#!/usr/bin/env ruby
require 'net/imap'
 
# Source server connection info.
SOURCE_HOST = 'imap.googlemail.com'
SOURCE_PORT = 993
SOURCE_SSL  = true
SOURCE_USER = 'EMAIL@googlemail.com'
SOURCE_PASS = 'PASSWORT'
 
# Destination server connection info.
DEST_HOST = 'imap.SERVER.com'
DEST_PORT = 143
DEST_SSL  = false
DEST_USER = 'USER'
DEST_PASS = 'PASSWORT'
 
# List of all Folder that should not be synced
FOLDERS_EXCLUDE = [
  '[Google Mail]',
  '[Google Mail]/Sent Mail', 
  '[Google Mail]/Spam',
  '[Google Mail]/Trash'
]
 
# Utility methods.
def dd(message)
   puts "[#{DEST_HOST}] #{message}"
end
 
def ds(message)
   puts "[#{SOURCE_HOST}] #{message}"
end
 
# Connect and log into both servers.
ds 'connecting...'
source = Net::IMAP.new(SOURCE_HOST, SOURCE_PORT, SOURCE_SSL)
 
ds 'logging in...'
source.login(SOURCE_USER, SOURCE_PASS)
 
dd 'connecting...'
dest = Net::IMAP.new(DEST_HOST, DEST_PORT, DEST_SSL)
 
dd 'logging in...'
dest.login(DEST_USER, DEST_PASS)
 
# Getting the folders to sync
folders = Array.new
source.list("", "%").each do |mailbox|
    if FOLDERS_EXCLUDE.include?(mailbox.name) == false
        folders << mailbox.name
    end
 
    if mailbox.attr.include?(Net::IMAP::NOSELECT)
        source.list("", "#{mailbox.name}/%").each do |mailboxChild|
            if FOLDERS_EXCLUDE.include?(mailboxChild.name) == false
                folders << mailboxChild.name
            end
        end 
    end 
end
#puts folders
 
 
# Loop through folders and copy messages.
folders.each do |foldername|
  # Open source folder in read-only mode.
  begin
    ds "selecting folder '#{foldername}'..."
    source.examine(foldername)
  rescue => e
    ds "error: select failed: #{e}"
    next
  end
 
  # Open (or create) destination folder in read-write mode.
  begin
    dd "selecting folder '#{foldername}'..."
    dest.select(foldername)
  rescue => e
    begin
      dd "folder not found; creating..."
      dest.create(foldername)
      dest.select(foldername)
    rescue => ee
      dd "error: could not create folder: #{e}"
      next
    end
  end
 
  # Build a lookup hash of all message ids present in the destination folder.
  dest_info = {}
 
  dd 'analyzing existing messages...'
  uids = dest.uid_search(['ALL'])
  if uids.length > 0
    dest.uid_fetch(uids, ['ENVELOPE']).each do |data|
      dest_info[data.attr['ENVELOPE'].message_id] = true      
    end
  end
 
  # Loop through all messages in the source folder.
  uids = source.uid_search(['ALL'])
  if uids.length > 0
    source.uid_fetch(uids, ['ENVELOPE']).each do |data|
      mid = data.attr['ENVELOPE'].message_id
 
      # If this message is already in the destination folder, skip it.
      next if dest_info[mid]
 
      # Download the full message body from the source folder.
      ds "downloading message #{mid}..."
      msg = source.uid_fetch(data.attr['UID'], ['RFC822', 'FLAGS',
          'INTERNALDATE']).first
 
      # Append the message to the destination folder, preserving flags and
      # internal timestamp.
      dd "storing message #{mid}..."
      dest.append(foldername, msg.attr['RFC822'], msg.attr['FLAGS'],
          msg.attr['INTERNALDATE'])
    end
  end
 
 
 
  # Build a lookup hash of all message ids present in the source folder.
  source_info = {}
 
  dd 'analyzing source messages...'
  uids = source.uid_search(['ALL'])
  if uids.length > 0
    source.uid_fetch(uids, ['ENVELOPE']).each do |data|
      source_info[data.attr['ENVELOPE'].message_id] = true      
    end
  end
 
  # Loop through all messages in the source folder.
  uids = dest.uid_search(['ALL'])
  if uids.length > 0
     dest.uid_fetch(uids, ['ENVELOPE']).each do |data|
      mid = data.attr['ENVELOPE'].message_id
 
      # If this message is already in the destination folder, skip it.
      next if source_info[mid]
 
      # Setting flag for deletion
      ds "deleting message #{mid}..."
     dest.store(data.seqno, "+FLAGS", [:Deleted])
    end
  end
 
 
  dest.expunge
  source.close
  dest.close
end
 
 
puts 'done'