mastodon/app/lib/activitypub/activity/accept.rb

# frozen_string_literal: true

class ActivityPub::Activity::Accept < ActivityPub::Activity
  def perform
    return accept_follow_for_relay if relay_follow?
    return accept_follow!(follow_request_from_object) unless follow_request_from_object.nil?
    return accept_quote!(quote_request_from_object) unless quote_request_from_object.nil?

    case @object['type']
    when 'Follow'
      accept_embedded_follow
    when 'QuoteRequest'
      accept_embedded_quote_request
    end
  end

  private

  def accept_embedded_follow
    target_account = account_from_uri(target_uri)

    return if target_account.nil? || !target_account.local?

    follow_request = FollowRequest.find_by(account: target_account, target_account: @account)
    accept_follow!(follow_request)
  end

  def accept_follow!(request)
    return if request.nil?

    is_first_follow = !request.target_account.followers.local.exists?
    request.authorize!

    RemoteAccountRefreshWorker.perform_async(request.target_account_id) if is_first_follow
  end

  def accept_embedded_quote_request
    approval_uri = value_or_id(first_of_value(@json['result']))
    return if approval_uri.nil?

    quote = quote_from_request_json(@object)
    return unless quote.present? && quote.status.local?

    accept_quote!(quote)
  end

  def accept_quote!(quote)
    approval_uri = value_or_id(first_of_value(@json['result']))
    return if unsupported_uri_scheme?(approval_uri) || quote.quoted_account != @account || !quote.status.local?

    # NOTE: we are not going through `ActivityPub::VerifyQuoteService` as the `Accept` is as authoritative
    # as the stamp, but this means we are not checking the stamp, which may lead to inconsistencies
    # in case of an implementation bug
    quote.update!(state: :accepted, approval_uri: approval_uri)

    DistributionWorker.perform_async(quote.status_id, { 'update' => true })
    ActivityPub::StatusUpdateDistributionWorker.perform_async(quote.status_id, { 'updated_at' => Time.now.utc.iso8601 })
  end

  def accept_follow_for_relay
    relay.update!(state: :accepted)
  end

  def relay
    @relay ||= Relay.find_by(follow_activity_id: object_uri) unless object_uri.nil?
  end

  def relay_follow?
    relay.present?
  end

  def target_uri
    @target_uri ||= value_or_id(@object['actor'])
  end
end