@echo off
setlocal EnableExtensions EnableDelayedExpansion

REM Check if being run from gameupdate folder (incorrect usage)
for %%I in ("%CD%") do set "CURRENT_FOLDER=%%~nxI"
if /I "%CURRENT_FOLDER%"=="gameupdate" (
    echo.
    echo ========================================
    echo ERROR: Do not run patch.bat directly!
    echo ========================================
    echo.
    echo You are running this from the gameupdate folder.
    echo This will not work correctly!
    echo.
    echo Please go back to the game's root folder and
    echo run GameUpdate.bat instead.
    echo ========================================
    echo.
    pause
    exit /b 1
)

REM Determine important paths
set "SCRIPT_DIR=%~dp0"
set "ROOT_DIR=%CD%"
set "CONFIG_FILE=%SCRIPT_DIR%patch-config.txt"

echo Using root directory: "%ROOT_DIR%"
echo Using config: "%CONFIG_FILE%"

echo Checking for pwsh...
set _my_shell=pwsh

REM Check if pwsh.exe exists
where /q !_my_shell!
if !errorlevel! neq 0 (
  echo pwsh not found. Falling back to powershell...
  REM If pwsh is not found, set to powershell
  set _my_shell=powershell

  REM Check if powershell.exe exists
  echo Checking for powershell...
  where /q !_my_shell!
  if !errorlevel! neq 0 (
    echo.Error: Powershell not found!
    pause
    exit /B 1
  ) else (
    echo powershell found.
  )
) else (
  echo pwsh found.
)

echo Using !_my_shell! for script execution.

REM Check if patch-config.txt exists in gameupdate folder
if not exist "%CONFIG_FILE%" (
    echo "Config file (gameupdate\patch-config.txt) not found! Assuming no patching needed."
    pause
    exit /b
)

REM Read configuration from file
for /f "usebackq tokens=1,2 delims==" %%a in ("%CONFIG_FILE%") do (
    if "%%a"=="username" set "username=%%b"
    if "%%a"=="repo" set "repo=%%b"
    if "%%a"=="branch" set "branch=%%b"
)

REM Get the latest hash
echo "Getting latest commit SHA hash"
!_my_shell! -Command "(Invoke-RestMethod -Uri 'https://gitgud.io/api/v4/projects/%username%%%2F%repo%/repository/branches/%branch%').commit.id" > "%ROOT_DIR%\latest_patch_sha.txt"

REM Read the latest SHA from the file
set /p latest_patch_sha=<"%ROOT_DIR%\latest_patch_sha.txt"

REM Check if previous_patch_sha.txt exists in gameupdate
if not exist "%SCRIPT_DIR%previous_patch_sha.txt" (
    echo "Previous SHA hash not found!"
    echo "Assuming first time patching..."
    goto download_extract
)

REM Read the stored SHA from previous check
set /p previous_patch_sha=<"%SCRIPT_DIR%previous_patch_sha.txt"

REM Trim whitespace from SHA strings
set "previous_patch_sha=%previous_patch_sha: =%"
set "latest_patch_sha=%latest_patch_sha: =%"

REM Compare trimmed SHAs
if "%latest_patch_sha%" neq "%previous_patch_sha%" (
    echo "Update found! Patching..."
    goto download_extract
) else (
    echo "Patch is up to date."
)

REM Delete latest_patch_sha.txt
del "%ROOT_DIR%\latest_patch_sha.txt"

endlocal
pause
exit /b

:download_extract

REM Escape single quotes in paths
set "escaped_root=%ROOT_DIR:'=''%" 

REM Download zip file to root
echo "Downloading latest patch..."
!_my_shell! -Command "Set-Location -LiteralPath '%escaped_root%'; $ProgressPreference = 'SilentlyContinue'; Invoke-WebRequest -Uri 'https://gitgud.io/%username%/%repo%/-/archive/%branch%/%repo%-%branch%.zip' -OutFile 'repo.zip'"
if !errorlevel! neq 0 (
    pause
    exit /b
)

REM Extract contents, overwriting conflicts into root
echo "Extracting..."
!_my_shell! -Command "Set-Location -LiteralPath '%escaped_root%'; $ProgressPreference = 'SilentlyContinue'; Expand-Archive -Path '.\repo.zip' -DestinationPath '.' -Force"
if !errorlevel! neq 0 (
    echo Extraction failed!
    del "%ROOT_DIR%\repo.zip"
    rmdir /s /q "%ROOT_DIR%\%repo%-%branch%"
    pause
    exit /b
)
echo "Applying patch..."
xcopy /s /e /y "%ROOT_DIR%\%repo%-%branch%\*" "%ROOT_DIR%\"
if !errorlevel! neq 0 (
    echo Patch application failed!
    del "%ROOT_DIR%\repo.zip"
    rmdir /s /q "%ROOT_DIR%\%repo%-%branch%"
    pause
    exit /b
)
REM Clean up
echo "Cleaning up..."
del "%ROOT_DIR%\repo.zip"
rmdir /s /q "%ROOT_DIR%\%repo%-%branch%"
del "%ROOT_DIR%\latest_patch_sha.txt"
REM Store latest SHA for next check in gameupdate
echo %latest_patch_sha% > "%SCRIPT_DIR%previous_patch_sha.txt"
endlocal
pause
exit /b