class PhusionPassenger::PlatformInfo::Depcheck::Dependency

def apt_get_install(package_name)
	install_instructions("Please install it with <b>apt-get install #{package_name}</b>")
end

def check
	@install_comments = nil
	@check_result ||= @checker.call
end

def check_for_command(name, *args)
	result = find_command(name, *args)
	if result
		{ :found => true,
		  "Location" => result }
	else
		false
	end
end

def check_for_header(header_name, language = :c, flags = nil)
	if result = PlatformInfo.find_header(header_name, language, flags)
		{ :found => true,
		  "Location" => result }
	else
		false
	end
end

def check_for_ruby_library(name)
	begin
		require(name)
		{ :found => true }
	rescue LoadError
		if defined?(Gem)
			false
		else
			begin
				require 'rubygems'
				require(name)
				{ :found => true }
			rescue LoadError
				false
			end
		end
	end
end

def check_for_ruby_tool(name)
	result = locate_ruby_tool(name)
	if result
		{ :found => true,
		  "Location" => result }
	else
		false
	end
end

def check_syntax_aspect(description)
	if !yield
		raise description
	end
end

def define_checker(&block)
	@checker = block
end

def emerge(package_name)
	install_instructions("Please install it with <b>emerge -av #{package_name}</b>")
end

def find_command(command, *args)
	PlatformInfo.find_command(command, *args)
end

def gem_command
	PlatformInfo.gem_command(:sudo => true) || 'gem'
end

def gem_install(package_name)
	install_instructions("Please make sure RubyGems is installed, then run " +
		"<b>#{gem_command} install #{package_name}</b>")
end

def initialize(&block)
	instance_eval(&block)
	check_syntax_aspect("Name must be given") { !!@name }
	check_syntax_aspect("A checker must be given") { !!@checker }
end

def install_comments(value = nil)
	value ? @install_comments = value : @install_comments
end

def install_instructions(value = nil)
	if value
		@install_instructions = value
	else
		if @install_instructions
			@install_instructions
		elsif @website
			result = "Please download it from <b>#{@website}</b>"
			result << "\n(#{@website_comments})" if @website_comments
			result
		else
			"Search Google for '#{@name}'."
		end
	end
end

def install_osx_command_line_tools
	require 'phusion_passenger/platform_info/compiler'
	if PlatformInfo.xcode_select_version.to_s >= "2333"
		install_instructions "Please install the Xcode command line tools: " +
			"<b>sudo xcode-select --install</b>"
	else
		install_instructions "Please install Xcode, then install the command line tools " +
			"though the menu <b>Xcode -> Preferences -> Downloads -> Components</b>"
	end
end

def linux_distro_tags
	PlatformInfo.linux_distro_tags
end

def locate_ruby_tool(name)
	PlatformInfo.locate_ruby_tool(name)
end

def name(value = nil)
	value ? @name = value : @name
end

def on(platform)
	return if @on_invoked
	invoke = false
	if (linux_distro_tags || []).include?(platform)
		invoke = true
	else
		case platform
		when :linux
			invoke = true if PlatformInfo.os_name =~ /linux/
		when :freebsd
			invoke = true if PlatformInfo.os_name =~ /freebsd/
		when :macosx
			invoke = true if PlatformInfo.os_name == "macosx"
		when :solaris
			invoke = true if PlatformInfo.os_name =~ /solaris/
		when :other_platforms
			invoke = true
		end
	end
	if invoke
		yield
		@on_invoked = true
	end
end

def ruby_command
	PlatformInfo.ruby_command
end

def urpmi(package_name)
	install_instructions("Please install it with <b>urpmi #{package_name}</b>")
end

def website(value = nil)
	value ? @website = value : @website
end

def website_comments(value = nil)
	value ? @website_comments = value : @website_comments
end

def yum_install(package_name, options = {})
	if options[:epel]
		install_instructions("Please enable <b>EPEL</b>, then install with <b>yum install #{package_name}</b>")
	else
		install_instructions("Please install it with <b>yum install #{package_name}</b>")
	end
end