outvoke.rb

#!/usr/bin/env ruby
#
# ==========================================================================
# Outvoke -- version 0.0.99.20250614
#
# written by cleemy desu wayo / Licensed under CC0 1.0
#
# official repository: https://gitlab.com/cleemy-desu-wayo/outvoke
# ==========================================================================
#
# * requirements:
#     * Ruby 3.0 or later
#

require 'time'
require 'yaml'
require 'json'
require 'bigdecimal'
require 'bigdecimal/util'
require 'bigdecimal/math'

class Outvoke
  attr_accessor :version, :ds, :hooks, :hooks_first_time, :wait, :nodup_list,
                :mutex_nodup, :init_time

  attr_reader   :last_msgid

  alias_method :sources, :ds    # eventually "sources" will be removed

  def initialize

    @version = Struct.new(:branch, :body).new(
      '0.1',
      '0.0.99.20250614'
    )

    @ds               = Hash.new
    @hooks            = []
    @hooks_first_time = []
    @wait             = 0.5

    @mutex_msgid      = Mutex.new
    @last_msgid       = 0
    @hookcnt          = 0

    @nodup_list       = Hash.new
    @mutex_nodup      = Mutex.new
    @init_time        = Process.clock_gettime(Process::CLOCK_MONOTONIC)

    @is_quiet_mode = false
  end

  def [](str)
    @ds[str]
  end

  def quiet_mode?
    @is_quiet_mode
  end

  def quiet_mode=(x)
    @is_quiet_mode = x
  end

  def elapsed
    Process.clock_gettime(Process::CLOCK_MONOTONIC) - @init_time
  end

  #
  # TODO: experimental and incomplete implementation
  #
  # (specifications are subject to sudden change without notice)
  #
  def nodup(time, cond)
    unless block_given?
      @mutex_nodup.synchronize do
        register_nodup(time, cond)
      end
      return
    end

    is_nodup = false

    @mutex_nodup.synchronize do
      is_nodup = sweep_and_check_nodup(cond)
      register_nodup(time, cond)
    end

    return unless is_nodup

    yield time, cond
  end
  def nodup?(x)
    @mutex_nodup.synchronize do
      sweep_and_check_nodup(x)
    end
  end

  #
  # TODO: experimental and incomplete implementation
  #
  # (specifications are subject to sudden change without notice)
  #
  def loputs(body = "", attachment = nil)
    @ds['lo'] << { "body" => body.to_s.dup, "attachment" => attachment }
    nil
  end

  def mainloop
    loop do
      @ds.each do |ds_label, ds|
        next unless ds.enabled?

        ds.before_each_event

        ds.each_event do |event|
          hooks = @hooks
          @hookcnt = 0

          if ds.is_first_time_log_check
            ds.first_time_log_check(ds, event)
            hooks = @hooks_first_time
          end

          hooks.each do |hook|
            hooks_exec(ds, hook, event)
          end
        end

        ds.after_each_event
      end

      sleep @wait
    end
  end

  def register_proc(ds_cond, event_cond, hookby, &block)
    hooks = @hooks
    if hookby.end_with?("ft")
      hooks = @hooks_first_time
    end

    extract_ds(ds_cond).each do |ds_label|
      @ds[ds_label].enabled = true

      hooks << {
        'ds_label'   => ds_label,
        'event_cond' => event_cond,
        'hookby'     => hookby,
        'proc'       => block
      }
    end
  end

  # extracts only the labels of the appropriate data sources from $sources
  def extract_ds(ds_cond)
    return @ds.keys if ds_cond == true

    ds_cond_array = [ds_cond]

    if ds_cond.respond_to?(:each)
      ds_cond_array = ds_cond
    end

    result = []

    ds_cond_array.each do |label_cond|
      next unless label_cond.respond_to?(:===)

