##
## Copyright (c) 2016, Alliance for Open Media. All rights reserved
##
## This source code is subject to the terms of the BSD 2 Clause License and
## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
## was not distributed with this source code in the LICENSE file, you can
## obtain it at www.aomedia.org/license/software. If the Alliance for Open
## Media Patent License 1.0 was not distributed with this source code in the
## PATENTS file, you can obtain it at www.aomedia.org/license/patent.
##
include(FindGit)
include(FindPerl)
include(FindThreads)
include(FindwxWidgets)

set(AOM_SUPPORTED_CPU_TARGETS
    "arm64 armv7 armv7s generic mips32 mips64 x86 x86_64")

option(ENABLE_CCACHE "Enable ccache support" OFF)
option(ENABLE_DISTCC "Enable distcc support" OFF)

# Generate the user config settings. This must occur before include of
# aom_config_defaults.cmake (because it turns every config variable into a cache
# variable with its own help string).
get_cmake_property(cmake_cache_vars CACHE_VARIABLES)
foreach(cache_var ${cmake_cache_vars})
  get_property(cache_var_helpstring CACHE ${cache_var} PROPERTY HELPSTRING)
  set(cmdline_helpstring  "No help, variable specified on the command line.")
  if("${cache_var_helpstring}" STREQUAL "${cmdline_helpstring}")
    set(AOM_CMAKE_CONFIG "${AOM_CMAKE_CONFIG} -D${cache_var}=${${cache_var}}")
  endif ()
endforeach()
string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)

include("${AOM_ROOT}/build/cmake/aom_config_defaults.cmake")
include("${AOM_ROOT}/build/cmake/aom_optimization.cmake")
include("${AOM_ROOT}/build/cmake/compiler_flags.cmake")
include("${AOM_ROOT}/build/cmake/compiler_tests.cmake")

# Build a list of all configurable variables.
get_cmake_property(cmake_cache_vars CACHE_VARIABLES)
foreach (var ${cmake_cache_vars})
  if ("${var}" MATCHES "^CONFIG_")
    list(APPEND AOM_CONFIG_VARS ${var})
  endif ()
endforeach ()

# Detect target CPU.
if (NOT AOM_TARGET_CPU)
  if ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64" OR
      "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86_64")
    if (${CMAKE_SIZEOF_VOID_P} EQUAL 4)
      set(AOM_TARGET_CPU "x86")
    elseif (${CMAKE_SIZEOF_VOID_P} EQUAL 8)
      set(AOM_TARGET_CPU "x86_64")
    else ()
      message(FATAL_ERROR
              "--- Unexpected pointer size (${CMAKE_SIZEOF_VOID_P}) for\n"
              "      CMAKE_SYSTEM_NAME=${CMAKE_SYSTEM_NAME}\n"
              "      CMAKE_SYSTEM_PROCESSOR=${CMAKE_SYSTEM_PROCESSOR}\n"
              "      CMAKE_GENERATOR=${CMAKE_GENERATOR}\n")
    endif ()
  elseif ("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "i386" OR
          "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86")
    set(AOM_TARGET_CPU "x86")
  elseif ("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "^arm" OR
          "${CMAKE_SYSTEM_PROCESSOR}" MATCHES "^mips")
    set(AOM_TARGET_CPU "${CMAKE_SYSTEM_PROCESSOR}")
  endif ()
endif ()

if (CMAKE_TOOLCHAIN_FILE)
  # Add toolchain file to config string.
  set(toolchain_string "-DCMAKE_TOOLCHAIN_FILE=\\\"${CMAKE_TOOLCHAIN_FILE}\\\"")
  set(AOM_CMAKE_CONFIG "${toolchain_string} ${AOM_CMAKE_CONFIG}")
else ()
  # Add detected CPU to the config string.
  set(AOM_CMAKE_CONFIG "-DAOM_TARGET_CPU=${AOM_TARGET_CPU} ${AOM_CMAKE_CONFIG}")
endif ()
set(AOM_CMAKE_CONFIG "-G \\\"${CMAKE_GENERATOR}\\\" ${AOM_CMAKE_CONFIG}")
string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)

