# frozen_string_literal: true

##
# Mixin methods for Gem::Command to promote available RubyGems update

module Gem::UpdateSuggestion
  # list taken from https://github.com/watson/ci-info/blob/7a3c30d/index.js#L56-L66
  CI_ENV_VARS = [
    "CI", # Travis CI, CircleCI, Cirrus CI, Gitlab CI, Appveyor, CodeShip, dsari
    "CONTINUOUS_INTEGRATION", # Travis CI, Cirrus CI
    "BUILD_NUMBER", # Jenkins, TeamCity
    "CI_APP_ID", "CI_BUILD_ID", "CI_BUILD_NUMBER", # Applfow
    "RUN_ID" # TaskCluster, dsari
  ].freeze

  ONE_WEEK = 7 * 24 * 60 * 60

  ##
  # Message to promote available RubyGems update with related gem update command.

  def update_suggestion
    <<-MESSAGE

A new release of RubyGems is available: #{Gem.rubygems_version} → #{Gem.latest_rubygems_version}!
Run `gem update --system #{Gem.latest_rubygems_version}` to update your installation.

    MESSAGE
  end

  ##
  # Determines if current environment is eligible for update suggestion.

  def eligible_for_update?
    # explicit opt-out
    return false if Gem.configuration[:prevent_update_suggestion]
    return false if ENV["RUBYGEMS_PREVENT_UPDATE_SUGGESTION"]

    # focus only on human usage of final RubyGems releases
    return false unless Gem.ui.tty?
    return false if Gem.rubygems_version.prerelease?
    return false if Gem.disable_system_update_message
    return false if ci?

    # check makes sense only when we can store timestamp of last try
    # otherwise we will not be able to prevent "annoying" update message
    # on each command call
    return unless Gem.configuration.state_file_writable?

    # load time of last check, ensure the difference is enough to repeat the suggestion
    check_time = Time.now.to_i
    last_update_check = Gem.configuration.last_update_check
    return false if (check_time - last_update_check) < ONE_WEEK

    # compare current and latest version, this is the part where
    # latest rubygems spec is fetched from remote
    (Gem.rubygems_version < Gem.latest_rubygems_version).tap do |eligible|
      # store the time of last successful check into state file
      Gem.configuration.last_update_check = check_time

      return eligible
    end
  rescue StandardError # don't block install command on any problem
    false
  end

  def ci?
    CI_ENV_VARS.any? {|var| ENV.include?(var) }
  end
end
