=begin

= net/pop.rb version 1.2.0

  Copyright (C) 1999-2001 Yukihiro Matsumoto

  written & maintained by Minero Aoki <aamine@dp.u-netsurf.ne.jp>

  This program is free software. You can re-distribute and/or
  modify this program under the same terms as Ruby itself,
  GNU General Public License or Ruby License.

  Japanese version of this document is in "net" full package.
  You can get it from RAA (Ruby Application Archive). RAA is:
  http://www.ruby-lang.org/en/raa.html


== Net::POP3

=== Super Class

Net::Protocol

=== Class Methods

: new( address = 'localhost', port = 110, apop = false )
  creates a new Net::POP3 object.
  This method does not open TCP connection yet.

: start( address = 'localhost', port = 110, account, password )
: start( address = 'localhost', port = 110, account, password ) {|pop| .... }
  equals to Net::POP3.new( address, port ).start( account, password )

    # typical usage
    Net::POP3.start( addr, port, acnt, pass ) do |pop|
      pop.each_mail do |m|
        any_file.write m.pop
        m.delete
      end
    end

: foreach( address = 'localhost', port = 110, account, password ) {|mail| .... }
  starts protocol and iterate for each POPMail object.
  This method equals to

    Net::POP3.start( address, port, account, password ) do |pop|
      pop.each do |m|
        yield m
      end
    end

  .

    # typical usage
    Net::POP3.foreach( addr, nil, acnt, pass ) do |m|
      m.pop file
      m.delete
    end

: delete_all( address = 'localhost', port = 110, account, password )
: delete_all( address = 'localhost', port = 110, account, password ) {|mail| .... }
  starts POP3 session and delete all mails.
  If block is given, iterates for each POPMail object before delete.

    # typical usage
    Net::POP3.delete_all( addr, nil, acnt, pass ) do |m|
      m.pop file
    end
  
=== Instance Methods

: start( account, password )
: start( account, password ) {|pop| .... }
  starts POP3 session.

  When called with block, gives a POP3 object to block and
  closes the session after block call finish.

: mails
  an array of ((URL:#POPMail)).
  This array is renewed when session started.

: each_mail {|popmail| .... }
: each {|popmail| .... }
  is equals to "pop3.mails.each"

: delete_all
: delete_all {|popmail| .... }
  deletes all mails.
  If called with block, gives mails to the block before deleting.

    # example 1
    # pop and delete all mails
    n = 1
    pop.delete_all do |m|
      File.open("inbox/#{n}") {|f| f.write m.pop }
      n += 1
    end

    # example 2
    # clear all mails on server
    Net::POP3.start( addr, port, acc, pass ) do |pop|
      pop.delete_all
    end

: reset
  reset the session. All "deleted mark" are removed.


== Net::APOP

This class defines no new methods.
Only difference from POP3 is using APOP authentification.

=== Super Class

Net::POP3


== Net::POPMail

A class of mail which exists on POP server.

=== Super Class

Object


=== Methods

: pop( dest = '' )
  This method fetches a mail and write to 'dest' using '<<' method.

    # usage example

    mailarr = []
    POP3.start( 'localhost', 110 ) do |pop|
      pop.each_mail do |popm|
        mailarr.push popm.pop   # all() returns 'dest' (this time, string)
        # or, you can also
        # popm.pop( $stdout )   # write mail to stdout

        # maybe you also want to delete mail after popping
        popm.delete
      end
    end

: pop {|str| .... }
  If pop() is called with block, it gives the block part strings of a mail.

    # usage example

    POP3.start( 'localhost', 110 ) do |pop3|
      pop3.each_mail do |m|
        m.pop do |str|
          # do anything
        end
      end
    end

: header
  This method fetches only mail header.

: top( lines )
  This method fetches mail header and 'lines' lines body.

: delete
: delete!
  This method deletes mail.

