require 'passenger/platform_info'
module Passenger
 
# Represents a dependency software that Passenger requires. It's used by the
# installer to check whether all dependencies are available. A Dependency object
# contains full information about a dependency, such as its name, code for
# detecting whether it is installed, and installation instructions for the
# current platform.
class Dependency # :nodoc: all
  [:name, :install_command, :install_instructions, :install_comments,
   :website, :website_comments, :provides].each do |attr_name|
    attr_writer attr_name
    
    define_method(attr_name) do
      call_init_block
      return instance_variable_get("@#{attr_name}")
    end
  end
  
  def initialize(&block)
    @included_by = []
    @init_block = block
  end
  
  def define_checker(&block)
    @checker = block
  end
  
  def check
    call_init_block
    result = Result.new
    @checker.call(result)
    return result
  end
 
private
  class Result
    def found(filename_or_boolean = nil)
      if filename_or_boolean.nil?
        @found = true
      else
        @found = filename_or_boolean
      end
    end
    
    def not_found
      found(false)
    end
    
    def found?
      return !@found.nil? && @found
    end
    
    def found_at
      if @found.is_a?(TrueClass) || @found.is_a?(FalseClass)
        return nil
      else
        return @found
      end
    end
  end
 
  def call_init_block
    if @init_block
      init_block = @init_block
      @init_block = nil
      init_block.call(self)
    end
  end
end
 
# Namespace which contains the different dependencies that Passenger may require.
# See Dependency for more information.
module Dependencies # :nodoc: all
  include PlatformInfo
  
  GCC = Dependency.new do |dep|
    dep.name = "GNU C++ compiler"
    dep.define_checker do |result|
      gxx = PlatformInfo.find_command('g++')
      if gxx.nil?
        result.not_found
      else
        result.found(gxx)
      end
    end
    if RUBY_PLATFORM =~ /linux/
      case LINUX_DISTRO
      when :ubuntu, :debian
        dep.install_command = "apt-get install build-essential"
      when :rhel, :fedora, :centos
        dep.install_command = "yum install gcc-c++"
      when :gentoo
        dep.install_command = "emerge -av gcc"
      end
    elsif RUBY_PLATFORM =~ /darwin/
      dep.install_instructions = "Please install the Apple Development Tools: http://developer.apple.com/tools/"
    end
    dep.website = "http://gcc.gnu.org/"
  end
  
  Ruby_DevHeaders = Dependency.new do |dep|
    dep.name = "Ruby development headers"
    dep.define_checker do |result|
      require 'rbconfig'
      begin
        require 'mkmf'
        result.found(File.exist?(Config::CONFIG['archdir'] + "/ruby.h"))
      rescue LoadError
        result.not_found
      end
    end
    if RUBY_PLATFORM =~ /linux/
      case LINUX_DISTRO
      when :ubuntu, :debian
        dep.install_command = "apt-get install ruby1.8-dev"
      when :rhel, :fedora, :centos
        dep.install_command = "yum install ruby-devel"
      when :gentoo
        dep.install_command = "emerge -av ruby"
      end
    elsif RUBY_PLATFORM =~ /freebsd/
      dep.install_command = "make -C /usr/ports/lang/ruby18 install"
    end
    dep.website = "http://www.ruby-lang.org/"
    dep.install_instructions = "Please reinstall Ruby by downloading it from <bold>#{dep.website}</b>"
  end
  
  Ruby_OpenSSL = Dependency.new do |dep|
    dep.name = "OpenSSL support for Ruby"
    dep.define_checker do |result|
      begin
        require 'openssl'
        result.found
      rescue LoadError
        result.not_found
      end
    end
    if RUBY_PLATFORM =~ /linux/
      case LINUX_DISTRO
      when :ubuntu, :debian
        dep.install_command = "apt-get install libopenssl-ruby"
      end
    else
      dep.website = "http://www.ruby-lang.org/"
      dep.install_instructions = "Please (re)install Ruby with OpenSSL " <<
        "support by downloading it from <bold>#{dep.website}</bold>."
    end
  end
  
  RubyGems = Dependency.new do |dep|
    dep.name = "RubyGems"
    dep.define_checker do |result|
      begin
        require 'rubygems'
        result.found
      rescue LoadError
        result.not_found
      end
    end
    dep.website = "http://www.rubygems.org/"
    dep.install_instructions = "Please download it from <b>#{dep.website}</b>. " <<
      "Extract the tarball, and run <b>ruby setup.rb</b>"
  end
  
  Rake = Dependency.new do |dep|
    dep.name = "Rake"
    dep.define_checker do |result|
      rake = PlatformInfo.find_command("rake")
      if rake.nil?
        result.not_found
      else
        result.found(rake)
      end
    end
    dep.website = "http://rake.rubyforge.org/"
    dep.install_instructions = "Please install RubyGems first, then run <b>gem install rake</b>"
  end
  
  Apache2 = Dependency.new do |dep|
    dep.name = "Apache 2"
    dep.define_checker do |result|
      if HTTPD.nil?
        result.not_found
      else
        result.found(HTTPD)
      end
    end
    if RUBY_PLATFORM =~ /linux/
      case LINUX_DISTRO
      when :ubuntu, :debian
        dep.install_command = "apt-get install apache2-mpm-prefork"
      when :rhel, :fedora, :centos
        dep.install_command = "yum install httpd"
      when :gentoo
        dep.install_command = "emerge -av apache"
      end
    elsif RUBY_PLATFORM =~ /freebsd/
      dep.install_command = "make -C /usr/ports/www/apache22 install"
      dep.provides = [Apache2_DevHeaders, APR_Headers]
    end
    dep.website = "http://httpd.apache.org/"
  end
  
  Apache2_DevHeaders = Dependency.new do |dep|
    dep.name = "Apache 2 development headers"
    dep.define_checker do |result|
      if APXS2.nil?
        result.not_found
      else
        result.found(APXS2)
      end
    end
    if RUBY_PLATFORM =~ /linux/
      case LINUX_DISTRO
      when :ubuntu, :debian
        dep.install_command = "apt-get install apache2-prefork-dev"
        dep.provides = [Apache2]
      when :rhel, :fedora, :centos
        dep.install_command = "yum install httpd-devel"
        dep.provides = [Apache2]
      when :gentoo
        dep.install_command = "emerge -av apache"
        dep.provides = [Apache2]
      end
    elsif RUBY_PLATFORM =~ /freebsd/
      dep.install_command = "make -C /usr/ports/www/apache22 install"
    end
    dep.website = "http://httpd.apache.org/"
  end
  
  APR_DevHeaders = Dependency.new do |dep|
    dep.name = "Apache Portable Runtime (APR) development headers"
    dep.define_checker do |result|
      result.found(!APR1_FLAGS.nil?)
    end
    if RUBY_PLATFORM =~ /linux/
      case LINUX_DISTRO
      when :ubuntu, :debian
        dep.install_command = "apt-get install libapr1-dev"
      when :rhel, :fedora, :centos
        dep.install_command = "yum install apr-devel"
      when :gentoo
        dep.install_command = "emerge -av apr"
      end
    end
    dep.website = "http://httpd.apache.org/"
    dep.website_comments = "APR is an integrated part of Apache."
  end
  
  FastThread = Dependency.new do |dep|
    dep.name = "fastthread"
    dep.define_checker do |result|
      begin
        begin
          require 'rubygems'
        rescue LoadError
        end
        require 'fastthread'
        result.found
      rescue LoadError
        result.not_found
      end
    end
    dep.install_instructions = "Please install RubyGems first, then run <b>gem install fastthread</b>"
  end
end
 
end # module Passenger