#!/usr/bin/env ruby
# encoding: binary
#  Phusion Passenger - https://www.phusionpassenger.com/
#  Copyright (c) 2010-2014 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.

## Magic comment: begin bootstrap ##
source_root = File.expand_path("..", File.dirname(__FILE__))
$LOAD_PATH.unshift("#{source_root}/lib")
begin
	require 'rubygems'
rescue LoadError
end
require 'phusion_passenger'
## Magic comment: end bootstrap ##

PhusionPassenger.locate_directories

# The Apache executable may be located in an 'sbin' folder. We add
# the 'sbin' folders to $PATH just in case. On some systems
# 'sbin' isn't in $PATH unless the user is logged in as root from
# the start (i.e. not via 'su' or 'sudo').
ENV["PATH"] += ":/usr/sbin:/sbin:/usr/local/sbin"

require 'optparse'
require 'stringio'
PhusionPassenger.require_passenger_lib 'constants'
PhusionPassenger.require_passenger_lib 'platform_info/ruby'
PhusionPassenger.require_passenger_lib 'platform_info/apache'
PhusionPassenger.require_passenger_lib 'platform_info/apache_detector'
PhusionPassenger.require_passenger_lib 'abstract_installer'
PhusionPassenger.require_passenger_lib 'utils/terminal_choice_menu'

class Installer < PhusionPassenger::AbstractInstaller
	include PhusionPassenger
	TerminalChoiceMenu = PhusionPassenger::Utils::TerminalChoiceMenu

	AUTOINSTALL_BEGIN_LOAD_BLOCK = "### Begin automatically installed #{PROGRAM_NAME} load snippet ###"
	AUTOINSTALL_END_LOAD_BLOCK   = "### End automatically installed #{PROGRAM_NAME} load snippet ###"
	AUTOINSTALL_BEGIN_CONF_BLOCK = "### Begin automatically installed #{PROGRAM_NAME} config snippet ###"
	AUTOINSTALL_END_CONF_BLOCK   = "### End automatically installed #{PROGRAM_NAME} config snippet ###"

	def dependencies
		specs = [
			'depcheck_specs/compiler_toolchain',
			'depcheck_specs/ruby',
			'depcheck_specs/gems',
			'depcheck_specs/libs',
			'depcheck_specs/apache2'
		]
		ids = [
			'cc',
			'c++',
			'libcurl-dev',
			'openssl-dev',
			'zlib-dev',
			'apache2',
			'apache2-dev',
			'rake',
			'ruby-openssl',
			'rubygems'
		]
		if @languages.include?("ruby")
			if PlatformInfo.passenger_needs_ruby_dev_header?
				ids << 'ruby-dev'
			end
			ids << 'rack'
		end
		# Some broken servers don't have apr-config or apu-config installed.
		# Nevertheless, it is possible to compile Apache modules if Apache
		# was configured with --included-apr. So here we check whether
		# apr-config and apu-config are available. If they're not available,
		# then we only register them as required dependency if no Apache
		# module can be compiled without their presence.
		if (PlatformInfo.apr_config && PlatformInfo.apu_config) ||
		   PlatformInfo.apr_config_needed_for_building_apache_modules?
			ids << 'apr-dev'
			ids << 'apu-dev'
		end
		return [specs, ids]
	end
	
	def users_guide_path
		return PhusionPassenger.apache2_doc_path
	end

	def users_guide_url
		return APACHE2_DOC_URL
	end
	
	def run_steps
		if PhusionPassenger.natively_packaged? && PhusionPassenger.apache2_module_source_dir.nil?
			if apache_module_available?
				notify_apache_module_installed
				show_deployment_example
			else
				install_apache_module_from_native_package || exit(1)
			end
			exit
		end
		