: size
  size of mail(bytes)

: deleted?
  true if mail was deleted

=end

require 'net/protocol'
require 'md5'


module Net

  class POP3 < Protocol

    protocol_param :port,         '110'
    protocol_param :command_type, '::Net::NetPrivate::POP3Command'
    protocol_param :apop_command_type, '::Net::NetPrivate::APOPCommand'

    protocol_param :mail_type,    '::Net::POPMail'

    class << self

      def foreach( address = nil, port = nil,
                   account = nil, password = nil, &block )
        start( address, port, account, password ) do |pop|
          pop.each_mail( &block )
        end
      end

      def delete_all( address = nil, port = nil,
                      account = nil, password = nil, &block )
        start( address, port, account, password ) do |pop|
          pop.delete_all( &block )
        end
      end
    
    end


    def initialize( addr = nil, port = nil, apop = false )
      super addr, port
      @mails = nil
      @apop = false
    end

    attr :mails

    def each_mail( &block )
      io_check
      @mails.each( &block )
    end

    alias each each_mail

    def delete_all
      @mails.each do |m|
        yield m if block_given?
        m.delete unless m.deleted?
      end
    end

    def reset
      io_check
      @command.rset
      @mails.each do |m|
        m.instance_eval { @deleted = false }
      end
    end


    private

    def conn_command( sock )
      @command =
          (@apop ? type.apop_command_type : type.command_type).new(sock)
    end

    def do_start( acnt, pwd )
      @command.auth( acnt, pwd )

      @mails = []
      mtype = type.mail_type
      @command.list.each_with_index do |size,idx|
        if size then
          @mails.push mtype.new( idx, size, @command )
        end
      end
      @mails.freeze
    end

    def io_check
      if not @socket or @socket.closed? then
        raise IOError, 'pop session is not opened yet'
      end
    end

  end

  POP         = POP3
  POPSession  = POP3
  POP3Session = POP3


  class APOP < POP3
    protocol_param :command_type, 'Net::NetPrivate::APOPCommand'
  end

  APOPSession = APOP


  class POPMail

    def initialize( n, s, cmd )
      @num     = n
      @size    = s
      @command = cmd

      @deleted = false
    end

    attr :size

    def inspect
      "#<#{type} #{@num}#{@deleted ? ' deleted' : ''}>"
    end

    def all( dest = '' )
      if block_given? then
        dest = NetPrivate::ReadAdapter.new( Proc.new )
      end
      @command.retr( @num, dest )
    end
    alias pop all
    alias mail all

    def top( lines, dest = '' )
      @command.top( @num, lines, dest )
    end

    def header( dest = '' )
      top 0, dest
    end

    def delete
      @command.dele( @num )
      @deleted = true
    end

    alias delete! delete

    def deleted?
      @deleted
    end

    def uidl
      @command.uidl @num
    end

  end



  module NetPrivate


  class POP3Command < Command

    def initialize( sock )
      super
      critical {
        check_reply SuccessCode
      }
    end

    def auth( acnt, pass )
      critical {
        @socket.writeline 'USER ' + acnt
        check_reply_auth

        @socket.writeline 'PASS ' + pass
        check_reply_auth
      }
    end

    def list
      arr = []
      critical {
        getok 'LIST'
        @socket.read_pendlist do |line|
          num, siz = line.split( / +/o )
          arr[ num.to_i ] = siz.to_i
        end
      }
      arr
    end

    def rset
      critical {
        getok 'RSET'
      }
    end


    def top( num, lines = 0, dest = '' )
      critical {
        getok sprintf( 'TOP %d %d', num, lines )
        @socket.read_pendstr( dest )
      }
    end

    def retr( num, dest = '', &block )
      critical {
        getok sprintf( 'RETR %d', num )
        @socket.read_pendstr( dest, &block )
      }
    end
    
    def dele( num )
      critical {
        getok sprintf( 'DELE %d', num )
      }
    end

    def uidl( num )
      critical {
        getok( sprintf 'UIDL %d', num ).msg.split(' ')[1]
      }
    end

    def quit
      critical {
        getok 'QUIT'
      }
    end


    private

    def check_reply_auth
      begin
        cod = check_reply( SuccessCode )
      rescue ProtocolError
        raise ProtoAuthError, 'Fail to POP authentication'
      end

      return cod
    end

    def get_reply
      str = @socket.readline

      if /\A\+/ === str then
        return Response.new( SuccessCode, str[0,3], str[3, str.size - 3].strip )
      else
        return Response.new( ErrorCode, str[0,4], str[4, str.size - 4].strip )
      end
    end

  end


  class APOPCommand < POP3Command

    def initialize( sock )
      rep = super( sock )

      m = /<.+>/.match( rep.msg )
      unless m then
        raise ProtoAuthError, "This is not APOP server: can't login"
      end
      @stamp = m[0]
    end

    def auth( account, pass )
      critical {
        @socket.writeline sprintf( 'APOP %s %s',
                            account, MD5.new(@stamp + pass).hexdigest )
        check_reply_auth
      }
    end

  end


  end   # module Net::NetPrivate

end   # module Net