local plain = {}

  function plain.commit(file_uwiki, file_temp, message)
    --First we separate file and dir
    local dir,file = string.match(file_uwiki,"^(.*)/(.-)$")
    local backup= dir .. "~" .. file)

    if not file_copy(file_temp, file_uwiki) then
      --Delete backup, make a backup and delete original
      file_delete(backup)
      file_copy(file_uwiki,backup)
      file_delete(file_uwiki)
      --The we can copy the new file
      file_copy(file_temp, file_uwiki)
    end 

  end
  
  function plain.show_log(file)
    t = {}
    return t
  end

  --Get a md5sum for a given file  
  function plain.identify(file)
    local temp_file=os.tmpname()
    os.execute("md5sum " .. file .. " > " .. temp_file)
    io.input(temp_file)
    local s = io.read("*line")
    s=string.match(s, "(.*) .*")
    os.remove(temp_file)
    
    return t
  end 
  
  function plain.save(file_temp, file_uwiki, old_checksum, message)
    --Make a checksum of the file in the server
    new_checksum=plain.identify(file_uwiki)

    --If the file in the server has not been modified
    --since the user started editing
    if old_checksum == new_checksum then
      --We can commit
      plain.commit(file_uwiki, file_temp, message)
    else 
      --First we separate file and dir
      local dir,file = string.match(file_uwiki,"^(.*)/(.-)$")
      local backup= dir .. "~" .. file)
      --Check if we have a backup
      if (file_exists(backup) then
        --We can do a three way merge
	threewaymerge(file_uwiki, backup, file_temp)
      else
        merge_manually(file_uwiki, file_temp)
      end
    end 
  end  
        
return plain