nadoka/nadoka

# -*-ruby-*-
#
# Copyright (C) 2004 Kazuhiro NISHIYAMA
#     All rights reserved.
#     This is free software with ABSOLUTELY NO WARRANTY.
#
# You can redistribute it and/or modify it under the terms of
# the Ruby's licence.
#
=begin
BotConfig = [
{
  :name     => :MailCheckBot,
  :Maildir  => "~/Maildir/.ml.debian-security-announce",
  :template => "biff(DSA): %{subject}s",
  :channels => ['#nadoka'],
},
{
  :name     => :MailCheckBot,
  :mh_dir   => [
    "~/Mail/ml/nadoka",
    "~/Mail/ml/yarv-dev",
  ],
  :channels => %w[#nadoka #nadoka_check],
  :template => "biff(%{x-ml-name}s): %{subject}s - http://www.atdot.net/mla/%{x-ml-name}s/%{x-mail-count}d",
}
]


=end

require 'nkf'

class MailCheckBot < Nadoka::NDK_Bot
  class Error < StandardError; end

  class MailCheckInfo
    def initialize
      @biffed = Hash.new
      update_entries do |fields|
        true
      end
    end

    def entries
      files = []
      @glob_patterns.each do |pattern|
        files.concat(Dir.glob(pattern))
      end
      files
    end

    def mailread(filename)
      fields = Hash.new("".freeze)
      header_lines = ""
      message_id = nil

      File.foreach(filename) do |line|
        case line
        when /^\s*$/
          break
        when /^message-id:\s*/i
          message_id = $'
          return message_id, fields if @biffed.key?(message_id)
        end
        header_lines.concat(line)
      end

      header_lines.split(/^(?!\s)/).each do |line|
        line = NKF.nkf("-e", line)
        line.gsub!(/\s+/, ' ')
        key, value = line.split(/:/, 2)
        key.downcase!
        value = value.to_s
        value.strip!
        # use last field if same keys found
        fields[key.freeze] = value.freeze
      end

      return message_id, fields
    rescue
      # ignore missing files after glob
    end

    def update_entries
      old_entries = @biffed.keys
      new_entries = entries
      (new_entries - old_entries).each do |filename|
        mid, fields = mailread(filename)
        next unless mid # the file is not probably a mail message
        next if @biffed.key?(mid) # already biffed
        yield(fields)
        @biffed[mid.freeze] = true
      end
      if not(old_entries.empty?) and new_entries.empty?
        @biffed.clear
      end
    end
  end

  class MaildirInfo < MailCheckInfo
    def initialize(dir)
      full_path = File.expand_path(dir).freeze
      @glob_patterns = [
        File.expand_path("cur/*,", dir).freeze,
        File.expand_path("new/*", dir).freeze,
      ].freeze
      super()
    end
  end

  class MhInfo < MailCheckInfo
    def initialize(dir)
      full_path = File.expand_path("#{dir}/*")
      @glob_patterns = [
        full_path.freeze,
      ].freeze
      super()
    end
  end

  def bot_initialize
    @on_timer = nil
    p [:MailCheckBot, :bot_initialize] if $DEBUG
    @m_infos = {}
    @bot_config.freeze

    @channels = @bot_config[:channels].collect do |ch|
      NKF.nkf("-j -m0", ch).freeze
    end.freeze
    @template = (@bot_config[:template] || "biff: %{subject}s").freeze

    if @bot_config.key?(:Maildir)
      if @bot_config.key?(:mh_dir)
        raise Error, "both :Maildir and :mh_dir found in #{@bot_config.inspect}"
      end
      @bot_config[:Maildir].each do |dir|
        raise Error, "duplicated Maildir: #{dir}" if @m_infos.key?(dir)
        @m_infos[dir] = MaildirInfo.new(dir)
      end
    elsif @bot_config.key?(:mh_dir)
      @bot_config[:mh_dir].each do |dir|
        raise Error, "duplicated MH dir: #{dir}" if @m_infos.key?(dir)
        @m_infos[dir] = MhInfo.new(dir)
      end
    else
      raise Error, ":Maildir or :mh_dir not found in #{@bot_config.inspect}"
    end
  end

  def bot_state
    keys = @m_infos.keys
    dir, = File.basename(keys[0])
    if keys.size > 1
      dir = "#{dir}, ..."
    end
    "\#<#{self.class}: #{dir} -> #{@channels.join(' ')}>"
  end

  def on_timer t
    p [:MailCheckBot, :on_timer, t] if $DEBUG
    if @on_timer
      $stderr.puts "MailCheckBot#on_timer duplicated (t=#{t} and old t=#{@on_timer})" if $DEBUG
      return
    end
    @on_timer = t

    mailcheck
  ensure
    @on_timer = false
  end

  def mailcheck
    @m_infos.each do |dir, m_info|
      m_info.update_entries do |fields|
        bark(apply_template(fields))
      end
    end
  end

  def apply_template(fields)
    msg = @template.dup
    msg.gsub!(/%\{([a-z0-9_\-]+)\}([sd])/i) do
      field_name, field_type  = $1, $2
      field_name.downcase!
      case field_type
      when 's'
        fields[field_name].to_s
      when 'd'
        fields[field_name].to_i.to_s
      else
        "(field type bug: `#{field_type}')"
      end
    end
    NKF.nkf("-j -m0", msg).freeze
  end

  def bark(msg)
    @channels.each do |ch|
      send_notice(ch, msg)
    end
  end
end