#  Phusion Passenger - https://www.phusionpassenger.com/
#  Copyright (c) 2010 Phusion
#
#  "Phusion Passenger" is a trademark of Hongli Lai & Ninh Bui.
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
#  in the Software without restriction, including without limitation the rights
#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included in
#  all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#  THE SOFTWARE.

require 'rbconfig'
PhusionPassenger.require_passenger_lib 'platform_info'
PhusionPassenger.require_passenger_lib 'platform_info/ruby'
PhusionPassenger.require_passenger_lib 'platform_info/operating_system'

module PhusionPassenger

module PlatformInfo
	# Returns a string that describes the current Ruby
	# interpreter's extension binary compatibility. A Ruby extension
	# compiled for a certain Ruby interpreter can also be loaded on
	# a different Ruby interpreter with the same binary compatibility
	# identifier.
	#
	# The result depends on the following factors:
	# - Ruby engine name.
	# - Ruby extension version.
	#   This is not the same as the Ruby language version, which
	#   identifies language-level compatibility. This is rather about
	#   binary compatibility of extensions.
	#   MRI seems to break source compatibility between tiny releases,
	#   though patchlevel releases tend to be source and binary
	#   compatible.
	# - Ruby extension architecture.
	#   This is not necessarily the same as the operating system
	#   runtime architecture or the CPU architecture.
	#   For example, in case of JRuby, the extension architecture is
	#   just "java" because all extensions target the Java platform;
	#   the architecture the JVM was compiled for has no effect on
	#   compatibility.
	#   On systems with universal binaries support there may be multiple
	#   architectures. In this case the architecture is "universal"
	#   because extensions must be able to support all of the Ruby
	#   executable's architectures.
	# - The operating system for which the Ruby interpreter was compiled.
	def self.ruby_extension_binary_compatibility_id
		ruby_engine = defined?(RUBY_ENGINE) ? RUBY_ENGINE : "ruby"
		ruby_ext_version = RUBY_VERSION
		if RUBY_PLATFORM =~ /darwin/
			if RUBY_PLATFORM =~ /universal/
				ruby_arch = "universal"
			else
				# OS X <  10.8: something like:
				#   "/opt/ruby-enterprise/bin/ruby: Mach-O 64-bit executable x86_64"
				output = `file -L "#{ruby_executable}"`.strip
				ruby_arch = output.sub(/.* /, '')
				if ruby_arch == "executable"
					# OS X >= 10.8: something like:
					#   "/opt/ruby-enterprise/bin/ruby: Mach-O 64-bit executable"
					if output =~ /Mach-O 64-bit/
						ruby_arch = "x86_64"
					else
						raise "Cannot autodetect the Ruby interpreter's architecture"
					end
				end
			end
		elsif RUBY_PLATFORM == "java"
			ruby_arch = "java"
		else
			ruby_arch = cpu_architectures[0]
		end
		return "#{ruby_engine}-#{ruby_ext_version}-#{ruby_arch}-#{os_name}"
	end
	memoize :ruby_extension_binary_compatibility_id
	
	# Returns an identifier string that describes the current
	# platform's binary compatibility with regard to C/C++
	# binaries. Two systems with the same binary compatibility
	# identifiers should be able to run the same C/C++ binaries.
	#
	# The the string depends on the following factors:
	# - The operating system name.
	# - Operating system runtime identifier.
	#   This may include the kernel version, libc version, C++ ABI version,
	#   etc. Everything that is of interest for binary compatibility with
	#   regard to C/C++ binaries.
	# - Operating system default runtime architecture.
	#   This is not the same as the CPU architecture; some CPUs support
	#   multiple architectures, e.g. Intel Core 2 Duo supports x86 and
	#   x86_64. Some operating systems actually support multiple runtime
	#   architectures: a lot of x86_64 Linux distributions also include
	#   32-bit runtimes, and OS X Snow Leopard is x86_64 by default but
	#   all system libraries also support x86.
	#   This component identifies the architecture that is used when
	#   compiling a binary with the system's C++ compiler with its default
	#   options.
	def self.cxx_binary_compatibility_id
		if os_name == "macosx"
			# RUBY_PLATFORM gives us the kernel version, but we want
			# the OS X version.
			os_version_string = `sw_vers -productVersion`.strip
			# sw_vers returns something like "10.6.2". We're only
			# interested in the first two digits (MAJOR.MINOR) since
			# tiny releases tend to be binary compatible with each
			# other.
			components = os_version_string.split(".")
			os_version = "#{components[0]}.#{components[1]}"
			os_runtime = os_version
			
			os_arch = cpu_architectures[0]
			if os_version >= "10.5" && os_arch =~ /^i.86$/
				# On Snow Leopard, 'uname -m' returns i386 but
				# we *know* that everything is x86_64 by default.
				os_arch = "x86_64"
			end
		else
			os_arch = cpu_architectures[0]
			os_runtime = nil
		end
		
		return [os_arch, os_name, os_runtime].compact.join("-")
	end
	memoize :cxx_binary_compatibility_id
end

end # module PhusionPassenger