      # TODO (automatically generate a new data source)
      if label_cond.is_a?(String)
        label_cond.match(/\Aauxin:(fifo)?:([1-9]+[0-9]*)\z/)&.then do |m|
          new_ds_label = "auxin:fifo:#{m[2]}"
          unless @ds[new_ds_label]
            @ds[new_ds_label] = OutvokeDataSourceAuxinFifo.new(self, new_ds_label)
          end
        end
      end

      @ds.keys.each do |label|
        result << label if label_cond === label
      end
    end
    result.uniq
  end

  def generate_new_msgid
    new_msgid = nil

    @mutex_msgid.synchronize do
      @last_msgid += 1
      new_msgid = @last_msgid
    end

    new_msgid
  end

  private

  #
  # TODO: experimental and incomplete implementation
  #
  # (specifications are subject to sudden change without notice)
  #
  def register_nodup(time, obj)
    expiration_time = Time.now + time

    @nodup_list.each_key do |key|
      @nodup_list[key] = expiration_time if key === obj
    end

    @nodup_list[obj] = expiration_time
  end
  def sweep_and_check_nodup(x)
    is_nodup = true

    tmp_now = Time.now

    # sweep (remove expired items)
    @nodup_list = @nodup_list.reject do |_, exp|
      tmp_now > exp
    end

    # immediately after sweep, the list can be considered as a simple blocklist
    @nodup_list.each_key do |key|
      if key === x
        is_nodup = false
        break
      end
    end

    is_nodup
  end

  def hooks_exec(ds, hook, event)
    # check data source
    return unless hook['ds_label'] == ds.label

    event_cond_array = [hook['event_cond']]
    if hook['event_cond'].respond_to?(:each)
      event_cond_array = hook['event_cond']
    end

    event.is_quiet_mode     = @is_quiet_mode    # TODO (is_quiet_mode is deprecated)
    event.status.quiet_mode = @is_quiet_mode

    # check condition
    event_cond_array.detect do |event_cond|
      event.m = nil

      if event_cond == true
        event.m = [event.body]
      elsif event_cond.is_a?(String)
        event.m = [event.body] if event.body.start_with?(event_cond)
      elsif event_cond.respond_to?(:match)
        event.m = event_cond.match(event.body)
      elsif event_cond.respond_to?(:call)
        proc_result = event_cond.call(event)
        if proc_result
          if proc_result.respond_to?(:each)
            event.m = proc_result.each
          else
            event.m = [proc_result]
          end
        end
      end

      event.m
    end

    return unless event.m

    event.m = event.m.to_a   # with YAML.unsafe_load and to_yaml in mind

    event.hookby = hook["hookby"]

    @hookcnt += 1
    event.hookcnt = @hookcnt

    hook_result                  = nil
    hook_result_for_post_process = nil

    # pre process
    ds.pre_procs.each do |proc|
      proc.call(event)
    end

    # execute
    if hook['proc']
      tmp_context = ds.generate_context(event)
      hook_result = tmp_context.instance_exec(event, &hook['proc'])
    else
      hook_result_for_post_process = event
    end

    if hook_result == true
      hook_result_for_post_process = event
    elsif hook_result.nil? || hook_result == false
      # nop
    else
      hook_result_for_post_process = hook_result
    end

    # post process
    ds.post_procs.each do |proc|
      proc.call(event, hook_result_for_post_process)
    end
  end

end

#
# this class provided only for instance_exec
#
class OutvokeProcExecContext
  def initialize(outvoke, ds, event)
    @outvoke    = outvoke
    @ds         = ds
    @event      = event
    @event_body = @event.body.dup
  end

  def to(ds_cond, attachment = nil)
    @outvoke.extract_ds(ds_cond).map{ @outvoke.ds[_1] }.each do |ds|
      ds << { "body" => @event_body.to_s.dup, "attachment" => attachment }
    end
    nil
  end

  def e = @event

  def loputs(x = @event)
    @outvoke["lo"] << { "body" => x.to_s.dup, "attachment" => nil }
    nil
  end
end

module OutvokeDSL
  refine Kernel do
    def hook(ds_cond, event_cond = true, &block)
      $outvoke.register_proc(ds_cond, event_cond, "hook", &block)
    end

    def hookft(ds_cond, event_cond = true, &block)
      $outvoke.register_proc(ds_cond, event_cond, "hookft", &block)
    end

