#!/usr/bin/env ruby
require 'mysql'
require 'readline'

help = "\
synopsis : #{$0} [--user USER] [--host HOST] [--password|-pPASSWORD] [--database DB] [--help] < --interactive | zone_file >
  
  #{$0} is used to inject zone configuration for bind server into an mysql database.
  There is two modes :
  - in interactive mode, you specify zone informations on standard input.
  - in file mode, you pass the configuration file as argument.

  options :
    --user, -u  USER : mysql user
    --host, -h  HOST : mysql host
    --password       : give mysql password in interactive mode
    -pPASSWORD       : give mysql password on the command line
    --database, -d   : name of the mysql database to use
    --interactive    : run in interactive mode
    --help           : print this help

See the end of the source code to know what table schema is required.
"

args = ARGV.reverse

Types = %w( SOA NS MX AAAA A CNAME PTR )

$mysql_user     = ENV['USER']
$mysql_host     = 'localhost'
$mysql_password = ''
$mysql_db       = 'dns'
files_to_parse  = []

puts help if args.empty? 

until args.empty?
  arg = args.pop

  case arg
    when '--user', '-u'
      $mysql_user = args.pop

    when '--host', '-h'
      $mysql_host = args.pop

    when '--password' 
      prompt_password = true

    when /^p(.*)/
      $mysql_password = $1

    when '--interactive', '-i'
      interactive_mode = true

    when '--database', '-d'
      $mysql_db = args.pop

    when '--help', '-h'
      puts help
      exit

  else
    files_to_parse << arg
  end
end

puts "invalid argument\n" << help if interactive_mode and not files_to_parse.empty?

ZoneInfo = Struct.new :zone, :ttl, :type, :host, 
                      :mx_priority, :data, :primary_ns, :resp_contact, 
                      :serial, :refresh, :retry, :expire, :minimum

class Zone

  def initialize zonename = nil

    @db = Mysql.new $mysql_host, $mysql_user, $mysql_password
    @db.select_db $mysql_db
    @zone_infos = []
    @end = false

    unless zonename 
      puts "Zone name:"
      zonename = Readline.readline "?> "

      puts "global ttl:"
      @gl_ttl = Readline.readline "?> "
    end

    @zonename = zonename
  end

  def interactive_zoneinfo

    infos = ZoneInfo.new

    puts "Type?"
    selection = Readline.readline( "?> " ).upcase
    Types.include?( selection ) ? ( infos.type = selection ) : ( puts "valid types are : #{Types.join ' ,'}"; return false )

    puts "\nHost? (default = @)"
    selection = Readline.readline "?> "
    infos.host = ( selection == '' ? '@' : selection )

    puts "\nTTL? (default = #{@gl_ttl})"
    selection = Readline.readline "?> "
    infos.ttl = ( selection == '' ? @gl_ttl : selection )

    if infos.type == 'MX'
      
      puts "\nMX priority? (e.g. 10, 20, 30 ...)"
      infos.mx_priority = Readline.readline "?> "
    end

    unless infos.type == 'SOA'
      
      puts "\ndata"
      infos.data = Readline.readline "?> "

    else

      %w( primary_ns resp_contact serial refresh retry expire minimum ).each { |field|

        puts "\n" + field
        infos[ field ] = Readline.readline "?> "
      }
    end

    infos.zone = @zonename
    return infos
  end

  def parse_file file
    ( puts "#{file} is not a valid filename" ; exit ) unless file.class == String and File.file? file
    stream = File.open file
    ( puts "can't open file #{file}" ; return false ) if stream == nil

    lines = stream.readlines.reverse

    while line = lines.pop

      infos = ZoneInfo.new

      line.chomp!
      line.gsub! /;.*$/, ''
      line.gsub! /\t/, ' '

      next if line[/^ *$/]

      # join splitted resource records
      if line[/\(/]
        until line[/\)/]
          more = lines.pop
          more.gsub! /;.*$/, ''
          more.gsub! /\t/, ' '
          line = line.chomp + ' ' + more.chomp
        end
      end

      line.gsub! /\(/, ''
      line.gsub! /\)/, ''

      if line[/^\$TTL +([^ ]+)/] 
        @gl_ttl = $1
        next
      end

      if line[/^\$ORIGIN +([^ ]+)/] 
        @zonename = $1
        next
      end

      if line[/^\$INCLUDE/] 
        puts "sorry, but inclusion isn't supported"
        exit
      end

      # parse host
      same = true
      ( same = false ; host = line[/^[^ ]+/] ) unless line[/^ /]
      ( puts "can't parse host" ; return false ) unless defined? host
      infos.host = host

      same ? ( line[/ +/] = '' ) : ( line[/^[^ ]+ +/] = '' )
      match = line[/^[^ ]+/]

      # parse TTL
      if match[/\d+(\w?)/]
        infos.ttl = ( $1 ? ( correct_date_style $& ) : ( $& ) )
        line[/^[^ ]+ +/] = ''
        match = line[/^[^ ]+/]
      else
        infos.ttl = @gl_ttl
      end
      