message("--- aom_configure: Detected CPU: ${AOM_TARGET_CPU}")
set(AOM_TARGET_SYSTEM ${CMAKE_SYSTEM_NAME})

if (NOT "${AOM_SUPPORTED_CPU_TARGETS}" MATCHES "${AOM_TARGET_CPU}")
  message(FATAL_ERROR "No RTCD support for ${AOM_TARGET_CPU}. Create it, or "
          "add -DAOM_TARGET_CPU=generic to your cmake command line for a "
          "generic build of libaom and tools.")
endif ()

if ("${AOM_TARGET_CPU}" STREQUAL "x86" OR "${AOM_TARGET_CPU}" STREQUAL "x86_64")
  # TODO(tomfinegan): Support nasm at least as well as the existing build
  # system.
  find_program(AS_EXECUTABLE yasm $ENV{YASM_PATH})
  if (NOT AS_EXECUTABLE)
    message(FATAL_ERROR "Unable to find yasm. To build without optimizations, "
            "add -DAOM_TARGET_CPU=generic to your cmake command line.")
  endif ()
  get_asm_obj_format("objformat")
  set(AOM_AS_FLAGS -f ${objformat} ${AOM_AS_FLAGS})
  string(STRIP "${AOM_AS_FLAGS}" AOM_AS_FLAGS)
elseif ("${AOM_TARGET_CPU}" MATCHES "arm")
  if ("${AOM_TARGET_SYSTEM}" STREQUAL "Darwin")
    set(AS_EXECUTABLE as)
    set(AOM_AS_FLAGS -arch ${AOM_TARGET_CPU} -isysroot ${CMAKE_OSX_SYSROOT})
  elseif ("${AOM_TARGET_SYSTEM}" STREQUAL "Linux")
    # arm linux assembler settings controlled by
    # build/cmake/toolchains/arm*-linux*.cmake
  endif ()
  if (NOT AS_EXECUTABLE)
    message(FATAL_ERROR
            "Unknown assembler for: ${AOM_TARGET_CPU}-${AOM_TARGET_SYSTEM}")
  endif ()

  string(STRIP "${AOM_AS_FLAGS}" AOM_AS_FLAGS)
endif ()

include("${AOM_ROOT}/build/cmake/cpu.cmake")

if (ENABLE_CCACHE)
  find_program(CCACHE "ccache")
  if (NOT "${CCACHE}" STREQUAL "")
    set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE}")
    set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE}")
  else ()
    message("--- Cannot find ccache, ENABLE_CCACHE ignored.")
  endif ()
endif ()

if (ENABLE_DISTCC)
  find_program(DISTCC "distcc")
  if (NOT "${DISTCC}" STREQUAL "")
    set(CMAKE_C_COMPILER_LAUNCHER "${DISTCC}")
    set(CMAKE_CXX_COMPILER_LAUNCHER "${DISTCC}")
  else ()
    message("--- Cannot find distcc, ENABLE_DISTCC ignored.")
  endif ()
endif ()

# Test compiler flags.
if (MSVC)
  add_compiler_flag_if_supported("/W3")
  # Disable MSVC warnings that suggest making code non-portable.
  add_compiler_flag_if_supported("/wd4996")
  if (ENABLE_WERROR)
    add_compiler_flag_if_supported("/WX")
  endif ()
else ()
  require_c_flag("-std=c99" YES)
  add_compiler_flag_if_supported("-Wall")
  add_compiler_flag_if_supported("-Wdisabled-optimization")
  add_compiler_flag_if_supported("-Wextra")
  add_compiler_flag_if_supported("-Wfloat-conversion")
  add_compiler_flag_if_supported("-Wimplicit-function-declaration")
  add_compiler_flag_if_supported("-Wpointer-arith")
  add_compiler_flag_if_supported("-Wsign-compare")
  add_compiler_flag_if_supported("-Wtype-limits")
  add_compiler_flag_if_supported("-Wuninitialized")
  add_compiler_flag_if_supported("-Wunused")
  add_compiler_flag_if_supported("-Wvla")
  # TODO(jzern): this could be added as a cxx flags for test/*.cc only,
  # avoiding third_party.
  add_c_flag_if_supported("-Wshorten-64-to-32")

