#
# Fluent
#
# Copyright (C) 2011 FURUHASHI Sadayuki
#
#    Licensed under the Apache License, Version 2.0 (the "License");
#    you may not use this file except in compliance with the License.
#    You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS,
#    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#    See the License for the specific language governing permissions and
#    limitations under the License.
#
module Fluent


class ExecFilterOutput < Output
  Plugin.register_output('exec_filter', self)

  def initialize
    super
  end

  config_param :command, :string
  config_param :in_keys, :string
  config_param :out_keys, :string
  config_param :tag, :string, :default => nil
  config_param :tag_key, :string, :default => nil
  config_param :time_key, :string, :default => nil
  config_param :time_format, :string, :default => nil
  config_param :localtime, :bool, :default => true

  def configure(conf)
    super

    if localtime = conf['localtime']
      @localtime = true
    elsif utc = conf['utc']
      @localtime = false
    end

    if !@tag && !@tag_key
      raise ConfigError, "'tag' or 'tag_key' option is required on exec_filter output"
    end

    @in_keys = @in_keys.split(',')
    @out_keys = @out_keys.split(',')

    if @time_key
      if @time_format
        f = @time_format
        tf = TimeFormatter.new(f, @localtime)
        @time_format_proc = tf.method(:format)
        @time_parse_proc = Proc.new {|str| Time.strptime(str, f).to_i }
      else
        @time_format_proc = Proc.new {|time| time.to_s }
        @time_parse_proc = Proc.new {|str| str.to_i }
      end
    end
  end

  def start
    @io = IO.popen(@command, "r+")
    @pid = @io.pid
    @io.sync = true
    @thread = Thread.new(&method(:run))
  end

  def shutdown
    Process.kill(:TERM, @pid)
    if @thread.join(60)  # TODO wait time
      return
    end
    Process.kill(:KILL, @pid)
    @thread.join
    nil
  end

  def emit(tag, es, chain)
    out = ''
    es.each {|time,record|
      last = @in_keys.length-1
      for i in 0..last
        key = @in_keys[i]
        if key == @time_key
          out << @time_format_proc.call(time)
        elsif key == @tag_key
          out << tag
        else
          out << record[key].to_s
        end
        out << "\t" if i != last
      end
      out << "\n"
    }
    @io.write out
    chain.next
  end

  def run
    @io.each_line {|line|
      begin
        line.chomp!
        vals = line.split("\t")

        tag = @tag
        time = nil
        record = {}
        for i in 0..@out_keys.length-1
          key = @out_keys[i]
          val = vals[i]
          if key == @time_key
            time = @time_parse_proc.call(val)
          elsif key == @tag_key
            tag = val
          else
            record[key] = val
          end
        end

        if tag
          time ||= Engine.now
          Engine.emit(tag, time, record)
        end
      rescue
        $log.error "exec_filter failed to emit", :error=>$!, :line=>line
        $log.warn_backtrace $!.backtrace
      end
    }
    Process.waitpid(@pid)
  rescue
    $log.error "exec_filter process exited", :error=>$!
    $log.warn_backtrace $!.backtrace
  end
end


end