    # if block is given, execute in another thread (concurrent computing)
    def hookcc(ds_cond, event_cond = true, &block)
      register_hookcc(ds_cond, event_cond, "hookcc", &block)
    end

    # if block is given, execute in another thread (concurrent computing)
    def hookccft(ds_cond, event_cond = true, &block)
      register_hookcc(ds_cond, event_cond, "hookccft", &block)
    end

    def register_hookcc(ds_cond, event_cond, hookby, &block)
      if block_given?
        $outvoke.register_proc(ds_cond, event_cond, hookby) do |e; tmp_event|
          tmp_event = YAML.unsafe_load(e.to_yaml)    # deep copy

          Thread.start do
            Thread.current["hookcc_result"] = instance_exec(tmp_event , &block)

            if Thread.current["hookcc_result"] == true
              Thread.current["hook_result_for_post_process"] = tmp_event
            elsif Thread.current["hookcc_result"].nil? || Thread.current["hookcc_result"] == false
              Thread.current["hook_result_for_post_process"] = nil
            else
              Thread.current["hook_result_for_post_process"] = Thread.current["hookcc_result"]
            end

            @ds.post_procs_cc.each do |proc|
              proc.call(e, Thread.current["hook_result_for_post_process"])
            end
          end

          nil
        end
      else
        hook(ds_cond, event_cond)
      end
    end

    def hooklo(event_cond = true, &block)
      hook("lo", event_cond, &block)
    end

    def hookstd(event_cond = true, &block)
      hook("stdin", event_cond, &block)
    end

    def hookaux(event_cond = true, &block)
      hook("auxin:fifo:1", event_cond, &block)
    end

    def hooksec(event_cond = true, &block)
      hook("every-sec", event_cond, &block)
    end

    def hookweb(event_cond = true, &block)
      hook("web-001", event_cond, &block)
    end

    def hookvr(event_cond = true, &block)
      hook(/^vr/, event_cond, &block)
    end

    def loputs(x = "", attachment = nil)
      $outvoke.loputs(x, attachment)
    end

    #
    # TODO: experimental and incomplete implementation
    #
    # (specifications are subject to sudden change without notice)
    #
    def nodup(time, cond)
      raise '$outvoke is not an Outvoke object' unless $outvoke.is_a?(Outvoke)

      if block_given?
        $outvoke.nodup(time, cond) {|time, cond| yield time, cond }
      else
        $outvoke.nodup(time, cond)
      end
    end
    def nodup?(x)
      raise '$outvoke is not an Outvoke object' unless $outvoke.is_a?(Outvoke)

      $outvoke.nodup?(x)
    end

  end

  #
  # TODO: experimental and incomplete implementation
  #
  # (specifications are subject to sudden change without notice)
  #
  refine BasicObject do
    def to(ds_cond, attachment = nil)
      $outvoke.extract_ds(ds_cond).map{ $outvoke.ds[_1] }.each do |ds|
        ds << { "body" => self.to_s.dup, "attachment" => attachment }
      end
      nil
    end
  end
end

class OutvokeEvent < String
  attr_accessor :status, :msgid, :time, :attachment, :m
  attr_accessor :hookby, :hookcnt
  attr_accessor :is_quiet_mode    # deprecated

  def initialize(x)
    super x.to_s
    @time = Time.now
    @hookcnt = 0
  end

  def body = self.to_s
end

class OutvokeDataSource
  attr_accessor :label, :status, :log_lines, :mutex_lo, :is_first_time_log_check,
                :pre_procs, :post_procs, :post_procs_cc

  attr_reader   :lo_data

  def initialize(outvoke, label)
    @outvoke                 = outvoke
    @label                   = label
    @status                  = nil
    @log_lines               = []
    @lo_data                 = []
    @mutex_lo                = Mutex.new
    @is_first_time_log_check = false

