ui_gem_cleanup

#!/usr/bin/env ruby
#
# Parses your Gemfile.lock to determine the current versions of the UI based
# gems, and then deletes the rest.
#
#
# A large portion of the disk usage code is pulled from Homebrew.
#
# License for Homebrew below:
#
# BSD 2-Clause License
#
# Copyright (c) 2009-present, Homebrew contributors
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

require 'optparse'

options = {
  :dry_run => false,
  :full    => false,
  :silent  => false
}

OptionParser.new do |opt|
  opt.banner = "Usage: #{File.basename $0} [options]"

  opt.separator ""
  opt.separator "Parses your Gemfile.lock to determine the current versions of"
  opt.separator "the UI based gems, and then deletes the rest."
  opt.separator ""
  opt.separator "By default, this will only delete the generated assets, but"
  opt.separator "running with `-f` will delete the entire gem dir."
  opt.separator ""
  opt.separator "Options"

  opt.on("-D", "--dry-run", "Skip delete operations") do
    options[:dry_run] = true
  end

  opt.on("-f", "--full",    "Delete whole gem dir") do
    options[:full]    = true
  end

  opt.on("-s", "--silent",  "Disable Disk Usage checking/printing") do
    options[:silent]  = true
  end

  opt.on("-h", "--help",   "Show this message") { puts opt; exit }
end.parse!


require 'bundler/setup'
require 'fileutils'

# The 7 or so lines here is a bit dense, so I will explain:
#
#   1. We collect all of the git gems from bundler
#     - Make sure they are prefixed with 'manageiq-*'
#     - Make sure they include a `app/javascript` dir
#   2. Convert the directory paths to an array of gem names sans git-SHA
#     - get the base name of dir
#     - Split on '-', select all but last element, re-join string
#   3. Build a regexp from those gem names
#   4. Scan the Bundler gem dir for similar gems, trim down via above Regexp
#   5. Removes the existing gems in the bundle from the list (stale_git_gems)

spec_git_paths = Bundler.definition.spec_git_paths
                        .select {|dir| File.basename(dir) =~ /^manageiq-/ }
                        .select {|dir| Dir.exist? File.join(dir, "app", "javascript") }
base_gem_names = spec_git_paths.map {|dir| File.basename(dir).split("-")[0..-2].join("-") }
gem_regexp     = Regexp.new "(#{base_gem_names.join('|')})"
git_gems       = Dir["#{Gem.dir}/bundler/gems/*"].grep(gem_regexp)
stale_ui_gems  = (git_gems - spec_git_paths)
total_savings  = 0


warn "DRY RUN:  NO OPERATIONS BEING EXECUTED!!" if options[:dry_run]

stale_ui_gems.each do |stale_miq_ui_gem_dir|
	delete_paths = if options[:full]
                   [stale_miq_ui_gem_dir]
                 else
                   [
                     File.join(stale_miq_ui_gem_dir, "node_modules"),
                     File.join(stale_miq_ui_gem_dir, "vendor", "assets", "bower")
                   ]
                 end
    
  delete_paths.each do |file_path_to_delete|
		path = Pathname.new(file_path_to_delete)
		next unless path.exist?

    unless options[:silent]
      # The code for setting `disk_usage` is basically all from Homebrew
      disk_usage = begin
                     disk_size_path = if path.symlink?
                                        path.dirname.join(path.readlink)
                                      else
                                        path
                                      end

                     if disk_size_path.directory?
                       scanned_files = Set.new
                       disk_usage = 0
                       path.find do |f|
                         if f.directory?
                           disk_usage += f.lstat.size
                         else
                           # use Pathname#lstat instead of Pathname#stat to get info of symlink itself.
                           stat    = f.lstat
                           file_id = [stat.dev, stat.ino]
                           # count hardlinks only once.
                           unless scanned_files.include?(file_id)
                             disk_usage += stat.size
                             scanned_files.add(file_id)
                           end
                         end
                       end
                     else
                       disk_usage = path.lstat.size
                     end

                     total_savings += disk_usage
                     disk_usage.to_f / 1_048_576
                   end
    end

		puts "Removing #{path}... #{'(%.1fMB)' % disk_usage unless options[:silent]}"
		FileUtils.rm_rf path, :secure => true, :noop => options[:dry_run]
	end
end


unless options[:silent]
  total = if total_savings >= 1_073_741_824
            "#{'%.1f' % (total_savings.to_f / 1_073_741_824)}GB"
          else
            "#{'%.1f' % (total_savings.to_f / 1_048_576)}MB"
          end

  puts "\nTotal Savings: #{total}"
end