# frozen_string_literal: false
#
#   tk/timer.rb : methods for Tcl/Tk after command
#
#   $Id$
#
require 'tk'

class TkTimer
  include TkCore
  extend TkCore

  TkCommandNames = ['after'.freeze].freeze

  (Tk_CBID = ['a'.freeze, TkUtil.untrust('00000')]).instance_eval{
    @mutex = Mutex.new
    def mutex; @mutex; end
    freeze
  }

  Tk_CBTBL = TkUtil.untrust({})

  TkCore::INTERP.add_tk_procs('rb_after', 'id', <<-'EOL')
    if {[set st [catch {eval {ruby_cmd TkTimer callback} $id} ret]] != 0} {
        return -code $st $ret
    } {
        return $ret
    }
  EOL

  DEFAULT_IGNORE_EXCEPTIONS = [ NameError, RuntimeError ].freeze

  ###############################
  # class methods
  ###############################
  def self.start(*args, &b)
    self.new(*args, &b).start
  end

  def self.callback(obj_id)
    ex_obj = Tk_CBTBL[obj_id]
    return "" if ex_obj == nil; # canceled
    ex_obj.cb_call
  end

  def self.info(obj = nil)
    if obj
      if obj.kind_of?(TkTimer)
        if obj.after_id
          inf = tk_split_list(tk_call_without_enc('after','info',obj.after_id))
          [Tk_CBTBL[inf[0][1]], inf[1]]
        else
          nil
        end
      else
        fail ArgumentError, "TkTimer object is expected"
      end
    else
      tk_call_without_enc('after', 'info').split(' ').collect!{|id|
        ret = Tk_CBTBL.find{|key,val| val.after_id == id}
        (ret == nil)? id: ret[1]
      }
    end
  end


  ###############################
  # instance methods
  ###############################
  def do_callback
    @in_callback = true
    @after_id = nil
    begin
      @return_value = @current_proc.call(self)
    rescue SystemExit
      exit(0)
    rescue Interrupt
      exit!(1)
    rescue Exception => e
      if @cancel_on_exception &&
          @cancel_on_exception.find{|exc| e.kind_of?(exc)}
        cancel
        @return_value = e
        @in_callback = false
        return e
      else
        fail e
      end
    end
    if @set_next
      set_next_callback(@current_args)
    else
      @set_next = true
    end
    @in_callback = false
    @return_value
  end

  def set_callback(sleep, args=nil)
    if TkCore::INTERP.deleted?
      self.cancel
      return self
    end
    @after_script = "rb_after #{@id}"
    @current_args = args
    @current_script = [sleep, @after_script]
    @after_id = tk_call_without_enc('after', sleep, @after_script)
    self
  end

  def set_next_callback(args)
    if @running == false || @proc_max == 0 || @do_loop == 0
      Tk_CBTBL.delete(@id) ;# for GC
      @running = false
      # @wait_var.value = 0
      __at_end__
      return
    end
    if @current_pos >= @proc_max
      if @do_loop < 0 || (@do_loop -= 1) > 0
        @current_pos = 0
      else
        Tk_CBTBL.delete(@id) ;# for GC
        @running = false
        # @wait_var.value = 0
        __at_end__
        return
      end
    end

    @current_args = args

    # if @sleep_time.kind_of?(Proc)
    if TkComm._callback_entry?(@sleep_time)
      sleep = @sleep_time.call(self)
    else
      sleep = @sleep_time
    end
    @current_sleep = sleep

    cmd, *cmd_args = @loop_proc[@current_pos]
    @current_pos += 1
    @current_proc = cmd

    set_callback(sleep, cmd_args)
  end

  def initialize(*args, &b)
    Tk_CBID.mutex.synchronize{
      # @id = Tk_CBID.join('')
      @id = Tk_CBID.join(TkCore::INTERP._ip_id_)
      Tk_CBID[1].succ!
    }

    @wait_var = TkVariable.new(0)

    @at_end_proc = nil

    @cb_cmd = TkCore::INTERP.get_cb_entry(self.method(:do_callback))

    @set_next = true

    @init_sleep = 0
    @init_proc = nil
    @init_args = []