      # parse class
      if match[/IN|CH/]
        ( puts "CHAOS class is not supported" ; return false ) if $& == 'CH'
        line[/^[^ ]+ +/] = ''
        match = line[/^[^ ]+/]
      end

      # parse type
      match[/AAAA|A|CNAME|HINFO|MX|NS|PTR|SOA/]
      ( puts "can't parse type" ; p match ; p $& ; p infos ; return false ) unless $&
      infos.type = $&

      line[/^[^ ]+ +/] = ''
      match = line[/^[^ ]+/]

      # parse data
      if %w( AAAA A CNAME HINFO NS PTR ).include? infos.type
        infos.data = match

      # parse MX data
      elsif infos.type == 'MX'
        infos.mx_priority = match
        line[/^[^ ]+ +/] = ''
        match = line[/^[^ ]+/]
        infos.data = match

      # parse SOA data
      elsif infos.type == 'SOA'
        %w( primary_ns resp_contact serial refresh retry expire minimum ).each { |parameter|
          infos[parameter] = match
          line[/^[^ ]+ +/] = ''
          match = line[/^[^ ]+/]
        }

      end

      infos.zone = @zonename
      ( puts "bad checks for zone #{infos.zone}, type #{infos.type}" ; p infos ; exit ) unless check infos
    end

    complete
  end

  def correct_date_style datestring

    datestring[/(\d+)(m|h|d|w)/i]
    return false unless $1 and $2
    conv    = { "m" => 60, "h" => 3600, "d" => 86400, "w" => 604800 }
    seconds = $1.to_i * conv[ $2.downcase ].to_i

    return seconds.to_s
  end

  def check infos

    return false unless infos.class == ZoneInfo
    return false unless infos.zone  and infos.type and infos.ttl and infos.host
    return false if     infos.type  == 'MX' and ( not infos.mx_priority or infos.mx_priority[/[^0-9]/] )
    return false if     infos.mx_priority and infos.type != 'MX'

    if infos.ttl[/[^0-9]/]
      infos.ttl = correct_date_style infos.ttl
      return false unless infos.ttl
    end

    if infos.type == 'SOA'
      %w( refresh retry expire minimum ).each { |field|
        if infos[ field ][/[^0-9]/]
          infos[ field ] = correct_date_style infos[ field ]
          return false unless infos[ field ]
        end
      }

      return false if infos.data

    else
      %w( primary_ns resp_contact serial refresh retry expire minimum ).each { |field|
        return false if infos[ field ]
      }

      return false unless infos.data
    end

    @zone_infos << infos
    return true
  end

  def complete

    @end = true
    @zone_infos.each { |infos|

      query = "insert into records( #{infos.members.join ", "} ) values ( #{infos.entries.collect {|e| ( e == nil ? ( "NULL" ) : ( "'"+ Mysql.escape_string(e.to_s) + "'" ) ) }.join ", "} )"


      begin
        res = @db.query query
      rescue
        puts "error while loading the #{infos.zone} zone"
        return false
      end
    }

    puts "zone successfuly loaded"
    self.freeze
    return true
  end

end

def continue?

  answer = Readline.readline( "?> " ).upcase

  while answer != 'Y' and answer != 'N'
    puts "please answer by 'y' or 'n'"
    answer = Readline.readline( "?> " ).upcase
  end

  return ( answer == 'Y' ? true : false )
end

if prompt_password
  puts "Password : "
  $mysql_password = Readline.readline "?> "
end

if interactive_mode
  continue_app = true

  while continue_app
    zone           = Zone.new
    continue_zone  = true
    while continue_zone

      infos   = zone.interactive_zoneinfo
      (sanity = zone.check infos ) if infos

      (puts "Bad zone infos, dropped"; p infos) unless sanity

      puts "\nIs there others infos to enter for this zone? <y|n>"
      continue_zone = continue?
    end

    zone.complete if sanity

    puts "\nDo you want to create an other zone? <y|n>"
    continue_app = continue?
  end
else
  files_to_parse.each { |file|

    # support db.name, name.zone, name.zones, name.host and name.hosts filename format
    # add gsub rules if you need others
    zonename = File.basename( file ).gsub( /^db\./, '').gsub( /\.(hosts?|zones?)$/, '')

    zone = Zone.new zonename
    result = zone.parse_file file
    puts ( result ? "succeded" : "failed" )
  }

end

# Here is how your mysql bind table should look like :

#  CREATE TABLE `records` (
#    `id` int(10) unsigned NOT NULL auto_increment,
#    `zone` varchar(255) NOT NULL,
#    `ttl` int(11) NOT NULL default '86400',
#    `type` varchar(255) NOT NULL,
#    `host` varchar(255) NOT NULL default '@',
#    `mx_priority` int(11) default NULL,
#    `data` text,
#    `primary_ns` varchar(255) default NULL,
#    `resp_contact` varchar(255) default NULL,
#    `serial` bigint(20) default NULL,
#    `refresh` int(11) default NULL,
#    `retry` int(11) default NULL,
#    `expire` int(11) default NULL,
#    `minimum` int(11) default NULL,
#    PRIMARY KEY  (`id`),
#    KEY `type` (`type`),
#    KEY `host` (`host`),
#    KEY `zone` (`zone`)
#  );