cmake_minimum_required(VERSION 3.6)

find_program(PATCH_EXECUTABLE patch)
if(NOT PATCH_EXECUTABLE)
    message(FATAL_ERROR "Patch utility not found! Install patch tool before continuing.")
endif()

set(PATCH_FILE "${CMAKE_SOURCE_DIR}/patches/config.patch")
set(PATCH_MARKER_FILE "${CMAKE_BINARY_DIR}/.config_patch_applied")

if(NOT EXISTS "${PATCH_FILE}")
    message(WARNING "Patch file not found: ${PATCH_FILE}")
endif()

add_custom_command(
    OUTPUT "${PATCH_MARKER_FILE}"
    COMMAND "${PATCH_EXECUTABLE}" -p1 -i "${PATCH_FILE}" --reject-file=- --silent || exit 0
    COMMAND cmake -E touch "${PATCH_MARKER_FILE}"
    WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}"
    COMMENT "Applying config.patch..."
    VERBATIM
)

add_custom_target(apply_config_patch
    DEPENDS "${PATCH_MARKER_FILE}"
)