    @current_script = []
    @current_proc = nil
    @current_args = nil
    @return_value = nil

    @sleep_time = 0
    @current_sleep = 0
    @loop_exec = 0
    @do_loop = 0
    @loop_proc = []
    @proc_max = 0
    @current_pos = 0

    @after_id = nil
    @after_script = nil

    @cancel_on_exception = DEFAULT_IGNORE_EXCEPTIONS
    # Unless @cancel_on_exception, Ruby/Tk shows an error dialog box when
    # an excepsion is raised on TkTimer callback procedure.
    # If @cancel_on_exception is an array of exception classes and the raised
    # exception is included in the array, Ruby/Tk cancels executing TkTimer
    # callback procedures silently (TkTimer#cancel is called and no dialog is
    # shown).

    if b
      case args.size
      when 0
        add_procs(b)
      when 1
        args << -1 << b
      else
        args << b
      end
    end

    set_procs(*args) if args != []

    @running = false
    @in_callback = false
  end

  attr :after_id
  attr :after_script
  attr :current_proc
  attr :current_args
  attr :current_sleep
  alias :current_interval :current_sleep
  attr :return_value

  attr_accessor :loop_exec

  def __at_end__
    @at_end_proc.call(self) if @at_end_proc
    @wait_var.value = 0  # for wait
  end
  private :__at_end__

  def cb_call
    @cb_cmd.call
  end

  def get_procs
    [@init_sleep, @init_proc, @init_args, @sleep_time, @loop_exec, @loop_proc]
  end

  def current_status
    [@running, @current_sleep, @current_proc, @current_args,
      @do_loop, @cancel_on_exception]
  end

  def cancel_on_exception?
    @cancel_on_exception
  end

  def cancel_on_exception=(mode)
    if mode.kind_of?(Array)
      @cancel_on_exception = mode
    elsif mode
      @cancel_on_exception = DEFAULT_IGNORE_EXCEPTIONS
    else
      @cancel_on_exception = false
    end
    #self
  end

  def running?
    @running
  end

  def loop_rest
    @do_loop
  end

  def loop_rest=(rest)
    @do_loop = rest
    #self
  end

  def set_interval(interval)
    #if interval != 'idle' && interval != :idle \
    #  && !interval.kind_of?(Integer) && !interval.kind_of?(Proc)
    if interval != 'idle' && interval != :idle \
      && !interval.kind_of?(Integer) && !TkComm._callback_entry?(interval)
      fail ArgumentError, "expect Integer or Proc"
    end
    @sleep_time = interval
  end

  def set_procs(interval, loop_exec, *procs)
    #if interval != 'idle' && interval != :idle \
    #   && !interval.kind_of?(Integer) && !interval.kind_of?(Proc)
    if interval != 'idle' && interval != :idle \
      && !interval.kind_of?(Integer) && !TkComm._callback_entry?(interval)
      fail ArgumentError, "expect Integer or Proc for 1st argument"
    end
    @sleep_time = interval

    @loop_proc = []
    procs.each{|e|
      # if e.kind_of?(Proc)
      if TkComm._callback_entry?(e)
        @loop_proc.push([e])
      else
        @loop_proc.push(e)
      end
    }
    @proc_max = @loop_proc.size
    @current_pos = 0

    if loop_exec.kind_of?(Integer) && loop_exec < 0
      @loop_exec = -1
    elsif loop_exec == true
      @loop_exec = -1
    elsif loop_exec == nil || loop_exec == false || loop_exec == 0
      @loop_exec = 0
    else
      if not loop_exec.kind_of?(Integer)
        fail ArgumentError, "expect Integer for 2nd argument"
      end
      @loop_exec = loop_exec
    end
    @do_loop = @loop_exec

    self
  end

  def add_procs(*procs)
    procs.each{|e|
      # if e.kind_of?(Proc)
      if TkComm._callback_entry?(e)
        @loop_proc.push([e])
      else
        @loop_proc.push(e)
      end
    }
    @proc_max = @loop_proc.size