		Dir.chdir(PhusionPassenger.apache2_module_source_dir)
		show_welcome_screen
		query_interested_languages
		check_gem_install_permission_problems || exit(1)
		check_directory_accessible_by_web_server
		check_dependencies || exit(1)
		check_whether_there_are_multiple_apache_installs || exit
		check_whether_apache_uses_compatible_mpm
		check_whether_os_is_broken
		check_whether_system_has_enough_ram
		check_write_permission_to_passenger_root || exit(1)
		check_write_permission_to_web_server_config_files || exit(1)
		if compile_apache2_module
			install_apache2_config_snippets || exit(1)
			show_deployment_example
		else
			show_possible_solutions_for_compilation_and_installation_problems
			exit(1)
		end
	end

private
	def show_welcome_screen
		render_template 'apache2/welcome', :version => VERSION_STRING
		wait
	end

	def query_interested_languages
		menu = TerminalChoiceMenu.new(["Ruby", "Python", "Node.js", "Meteor"])
		menu["Ruby"].checked = interesting_language?('ruby')
		menu["Python"].checked = interesting_language?('python')
		menu["Node.js"].checked = interesting_language?('nodejs', 'node')
		menu["Meteor"].checked = interesting_language?('meteor')

		new_screen
		puts "<banner>Which languages are you interested in?</banner>"
		puts
		if interactive?
			puts "Use <space> to select."
			puts "<dgray>If the menu doesn't display correctly, ensure that your terminal supports UTF-8.</dgray>"
		else
			puts "Override selection with --languages."
		end
		puts

		if interactive?
			begin
				menu.query
			rescue Interrupt
				raise Abort
			end
		else
			menu.display_choices
			puts
		end

		@languages = menu.selected_choices.map{ |x| x.downcase.gsub(/\./, '') }
	end

	def interesting_language?(name, command = nil)
		if @languages
			return @languages.include?(name)
		else
			return !!PlatformInfo.find_command(command || name)
		end
	end

	def check_whether_there_are_multiple_apache_installs
		new_screen
		puts '<banner>Sanity checking Apache installation...</banner>'

		output = StringIO.new
		detector = PlatformInfo::ApacheDetector.new(output)
		begin
			detector.detect_all
			detector.report
			@apache2 = detector.result_for(PlatformInfo.apxs2)
			if @apache2.nil?
				render_template 'apache2/apache_install_broken',
					:apxs2 => PlatformInfo.apxs2,
					:sudo_s_e => PhusionPassenger::PlatformInfo.ruby_sudo_shell_command("-E"),
					:ruby => PhusionPassenger::PlatformInfo.ruby_command,
					:passenger_config => "#{PhusionPassenger.bin_dir}/passenger-config"
				return false
			end
			if detector.results.size > 1
				other_installs = detector.results - [@apache2]
				render_template 'apache2/multiple_apache_installations_detected',
					:current => @apache2,
					:other_installs => other_installs
				puts
				if interactive?
					result = prompt_confirmation "Are you sure you want to install " +
						"against Apache #{@apache2.version} (#{@apache2.apxs2})?"
					if !result
						puts
						line
						render_template 'apache2/installing_against_a_different_apache',
							:other_installs => other_installs
					end
					return result
				else
					puts '<yellow>Continuing installation because --auto is given.</yellow>'
					return true
				end
			else
				puts '<green>All good!</green>'
				return true
			end
		ensure
			detector.finish
		end
	end
	
	def check_whether_apache_uses_compatible_mpm
		# 'httpd -V' output is in the form of:
		#
		# Server MPM:      Prefork     # <--- this line is not always available!
		# ...
		# Server compiled with....
		#  -D APACHE_MPM_DIR="server/mpm/prefork"
		output = PlatformInfo.httpd_V
		output =~ /^Server MPM: +(.*)$/
		if $1
			mpm = $1.downcase
		else
			output =~ /APACHE_MPM_DIR="server\/mpm\/(.*)"/
			if $1
				mpm = $1.downcase
			else
				mpm = nil
			end
		end
		if mpm != "prefork" && mpm != "worker" && mpm != "event"
			new_screen
			render_template 'apache2/apache_must_be_compiled_with_compatible_mpm',
				:current_mpm => mpm
			wait
		end
	end
	
