Synchronization Script (not working)

::@echo off
color f0
setlocal enabledelayedexpansion
goto begin


:stringLength ::string
set tempstring=%1
set /a stringLen=0
call:stringLengthLoop %tempstring%
goto:eof

:stringLengthLoop
if defined tempstring (
  set tempstring=%tempstring:~1%
  set /a stringLen += 1
  goto stringLengthLoop
)
goto:eof

:analyzeTime ::time
set lastMod=%1
set year=%lastMod:~0,4%
set month=%lastMod:~5,2%
set day=%lastMod:~8,2%
set hour=%lastMod:~11,2%
set minute=%lastMod:~14,2%
goto:eof

:compareModifiedDate ::file1 file2
echo Comparing files
for %%i in (%1) do (set time1=%%~ti)
for %%i in (%2) do (set time2=%%~ti)
call:analyzeTime %time1%
set /a year1=%year%
set /a month1=%month%
set /a day1=%day%
set /a hour1=%hour%
set /a minute1=%minute%
call:analyzeTime %time2%
set /a year2=%year%
set /a month2=%month%
set /a day2=%day%
set /a hour2=%hour%
set /a minute2=%minute%
if %year1% EQU %year2% (
  if %month1% EQU %month2% (
    if %day1% EQU %day2% (
      if %hour1% EQU %hour2% (
        if %minute1% EQU %minute2% (
          set recent=none
        ) else if %minute1% GTR %minute2% (
          set recent=file1
        ) else (
          set recent=file2
        )
      ) else if %hour1% GTR %hour2% (
        set recent=file1
      ) else (
        set recent=file2
      )
    ) else if %day1% GTR %day2% (
      set recent=file1
    ) else (
      set recent=file2
    )
  ) else if %month1% GTR %month2% (
    set recent=file1
  ) else (
    set recent=file2
  )
) else if %year1% GTR %year2% (
  set recent=file1
) else (
  set recent=file2
)
goto:eof

:begin
if exist "%homedrive%%homepath%\Drive" (
set drivePath=%homedrive%%homepath%\Drive
goto deviceSetup) else (
goto customDrivePath)

:customDrivePath
set /p drivePath=Google Drive folder was not found. Specify its path:
if exist %drivePath% (goto sync) else (goto customPath)

:deviceSetup
set /p devicePath=Which folder path would you like to sync?
if exist %devicePath% (goto syncDrivetoDevice) else (goto deviceSetup)

:syncDrivetoDevice
call:stringLength %drivePath%
set /a driveLength=%stringLen%
call:stringLength %devicePath%
set /a deviceLength=%stringLen%

for /d /r %drivePath% %%d in (*) do (
  set currentDriveFolderPath=%%d
  if not exist "%devicePath%!currentDriveFolderPath:~%driveLength%!" (
    mkdir "%devicePath%!currentDriveFolderPath:~%driveLength%!"
  )
  for %%f in (*.*) do (
    set currentFile=%%f
    if exist "%devicePath%!currentDriveFolderPath:~%driveLength%!!currentFile!" (
      set currentDriveFile="!currentDriveFolderPath!\!currentFile!"
      set currentDeviceFile="%devicePath%!currentDriveFolderPath:~%driveLength%!!currentFile!"
      call:compareModifiedDate !currentDriveFile! !currentDeviceFile!
      if !recent! == file1 (
        copy /y !currentDriveFile! !currentDeviceFile!
      ) else if !recent! == file2 (
        copy /y !currentDeviceFile! !currentDriveFile!
      )
    ) else (
      set source
      copy /y !currentDriveFile! !currentDeviceFile!
    )
  )
)

:syncDevicetoDrive
for /d /r %devicePath% %%d in (*) do (
  set currentDeviceFolderPath=%%d
  if not exist %drivePath%!currentDeviceFolderPath:~%deviceLength%! (
    mkdir "%drivePath%!currentDeviceFolderPath:~%deviceLength%!"
    for %%f in (*.*) do (
      set currentFile=%%f
      if not exist "%drivePath%!currentDeviceFolderPath:~%DeviceLength%!!currentFile!" (
        copy /y !currentDriveFile! !currentDeviceFile!
      )
    )
  )
)

pause