @in_reply_to_external_id if @in_reply_to_external_id.present?
     referral_content_attrs = referral_attributes(message)
     content_attrs[:referral] = referral_content_attrs if referral_content_attrs.present?

app/services/whatsapp/incoming_message_service_helpers.rb

@@ -69,6 +69,12 @@ module Whatsapp::IncomingMessageServiceHelpers
 
   def process_in_reply_to(message)
     @in_reply_to_external_id = message['context']&.[]('id')
+    return if @in_reply_to_external_id.blank?
+
+    @in_reply_to_message_id = Whatsapp::InReplyToMessageFinder.new(
+      conversation: @conversation,
+      source_id: @in_reply_to_external_id
+    ).perform&.id
   end
 
   def referral_attributes(message)