##  Copyright (c) 2012-2020 Leonid Yuriev <leo@yuriev.ru>.
##
##  Licensed under the Apache License, Version 2.0 (the "License");
##  you may not use this file except in compliance with the License.
##  You may obtain a copy of the License at
##
##      http://www.apache.org/licenses/LICENSE-2.0
##
##  Unless required by applicable law or agreed to in writing, software
##  distributed under the License is distributed on an "AS IS" BASIS,
##  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
##  See the License for the specific language governing permissions and
##  limitations under the License.
##

cmake_minimum_required(VERSION 3.8.2)
cmake_policy(PUSH)
cmake_policy(VERSION 3.8.2)

macro(add_compile_flags langs)
  foreach(_lang ${langs})
    string(REPLACE ";" " " _flags "${ARGN}")
    if(CMAKE_CXX_COMPILER_LOADED AND _lang STREQUAL "CXX")
      set("${_lang}_FLAGS" "${${_lang}_FLAGS} ${_flags}")
    endif()
    if(CMAKE_C_COMPILER_LOADED AND _lang STREQUAL "C")
      set("${_lang}_FLAGS" "${${_lang}_FLAGS} ${_flags}")
    endif()
  endforeach()
  unset(_lang)
  unset(_flags)
endmacro(add_compile_flags)

macro(set_source_files_compile_flags)
  foreach(file ${ARGN})
    get_filename_component(_file_ext ${file} EXT)
    set(_lang "")
    if("${_file_ext}" STREQUAL ".m")
      set(_lang OBJC)
      # CMake believes that Objective C is a flavor of C++, not C,
      # and uses g++ compiler for .m files.
      # LANGUAGE property forces CMake to use CC for ${file}
      set_source_files_properties(${file} PROPERTIES LANGUAGE C)
    elseif("${_file_ext}" STREQUAL ".mm")
      set(_lang OBJCXX)
    endif()

    if(_lang)
      get_source_file_property(_flags ${file} COMPILE_FLAGS)
      if("${_flags}" STREQUAL "NOTFOUND")
        set(_flags "${CMAKE_${_lang}_FLAGS}")
      else()
        set(_flags "${_flags} ${CMAKE_${_lang}_FLAGS}")
      endif()
      # message(STATUS "Set (${file} ${_flags}")
      set_source_files_properties(${file} PROPERTIES COMPILE_FLAGS
        "${_flags}")
    endif()
  endforeach()
  unset(_file_ext)
  unset(_lang)
endmacro(set_source_files_compile_flags)

macro(fetch_version name version_file)
  set(${name}_VERSION "")
  set(${name}_GIT_DESCRIBE "")
  set(${name}_GIT_TIMESTAMP "")
  set(${name}_GIT_TREE "")
  set(${name}_GIT_COMMIT "")
  set(${name}_GIT_REVISION 0)
  set(${name}_GIT_VERSION "")
  if(GIT)
    execute_process(COMMAND ${GIT} describe --tags --long --dirty=-dirty
      OUTPUT_VARIABLE ${name}_GIT_DESCRIBE
      OUTPUT_STRIP_TRAILING_WHITESPACE
      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
      RESULT_VARIABLE rc)
    if(rc OR "${name}_GIT_DESCRIBE" STREQUAL "")
      message(FATAL_ERROR "Please fetch tags and/or install latest version of git ('describe --tags --long --dirty' failed)")
    endif()

    execute_process(COMMAND ${GIT} show --no-patch --format=%cI HEAD
      OUTPUT_VARIABLE ${name}_GIT_TIMESTAMP
      OUTPUT_STRIP_TRAILING_WHITESPACE
      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
      RESULT_VARIABLE rc)
    if(rc OR "${name}_GIT_TIMESTAMP" STREQUAL "%cI")
      execute_process(COMMAND ${GIT} show --no-patch --format=%ci HEAD
        OUTPUT_VARIABLE ${name}_GIT_TIMESTAMP
        OUTPUT_STRIP_TRAILING_WHITESPACE
        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
        RESULT_VARIABLE rc)
      if(rc OR "${name}_GIT_TIMESTAMP" STREQUAL "%ci")
        message(FATAL_ERROR "Please install latest version of git ('show --no-patch --format=%cI HEAD' failed)")
      endif()
    endif()

    execute_process(COMMAND ${GIT} show --no-patch --format=%T HEAD
      OUTPUT_VARIABLE ${name}_GIT_TREE
      OUTPUT_STRIP_TRAILING_WHITESPACE
      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
      RESULT_VARIABLE rc)
    if(rc OR "${name}_GIT_TREE" STREQUAL "")
      message(FATAL_ERROR "Please install latest version of git ('show --no-patch --format=%T HEAD' failed)")
    endif()