  # Add -Wshadow only for C files to avoid massive gtest warning spam.
  add_c_flag_if_supported("-Wshadow")

  # Add -Wundef only for C files to avoid massive gtest warning spam.
  add_c_flag_if_supported("-Wundef")

  if (ENABLE_WERROR)
    add_compiler_flag_if_supported("-Werror")
  endif ()
  # Flag(s) added here negate CMake defaults and produce build output similar
  # to the existing configure/make build system.
  add_compiler_flag_if_supported("-Wno-unused-function")

  if (CMAKE_C_COMPILER_ID MATCHES "GNU\|Clang")
    set(CONFIG_GCC 1)
  endif ()

  if ("${CMAKE_BUILD_TYPE}" MATCHES "Rel")
    add_compiler_flag_if_supported("-U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=0")
  endif ()
  add_compiler_flag_if_supported("-D_LARGEFILE_SOURCE")
  add_compiler_flag_if_supported("-D_FILE_OFFSET_BITS=64")
endif ()

if ("${AOM_TARGET_SYSTEM}" MATCHES "Darwin\|Linux\|Windows")
  set(CONFIG_OS_SUPPORT 1)
endif ()

# Test compiler support.
aom_get_inline("INLINE")

# TODO(tomfinegan): aom_ports_check is legacy; HAVE_AOM_PORTS is not used
# anywhere in the aom sources. To be removed after parity with the legacy
# build system stops being important.
aom_check_source_compiles("aom_ports_check"
                          "#include \"${AOM_ROOT}/aom/aom_integer.h\""
                          HAVE_AOM_PORTS)
aom_check_source_compiles("pthread_check" "#include <pthread.h>" HAVE_PTHREAD_H)
aom_check_source_compiles("unistd_check" "#include <unistd.h>" HAVE_UNISTD_H)

if (CONFIG_ANALYZER)
  find_package(wxWidgets REQUIRED adv base core)
  include(${wxWidgets_USE_FILE})

  if (NOT CONFIG_INSPECTION)
    set(CONFIG_INSPECTION 1)
    message(WARNING
            "--- Enabled CONFIG_INSPECTION, required for CONFIG_ANALYZER.")
  endif ()
endif ()

if (CONFIG_ANS AND CONFIG_DAALA_EC)
  message(FATAL_ERROR
          "CONFIG_ANS and CONFIG_DAALA_EC cannot be enabled together.")
endif ()

if (NOT MSVC)
  aom_push_var(CMAKE_REQUIRED_LIBRARIES "m")
  aom_check_c_compiles("fenv_check"
                       "#define _GNU_SOURCE
                        #include <fenv.h>
                        void unused(void) {
                          (void)feenableexcept(FE_DIVBYZERO | FE_INVALID);
                        }" HAVE_FEXCEPT)
  aom_pop_var(CMAKE_REQUIRED_LIBRARIES)
endif()

set(AOM_LIB_LINK_TYPE PUBLIC)
if (EMSCRIPTEN)
  # Avoid CMake generation time errors resulting from collisions with the form
  # of target_link_libraries() used by Emscripten.cmake.
  unset(AOM_LIB_LINK_TYPE)
endif ()

# Generate aom_config templates.
set(aom_config_asm_template "${AOM_CONFIG_DIR}/aom_config.asm.cmake")
set(aom_config_h_template "${AOM_CONFIG_DIR}/aom_config.h.cmake")
execute_process(COMMAND ${CMAKE_COMMAND}
  -DAOM_CONFIG_DIR=${AOM_CONFIG_DIR}
  -DAOM_ROOT=${AOM_ROOT}
  -P "${AOM_ROOT}/build/cmake/generate_aom_config_templates.cmake")

