#!/usr/bin/env ruby
#  Phusion Passenger - http://www.modrails.com/
#  Copyright (C) 2008  Phusion
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; version 2 of the License.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License along
#  with this program; if not, write to the Free Software Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
PASSENGER_ROOT = File.expand_path(File.dirname(__FILE__) << "/..")
$LOAD_PATH.unshift("#{PASSENGER_ROOT}/lib")
 
# 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 'passenger/platform_info'
require 'passenger/dependencies'
require 'passenger/console_text_template'
include PlatformInfo
 
class Installer
  include Passenger
  
  PASSENGER_WEBSITE = "http://www.modrails.com/"
  PHUSION_WEBSITE = "www.phusion.nl"
  USERS_GUIDE = "#{PASSENGER_ROOT}/doc/Users guide.html"
  
  REQUIRED_DEPENDENCIES = [
    Dependencies::GCC,
    Dependencies::Ruby_DevHeaders,
    Dependencies::Ruby_OpenSSL,
    Dependencies::RubyGems,
    Dependencies::Rake,
    Dependencies::Apache2,
    Dependencies::Apache2_DevHeaders,
    Dependencies::APR_DevHeaders,
    Dependencies::FastThread
  ]
  
  def start
    Dir.chdir(PASSENGER_ROOT)
    show_welcome_screen
    check_dependencies || exit(1)
    check_whether_apache_uses_prefork_mpm
    check_write_permission_to_passenger_root || exit(1)
    if install_apache2_module
      show_apache2_config_snippets
      show_deployment_example
    else
      show_possible_solutions_for_compilation_and_installation_problems
      exit(1)
    end
  ensure
    reset_terminal_colors
  end
 
private
  def init_terminal_colors
    STDOUT.write("\e[0m\e[37m\e[40m")
    STDOUT.flush
  end
  
  def reset_terminal_colors
    STDOUT.write("\e[0m")
    STDOUT.flush
  end
  
  def show_welcome_screen
    render_template 'welcome'
    wait
  end
 
  def check_dependencies
    missing_dependencies = []
    color_puts "<banner>Checking for required software...</banner>"
    puts
    REQUIRED_DEPENDENCIES.each do |dep|
      color_print " * #{dep.name}... "
      result = dep.check
      if result.found?
        if result.found_at
          color_puts "<green>found at #{result.found_at}</green>"
        else
          color_puts "<green>found</green>"
        end
      else
        color_puts "<red>not found</red>"
        missing_dependencies << dep
      end
    end
    
    if missing_dependencies.empty?
      return true
    else
      puts
      color_puts "<red>Some required software is not installed.</red>"
      color_puts "But don't worry, this installer will tell you how to install them.\n"
      color_puts "<b>Press Enter to continue, or Ctrl-C to abort.</b>"
      wait
      
      line
      color_puts "<banner>Installation instructions for required software</banner>"
      puts
      missing_dependencies.each do |dep|
        print_dependency_installation_instructions(dep)
        puts
      end
      return false
    end
  end
  
  def check_whether_apache_uses_prefork_mpm
    line
    # '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 = `#{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"
      render_template 'apache_must_be_compiled_with_prefork_mpm',
        :current_mpm => mpm
      wait
    end
  end
  
  def check_write_permission_to_passenger_root
    File.new("__test__.txt", "w").close
    return true
  rescue
    puts
    line
    if Process.uid == 0
      render_template 'no_write_permission_to_passenger_root'
    else
      render_template 'run_installer_as_root'
    end
    return false
  ensure
    File.unlink("__test__.txt") rescue nil
  end
  
  def install_apache2_module
    puts
    line
    color_puts '<banner>Compiling and installing Apache 2 module...</banner>'
    puts "cd #{PASSENGER_ROOT}"
    puts "rake clean apache2"
    return system("rake", "clean", "apache2")
  end
  
  def show_apache2_config_snippets
    puts
    line
    render_template 'apache2_config_snippets',
      :module_location => "#{PASSENGER_ROOT}/ext/apache2/mod_passenger.so",
      :spawn_server_location => "#{PASSENGER_ROOT}/bin/passenger-spawn-server",
      :ruby => RUBY
    wait
  end
  
  def show_deployment_example
    puts
    line
    render_template 'deployment_example',
      :users_guide => USERS_GUIDE,
      :phusion_website => PHUSION_WEBSITE,
      :passenger_website => PASSENGER_WEBSITE
  end
  
  def show_possible_solutions_for_compilation_and_installation_problems
    puts
    line
    render_template 'possible_solutions_for_compilation_and_installation_problems',
      :users_guide => USERS_GUIDE,
      :passenger_website => PASSENGER_WEBSITE
  end
 
private
  def color_print(text)
    STDOUT.write(ConsoleTextTemplate.new(:text => text).result)
    STDOUT.flush
  end
  
  def color_puts(text)
    color_print("#{text}\n")
  end
  
  def render_template(name, options = {})
    puts ConsoleTextTemplate.new({ :file => name }, options).result
  end
  
  def line
    puts "--------------------------------------------"
  end
  
  def wait
    begin
      STDIN.readline
    rescue Interrupt
      exit 2
    end
  end
  
  def print_dependency_installation_instructions(dep)
    color_puts " * To install <yellow>#{dep.name}</yellow>:"
    if !dep.install_command.nil?
      color_puts "   Please run <b>#{dep.install_command}</b> as root."
    elsif !dep.install_instructions.nil?
      color_puts "   " << dep.install_instructions
    elsif !dep.website.nil?
      color_puts "   Please download it from <b>#{dep.website}</b>"
      if !dep.website_comments.nil?
        color_puts "   (#{dep.website_comments})"
      end
    else
      color_puts "   Search Google."
    end
  end
end
 
Installer.new.start