#!/usr/bin/env ruby

if RUBY_PLATFORM =~ /mswin$|mingw32|mingw64|win32\-|\-win32/
  platform = (RUBY_PLATFORM =~ /^x64-/ ? 'x64-mingw32' : 'i386-mingw32')
  
  puts "This gem is not meant to be installed on Windows. Instead, please use:"
  puts "gem install gosu --platform=#{platform}"
  exit 1
end

puts 'The Gosu gem requires some libraries to be installed system-wide.'
puts 'See the following site for a list:'
if `uname`.chomp == 'Darwin'
  puts 'https://github.com/gosu/gosu/wiki/Getting-Started-on-OS-X'
else
  puts 'https://github.com/gosu/gosu/wiki/Getting-Started-on-Linux'
end

require 'mkmf'
require 'fileutils'

# Silence internal deprecation warnings in Gosu
$CFLAGS << " -DGOSU_DEPRECATED="

$CXXFLAGS ||= ""
$CXXFLAGS << " -std=gnu++11"

# For #include <Gosu/...>
$INCFLAGS << " -I../.."

if `uname`.chomp == 'Darwin'
  # To make everything work with the Objective C runtime
  $CFLAGS   << " -x objective-c -fobjc-arc -DNDEBUG"
  # Compile all C++ files as Objective C++ on macOS since mkmf does not support .mm files.
  $CXXFLAGS << " -x objective-c++ -fobjc-arc -DNDEBUG"

  # Explicitly specify libc++ as the standard library.
  # rvm will sometimes try to override this:
  # https://github.com/shawn42/gamebox/issues/96
  $CXXFLAGS << " -stdlib=libc++"
  
  # Dependencies.
  $CXXFLAGS << " #{`sdl2-config --cflags`.chomp}"
  # Prefer statically linking SDL 2.
  $LDFLAGS  << " #{`sdl2-config --static-libs`.chomp} -framework OpenGL -framework OpenAL"
  
  # Disable building of 32-bit slices in Apple's Ruby.
  # (RbConfig::CONFIG['CXXFLAGS'] on 10.11: -arch x86_64 -arch i386 -g -Os -pipe)
  $CFLAGS.gsub! "-arch i386", ""
  $CXXFLAGS.gsub! "-arch i386", ""
  $LDFLAGS.gsub! "-arch i386", ""
  $ARCH_FLAG.gsub! "-arch i386", ""
  CONFIG['LDSHARED'].gsub! "-arch i386", ""
else
  if /BCM2708/ =~ `cat /proc/cpuinfo`
    $INCFLAGS << " -I/opt/vc/include/GLES"
    $INCFLAGS << " -I/opt/vc/include"
    $LDFLAGS << " -L/opt/vc/lib"
    $LDFLAGS << " -lGLESv1_CM"
    $CFLAGS   << " -DGOSU_IS_OPENGLES"
    $CXXFLAGS << " -DGOSU_IS_OPENGLES"
  else
    pkg_config 'gl'
  end

  pkg_config 'sdl2'
  pkg_config 'pangoft2'
  pkg_config 'vorbisfile'
  pkg_config 'openal'
  pkg_config 'sndfile'
  pkg_config 'libmpg123'
  
  have_header 'SDL_ttf.h' if have_library('SDL2_ttf', 'TTF_RenderUTF8_Blended')
  have_header 'AL/al.h'   if have_library('openal')
end

# This is necessary to build with stock Ruby on OS X 10.7.
CONFIG['CXXFLAGS'] ||= $CXXFLAGS

# Gem::Version#initialize is apparently broken in some versions of Ruby, so use a local helper.
def ruby_newer_than?(want_version)
  have_parts = RUBY_VERSION.split('.').map { |part| part.to_i }
  want_parts = want_version.split('.').map { |part| part.to_i }
  have_parts << 0 while have_parts.size < want_parts.size
  want_parts << 0 while want_parts.size < have_parts.size
  (have_parts <=> want_parts) == 1
end

# In some versions of Ruby/mkmf, the $CXXFLAGS variable does not work.
# We can modify CONFIG instead, and our changes will end up in the Makefile.
# See: http://bugs.ruby-lang.org/issues/8315
# The lower bound was reduced to 1.9.3 here: https://github.com/gosu/gosu/issues/321
if ruby_newer_than?("1.9.2") and not ruby_newer_than?("2.2.0")
  CONFIG['CXXFLAGS'] = "#$CFLAGS #$CXXFLAGS"
end

create_makefile "gosu", "../../src"