# Generate aom_config.{asm,h}.
configure_file("${aom_config_asm_template}" "${AOM_CONFIG_DIR}/aom_config.asm")
configure_file("${aom_config_h_template}" "${AOM_CONFIG_DIR}/aom_config.h")

# Read the current git hash.
find_package(Git)
set(AOM_GIT_DESCRIPTION)
set(AOM_GIT_HASH)
if (GIT_FOUND)
  # TODO(tomfinegan): Add build rule so users don't have to re-run cmake to
  # create accurately versioned cmake builds.
  execute_process(COMMAND ${GIT_EXECUTABLE}
                  --git-dir=${AOM_ROOT}/.git rev-parse HEAD
                  OUTPUT_VARIABLE AOM_GIT_HASH)
  execute_process(COMMAND ${GIT_EXECUTABLE} --git-dir=${AOM_ROOT}/.git describe
                  OUTPUT_VARIABLE AOM_GIT_DESCRIPTION ERROR_QUIET)
  # Consume the newline at the end of the git output.
  string(STRIP "${AOM_GIT_HASH}" AOM_GIT_HASH)
  string(STRIP "${AOM_GIT_DESCRIPTION}" AOM_GIT_DESCRIPTION)
endif ()

configure_file("${AOM_ROOT}/build/cmake/aom_config.c.cmake"
               "${AOM_CONFIG_DIR}/aom_config.c")

# Find Perl and generate the RTCD sources.
find_package(Perl)
if (NOT PERL_FOUND)
  message(FATAL_ERROR "Perl is required to build libaom.")
endif ()

configure_file("${AOM_CONFIG_DIR}/rtcd_config.cmake"
               "${AOM_CONFIG_DIR}/${AOM_TARGET_CPU}_rtcd_config.rtcd")

set(AOM_RTCD_CONFIG_FILE_LIST
    "${AOM_ROOT}/aom_dsp/aom_dsp_rtcd_defs.pl"
    "${AOM_ROOT}/aom_scale/aom_scale_rtcd.pl"
    "${AOM_ROOT}/av1/common/av1_rtcd_defs.pl")
set(AOM_RTCD_HEADER_FILE_LIST
    "${AOM_CONFIG_DIR}/aom_dsp_rtcd.h"
    "${AOM_CONFIG_DIR}/aom_scale_rtcd.h"
    "${AOM_CONFIG_DIR}/av1_rtcd.h")
set(AOM_RTCD_SOURCE_FILE_LIST
    "${AOM_ROOT}/aom_dsp/aom_dsp_rtcd.c"
    "${AOM_ROOT}/aom_scale/aom_scale_rtcd.c"
    "${AOM_ROOT}/av1/common/av1_rtcd.c")
set(AOM_RTCD_SYMBOL_LIST aom_dsp_rtcd aom_scale_rtcd av1_rtcd)
list(LENGTH AOM_RTCD_SYMBOL_LIST AOM_RTCD_CUSTOM_COMMAND_COUNT)
math(EXPR AOM_RTCD_CUSTOM_COMMAND_COUNT "${AOM_RTCD_CUSTOM_COMMAND_COUNT} - 1")

