build-spoons

#!/usr/bin/env ruby

require 'yaml'
require 'digest/sha2'
require 'open-uri'
require 'fileutils'
require 'pathname'
require 'benchmark'

FILE_MANIFEST_PATH = 'files.yml'
PLATFORM_LAYOUT_PATH = 'layout.yml'
CACHE_PATH = 'cache'
USB_MASTER_PATH = 'usb-image'
DEFAULT_USB_PATH = '/Volumes/RBB*'
MAC_CRUFT = %w[.Spotlight-V100 .Trashes .fseventsd]

class SpoonBuilder
  def initialize(paths)
    @file_manifest = YAML.load_file(FILE_MANIFEST_PATH)
    @platform_layout = YAML.load_file(PLATFORM_LAYOUT_PATH)
    @usb_paths = paths.empty? ? Dir.glob(DEFAULT_USB_PATH) : paths
  end

  def run
    cleanup_cache
    download_files
    build_usb_master
    sync_usb_drives
  end

  def cleanup_cache
    puts "Looking for old files to remove"
    Dir.glob("#{CACHE_PATH}/*").each do |path|
      file = File.basename(path)
      unless @file_manifest.keys.include?(file)
        print "I don't see #{file} in files.yml; it's probably from an older workshop. Delete it? "
        answer = STDIN.gets.strip
        FileUtils.rm(path) if answer.downcase.start_with?('y')
      end
    end
  end

  def download_files
    puts "Checking and updating files in cache"
    @file_manifest.each do |file, info|
      file_cache_path = "#{CACHE_PATH}/#{file}"
      if checksum_matches?(file_cache_path, info['checksum'])
        puts "- up to date: #{file_cache_path}"
      else
        puts "- need to download (this may take a minute, it's working...): #{file_cache_path}"
        IO.copy_stream(open(info['url']), file_cache_path)
      end
    end
  end

  def checksum_matches?(path, checksum)
    File.exist?(path) && Digest::SHA256.hexdigest(File.read(path)) == checksum
  end

  def build_usb_master
    return if ENV['CONCURRENT_SPOONS'] && File.exist?(USB_MASTER_PATH)
    puts "Deleting and recreating #{USB_MASTER_PATH} directory"
    FileUtils.rm_rf USB_MASTER_PATH
    FileUtils.mkdir_p USB_MASTER_PATH
    MAC_CRUFT.each {|c| FileUtils.touch "#{USB_MASTER_PATH}/#{c}" }
    @platform_layout.each do |p_name, p_dir|
      puts "Linking files for #{p_name}"
      p_path = "#{USB_MASTER_PATH}/#{p_dir}"
      FileUtils.mkdir_p(p_path)
      @file_manifest.each do |file, info|
        if info['platforms'].include?(p_name)
          relative_symlink("#{CACHE_PATH}/#{file}", "#{p_path}/#{file}")
        end
      end
    end
  end

  def relative_symlink(target, symlink)
    unless File.exist?(symlink)
      relative_target = Pathname.new(target).relative_path_from(Pathname.new(File.dirname(symlink)))
      puts "- creating link: #{symlink} -> #{relative_target}"
      FileUtils.ln_s(relative_target, symlink)
    end
  end

  def sync_usb_drives
    if @usb_paths.empty?
      puts "Can't find any usb drives at #{DEFAULT_USB_PATH} -- are they plugged in?"
      puts "If they are somewhere else on your computer (i.e. Linux), please specify them by path."
    else
      log_time 'synchronizing all RailsBridge USB drives' do
        @usb_paths.each do |usb_path|
          puts "-" * 80
          puts "Synchronizing #{usb_path}"
          puts "-" * 80
          log_time usb_path do
            system 'rsync', '-rtPh', '--del', '--modify-window=5', '--copy-links', "#{USB_MASTER_PATH}/", "#{usb_path}/"
          end
        end
      end
    end
  end

  def log_time(message)
    elapsed = Benchmark.measure { yield }.real.round
    minutes = elapsed / 60
    seconds = elapsed % 60
    end_message = "Finished #{message} in #{minutes} minutes #{seconds} seconds"
    puts "#{end_message}!"
    if system 'command -v say >/dev/null 2>&1'
      system 'say', end_message
    end
  end

end

SpoonBuilder.new(ARGV).run