    @is_enabled              = false

    #
    # Proc objects for pre process
    # (Procs to process before the execution of a Proc registered by hook)
    #
    @pre_procs = []

    #
    # Proc objects for post process
    # (Procs to process the value returned by Proc registered by hook)
    #
    @post_procs = []
    @post_procs << ->(e, hook_result) {
      return unless hook_result

      if e.status.quiet_mode
        puts hook_result.to_s
      else
        puts "[#{e.time}] #{hook_result}".gsub("\n", " ")
      end
    }

    #
    # Proc objects for post process
    # (Procs to process the value returned by Proc registered by hook)
    #
    @post_procs_cc = []
    @post_procs_cc << ->(e, hook_result) {
      return unless hook_result

      if e.status.quiet_mode
        puts hook_result.to_s
      else
        puts "[#{Time.now}] #{hook_result}".gsub("\n", " ")
      end
    }
  end

  def enabled?
    @is_enabled
  end

  def enabled=(x)
    @is_enabled = !!x
  end

  def <<(x)
    new_msgid = @outvoke.generate_new_msgid
    x["msgid"] = new_msgid

    @mutex_lo.synchronize do
      @lo_data << x
    end

    new_msgid
  end

  def each_event
    raise NotImplementedError
  end

  def before_each_event
    raise NotImplementedError
  end

  def after_each_event
    raise NotImplementedError
  end

  def first_time_log_check
    raise NotImplementedError
  end

  def generate_context(event)
    OutvokeProcExecContext.new(@outvoke, self, event)
  end
end

#
# TODO: experimental and incomplete implementation
#
# (specifications are subject to sudden change without notice)
#
StructDSStdinStatus = Struct.new(:now, :quiet_mode, :last_time)

class OutvokeDataSourceStdin < OutvokeDataSource
  def initialize(outvoke, label)
    super
    @status = StructDSStdinStatus.new
    @status.last_time = Time.now.floor
    @stdin = $stdin.each_line

    @stdin_new_lines  = []
    @mutex_stdin  = Mutex.new

    @thread_stdin = Thread.start do
      Thread.stop
      loop do
        Thread.stop unless @is_enabled
        Thread.current["tmp"] = @stdin.next
        Thread.stop unless @is_enabled

        Thread.current["new_msgid"] = @outvoke.generate_new_msgid
        @mutex_stdin.synchronize do
          @stdin_new_lines << {
            "msgid" => Thread.current["new_msgid"],
            "body"  => Thread.current["tmp"].chomp
          }
        end
      end
    end
  end

  def enabled=(x)
    return true if @is_enabled == true && x
    @is_enabled = !!x
    return false unless @is_enabled

    sleep 0.05    # TODO

    tmp_status = @thread_stdin.status

    if tmp_status == "run" || tmp_status == "sleep"
      begin
        @thread_stdin.run
      rescue ThreadError
        return false
      end
    end

    true
  end

  def each_event
    @log_lines.each do |line|
      event = OutvokeEvent.new(line["body"])
      event.msgid      = line["msgid"]
      event.status     = @status
      event.status.now = event.time

      yield event

      @status.last_time = event.time
    end
    self
  end

  def before_each_event
    @log_lines = []

    return unless @is_enabled

    @mutex_stdin.synchronize do
      @log_lines = @stdin_new_lines
      @stdin_new_lines = []
    end
  end

  def after_each_event
    nil
  end

  def first_time_log_check(ds, event)
    nil
  end
end

#
# TODO: experimental and incomplete implementation
#
# (specifications are subject to sudden change without notice)
#
StructDSAuxinStatus = Struct.new(:now, :quiet_mode, :last_time)

class OutvokeDataSourceAuxinFifo < OutvokeDataSource
  def initialize(outvoke, label)
    super
    @status = StructDSAuxinStatus.new
    @status.last_time = Time.now.floor