	def check_write_permission_to_passenger_root
		File.new("__test__.txt", "w").close
		return true
	rescue SystemCallError
		puts
		line
		if Process.uid == 0
			render_template 'installer_common/cannot_access_files_as_root',
				:type => "directory",
				:files => [PhusionPassenger.apache2_module_source_dir]
		else
			render_template 'installer_common/run_installer_as_root',
				:dir  => PhusionPassenger.apache2_module_source_dir,
				:sudo => PhusionPassenger::PlatformInfo.ruby_sudo_command,
				:sudo_s_e => PhusionPassenger::PlatformInfo.ruby_sudo_shell_command("-E"),
				:ruby => PhusionPassenger::PlatformInfo.ruby_command,
				:installer => "#{PhusionPassenger.bin_dir}/passenger-install-apache2-module #{ORIG_ARGV.join(' ')}"
		end
		return false
	ensure
		File.unlink("__test__.txt") rescue nil
	end

	def check_write_permission_to_web_server_config_files
		return true if !@update_config
		config_file = PlatformInfo.httpd_default_config_file
		return if !config_file || !File.exist?(config_file)

		all_config_files = PlatformInfo.httpd_included_config_files(config_file)
		if all_config_files[:unreadable_files].any?
			puts
			line
			if Process.uid == 0
				render_template 'installer_common/cannot_access_files_as_root',
					:access => "read from",
					:files => all_config_files[:unreadable_files]
			else
				render_template 'installer_common/run_installer_as_root',
					:access => "read from",
					:desc => "an Apache configuration file",
					:sudo => PhusionPassenger::PlatformInfo.ruby_sudo_command,
					:sudo_s_e => PhusionPassenger::PlatformInfo.ruby_sudo_shell_command("-E"),
					:ruby => PhusionPassenger::PlatformInfo.ruby_command,
					:installer => "#{PhusionPassenger.bin_dir}/passenger-install-apache2-module #{ORIG_ARGV.join(' ')}"
			end
			puts
			render_template 'apache2/present_choice_for_no_update_config'
			return false
		end

		unwriteable_files = []
		all_config_files[:files].each do |filename|
			if !File.writable_real?(filename)
				unwriteable_files << filename
			end
		end
		if unwriteable_files.empty?
			return true
		else
			puts
			line
			if Process.uid == 0
				render_template 'installer_common/cannot_access_files_as_root',
					:files => unwriteable_files
			else
				render_template 'installer_common/run_installer_as_root',
					:desc => "an Apache configuration file",
					:sudo => PhusionPassenger::PlatformInfo.ruby_sudo_command,
					:sudo_s_e => PhusionPassenger::PlatformInfo.ruby_sudo_shell_command("-E"),
					:ruby => PhusionPassenger::PlatformInfo.ruby_command,
					:installer => "#{PhusionPassenger.bin_dir}/passenger-install-apache2-module #{ORIG_ARGV.join(' ')}"
			end
			puts
			render_template 'apache2/present_choice_for_no_update_config'
			return false
		end
	end
	
	def compile_apache2_module
		puts
		line
		puts '<banner>Compiling and installing Apache 2 module...</banner>'
		if @compile
			puts "cd #{PhusionPassenger.apache2_module_source_dir}"
			if ENV['TRACE']
				rake = "#{PlatformInfo.rake_command} --trace RELEASE=yes"
			else
				rake = "#{PlatformInfo.rake_command} RELEASE=yes"
			end
			command = "#{rake} apache2:clean apache2"
			if PhusionPassenger.native_packaging_method == "homebrew"
				# Running apache2:clean deletes some object files needed
				# by passenger-install-nginx-module, so we ensure those
				# object files are compiled.
				command << " nginx"
			end
			return sh(command)
		else
			puts "Skipping compilation"
			return true
		end
	end
	
	def load_snippet
		return "LoadModule passenger_module #{PhusionPassenger.apache2_module_path}"
	end

	def config_snippet
		return "<IfModule mod_passenger.c>\n" +
			"  PassengerRoot #{PhusionPassenger.source_root}\n" +
			"  PassengerDefaultRuby #{PlatformInfo.ruby_command}\n" +
			"</IfModule>"
	end

	def apache2_config_snippets
		return "#{load_snippet}\n#{config_snippet}\n"
	end

	def backup_config_files(config_file, all_config_files)
		now = Time.now.strftime("%Y-%m-%d-%H:%M:%S")
		archive = "#{config_file}.#{GLOBAL_NAMESPACE_DIRNAME}-backup-#{now}.tar.gz"
		backup_files = all_config_files.dup

