#  Copyright (c) 2021 Google LLC.
#
#  Use of this source code is governed by a BSD-style license
#  that can be found in the LICENSE file in the root of the source
#  tree. An additional intellectual property rights grant can be found
#  in the file PATENTS.  All contributing project authors may
#  be found in the AUTHORS file in the root of the source tree.

# Generate the config.h to compile with specific intrinsics / libs.

# Check for compiler options.
include(CheckCSourceCompiles)
check_c_source_compiles(
  "
    int main(void) {
      (void)__builtin_bswap16(0);
      return 0;
    }
  "
  HAVE_BUILTIN_BSWAP16)
check_c_source_compiles(
  "
    int main(void) {
      (void)__builtin_bswap32(0);
      return 0;
    }
  "
  HAVE_BUILTIN_BSWAP32)
check_c_source_compiles(
  "
    int main(void) {
      (void)__builtin_bswap64(0);
      return 0;
    }
  "
  HAVE_BUILTIN_BSWAP64)

# Check for libraries.
if(WEBP_USE_THREAD)
  find_package(Threads)
  if(Threads_FOUND)
    # work around cmake bug on QNX (https://cmake.org/Bug/view.php?id=11333)
    if(CMAKE_USE_PTHREADS_INIT AND NOT CMAKE_SYSTEM_NAME STREQUAL "QNX")
      set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pthread")
    endif()
    list(APPEND WEBP_DEP_LIBRARIES Threads::Threads)
  endif()
  set(WEBP_USE_THREAD ${Threads_FOUND})
endif()

# TODO: this seems unused, check with autotools.
set(LT_OBJDIR ".libs/")

# Only useful for vwebp, so useless for now.
find_package(OpenGL)
set(WEBP_HAVE_GL ${OPENGL_FOUND})

# Check if we need to link to the C math library. We do not look for it as it is
# not found when cross-compiling, while it is here.
check_c_source_compiles(
  "
    #include <math.h>
    int main(int argc, char** argv) {
      return (int)pow(argc, 2.5);
    }
  "
  HAVE_MATH_LIBRARY)
if(NOT HAVE_MATH_LIBRARY)
  message(STATUS "Adding -lm flag.")
  list(APPEND SHARPYUV_DEP_LIBRARIES m)
  list(APPEND WEBP_DEP_LIBRARIES m)
endif()

# Find the standard image libraries.
set(WEBP_DEP_IMG_LIBRARIES)
set(WEBP_DEP_IMG_INCLUDE_DIRS)
if(WEBP_FIND_IMG_LIBS)
  foreach(I_LIB PNG JPEG TIFF)
    # Disable tiff when compiling in static mode as it is failing on Ubuntu.
    if(WEBP_LINK_STATIC AND ${I_LIB} STREQUAL "TIFF")
      message(STATUS "TIFF is disabled when statically linking.")
      continue()
    endif()
    find_package(${I_LIB})
    set(WEBP_HAVE_${I_LIB} ${${I_LIB}_FOUND})
    if(${I_LIB}_FOUND)
      list(APPEND WEBP_DEP_IMG_LIBRARIES ${${I_LIB}_LIBRARIES})
      list(APPEND WEBP_DEP_IMG_INCLUDE_DIRS ${${I_LIB}_INCLUDE_DIR}
           ${${I_LIB}_INCLUDE_DIRS})
    endif()
  endforeach()
  if(WEBP_DEP_IMG_INCLUDE_DIRS)
    list(REMOVE_DUPLICATES WEBP_DEP_IMG_INCLUDE_DIRS)
  endif()

  # GIF detection, gifdec isn't part of the imageio lib.
  include(CMakePushCheckState)
  set(WEBP_DEP_GIF_LIBRARIES)
  set(WEBP_DEP_GIF_INCLUDE_DIRS)
  find_package(GIF)
  set(WEBP_HAVE_GIF ${GIF_FOUND})
  if(GIF_FOUND)
    # GIF find_package only locates the header and library, it doesn't fail
    # compile tests when detecting the version, but falls back to 3 (as of at
    # least cmake 3.7.2). Make sure the library links to avoid incorrect
    # detection when cross compiling.
    cmake_push_check_state()
    set(CMAKE_REQUIRED_LIBRARIES ${GIF_LIBRARIES})
    set(CMAKE_REQUIRED_INCLUDES ${GIF_INCLUDE_DIR})
    check_c_source_compiles(
      "
      #include <gif_lib.h>
      int main(void) {
        (void)DGifOpenFileHandle;
        return 0;
      }
      "
      GIF_COMPILES)
    cmake_pop_check_state()
    if(GIF_COMPILES)
      list(APPEND WEBP_DEP_GIF_LIBRARIES ${GIF_LIBRARIES})
      list(APPEND WEBP_DEP_GIF_INCLUDE_DIRS ${GIF_INCLUDE_DIR})
    else()
      unset(GIF_FOUND)
    endif()
  endif()
endif()

# Check for specific headers.
include(CheckIncludeFiles)
check_include_files(GLUT/glut.h HAVE_GLUT_GLUT_H)
check_include_files(GL/glut.h HAVE_GL_GLUT_H)
check_include_files(OpenGL/glut.h HAVE_OPENGL_GLUT_H)
check_include_files(shlwapi.h HAVE_SHLWAPI_H)
check_include_files(unistd.h HAVE_UNISTD_H)
check_include_files(wincodec.h HAVE_WINCODEC_H)
check_include_files(windows.h HAVE_WINDOWS_H)

# Windows specifics
if(HAVE_WINCODEC_H)
  list(APPEND WEBP_DEP_LIBRARIES shlwapi ole32 windowscodecs)
endif()

# Check for SIMD extensions.
include(${CMAKE_CURRENT_LIST_DIR}/cpu.cmake)

# Define extra info.
set(PACKAGE ${PROJECT_NAME})
set(PACKAGE_NAME ${PROJECT_NAME})

# Read from configure.ac.
file(READ ${CMAKE_CURRENT_SOURCE_DIR}/configure.ac CONFIGURE_AC)
string(REGEX MATCHALL "\\[([0-9a-z\\.:/]*)\\]" CONFIGURE_AC_PACKAGE_INFO
             ${CONFIGURE_AC})
function(strip_bracket VAR)
  string(LENGTH ${${VAR}} TMP_LEN)
  math(EXPR TMP_LEN ${TMP_LEN}-2)
  string(SUBSTRING ${${VAR}} 1 ${TMP_LEN} TMP_SUB)
  set(${VAR} ${TMP_SUB} PARENT_SCOPE)
endfunction()

list(GET CONFIGURE_AC_PACKAGE_INFO 1 PACKAGE_VERSION)
strip_bracket(PACKAGE_VERSION)
list(GET CONFIGURE_AC_PACKAGE_INFO 2 PACKAGE_BUGREPORT)
strip_bracket(PACKAGE_BUGREPORT)
list(GET CONFIGURE_AC_PACKAGE_INFO 3 PACKAGE_URL)
strip_bracket(PACKAGE_URL)

# Build more info.
set(PACKAGE_STRING "${PACKAGE_NAME} ${PACKAGE_VERSION}")
set(PACKAGE_TARNAME ${PACKAGE_NAME})
set(VERSION ${PACKAGE_VERSION})