class Bundler::Installer

def self.install(root, definition, options = {})
  installer = new(root, definition)
  installer.run(options)
  installer
end

def generate_bundler_executable_stubs(spec)
  bin_path = Bundler.bin_path
  template = File.read(File.expand_path('../templates/Executable', __FILE__))
  relative_gemfile_path = Bundler.default_gemfile.relative_path_from(bin_path)
  ruby_command = Thor::Util.ruby_command
  spec.executables.each do |executable|
    next if executable == "bundle"
    File.open "#{bin_path}/#{executable}", 'w', 0755 do |f|
      f.puts ERB.new(template, nil, '-').result(binding)
    end
  end
end

def generate_standalone(groups)
  standalone_path = Bundler.settings[:path]
  bundler_path = File.join(standalone_path, "bundler")
  FileUtils.mkdir_p(bundler_path)
  paths = []
  if groups.empty?
    specs = Bundler.definition.requested_specs
  else
    specs = Bundler.definition.specs_for groups.map { |g| g.to_sym }
  end
  specs.each do |spec|
    next if spec.name == "bundler"
    spec.require_paths.each do |path|
      full_path = File.join(spec.full_gem_path, path)
      paths << Pathname.new(full_path).relative_path_from(Bundler.root.join(bundler_path))
    end
  end
  File.open File.join(bundler_path, "setup.rb"), "w" do |file|
    file.puts "path = File.expand_path('..', __FILE__)"
    paths.each do |path|
      file.puts %{$:.unshift File.expand_path("\#{path}/#{path}")}
    end
  end
end

def generate_standalone_bundler_executable_stubs(spec)
  bin_path = Bundler.bin_path
  template = File.read(File.expand_path('../templates/Executable.standalone', __FILE__))
  ruby_command = Thor::Util.ruby_command
  spec.executables.each do |executable|
    next if executable == "bundle"
    standalone_path = Pathname(Bundler.settings[:path]).expand_path.relative_path_from(bin_path)
    executable_path = Pathname(spec.full_gem_path).join(spec.bindir, executable).relative_path_from(bin_path)
    File.open "#{bin_path}/#{executable}", 'w', 0755 do |f|
      f.puts ERB.new(template, nil, '-').result(binding)
    end
  end
end

def install_gem_from_spec(spec, standalone = false)
  # Download the gem to get the spec, because some specs that are returned
  # by rubygems.org are broken and wrong.
  Bundler::Fetcher.fetch(spec) if spec.source.is_a?(Bundler::Source::Rubygems)
  # Fetch the build settings, if there are any
  settings = Bundler.settings["build.#{spec.name}"]
  Bundler.rubygems.with_build_args [settings] do
    spec.source.install(spec)
    Bundler.ui.debug "from #{spec.loaded_from} "
  end
  # newline comes after installing, some gems say "with native extensions"
  Bundler.ui.info ""
  if Bundler.settings[:bin]
    standalone ? generate_standalone_bundler_executable_stubs(spec) : generate_bundler_executable_stubs(spec)
  end
  FileUtils.rm_rf(Bundler.tmp)
rescue Exception => e
  # install hook failed
  raise e if e.is_a?(Bundler::InstallHookError)
  # other failure, likely a native extension build failure
  Bundler.ui.info ""
  Bundler.ui.warn "#{e.class}: #{e.message}"
  msg = "An error occurred while installing #{spec.name} (#{spec.version}),"
  msg << " and Bundler cannot continue.\nMake sure that `gem install"
  msg << " #{spec.name} -v '#{spec.version}'` succeeds before bundling."
  Bundler.ui.debug e.backtrace.join("\n")
  raise Bundler::InstallError, msg
end

def run(options)
  # Create the BUNDLE_PATH directory
  begin
    Bundler.bundle_path.mkpath unless Bundler.bundle_path.exist?
  rescue Errno::EEXIST
    raise PathError, "Could not install to path `#{Bundler.settings[:path]}` " +
      "because of an invalid symlink. Remove the symlink so the directory can be created."
  end
  if Bundler.settings[:frozen]
    @definition.ensure_equivalent_gemfile_and_lockfile(options[:deployment])
  end
  if dependencies.empty?
    Bundler.ui.warn "The Gemfile specifies no dependencies"
    lock
    return
  end
  if Bundler.default_lockfile.exist? && !options["update"]
    begin
      tmpdef = Definition.build(Bundler.default_gemfile, Bundler.default_lockfile, nil)
      local = true unless tmpdef.new_platform? || tmpdef.missing_specs.any?
    rescue BundlerError
    end
  end
  # Since we are installing, we can resolve the definition
  # using remote specs
  unless local
    options["local"] ?
      @definition.resolve_with_cache! :
      @definition.resolve_remotely!
  end
  # Must install gems in the order that the resolver provides
  # as dependencies might actually affect the installation of
  # the gem.
  Installer.post_install_messages = {}
  specs.each do |spec|
    install_gem_from_spec(spec, options[:standalone])
  end
  lock
  generate_standalone(options[:standalone]) if options[:standalone]
end