foreach(NUM RANGE ${AOM_RTCD_CUSTOM_COMMAND_COUNT})
  list(GET AOM_RTCD_CONFIG_FILE_LIST ${NUM} AOM_RTCD_CONFIG_FILE)
  list(GET AOM_RTCD_HEADER_FILE_LIST ${NUM} AOM_RTCD_HEADER_FILE)
  list(GET AOM_RTCD_SOURCE_FILE_LIST ${NUM} AOM_RTCD_SOURCE_FILE)
  list(GET AOM_RTCD_SYMBOL_LIST ${NUM} AOM_RTCD_SYMBOL)
  execute_process(
    COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/make/rtcd.pl"
      --arch=${AOM_TARGET_CPU} --sym=${AOM_RTCD_SYMBOL} ${AOM_RTCD_FLAGS}
      --config=${AOM_CONFIG_DIR}/${AOM_TARGET_CPU}_rtcd_config.rtcd
      ${AOM_RTCD_CONFIG_FILE}
    OUTPUT_FILE ${AOM_RTCD_HEADER_FILE})
endforeach()

function (add_rtcd_build_step config output source symbol)
  add_custom_command(
    OUTPUT ${output}
    COMMAND ${PERL_EXECUTABLE}
    ARGS "${AOM_ROOT}/build/make/rtcd.pl"
      --arch=${AOM_TARGET_CPU}
      --sym=${symbol}
      ${AOM_RTCD_FLAGS}
      --config=${AOM_CONFIG_DIR}/${AOM_TARGET_CPU}_rtcd_config.rtcd
      ${config}
      > ${output}
    DEPENDS ${config}
    COMMENT "Generating ${output}"
    WORKING_DIRECTORY ${AOM_CONFIG_DIR}
    VERBATIM)
  set_property(SOURCE ${source} PROPERTY OBJECT_DEPENDS ${output})
  set_property(SOURCE ${output} PROPERTY GENERATED)
endfunction ()

# Generate aom_version.h.
if ("${AOM_GIT_DESCRIPTION}" STREQUAL "")
  set(AOM_GIT_DESCRIPTION "${AOM_ROOT}/CHANGELOG")
endif ()
execute_process(
  COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/cmake/aom_version.pl"
  --version_data=${AOM_GIT_DESCRIPTION}
  --version_filename=${AOM_CONFIG_DIR}/aom_version.h)

# Generate aom.pc (pkg-config file).
if (NOT MSVC)
  # Extract the version string from aom_version.h
  file(STRINGS "${AOM_CONFIG_DIR}/aom_version.h" aom_version
       REGEX "VERSION_STRING_NOSP")
  string(REPLACE "#define VERSION_STRING_NOSP \"v" "" aom_version
         "${aom_version}")
  string(REPLACE "\"" "" aom_version "${aom_version}")

  # Write pkg-config info.
  set(prefix "${CMAKE_INSTALL_PREFIX}")
  set(pkgconfig_file "${AOM_CONFIG_DIR}/aom.pc")
  string(TOLOWER ${CMAKE_PROJECT_NAME} pkg_name)
  file(WRITE "${pkgconfig_file}" "# libaom pkg-config.\n")
  file(APPEND "${pkgconfig_file}" "prefix=${prefix}\n")
  file(APPEND "${pkgconfig_file}" "exec_prefix=${prefix}/bin\n")
  file(APPEND "${pkgconfig_file}" "libdir=${prefix}/lib\n")
  file(APPEND "${pkgconfig_file}" "includedir=${prefix}/include\n\n")
  file(APPEND "${pkgconfig_file}" "Name: ${pkg_name}\n")
  file(APPEND "${pkgconfig_file}" "Description: AV1 codec library.\n")
  file(APPEND "${pkgconfig_file}" "Version: ${aom_version}\n")
  file(APPEND "${pkgconfig_file}" "Requires:\n")
  file(APPEND "${pkgconfig_file}" "Conflicts:\n")
  file(APPEND "${pkgconfig_file}" "Libs: -L${prefix}/lib -l${pkg_name} -lm\n")
  if (CONFIG_MULTITHREAD AND HAVE_PTHREAD_H)
    file(APPEND "${pkgconfig_file}" "Libs.private: -lm -lpthread\n")
  else ()
    file(APPEND "${pkgconfig_file}" "Libs.private: -lm\n")
  endif ()
  file(APPEND "${pkgconfig_file}" "Cflags: -I${prefix}/include\n")
endif ()