    @new_lines = []
    @mutex_new_lines = Mutex.new

    m = label.match(/\Aauxin:fifo:([1-9]+[0-9]*)\z/)
    @fifo_file_name = "./.outvoke.auxin.#{m[1]}.fifo"

    @thread_auxin = Thread.start do
      Thread.stop
      loop do
        next if File.symlink?(@fifo_file_name)

        @fifo_file = File.open(@fifo_file_name).each_line

        loop do
          Thread.stop unless @is_enabled
          Thread.current["tmp"] = @fifo_file.next
          Thread.stop unless @is_enabled

          Thread.current["new_msgid"] = @outvoke.generate_new_msgid
          @mutex_new_lines.synchronize do
            @new_lines << {
              "msgid" => Thread.current["new_msgid"],
              "body"  => Thread.current["tmp"].chomp
            }
          end
        end
      end
    end
  end

  def enabled=(x)
    return true if @is_enabled == true && x

    @is_enabled = !!x

    return false unless @is_enabled

    sleep 0.05    # TODO

    # create fifo file (named pipe)
    unless File.pipe?(@fifo_file_name)
      unless File.exist?(@fifo_file_name)
        File.mkfifo(@fifo_file_name, 0606)
      end
    end

    unless File.pipe?(@fifo_file_name)
      @is_enabled = false
      return
    end

    tmp_status = @thread_auxin.status

    if tmp_status == "run" || tmp_status == "sleep"
      begin
        @thread_auxin.run
      rescue ThreadError
        return false
      end
    end

    true
  end

  def each_event
    @log_lines.each do |line|
      event = OutvokeEvent.new(line["body"])
      event.msgid      = line["msgid"]
      event.status     = @status
      event.status.now = event.time

      yield event

      @status.last_time = event.time
    end
    self
  end

  def before_each_event
    @log_lines = []

    return unless @is_enabled

    @mutex_new_lines.synchronize do
      @log_lines = @new_lines
      @new_lines = []
    end
  end

  def after_each_event
    nil
  end

  def first_time_log_check(ds, event)
    nil
  end
end


#
# TODO: experimental and incomplete implementation
#
# (specifications are subject to sudden change without notice)
#
StructDSLoopbackStatus = Struct.new(:now, :quiet_mode, :last_time)

class OutvokeDataSourceLoopback < OutvokeDataSource

  def initialize(outvoke, label)
    super
    @status = StructDSLoopbackStatus.new
    @status.last_time = Time.now.floor
  end

  def each_event
    @log_lines.each do |line|
      event = OutvokeEvent.new(line["body"])
      event.msgid      = line["msgid"]
      event.attachment = line["attachment"]
      event.status     = @status
      event.status.now = event.time

      yield event

      @status.last_time = event.time
    end
    self
  end

  def before_each_event
    @log_lines = []

    @mutex_lo.synchronize do
      @log_lines = @lo_data
      @lo_data = []
    end
  end

  def after_each_event
    nil
  end

  def first_time_log_check(ds, event)
    nil
  end
end

#
# TODO: experimental and incomplete implementation
#
# (specifications are subject to sudden change without notice)
#
StructDSWebStatus = Struct.new(:now, :quiet_mode, :last_time, :ds_label)

class OutvokeEventWeb < OutvokeEvent
  attr_accessor :req, :get, :post, :res
end

class OutvokeDataSourceWeb < OutvokeDataSource
  attr_accessor :port, :document_root, :mount_proc_dir, :timeout
  attr_reader   :first_res_list

  def initialize(outvoke, label)
    super
    @status = StructDSWebStatus.new
    @status.last_time = Time.now.floor

