#!/usr/bin/ruby
# Created by Alvise Susmel on 9/8/08.
# Copyright 2008 GecoSoftware.com(alvise@gecosoftware.com). All rights reserved.
#
NAME="geco"
TO_BACKUP_DIRECTORIES = []
TO_BACKUP_LABELS = []
STORE_DIRECTORIES = []

TO_BACKUP_LABELS << "Logs"
TO_BACKUP_DIRECTORIES << "/var/log/"
STORE_DIRECTORIES << "/tmp/"




## backup dirs format   name_label_yyyy-mm-dd/
def main_process
  TO_BACKUP_DIRECTORIES.each do |dir|
    index = TO_BACKUP_DIRECTORIES.index(dir)
    label = TO_BACKUP_LABELS.at(index)
    store_dir = STORE_DIRECTORIES.at(index)
    process(label,dir,store_dir)
  end
end

def process(label,to_backup_dir, store_dir)
  old_backups = find_old_backups(store_dir)
  
  ##cerco i vecchi backup
  if old_backups.size == 0
    #backup da zero
    start_rsync(label,to_backup_dir,"#{store_dir}/#{NAME}_#{label}_#{date}")
  else
    #faccio una HARD_LINK COPY del vecchio backup
    hard_link_copy_from_last_backup(old_backups,label,to_backup_dir,store_dir)
  end
  
end


#fa una copia in hard link di una directory
def hard_link_dir(from_dir,to_dir)
  system("mkdir -p #{to_dir}") #crea le directory necessarie

  fdir = Dir.open(from_dir)
  fdir.each do |filename|
    fullpath = "#{from_dir}/#{filename}"
    to_fullpath = "#{to_dir}/#{filename}"
    if(filename == "." or filename == "..")
      next
    elsif File.directory?(fullpath)
      hard_link_dir(fullpath,to_fullpath)
    else
      command = "ln #{fullpath} #{to_fullpath}"
      #puts command
      system(command)
    end
  end
  fdir.close
end

#fa un hard link del vecchio backup
def hard_link_copy_from_last_backup(old_backups,label,to_backup_dir,store_dir)
  last_backup = "#{store_dir}/#{old_backups.pop}/"
  dst_dir = "#{store_dir}/#{NAME}_#{label}_#{date}/"

  #faccio tutti gli hard link
  puts "hard_link_dir: #{last_backup} -> #{dst_dir}"
  hard_link_dir(last_backup,dst_dir)
  
  puts "start updating"
  start_rsync(label,to_backup_dir,dst_dir)
end  



#label: label di riconoscimento del backup
#to_backup_dir: directory da backuppare
#sync_dir: la directory dove verra` salvato il backup
def start_rsync(label,to_backup_dir, sync_dir)
  command = "rsync -a  --backup #{to_backup_dir} #{sync_dir}"
  puts command
  system(command)
end



def date
  return Time.new.strftime("%Y-%m-%d_%H_%M")
end


#restituisce l' elenco dei vecchi backup
def find_old_backups(store_dir)
  old_backups = []
  store = Dir.open(store_dir)
  store.each do |filename|
    if filename.include?(NAME)
      old_backups << filename
    end
  end
  store.close
  #ordino i backup
  old_backups.sort! {|a,b| a <=> b}
  return old_backups
end



main_process