		# Some people create a regular file in /etc/apache2/mods-enabled, for convenience
		# reasons. This file is not actually managed by a2enmod. We will remove such files
		# because we're going to use mods-eanbled ourselves, so we need to back them up.
		if (dir = PlatformInfo.httpd_mods_enabled_directory) && PlatformInfo.a2enmod
			if File.file?("#{dir}/#{APACHE2_MODULE_CONF_NAME}.load")
				backup_files << "#{dir}/#{APACHE2_MODULE_CONF_NAME}.load"
			end
			if File.file?("#{dir}/#{APACHE2_MODULE_CONF_NAME}.conf")
				backup_files << "#{dir}/#{APACHE2_MODULE_CONF_NAME}.conf"
			end
		end

		puts "Backing up existing configuration files to #{archive}..."
		backup_files.uniq!
		backup_files.map! { |x| x.sub(/^\//, '') }
		Dir.chdir("/") do
			sh! "tar", "-czf", archive, *backup_files
		end
	end

	def uninstall_or_comment_out_existing_config_snippets(all_config_files)
		files_containing_autoinstall_load_blocks = []
		files_containing_autoinstall_conf_blocks = []

		# Some people create a regular file in /etc/apache2/mods-enabled, for convenience
		# reasons. This file is not actually managed by a2enmod. We remove such files
		# because we're going to use mods-enabled ourselves. They've already been backed up.
		if (dir = PlatformInfo.httpd_mods_enabled_directory) && PlatformInfo.a2enmod
			filename = "#{dir}/#{APACHE2_MODULE_CONF_NAME}.load"
			if File.file?(filename) && !File.symlink?(filename)
				puts "Removing #{filename}"
				File.unlink(filename)
			end
			filename = "#{dir}/#{APACHE2_MODULE_CONF_NAME}.conf"
			if File.file?(filename) && !File.symlink?(filename)
				puts "Removing #{filename}"
				File.unlink(filename)
			end
		end

		# Uncomment Phusion Passenger config snippets.
		all_config_files.each do |filename|
			next if !File.exist?(filename)

			contents = File.open(filename, "rb") do |f|
				f.read
			end
			if contents =~ /#{Regexp.escape AUTOINSTALL_BEGIN_LOAD_BLOCK}.*?#{Regexp.escape AUTOINSTALL_END_LOAD_BLOCK}/m
				files_containing_autoinstall_load_blocks << filename
			end
			if contents =~ /#{Regexp.escape AUTOINSTALL_BEGIN_CONF_BLOCK}.*?#{Regexp.escape AUTOINSTALL_END_CONF_BLOCK}/m
				files_containing_autoinstall_conf_blocks << filename
			end
			subst1 = contents.gsub!(/^([ \t]*LoadModule[ \t]+passenger_module[ \t]+.*)$/i, '# \1')
			subst2 = contents.gsub!(/^([ \t]*PassengerRoot[ \t]+.*)$/i, '# \1')
			subst3 = contents.gsub!(/^([ \t]*PassengerDefaultRuby[ \t]+.*)$/i, '# \1')
			if subst1 || subst2 || subst3
				puts "Uninstalling previous #{PROGRAM_NAME} from #{filename}..."
				File.open(filename, "wb") do |f|
					f.write(contents)
				end
			end
		end