    self
  end

  def delete_procs(*procs)
    procs.each{|e|
      # if e.kind_of?(Proc)
      if TkComm._callback_entry?(e)
        @loop_proc.delete([e])
      else
        @loop_proc.delete(e)
      end
    }
    @proc_max = @loop_proc.size

    cancel if @proc_max == 0

    self
  end

  def delete_at(n)
    @loop_proc.delete_at(n)
    @proc_max = @loop_proc.size
    cancel if @proc_max == 0
    self
  end

  def set_start_proc(sleep=nil, init_proc=nil, *init_args, &b)
    # set parameters for 'restart'
    sleep = @init_sleep unless sleep

    if sleep != 'idle' && sleep != :idle && !sleep.kind_of?(Integer)
      fail ArgumentError, "expect Integer or 'idle' for 1st argument"
    end

    @init_sleep = sleep
    @init_proc = init_proc
    @init_args = init_args

    @init_proc = b if !@init_proc && b
    @init_proc = proc{|*args| } if @init_sleep > 0 && !@init_proc

    self
  end

  def start(*init_args, &b)
    return nil if @running

    Tk_CBTBL[@id] = self
    @do_loop = @loop_exec
    @current_pos = 0
    @return_value = nil
    @after_id = nil

    @init_sleep = 0
    @init_proc  = nil
    @init_args  = nil

    argc = init_args.size
    if argc > 0
      sleep = init_args.shift
      if sleep != 'idle' && sleep != :idle && !sleep.kind_of?(Integer)
        fail ArgumentError, "expect Integer or 'idle' for 1st argument"
      end
      @init_sleep = sleep
    end
    @init_proc = init_args.shift if argc > 1
    @init_args = init_args if argc > 2

    @init_proc = b if !@init_proc && b
    @init_proc = proc{|*args| } if @init_sleep > 0 && !@init_proc

    @current_sleep = @init_sleep
    @running = true
    if @init_proc
      # if not @init_proc.kind_of?(Proc)
      if !TkComm._callback_entry?(@init_proc)
        fail ArgumentError, "Argument '#{@init_proc}' need to be Proc"
      end
      @current_proc = @init_proc
      set_callback(@init_sleep, @init_args)
      @set_next = false if @in_callback
    else
      set_next_callback(@init_args)
    end

    self
  end

  def reset(*reset_args)
    restart() if @running

    if @init_proc
      @return_value = @init_proc.call(self)
    else
      @return_value = nil
    end

    @current_pos   = 0
    @current_args  = @init_args
    @current_script = []

    @set_next = false if @in_callback

    self
  end

  def restart(*restart_args, &b)
    cancel if @running
    if restart_args.empty? && !b
      start(@init_sleep, @init_proc, *@init_args)
    else
      start(*restart_args, &b)
    end
  end

  def cancel
    @running = false
    # @wait_var.value = 0
    __at_end__
    tk_call 'after', 'cancel', @after_id if @after_id
    @after_id = nil

    Tk_CBTBL.delete(@id) ;# for GC
    self
  end
  alias stop cancel

  def continue(wait=nil)
    fail RuntimeError, "is already running" if @running
    return restart() if @current_script.empty?
    sleep, cmd = @current_script
    fail RuntimeError, "no procedure to continue" unless cmd
    if wait
      unless wait.kind_of?(Integer)
        fail ArgumentError, "expect Integer for 1st argument"
      end
      sleep = wait
    end
    Tk_CBTBL[@id] = self
    @running = true
    @after_id = tk_call_without_enc('after', sleep, cmd)
    self
  end

  def skip
    fail RuntimeError, "is not running now" unless @running
    cancel
    Tk_CBTBL[@id] = self
    @running = true
    set_next_callback(@current_args)
    self
  end

  def info
    if @after_id
      inf = tk_split_list(tk_call_without_enc('after', 'info', @after_id))
      [Tk_CBTBL[inf[0][1]], inf[1]]
    else
      nil
    end
  end

  def at_end(*arg, &b)
    if arg.empty?
      if b
        @at_end_proc = b
      else
        # no proc
        return @at_end_proc
      end
    else
      fail ArgumentError, "wrong number of arguments" if arg.length != 1 || b
      @at_end_proc = arg[0]
    end
    self
  end

  def wait(on_thread = true, check_root = false)
    unless @running
      if @return_value.kind_of?(Exception)
        fail @return_value
      else
        return @return_value
      end
    end