    @websrv          = nil
    @port            = 8080
    @document_root   = nil
    @mount_proc_dir  = "/"
    @timeout         = 5

    @first_res_list  = Hash.new
    @mutex_first_res = Mutex.new

    @post_procs = []
    @post_procs << ->(e, hook_result) {
      register_first_res(e.msgid, hook_result)
    }
  end

  # TODO
  def enabled=(x)
    @is_enabled = !!x
  end

  def websrv_start
    require 'uri'
    require 'webrick'

    websrv = WEBrick::HTTPServer.new({:Port         => @port,
                                      :DocumentRoot => @document_root})

    if @mount_proc_dir
      websrv.mount_proc @mount_proc_dir do |req, res|
        req.query    # TODO
        msgid = self << { "body" => req.path.to_s.dup, "attachment" => [req, res] }

        res_found = false

        loop_start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
        loop do
          break if loop_start_time + @timeout < Process.clock_gettime(Process::CLOCK_MONOTONIC)

          # TODO (delete from @first_res_list when done)
          tmp_res = nil
          @mutex_first_res.synchronize do
            tmp_res = @first_res_list[msgid]
          end

          if tmp_res
            if res == tmp_res
              # nop

            elsif tmp_res.is_a?(WEBrick::HTTPResponse)   # maybe hookcc
              res.body = tmp_res.body

              tmp_res.header.each do |key, value|
                res.header[key] = value
              end

            else
              res.body = tmp_res.to_s
              res.body += "\n" if res.body[-1] != "\n"
            end

            res_found = true
            break
          end
        end

        unless res_found
          res.status = 500
          res.body = "error\n"
        end
      end
    end

    Thread.start { websrv.start }
  end

  def each_event
    @log_lines.each do |line|
      event = OutvokeEventWeb.new(line["body"])
      event.msgid      = line["msgid"]
      event.attachment = line["attachment"]
      event.req        = line["attachment"][0]
      event.res        = line["attachment"][1]

      if event.req.request_method == "GET"
        event.get  = event.req.query
        event.post = Hash.new
      elsif event.req.request_method == "POST"
        event.get  = Hash[URI::decode_www_form(event.req.request_uri.query)]
        event.post = event.req.query
      end

      event.status     = @status
      event.status.now = event.time
      event.status.ds_label = @label

      yield event

      @status.last_time = event.time
    end
    self
  end

  def before_each_event
    @log_lines = []

    @mutex_lo.synchronize do
      @log_lines = @lo_data
      @lo_data = []
    end
  end

  def after_each_event
    nil
  end

  def first_time_log_check(ds, event)
    nil
  end

  def register_first_res(msgid, res)
    return if res.nil?

    @mutex_first_res.synchronize do
      if @first_res_list[msgid].nil?
        @first_res_list[msgid] = res
      end
    end
  end

  def generate_context(event)
    context = OutvokeProcExecContext.new(@outvoke, self, event)

    context.extend(Module.new do
      def res(hook_result)
        @ds.register_first_res(@event.msgid, hook_result)
      end
    end)
  end
end

StructDSVrchatStatus = Struct.new(:now, :quiet_mode, :logfile, :file_size,
                                  :last_joined_time, :elapsed, :count, :lineno)

class OutvokeEventVrchat < OutvokeEvent
  attr_accessor :raw, :type
end

class OutvokeDataSourceVrchat < OutvokeDataSource
  attr_accessor :log_dir

  def initialize(outvoke, label)
    super

    @status = StructDSVrchatStatus.new
    @status.logfile = nil
    @status.file_size = 0
    @status.count = 0
    @status.lineno = 0
    @status.last_joined_time = Time.now

