class Gem::Installer

# File rubygems/installer.rb, line 109
def self.at(path, options = {})
  security_policy = options[:security_policy]
  package = Gem::Package.new path, security_policy
  new package, options
end

# File rubygems/installer.rb, line 100
def exec_format
  @exec_format ||= Gem.default_exec_format
end

# File rubygems/installer.rb, line 149
def self.for_spec(spec, options = {})
  # FIXME: we should have a real Package class for this
  new FakePackage.new(spec), options
end

# File rubygems/installer.rb, line 179
def initialize(package, options={})
  require 'fileutils'

  @options = options
  if package.is_a? String
    security_policy = options[:security_policy]
    @package = Gem::Package.new package, security_policy
    if $VERBOSE
      warn "constructing an Installer object with a string is deprecated. Please use Gem::Installer.at (called from: #{caller.first})"
    end
  else
    @package = package
  end

  process_options

  @package.dir_mode = options[:dir_mode]
  @package.prog_mode = options[:prog_mode]
  @package.data_mode = options[:data_mode]

  if options[:user_install]
    @gem_home = Gem.user_dir
    @bin_dir = Gem.bindir gem_home unless options[:bin_dir]
    check_that_user_bin_dir_is_in_path
  end
end

# File rubygems/installer.rb, line 767
  def app_script_text(bin_file_name)
    # note that the `load` lines cannot be indented, as old RG versions match
    # against the beginning of the line
    return <<-TEXT
#{shebang bin_file_name}
#
# This file was generated by RubyGems.
#
# The application '#{spec.name}' is installed as part of a gem, and
# this file is here to facilitate running it.
#

require 'rubygems'

version = "#{Gem::Requirement.default_prerelease}"

str = ARGV.first
if str
  str = str.b[/\\A_(.*)_\\z/, 1]
  if str and Gem::Version.correct?(str)
    version = str
    ARGV.shift
  end
end

if Gem.respond_to?(:activate_bin_path)
load Gem.activate_bin_path('#{spec.name}', '#{bin_file_name}', version)
else
gem #{spec.name.dump}, version
load Gem.bin_path(#{spec.name.dump}, #{bin_file_name.dump}, version)
end
TEXT
  end

# File rubygems/installer.rb, line 841
def build_extensions
  builder = Gem::Ext::Builder.new spec, @build_args

  builder.build_extensions
end

# File rubygems/installer.rb, line 448
def default_spec_file
  File.join Gem.default_specifications_dir, "#{spec.full_name}.gemspec"
end

# File rubygems/installer.rb, line 894
def dir
  gem_dir.to_s
end

# File rubygems/installer.rb, line 410
def ensure_dependency(spec, dependency)
  unless installation_satisfies_dependency? dependency
    raise Gem::InstallError, "#{spec.name} requires #{dependency}"
  end
  true
end

# File rubygems/installer.rb, line 632
def ensure_loadable_spec
  ruby = spec.to_ruby_for_cache
  ruby.tap(&Gem::UNTAINT)

  begin
    eval ruby
  rescue StandardError, SyntaxError => e
    raise Gem::InstallError,
          "The specification for #{spec.full_name} is corrupt (#{e.class})"
  end
end

# File rubygems/installer.rb, line 873
def extract_bin
  @package.extract_files gem_dir, "#{spec.bindir}/*"
end

# File rubygems/installer.rb, line 864
def extract_files
  @package.extract_files gem_dir
end

# File rubygems/installer.rb, line 880
def formatted_program_filename(filename)
  if @format_executable
    self.class.exec_format % File.basename(filename)
  else
    filename
  end
end

# File rubygems/installer.rb, line 276
def gem_dir
  @gem_dir ||= File.join(gem_home, "gems", spec.full_name)
end

# File rubygems/installer.rb, line 534
def generate_bin_script(filename, bindir)
  bin_script_path = File.join bindir, formatted_program_filename(filename)

  FileUtils.rm_f bin_script_path # prior install may have been --no-wrappers

  File.open bin_script_path, 'wb', 0755 do |file|
    file.print app_script_text(filename)
    file.chmod(options[:prog_mode] || 0755)
  end

  verbose bin_script_path

  generate_windows_script filename, bindir
end

# File rubygems/installer.rb, line 553
def generate_bin_symlink(filename, bindir)
  src = File.join gem_dir, spec.bindir, filename
  dst = File.join bindir, formatted_program_filename(filename)

  if File.exist? dst
    if File.symlink? dst
      link = File.readlink(dst).split File::SEPARATOR
      cur_version = Gem::Version.create(link[-3].sub(/^.*-/, ''))
      return if spec.version < cur_version
    end
    File.unlink dst
  end