    @wait_var.wait(on_thread, check_root)
    if @return_value.kind_of?(Exception)
      fail @return_value
    else
      @return_value
    end
  end
  def eventloop_wait(check_root = false)
    wait(false, check_root)
  end
  def thread_wait(check_root = false)
    wait(true, check_root)
  end
  def tkwait(on_thread = true)
    wait(on_thread, true)
  end
  def eventloop_tkwait
    wait(false, true)
  end
  def thread_tkwait
    wait(true, true)
  end
end

TkAfter = TkTimer


class TkRTTimer < TkTimer
  DEFAULT_OFFSET_LIST_SIZE = 5

  def initialize(*args, &b)
    super(*args, &b)

    @offset_list = Array.new(DEFAULT_OFFSET_LIST_SIZE){ [0, 0] }
    @offset_s = 0
    @offset_u = 0
    @est_time = nil
  end

  def start(*args, &b)
    return nil if @running
    @est_time = nil
    @cb_start_time = Time.now
    super(*args, &b)
  end

  def cancel
    super()
    @est_time = nil
    @cb_start_time = Time.now
    self
  end
  alias stop cancel

  def continue(wait=nil)
    fail RuntimeError, "is already running" if @running
    @cb_start_time = Time.now
    super(wait)
  end

  def set_interval(interval)
    super(interval)
    @est_time = nil
  end

  def _offset_ave
    size = 0
    d_sec = 0; d_usec = 0
    @offset_list.each_with_index{|offset, idx|
      # weight = 1
      weight = idx + 1
      size += weight
      d_sec += offset[0] * weight
      d_usec += offset[1] * weight
    }
    offset_s, mod = d_sec.divmod(size)
    offset_u = ((mod * 1000000 + d_usec) / size.to_f).round
    [offset_s, offset_u]
  end
  private :_offset_ave

  def set_next_callback(args)
    if @running == false || @proc_max == 0 || @do_loop == 0
      Tk_CBTBL.delete(@id) ;# for GC
      @running = false
      # @wait_var.value = 0
      __at_end__
      return
    end
    if @current_pos >= @proc_max
      if @do_loop < 0 || (@do_loop -= 1) > 0
        @current_pos = 0
      else
        Tk_CBTBL.delete(@id) ;# for GC
        @running = false
        # @wait_var.value = 0
        __at_end__
        return
      end
    end

    @current_args = args

    cmd, *cmd_args = @loop_proc[@current_pos]
    @current_pos += 1
    @current_proc = cmd

    @offset_s, @offset_u = _offset_ave

    if TkComm._callback_entry?(@sleep_time)
      sleep = @sleep_time.call(self)
    else
      sleep = @sleep_time
    end

    if @est_time
      @est_time = Time.at(@est_time.to_i, @est_time.usec + sleep*1000)
    else
      @est_time = Time.at(@cb_start_time.to_i,
                          @cb_start_time.usec + sleep*1000)
    end

    now = Time.now
    real_sleep = ((@est_time.to_i - now.to_i + @offset_s)*1000.0 +
                  (@est_time.usec - now.usec + @offset_u)/1000.0).round
    if real_sleep <= 0
      real_sleep = 0
      @offset_s = now.to_i
      @offset_u = now.usec
    end
    @current_sleep = real_sleep

    set_callback(real_sleep, cmd_args)
  end

  def cb_call
    if @est_time
      @offset_list.shift

      @cb_start_time = Time.now

      if @current_sleep == 0
        @offset_list.push([
                            @offset_s - @cb_start_time.to_i,
                            @offset_u - @cb_start_time.usec
                          ])
      else
        @offset_list.push([
                            @offset_s + (@est_time.to_i - @cb_start_time.to_i),
                            @offset_u + (@est_time.usec - @cb_start_time.usec)
                          ])
      end
    end

    @cb_cmd.call
  end
end