    @is_first_time_log_check = true

    @log_dir = ''
    @has_new_log_lines = false
  end

  def each_event
    return unless @has_new_log_lines

    loop do
      cnt      = 0
      line_raw = ''
      m        = nil
      @log_lines[@status.lineno..].each do |line|
        cnt += 1
        line_raw = line
        m = line.chomp.match(/\A([0-9]{4}\.[0-9]{2}\.[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}) +([-_a-zA-Z0-9]+) +(.*)\z/)
        break if m    # if found
      end
      @status.lineno += cnt
      @has_new_log_lines = false
      return self unless m

      event = OutvokeEventVrchat.new(m[3].sub(/\A *- */, ''))
      event.raw    = line_raw
      event.time   = Time.parse(m[1])   # unlike event.status.now, a value taken from log data
      event.type   = m[2]
      event.msgid  = @outvoke.generate_new_msgid

      event.status = @status
      event.status.now = Time.now

      if event.body.start_with?('[Behaviour] Joining or Creating Room: ')
        event.status.last_joined_time = event.time
      end

      event.status.elapsed = event.status.now - event.status.last_joined_time

      yield event
    end
    self
  end

  def before_each_event
    tmp_now = Time.now
    has_file_changed = false

    # check if it is a new file
    Dir.glob("#{@log_dir}/output_log_*.txt").last.then do
      if @status.logfile != _1
        has_file_changed = true
        @status.logfile = _1
        @status.lineno = 0
        if not $outvoke.quiet_mode?    # TODO
          puts "[#{tmp_now}] [outvoke-system] #{@label}: a new log file was found." if @status.logfile
        end
      end
    end

    # return if not found
    unless @status.logfile
      if @is_first_time_log_check
        puts "[#{tmp_now}] [outvoke-system] #{@label}: ERROR: VRChat log file not found"
      end
      return
    end

    # return if not readable
    return unless File.readable?(@status.logfile)

    # check if file size has increased
    unless has_file_changed
      if @status.file_size < File.size(@status.logfile)
        has_file_changed = true
      end
    end

    # return if the log file has not changed
    return unless has_file_changed

    if @is_first_time_log_check
      tmp = @status.logfile.sub(
                  /\A.*output_log_([0-9]{4}-[0-9]{2}-[0-9]{2})_([0-9]{2})-([0-9]{2})-([0-9]{2})\.txt\z/,
                  "\\1 \\2:\\3:\\4")
      @status.last_joined_time = Time.parse(tmp)
    end

    # read VRChat log file
    File.read(@status.logfile).then do |file_body|
      @log_lines = file_body.split("\n")
      @status.file_size = file_body.bytesize
    end
    @has_new_log_lines = true
  end

  def after_each_event
    if @is_first_time_log_check
      if not $outvoke.quiet_mode?    # TODO
        puts "[#{Time.now}] [outvoke-system] #{@label}: first time log check has done."
      end
      @is_first_time_log_check = false
    end
  end

  def first_time_log_check(ds, event)
    return unless event.body.start_with?('[B')

    if event.body.start_with?('[Behaviour] Entering Room: ')
      @status.count = 0
    elsif event.body.start_with?('[Behaviour] OnPlayerJoined ')
      @status.count += 1
    elsif event.body.start_with?('[Behaviour] OnPlayerLeft ')
      @status.count -= 1
      @status.count = 0 if @status.count < 0
    end
  end
end

StructDSEverySecStatus = Struct.new(:now, :quiet_mode, :last_time)

class OutvokeDataSourceEverySec < OutvokeDataSource

  def initialize(outvoke, label)
    super
    @status = StructDSEverySecStatus.new
    @status.last_time = Time.now.floor
  end

  def each_event
    @log_lines.each do |line|
      event = OutvokeEvent.new(line["body"])
      event.time       = line["body"]    # TODO
      event.msgid      = line["msgid"]
      event.status     = @status
      event.status.now = Time.now

      yield event

      @status.last_time = line["body"]
    end
    self
  end

  def before_each_event
    @log_lines = []
    tmp_time = @status.last_time.floor
    loop do
      tmp_time += 1
      return if tmp_time >= Time.now
      @log_lines << {"msgid" => @outvoke.generate_new_msgid, "body" => tmp_time}
    end
  end

  def after_each_event
    nil
  end

  def first_time_log_check(ds, event)
    nil
  end
end

# --------------------------------------------------------------------
# from this point forward, it will only be executed when this file run
# as a command, not when this file included by require.

