class UniqueThread

# File lib/unique_thread.rb, line 20
def error_handlers
  @error_handlers ||= []
end

# File lib/unique_thread.rb, line 12
def logger
  @logger ||= default_logger
end

# File lib/unique_thread.rb, line 56
def initialize(name, downtime: 30)
  @stopwatch = Stopwatch.new(downtime: downtime)
  @locksmith = Locksmith.new(name: name, stopwatch: stopwatch)
end

# File lib/unique_thread.rb, line 16
def redis
  @redis ||= Redis.new
end

# File lib/unique_thread.rb, line 24
def safe_thread
  Thread.new do
    begin
      yield
    rescue StandardError => error
      report_error(error)
      retry
    end
  end
end

# File lib/unique_thread.rb, line 37
def default_logger
  case
  when defined?(Rails) && defined?(Rails::Console)
    Logger.new('/dev/null')
  when defined?(Rails)
    Rails.logger
  else
    Logger.new($stdout)
  end
end

# File lib/unique_thread.rb, line 48
def report_error(exception)
  logger.error(exception.inspect)
  error_handlers.each { |handler| handler.call(exception) }
end

# File lib/unique_thread.rb, line 61
def run(&block)
  self.class.safe_thread do
    loop { try_being_the_unique_thread(&block) }
  end
end

# File lib/unique_thread.rb, line 69
def try_being_the_unique_thread(&block)
  lock = locksmith.new_lock

  if lock.acquired?
    self.class.logger.info('Lock acquired! Running the unique thread.')
    lock.while_held(&block)
  else
    self.class.logger.debug('Could not acquire the lock. Sleeping until next attempt.')
    stopwatch.sleep_until_next_attempt(lock.locked_until.to_f)
  end
end