  FileUtils.symlink src, dst, :verbose => Gem.configuration.really_verbose
rescue NotImplementedError, SystemCallError
  alert_warning "Unable to use symlinks, installing wrapper"
  generate_bin_script filename, bindir
end

# File rubygems/installer.rb, line 479
def generate_windows_script(filename, bindir)
  if Gem.win_platform?
    script_name = formatted_program_filename(filename) + ".bat"
    script_path = File.join bindir, File.basename(script_name)
    File.open script_path, 'w' do |file|
      file.puts windows_stub_script(bindir, filename)
    end

    verbose script_path
  end
end

# File rubygems/installer.rb, line 300
def install
  pre_install_checks

  FileUtils.rm_f File.join gem_home, 'specifications', spec.spec_name

  run_pre_install_hooks

  # Set loaded_from to ensure extension_dir is correct
  if @options[:install_as_default]
    spec.loaded_from = default_spec_file
  else
    spec.loaded_from = spec_file
  end

  # Completely remove any previous gem files
  FileUtils.rm_rf gem_dir
  FileUtils.rm_rf spec.extension_dir

  dir_mode = options[:dir_mode]
  FileUtils.mkdir_p gem_dir, :mode => dir_mode && 0755

  if @options[:install_as_default]
    extract_bin
    write_default_spec
  else
    extract_files

    build_extensions
    write_build_info_file
    run_post_build_hooks
  end

  generate_bin

  unless @options[:install_as_default]
    write_spec
    write_cache_file
  end

  File.chmod(dir_mode, gem_dir) if dir_mode

  say spec.post_install_message if options[:post_install_message] && !spec.post_install_message.nil?

  Gem::Installer.install_lock.synchronize { Gem::Specification.reset }

  run_post_install_hooks

  spec

# TODO This rescue is in the wrong place. What is raising this exception?
# move this rescue to around the code that actually might raise it.
rescue Zlib::GzipFile::Error
  raise Gem::InstallError, "gzip error installing #{gem}"
end

# File rubygems/installer.rb, line 420
def installation_satisfies_dependency?(dependency)
  return true if @options[:development] and dependency.type == :development
  return true if installed_specs.detect { |s| dependency.matches_spec? s }
  return false if @only_install_dir
  not dependency.matching_specs.empty?
end

# File rubygems/installer.rb, line 390
def installed_specs
  @specs ||= begin
    specs = []

    Gem::Util.glob_files_in_dir("*.gemspec", File.join(gem_home, "specifications")).each do |path|
      spec = Gem::Specification.load path.tap(&Gem::UNTAINT)
      specs << spec if spec
    end

    specs
  end
end

# File rubygems/installer.rb, line 907
def pre_install_checks
  verify_gem_home

  # The name and require_paths must be verified first, since it could contain
  # ruby code that would be eval'ed in #ensure_loadable_spec
  verify_spec

  ensure_loadable_spec

  if options[:install_as_default]
    Gem.ensure_default_gem_subdirectories gem_home
  else
    Gem.ensure_gem_subdirectories gem_home
  end

  return true if @force

  ensure_required_ruby_version_met
  ensure_required_rubygems_version_met
  ensure_dependencies_met unless @ignore_dependencies

  true
end

# File rubygems/installer.rb, line 587
def shebang(bin_file_name)
  ruby_name = RbConfig::CONFIG['ruby_install_name'] if @env_shebang
  path = File.join gem_dir, spec.bindir, bin_file_name
  first_line = File.open(path, "rb") {|file| file.gets}

  if /\A#!/ =~ first_line
    # Preserve extra words on shebang line, like "-w".  Thanks RPA.
    shebang = first_line.sub(/\A\#!.*?ruby\S*((\s+\S+)+)/, "#!#{Gem.ruby}")
    opts = $1
    shebang.strip! # Avoid nasty ^M issues.
  end

  if which = Gem.configuration[:custom_shebang]
    # replace bin_file_name with "ruby" to avoid endless loops
    which = which.gsub(/ #{bin_file_name}$/," #{RbConfig::CONFIG['ruby_install_name']}")

    which = which.gsub(/\$(\w+)/) do
      case $1
      when "env"
        @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
      when "ruby"
        "#{Gem.ruby}#{opts}"
      when "exec"
        bin_file_name
      when "name"
        spec.name
      end
    end