if $0 == __FILE__

  $stdout.sync = true

  def log_puts(str, line_head = '')
    return if $outvoke.quiet_mode?

    if line_head == ''
      puts "#{str.gsub("\n", " ")}"
    else
      puts "#{line_head}#{str.gsub("\n", "\n" + line_head)}"
    end
  end

  $outvoke = Outvoke.new

  version_str = "#{$outvoke.version.branch} (version #{$outvoke.version.body})"

  require 'optparse'

  is_ruby_code_given = false
  ruby_code         = nil
  mainloop_interval = nil

  opts = OptionParser.new
  opts.default_argv = ['main.rb']
  opts.on('-e CODE')           { |optvalue| ruby_code  = optvalue }
  opts.on('-q', '--quiet')     { $outvoke.quiet_mode = true }

  opts.on('--wait INTERVAL') do |optvalue|
    raise "--wait option allows only numeric" if optvalue !~ /\A[0-9]+(\.[0-9]+)?\z/
    mainloop_interval = optvalue.to_f
  end

  if ARGV[0]
    specified_file = opts.parse!(ARGV)[0]
  else
    specified_file = opts.parse![0]
  end

  log_puts "# starting Outvoke #{version_str} ---- #{Time.now}"
  log_puts "# ----"

  $outvoke.wait = mainloop_interval if mainloop_interval

  'stdin'.then do
    $outvoke.ds[_1] = OutvokeDataSourceStdin.new($outvoke, _1)
  end

  'auxin:fifo:1'.then do
    $outvoke.ds[_1] = OutvokeDataSourceAuxinFifo.new($outvoke, _1)
  end

  'lo'.then do
    $outvoke.ds[_1] = OutvokeDataSourceLoopback.new($outvoke, _1)
  end

  'every-sec'.then do
    $outvoke.ds[_1] = OutvokeDataSourceEverySec.new($outvoke, _1)
  end

  'web-001'.then do
    $outvoke.ds[_1] = OutvokeDataSourceWeb.new($outvoke, _1)
  end

  'vrchat-001'.then do
    vrchat_log_dir = "#{Dir.home}/.steam/debian-installation/steamapps/compatdata/438100/pfx/drive_c/users/steamuser/AppData/LocalLow/VRChat/VRChat"
    $outvoke.ds[_1] = OutvokeDataSourceVrchat.new($outvoke, _1)
    $outvoke.ds[_1].log_dir = vrchat_log_dir
  end

  './outvoke.conf.rb'.then do
    if File.readable?(_1)
      log_puts "# loading #{_1} ..."
      require _1
    end
  end

  if ruby_code
    log_puts '# given ruby code:'
    log_puts ruby_code, '# '
    eval "using OutvokeDSL;#{ruby_code}"
  else
    file_prefix = ''
    file_prefix = './' if not specified_file.start_with?('/')
    specified_file = "#{file_prefix }#{specified_file}"
    log_puts "# loading #{specified_file} ..."

    if File.readable?(specified_file)
      require specified_file
    else
      log_puts "# ERROR: #{specified_file} does not exist or is not readable"
      exit 1
    end
  end

  'web-001'.then do
    if $outvoke[_1].enabled?
      log_puts "# =========================== websrv start ==========================="
      $outvoke[_1].websrv_start
    end
  end

  log_puts '# ----'
  log_puts ''

  # execute mainloop
  begin
    $outvoke.mainloop
  rescue Interrupt
    if not $outvoke.quiet_mode?
      puts "[#{Time.now}] [outvoke-system] interrupted"
    end
  end
end