		# If there are multiple auto-install comment blocks, remove the duplicates.
		# First, we remove all comment blocks from all files besides the first one.
		if files_containing_autoinstall_load_blocks.size > 1
			files_containing_autoinstall_load_blocks[1..-1].each do |filename|
				puts "Removing duplicate load snippets from #{filename}..."
				remove_comment_blocks(filename,
					AUTOINSTALL_BEGIN_LOAD_BLOCK,
					AUTOINSTALL_END_LOAD_BLOCK)
			end
		end
		if files_containing_autoinstall_conf_blocks.size > 1
			files_containing_autoinstall_conf_blocks[1..-1].each do |filename|
				puts "Removing duplicate conf snippets from #{filename}..."
				remove_comment_blocks(filename,
					AUTOINSTALL_BEGIN_CONF_BLOCK,
					AUTOINSTALL_END_CONF_BLOCK)
			end
		end

		# Then we are left with exactly 0 or exactly 1 file with comment blocks
		# of each type. There may be duplicates inside that single file, so
		# remove duplicates there too.
		if files_containing_autoinstall_load_blocks.size > 0
			filename = files_containing_autoinstall_load_blocks[0]
			puts "Removing duplicate load snippets inside #{filename}..."
			remove_duplicate_comment_blocks(filename,
				AUTOINSTALL_BEGIN_LOAD_BLOCK,
				AUTOINSTALL_END_LOAD_BLOCK)
		end
		if files_containing_autoinstall_conf_blocks.size > 0
			filename = files_containing_autoinstall_conf_blocks[0]
			puts "Removing duplicate configuration snippets inside #{filename}..."
			remove_duplicate_comment_blocks(filename,
				AUTOINSTALL_BEGIN_CONF_BLOCK,
				AUTOINSTALL_END_CONF_BLOCK)
		end

		# One or more files may have been removed, so filter out the ones
		# that are left.
		all_config_files.reject! do |filename|
			!File.exist?(filename)
		end
	end

	def remove_comment_blocks(filename, begin_marker, end_marker)
		contents = File.open(filename, "rb") do |f|
			f.read
		end
		regexp = /#{Regexp.escape begin_marker}.*?#{Regexp.escape end_marker}\n?/m
		contents.gsub!(regexp, '')
		File.open(filename, "wb") do |f|
			f.write(contents)
		end
	end

	def remove_duplicate_comment_blocks(filename, begin_marker, end_marker)
		contents = File.open(filename, "rb") do |f|
			f.read
		end
		regexp = /#{Regexp.escape begin_marker}.*?#{Regexp.escape end_marker}\n?/m
		if m = regexp.match(contents)
			offset = m.end(0)
			rest = contents.slice!(m.end(0) .. -1)
			rest.gsub!(regexp, '')
			contents << rest
			File.open(filename, "wb") do |f|
				f.write(contents)
			end
		end
	end

