# Builds the React web UI via npm at CMake build time, into ${CMAKE_BINARY_DIR}/webui/dist.
find_program(NPM_EXECUTABLE npm)
if(NOT NPM_EXECUTABLE)
    message(WARNING "npm not found — skipping web UI build (set BUILD_WEBUI=OFF to silence)")
    return()
endif()

set(WEBUI_SRC  "${CMAKE_SOURCE_DIR}/webui")
set(WEBUI_DIST "${CMAKE_BINARY_DIR}/webui/dist")

# Install dependencies once (when node_modules is absent).
add_custom_command(
    OUTPUT "${WEBUI_SRC}/node_modules/.package-lock.json"
    COMMAND ${NPM_EXECUTABLE} ci --no-audit --no-fund
    WORKING_DIRECTORY "${WEBUI_SRC}"
    COMMENT "webui: npm ci"
    VERBATIM)

# Build the UI into the CMake build tree (outDir override).
add_custom_command(
    OUTPUT "${WEBUI_DIST}/index.html"
    COMMAND ${NPM_EXECUTABLE} run build -- --outDir "${WEBUI_DIST}" --emptyOutDir
    WORKING_DIRECTORY "${WEBUI_SRC}"
    DEPENDS "${WEBUI_SRC}/node_modules/.package-lock.json"
    COMMENT "webui: npm run build -> ${WEBUI_DIST}"
    VERBATIM)

add_custom_target(webui ALL DEPENDS "${WEBUI_DIST}/index.html")