@echo off
rem Builds the local HTML overview and Doxygen API reference in Doc\build.
rem Prefers the pinned Doc\.tools Doxygen, then falls back to a system install.
rem If Doxygen is unavailable, installs the explanatory API placeholder instead.
setlocal EnableExtensions

set "DOC_DIR=%~dp0"
set "SOURCE=%DOC_DIR%index.html"
set "BUILD_DIR=%DOC_DIR%build"
set "OVERVIEW=%BUILD_DIR%\index.html"
set "DOXYGEN_EXE=%DOC_DIR%.tools\doxygen-1.18.0\doxygen.exe"

echo [BALSAM 167] Building HTML documentation...

if not exist "%SOURCE%" (
    echo [ERROR] Source HTML not found:
    echo         %SOURCE%
    exit /b 1
)

if not exist "%BUILD_DIR%" mkdir "%BUILD_DIR%"
if errorlevel 1 (
    echo [ERROR] Cannot create build directory:
    echo         %BUILD_DIR%
    exit /b 2
)

copy /Y "%SOURCE%" "%OVERVIEW%" >nul
if errorlevel 1 (
    echo [ERROR] Cannot build overview HTML.
    exit /b 3
)

if not exist "%DOXYGEN_EXE%" (
    where doxygen >nul 2>nul
    if not errorlevel 1 set "DOXYGEN_EXE=doxygen"
)

if not exist "%DOXYGEN_EXE%" if /I not "%DOXYGEN_EXE%"=="doxygen" (
    if not exist "%BUILD_DIR%\api\html" mkdir "%BUILD_DIR%\api\html"
    copy /Y "%DOC_DIR%api-unavailable.html" "%BUILD_DIR%\api\html\index.html" >nul
    echo [WARN] Doxygen is not installed; API reference was not regenerated.
    echo [OK]   Overview: %OVERVIEW%
    exit /b 0
)

pushd "%DOC_DIR%"
"%DOXYGEN_EXE%" Doxyfile
set "DOXYGEN_RESULT=%ERRORLEVEL%"
popd

if not "%DOXYGEN_RESULT%"=="0" (
    echo [ERROR] Doxygen failed with code %DOXYGEN_RESULT%.
    exit /b %DOXYGEN_RESULT%
)

if not exist "%BUILD_DIR%\api\html\index.html" (
    echo [ERROR] Doxygen did not create the expected API index.
    exit /b 4
)

echo [OK] Overview: %OVERVIEW%
echo [OK] API:      %BUILD_DIR%\api\html\index.html
exit /b 0