	def add_new_config_snippets(all_config_files)
		# Look for the file containing the auto-install load and conf comment blocks.
		# The uninstall_or_comment_out_existing_config_snippets method has already
		# guaranteed that there is at most 1 file per comment block type, and that
		# inside each file there are no duplicate comment blocks.
		load_block_file = find_config_file_containing_comment_block(all_config_files,
			AUTOINSTALL_BEGIN_LOAD_BLOCK,
			AUTOINSTALL_END_LOAD_BLOCK)
		conf_block_file = find_config_file_containing_comment_block(all_config_files,
			AUTOINSTALL_BEGIN_CONF_BLOCK,
			AUTOINSTALL_END_CONF_BLOCK)
		if load_block_file && conf_block_file
			puts "Updating #{PROGRAM_NAME} module load snippet inside #{load_block_file}..."
			update_comment_block(load_block_file,
				AUTOINSTALL_BEGIN_LOAD_BLOCK,
				AUTOINSTALL_END_LOAD_BLOCK,
				load_snippet)
			puts "Updating #{PROGRAM_NAME} configuration snippet inside #{conf_block_file}..."
			update_comment_block(conf_block_file,
				AUTOINSTALL_BEGIN_CONF_BLOCK,
				AUTOINSTALL_END_CONF_BLOCK,
				config_snippet)
		elsif !load_block_file && !conf_block_file
			create_load_snippet_file(:maybe_in_mods_available)
			create_conf_snippet_file(:maybe_in_mods_available)
			if PlatformInfo.httpd_mods_available_directory && PlatformInfo.a2enmod
				sh! "#{PlatformInfo.a2enmod} #{APACHE2_MODULE_CONF_NAME}"
			end
		# It looks like either the load or conf file isn't available.
		# If the file that is available is inside mods-available, then it
		# means that the mods-available files are broken.
		elsif is_file_inside_mods_available?(load_block_file, "#{APACHE2_MODULE_CONF_NAME}.load") ||
		      is_file_inside_mods_available?(conf_block_file, "#{APACHE2_MODULE_CONF_NAME}.conf")
			# We fix it if a2enmod is available. Otherwise, we remove the block.
			if PlatformInfo.a2enmod
				if !load_block_file
					create_load_snippet_file(:must_be_in_mods_available)
				else
					create_conf_snippet_file(:must_be_in_mods_available)
				end
			else
				if load_block_file
					puts "Removing load snippets from #{filename}..."
					remove_comment_blocks(load_block_file,
						AUTOINSTALL_BEGIN_LOAD_BLOCK,
						AUTOINSTALL_END_LOAD_BLOCK)
				else
					puts "Removing configuration snippets from #{filename}..."
					remove_comment_blocks(conf_block_file,
						AUTOINSTALL_BEGIN_CONF_BLOCK,
						AUTOINSTALL_END_CONF_BLOCK)
				end
				create_load_snippet_file(:must_be_in_mods_available)
				create_conf_snippet_file(:must_be_in_mods_available)
			end
			sh! "#{PlatformInfo.a2enmod} passenger"
		else
			if !load_block_file
				create_load_snippet_file(:not_in_mods_available)
				puts "Updating #{PROGRAM_NAME} configuration snippet inside #{conf_block_file}..."
				update_comment_block(conf_block_file,
					AUTOINSTALL_BEGIN_CONF_BLOCK,
					AUTOINSTALL_END_CONF_BLOCK,
					config_snippet)
			else
				create_conf_snippet_file(:not_in_mods_available)
				puts "Updating #{PROGRAM_NAME} module load snippet inside #{load_block_file}..."
				update_comment_block(load_block_file,
					AUTOINSTALL_BEGIN_LOAD_BLOCK,
					AUTOINSTALL_END_LOAD_BLOCK,
					load_snippet)
			end
		end
	end

	def find_config_file_containing_comment_block(all_config_files, begin_marker, end_marker)
		regexp = /#{Regexp.escape begin_marker}.*?#{Regexp.escape end_marker}/m
		all_config_files.each do |filename|
			contents = File.open(filename, "rb") do |f|
				f.read
			end
			if contents =~ regexp
				return filename
			end
		end
		return nil
	end

	def update_comment_block(filename, begin_marker, end_marker, block_contents)
		regexp = /#{Regexp.escape begin_marker}.*?#{Regexp.escape end_marker}\n?/m
		contents = File.open(filename, "rb") do |f|
			f.read
		end
		if contents.sub!(regexp, "#{begin_marker}\n#{block_contents}\n#{end_marker}\n")
			File.open(filename, "wb") do |f|
				f.write(contents)
			end
			return true
		else
			return false
		end
	end

	def remove_comment_blocks(filename, begin_marker, end_marker)
		regexp = /#{Regexp.escape begin_marker}.*?#{Regexp.escape end_marker}\n?/m
		contents = File.open(filename, "rb") do |f|
			f.read
		end
		contents.gsub!(regexp, "")
		File.open(filename, "wb") do |f|
			f.write(contents)
		end
	end

	def is_file_inside_mods_available?(filename, basename)
		if dir = PlatformInfo.httpd_mods_available_directory
			return filename == "#{dir}/#{basename}"
		else
			return false
		end
	end

