class Concurrent::JavaThreadPoolExecutor

def completed_task_count
  @executor.getCompletedTaskCount
end

def idletime
  @executor.getKeepAliveTime(java.util.concurrent.TimeUnit::SECONDS)
end

def initialize(opts = {})
  min_length = opts.fetch(:min_threads, DEFAULT_MIN_POOL_SIZE).to_i
  max_length = opts.fetch(:max_threads, DEFAULT_MAX_POOL_SIZE).to_i
  idletime = opts.fetch(:idletime, DEFAULT_THREAD_IDLETIMEOUT).to_i
  @max_queue = opts.fetch(:max_queue, DEFAULT_MAX_QUEUE_SIZE).to_i
  @overflow_policy = opts.fetch(:overflow_policy, :abort)
  raise ArgumentError.new('max_threads must be greater than zero') if max_length <= 0
  raise ArgumentError.new('min_threads cannot be less than zero') if min_length < 0
  raise ArgumentError.new("#{@overflow_policy} is not a valid overflow policy") unless OVERFLOW_POLICIES.keys.include?(@overflow_policy)
  if min_length == 0 && @max_queue == 0
    queue = java.util.concurrent.SynchronousQueue.new
  elsif @max_queue == 0
    queue = java.util.concurrent.LinkedBlockingQueue.new
  else
    queue = java.util.concurrent.LinkedBlockingQueue.new(@max_queue)
  end
  @executor = java.util.concurrent.ThreadPoolExecutor.new(
    min_length, max_length,
    idletime, java.util.concurrent.TimeUnit::SECONDS,
    queue, OVERFLOW_POLICIES[@overflow_policy].new)
  set_shutdown_hook
end

def largest_length
  @executor.getLargestPoolSize
end

def length
  @executor.getPoolSize
end

def max_length
  @executor.getMaximumPoolSize
end

def min_length
  @executor.getCorePoolSize
end

def queue_length
  @executor.getQueue.size
end

def remaining_capacity
  @max_queue == 0 ? -1 : @executor.getQueue.remainingCapacity
end

def running?
  super && ! @executor.isTerminating
end

def scheduled_task_count
  @executor.getTaskCount
end

def shutdown
  super
  @executor.getQueue.clear
  nil
end

def status
  warn '[DEPRECATED] `status` is deprecated and will be removed soon.'
  warn "Calls to `status` return an empty Array. Java ThreadPoolExecutor does not provide thread's status."
  []
end