    "#!#{which}"
  elsif not ruby_name
    "#!#{Gem.ruby}#{opts}"
  elsif opts
    "#!/bin/sh\n'exec' #{ruby_name.dump} '-x' \"$0\" \"$@\"\n#{shebang}"
  else
    # Create a plain shebang line.
    @env_path ||= ENV_PATHS.find {|env_path| File.executable? env_path }
    "#!#{@env_path} #{ruby_name}"
  end
end

# File rubygems/installer.rb, line 283
def spec
  @package.spec
rescue Gem::Package::Error => e
  raise Gem::InstallError, "invalid gem: #{e.message}"
end

# File rubygems/installer.rb, line 440
def spec_file
  File.join gem_home, "specifications", "#{spec.full_name}.gemspec"
end

# File rubygems/installer.rb, line 430
def unpack(directory)
  @gem_dir = directory
  extract_files
end

# File rubygems/installer.rb, line 738
def verify_spec
  unless spec.name =~ Gem::Specification::VALID_NAME_PATTERN
    raise Gem::InstallError, "#{spec} has an invalid name"
  end

  if spec.raw_require_paths.any?{|path| path =~ /\R/ }
    raise Gem::InstallError, "#{spec} has an invalid require_paths"
  end

  if spec.extensions.any?{|ext| ext =~ /\R/ }
    raise Gem::InstallError, "#{spec} has an invalid extensions"
  end

  unless spec.specification_version.to_s =~ /\A\d+\z/
    raise Gem::InstallError, "#{spec} has an invalid specification_version"
  end

  if spec.dependencies.any? {|dep| dep.type != :runtime && dep.type != :development }
    raise Gem::InstallError, "#{spec} has an invalid dependencies"
  end

  if spec.dependencies.any? {|dep| dep.name =~ /(?:\R|[<>])/ }
    raise Gem::InstallError, "#{spec} has an invalid dependencies"
  end
end

# File rubygems/installer.rb, line 804
  def windows_stub_script(bindir, bin_file_name)
    rb_config = RbConfig::CONFIG
    rb_topdir = RbConfig::TOPDIR || File.dirname(rb_config["bindir"])

    # get ruby executable file name from RbConfig
    ruby_exe = "#{rb_config['RUBY_INSTALL_NAME']}#{rb_config['EXEEXT']}"
    ruby_exe = "ruby.exe" if ruby_exe.empty?

    if File.exist?(File.join bindir, ruby_exe)
      # stub & ruby.exe withing same folder.  Portable
      <<-TEXT
@ECHO OFF
@"%~dp0#{ruby_exe}" "%~dpn0" %*
      TEXT
    elsif bindir.downcase.start_with? rb_topdir.downcase
      # stub within ruby folder, but not standard bin.  Portable
      require 'pathname'
      from = Pathname.new bindir
      to   = Pathname.new "#{rb_topdir}/bin"
      rel  = to.relative_path_from from
      <<-TEXT
@ECHO OFF
@"%~dp0#{rel}/#{ruby_exe}" "%~dpn0" %*
      TEXT
    else
      # outside ruby folder, maybe -user-install or bundler.  Portable, but ruby
      # is dependent on PATH
      <<-TEXT
@ECHO OFF
@#{ruby_exe} "%~dpn0" %*
      TEXT
    end
  end

# File rubygems/installer.rb, line 935
def write_build_info_file
  return if @build_args.empty?

  build_info_dir = File.join gem_home, 'build_info'

  dir_mode = options[:dir_mode]
  FileUtils.mkdir_p build_info_dir, :mode => dir_mode && 0755

  build_info_file = File.join build_info_dir, "#{spec.full_name}.info"

  File.open build_info_file, 'w' do |io|
    @build_args.each do |arg|
      io.puts arg
    end
  end

  File.chmod(dir_mode, build_info_dir) if dir_mode
end

# File rubygems/installer.rb, line 957
def write_cache_file
  cache_file = File.join gem_home, 'cache', spec.file_name
  @package.copy_to cache_file
end

# File rubygems/installer.rb, line 470
def write_default_spec
  File.open(default_spec_file, "w") do |file|
    file.puts spec.to_ruby
  end
end

# File rubygems/installer.rb, line 456
def write_spec
  File.open spec_file, 'w' do |file|
    spec.installed_by_version = Gem.rubygems_version

    file.puts spec.to_ruby_for_cache

    file.fsync rescue nil # for filesystems without fsync(2)
  end
end