	def create_load_snippet_file(where)
		case where
		when :maybe_in_mods_available
			if PlatformInfo.httpd_mods_available_directory && PlatformInfo.a2enmod
				filename = "#{PlatformInfo.httpd_mods_available_directory}/#{APACHE2_MODULE_CONF_NAME}.load"
			else
				filename = PlatformInfo.httpd_default_config_file
			end
		when :must_be_in_mods_available
			if PlatformInfo.httpd_mods_available_directory && PlatformInfo.a2enmod
				filename = "#{PlatformInfo.httpd_mods_available_directory}/#{APACHE2_MODULE_CONF_NAME}.load"
			else
				raise "Apache does not support the mods-available directory"
			end
		when :not_in_mods_available
			filename = PlatformInfo.httpd_default_config_file
		else
			raise ArgumentError
		end

		if File.exist?(filename)
			# If this is a file inside mods-available, and the file didn't have a symlink
			# in mods-enabled, then the uninstall phase did not remove duplicates from this
			# file. So here we remove duplicates again.
			puts "Removing duplicate load snippets inside #{filename}..."
			remove_duplicate_comment_blocks(filename,
				AUTOINSTALL_BEGIN_LOAD_BLOCK,
				AUTOINSTALL_END_LOAD_BLOCK)

			puts "Installing #{PROGRAM_NAME} module load snippet to #{filename}..."
			should_add = !update_comment_block(filename,
				AUTOINSTALL_BEGIN_LOAD_BLOCK,
				AUTOINSTALL_END_LOAD_BLOCK,
				load_snippet)
		else
			puts "Installing #{PROGRAM_NAME} module load snippet to #{filename}..."
			should_add = true
		end
		if should_add
			File.open(filename, "ab") do |f|
				f.write("\n#{AUTOINSTALL_BEGIN_LOAD_BLOCK}\n" +
					"#{load_snippet}\n" +
					"#{AUTOINSTALL_END_LOAD_BLOCK}\n")
			end
		end
	end

	def create_conf_snippet_file(where)
		case where
		when :maybe_in_mods_available
			if PlatformInfo.httpd_mods_available_directory && PlatformInfo.a2enmod
				filename = "#{PlatformInfo.httpd_mods_available_directory}/#{APACHE2_MODULE_CONF_NAME}.conf"
			else
				filename = PlatformInfo.httpd_default_config_file
			end
		when :must_be_in_mods_available
			if PlatformInfo.httpd_mods_available_directory && PlatformInfo.a2enmod
				filename = "#{PlatformInfo.httpd_mods_available_directory}/#{APACHE2_MODULE_CONF_NAME}.conf"
			else
				raise "Apache does not support the mods-available directory"
			end
		when :not_in_mods_available
			filename = PlatformInfo.httpd_default_config_file
		else
			raise ArgumentError
		end

		if File.exist?(filename)
			# If this is a file inside mods-available, and the file didn't have a symlink
			# in mods-enabled, then the uninstall phase did not remove duplicates from this
			# file. So here we remove duplicates again.
			puts "Removing duplicate configuration snippets inside #{filename}..."
			remove_duplicate_comment_blocks(filename,
				AUTOINSTALL_BEGIN_CONF_BLOCK,
				AUTOINSTALL_END_CONF_BLOCK)

			puts "Installing #{PROGRAM_NAME} module configuration snippet to #{filename}..."
			should_add = !update_comment_block(filename,
				AUTOINSTALL_BEGIN_CONF_BLOCK,
				AUTOINSTALL_END_CONF_BLOCK,
				config_snippet)
		else
			puts "Installing #{PROGRAM_NAME} module configuration snippet to #{filename}..."
			should_add = true
		end
		if should_add
			File.open(filename, "ab") do |f|
				f.write("\n#{AUTOINSTALL_BEGIN_CONF_BLOCK}\n" +
					"#{config_snippet}\n" +
					"#{AUTOINSTALL_END_CONF_BLOCK}\n")
			end
		end
	end

	def install_apache2_config_snippets
		if !@update_config
			show_apache2_config_snippets
			return true
		end

