#  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.

PhusionPassenger.require_passenger_lib 'platform_info'
PhusionPassenger.require_passenger_lib 'platform_info/operating_system'

module PhusionPassenger

module PlatformInfo
	# An identifier for the current Linux distribution. nil if the operating system is not Linux.
	def self.linux_distro
		tags = linux_distro_tags
		if tags
			return tags.first
		else
			return nil
		end
	end
	
	# Autodetects the current Linux distribution and return a number of identifier tags.
	# The first tag identifies the distribution while the other tags indicate which
	# distributions it is likely compatible with.
	# Returns nil if the operating system is not Linux.
	def self.linux_distro_tags
		if os_name != "linux"
			return nil
		end
		lsb_release = read_file("/etc/lsb-release")
		if lsb_release =~ /Ubuntu/
			return [:ubuntu, :debian]
		elsif File.exist?("/etc/debian_version")
			return [:debian]
		elsif File.exist?("/etc/redhat-release")
			redhat_release = read_file("/etc/redhat-release")
			if redhat_release =~ /CentOS/
				return [:centos, :redhat]
			elsif redhat_release =~ /Fedora/
				return [:fedora, :redhat]
			elsif redhat_release =~ /Mandriva/
				return [:mandriva, :redhat]
			else
				# On official RHEL distros, the content is in the form of
				# "Red Hat Enterprise Linux Server release 5.1 (Tikanga)"
				return [:rhel, :redhat]
			end
		elsif File.exist?("/etc/system-release")
			system_release = read_file("/etc/system-release")
			if system_release =~ /Amazon Linux/
				return [:amazon, :redhat]
			else
				return [:unknown]
			end
		elsif File.exist?("/etc/suse-release")
			return [:suse]
		elsif File.exist?("/etc/gentoo-release")
			return [:gentoo]
		else
			return [:unknown]
		end
		# TODO: Slackware
	end
	memoize :linux_distro_tags
end

end # PhusionPassenger