cmake_minimum_required(VERSION 3.14)

# fetch_git_dependency()
#
# CMake function to download, build and install (in staging area) a dependency at configure
# time.
#
# Parameters:
# NAME: name of the dependency
# REPOSITORY: git url of the dependency
# TAG: tag of the dependency
# PATCH_COMMAND: apply patch
# SOURCE_SUBDIR: Path to source CMakeLists.txt relative to root dir
# CMAKE_ARGS: List of specific CMake args to add
#
# e.g.:
# fetch_git_dependency(
#   NAME
#     abseil-cpp
#   URL
#     https://github.com/abseil/abseil-cpp.git
#   TAG
#     master
#   PATCH_COMMAND
#     "git apply ${CMAKE_SOURCE_DIR}/patches/abseil-cpp.patch"
# )
function(fetch_git_dependency)
  set(options "")
  set(oneValueArgs NAME REPOSITORY TAG PATCH_COMMAND SOURCE_SUBDIR)
  set(multiValueArgs CMAKE_ARGS)
  cmake_parse_arguments(GIT_DEP
    "${options}"
    "${oneValueArgs}"
    "${multiValueArgs}"
    ${ARGN}
  )
  message(STATUS "Building ${GIT_DEP_NAME}: ...")
  string(TOLOWER ${GIT_DEP_NAME} NAME_LOWER)

  if(GIT_DEP_PATCH_COMMAND)
    set(PATCH_CMD "${GIT_DEP_PATCH_COMMAND}")
  else()
    set(PATCH_CMD "")
  endif()
  configure_file(
    ${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt.in
    ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-subbuild/CMakeLists.txt @ONLY)

  execute_process(
    COMMAND ${CMAKE_COMMAND} -S. -Bproject_build -G "${CMAKE_GENERATOR}"
    RESULT_VARIABLE result
    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-subbuild)
  if(result)
    message(FATAL_ERROR "CMake step for ${GIT_DEP_NAME} failed: ${result}")
  endif()

  execute_process(
    COMMAND ${CMAKE_COMMAND} --build project_build --config ${CMAKE_BUILD_TYPE}
    RESULT_VARIABLE result
    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-subbuild)
  if(result)
    message(FATAL_ERROR "Build step for ${GIT_DEP_NAME} failed: ${result}")
  endif()

  if(GIT_DEP_SOURCE_SUBDIR)
    add_subdirectory(
      ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-src/${GIT_DEP_SOURCE_SUBDIR}
      ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-build)
  else()
    add_subdirectory(
      ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-src
      ${CMAKE_BINARY_DIR}/_deps/${NAME_LOWER}-build)
  endif()

  message(STATUS "Building ${GIT_DEP_NAME}: ...DONE")
endfunction()

project(host-meta CXX)

include(FetchContent)
set(FETCHCONTENT_QUIET OFF)
set(FETCHCONTENT_UPDATES_DISCONNECTED ON)
set(BUILD_SHARED_LIBS OFF)
set(CMAKE_POSITION_INDEPENDENT_CODE ON)
set(BUILD_TESTING OFF)

message(CHECK_START "Fetching ZLIB")
list(APPEND CMAKE_MESSAGE_INDENT "  ")
FetchContent_Declare(
  zlib
  GIT_REPOSITORY "https://github.com/madler/ZLIB.git"
  GIT_TAG "v1.2.11"
  PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../../patches/ZLIB.patch")
FetchContent_MakeAvailable(zlib)
list(POP_BACK CMAKE_MESSAGE_INDENT)
message(CHECK_PASS "fetched")

message(CHECK_START "Fetching Protobuf")
list(APPEND CMAKE_MESSAGE_INDENT "  ")
set(protobuf_BUILD_TESTS OFF)
set(protobuf_BUILD_EXPORT OFF)
set(protobuf_MSVC_STATIC_RUNTIME OFF)

# FetchContent_Declare(SOURCE_SUBDIR) was introduced in 3.18
if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.18")
  FetchContent_Declare(
      protobuf
      GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
      GIT_TAG "v3.15.3"
      GIT_SUBMODULES ""
      PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v3.15.3.patch"
      SOURCE_SUBDIR cmake)
  FetchContent_MakeAvailable(protobuf)
else()
  fetch_git_dependency(
      NAME Protobuf
      REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
      TAG "v3.15.3"
      PATCH_COMMAND "git apply \"${CMAKE_CURRENT_LIST_DIR}/../../../patches/protobuf-v3.15.3.patch\""
      SOURCE_SUBDIR cmake)
endif()
list(POP_BACK CMAKE_MESSAGE_INDENT)
message(CHECK_PASS "fetched")