		config_file = PlatformInfo.httpd_default_config_file
		if config_file && File.exist?(config_file)
			puts
			line
			puts "<banner>Updating Apache configuration files...</banner>"
			config_file = PlatformInfo.httpd_default_config_file
			all_config_files = PlatformInfo.httpd_included_config_files(config_file)[:files]
			backup_config_files(config_file, all_config_files) if @backup_config
			uninstall_or_comment_out_existing_config_snippets(all_config_files)
			add_new_config_snippets(all_config_files)
			return true
		else
			show_apache2_config_snippets
			return true
		end
	end

	def show_apache2_config_snippets
		puts
		line
		render_template 'apache2/config_snippets',
			:snippet => apache2_config_snippets
		wait
	end

	def show_deployment_example
		new_screen
		render_template 'apache2/deployment_example',
			:users_guide_path => users_guide_path,
			:users_guide_url => users_guide_url,
			:phusion_website => PHUSION_WEBSITE,
			:passenger_website => PASSENGER_WEBSITE,
			:languages => @languages
	end
	
	def show_possible_solutions_for_compilation_and_installation_problems
		new_screen
		render_template 'apache2/possible_solutions_for_compilation_and_installation_problems',
			:users_guide_path => users_guide_path,
			:users_guide_url => users_guide_url,
			:support_url => SUPPORT_URL
	end

	def apache_module_available?
		return File.exist?(PhusionPassenger.apache2_module_path)
	end

	def install_apache_module_from_native_package
		case PhusionPassenger.native_packaging_method
		when 'deb'
			sh! "sudo apt-get update"
			sh! "sudo apt-get install #{DEB_APACHE_MODULE_PACKAGE}"
			return true
		when 'rpm'
			sh! "sudo yum install #{RPM_APACHE_MODULE_PACKAGE}-#{VERSION_STRING}"
			return true
		else
			puts "<red>The #{PROGRAM_NAME} Apache module package is not installed.</red>"
			puts "Please ask your operating system vendor how to install it."
			return false
		end
	end

	def notify_apache_module_installed
		render_template 'apache2/notify_apache_module_installed'
		wait
	end
end

ORIG_ARGV = ARGV.dup
options = { :compile => true, :update_config => false, :backup_config => true }
parser = OptionParser.new do |opts|
	opts.banner = "Usage: passenger-install-apache2-module [options]"
	opts.separator ""
	
	indent = ' ' * 37
	opts.separator "Options:"
	opts.on("-a", "--auto", String, "Automatically build the Apache module,\n" <<
	        "#{indent}without interactively asking for user\n" <<
	        "#{indent}input.") do
		options[:auto] = true
	end
	opts.on("--apxs2-path PATH", String, "Path to 'apxs2' command.") do |value|
		ENV['APXS2'] = value
	end
	opts.on("--apr-config-path PATH", String, "Path to 'apr-config' command.") do |value|
		ENV['APR_CONFIG'] = value
	end
	opts.on("--languages NAMES", "Comma-separated list of interested\n" <<
			"#{indent}languages (e.g.\n" <<
			"#{indent}'ruby,python,nodejs,meteor')") do |value|
		options[:languages] = value.split(",")
	end
	opts.on("--no-compile", "Skip compilation.") do
		options[:compile] = false
	end
	#opts.on("--no-update-config", "Do not automatically update Apache config\n" <<
	#		"#{indent}files.") do
	#	options[:update_config] = false
	#end
	#opts.on("--no-backup-config", "When updating Apache config files, do not\n" <<
	#		"#{indent}create backups of the existing files.") do
	#	options[:backup_config] = false
	#end
	opts.on("--snippet", "Show just the Apache config snippet.") do
		options[:snippet] = true
	end
end
begin
	parser.parse!
rescue OptionParser::ParseError => e
	puts e
	puts
	puts "Please see '--help' for valid options."
	exit 1
end

installer = Installer.new(options)
if options[:snippet]
	puts installer.send(:apache2_config_snippets)
else
	installer.run
end