    execute_process(COMMAND ${GIT} show --no-patch --format=%H HEAD
      OUTPUT_VARIABLE ${name}_GIT_COMMIT
      OUTPUT_STRIP_TRAILING_WHITESPACE
      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
      RESULT_VARIABLE rc)
    if(rc OR "${name}_GIT_COMMIT" STREQUAL "")
      message(FATAL_ERROR "Please install latest version of git ('show --no-patch --format=%H HEAD' failed)")
    endif()

    execute_process(COMMAND ${GIT} rev-list --count --no-merges HEAD
      OUTPUT_VARIABLE ${name}_GIT_REVISION
      OUTPUT_STRIP_TRAILING_WHITESPACE
      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
      RESULT_VARIABLE rc)
    if(rc OR "${name}_GIT_REVISION" STREQUAL "")
      message(FATAL_ERROR "Please install latest version of git ('rev-list --count --no-merges HEAD' failed)")
    endif()

    string(REGEX MATCH "^(v)?([0-9]+)\\.([0-9]+)\\.([0-9]+)(.*)?" git_version_valid "${${name}_GIT_DESCRIBE}")
    if(git_version_valid)
      string(REGEX REPLACE "^(v)?([0-9]+)\\.([0-9]+)\\.([0-9]+)(.*)?" "\\2;\\3;\\4" ${name}_GIT_VERSION ${${name}_GIT_DESCRIBE})
    else()
      string(REGEX MATCH "^(v)?([0-9]+)\\.([0-9]+)(.*)?" git_version_valid "${${name}_GIT_DESCRIBE}")
      if(git_version_valid)
        string(REGEX REPLACE "^(v)?([0-9]+)\\.([0-9]+)(.*)?" "\\2;\\3;0" ${name}_GIT_VERSION ${${name}_GIT_DESCRIBE})
      else()
        message(AUTHOR_WARNING "Bad ${name} version \"${${name}_GIT_DESCRIBE}\"; falling back to 0.0.0 (have you made an initial release?)")
        set(${name}_GIT_VERSION "0;0;0")
      endif()
    endif()
  endif()

  if(NOT ${name}_GIT_VERSION OR NOT ${name}_GIT_TIMESTAMP OR NOT ${name}_GIT_REVISION)
    message(WARNING "Unable to retrive ${name} version from git.")
    set(${name}_GIT_VERSION "0;0;0;0")
    set(${name}_GIT_TIMESTAMP "")
    set(${name}_GIT_REVISION 0)

    # Try to get version from VERSION file
    if(EXISTS "${version_file}")
      file(STRINGS "${version_file}" ${name}_VERSION)
    endif()

    if(NOT ${name}_VERSION)
      message(WARNING "Unable to retrive ${name} version from \"${version_file}\" file.")
      set(${name}_VERSION_LIST ${${name}_GIT_VERSION})
      string(REPLACE ";" "." ${name}_VERSION "${${name}_GIT_VERSION}")
    else()
      string(REPLACE "." ";" ${name}_VERSION_LIST ${${name}_VERSION})
    endif()

  else()
    list(APPEND ${name}_GIT_VERSION ${${name}_GIT_REVISION})
    set(${name}_VERSION_LIST ${${name}_GIT_VERSION})
    string(REPLACE ";" "." ${name}_VERSION "${${name}_GIT_VERSION}")
  endif()

  list(GET ${name}_VERSION_LIST 0 "${name}_VERSION_MAJOR")
  list(GET ${name}_VERSION_LIST 1 "${name}_VERSION_MINOR")
  list(GET ${name}_VERSION_LIST 2 "${name}_VERSION_RELEASE")
  list(GET ${name}_VERSION_LIST 3 "${name}_VERSION_REVISION")

  set(${name}_VERSION_MAJOR ${${name}_VERSION_MAJOR} PARENT_SCOPE)
  set(${name}_VERSION_MINOR ${${name}_VERSION_MINOR} PARENT_SCOPE)
  set(${name}_VERSION_RELEASE ${${name}_VERSION_RELEASE} PARENT_SCOPE)
  set(${name}_VERSION_REVISION ${${name}_VERSION_REVISION} PARENT_SCOPE)
  set(${name}_VERSION ${${name}_VERSION} PARENT_SCOPE)

  set(${name}_GIT_DESCRIBE ${${name}_GIT_DESCRIBE} PARENT_SCOPE)
  set(${name}_GIT_TIMESTAMP ${${name}_GIT_TIMESTAMP} PARENT_SCOPE)
  set(${name}_GIT_TREE ${${name}_GIT_TREE} PARENT_SCOPE)
  set(${name}_GIT_COMMIT ${${name}_GIT_COMMIT} PARENT_SCOPE)
  set(${name}_GIT_REVISION ${${name}_GIT_REVISION} PARENT_SCOPE)
  set(${name}_GIT_VERSION ${${name}_GIT_VERSION} PARENT_SCOPE)
endmacro(fetch_version)

cmake_policy(POP)