#!/usr/bin/env ruby
# Small gem to sync multiple gem installations.
# (c) 2010 Josh Ellithorpe

require 'rubygems'
require 'trollop'

# Setup arguments from the command line.
# This uses the trollop library on github.
opts = Trollop::options do
  version "gemsync 0.1.5 (c) 2010 Josh Ellithorpe"
  banner <<-EOS
Small gem to sync multiple gem installations.

Usage: gemsync [options]

Available Options:
EOS
  opt :source, "Either the ruby installation directory, or a list of gems produced from 'gem list'. Ex: /usr or /path/to/gemlist.txt", :type => String, :required => true
  opt :destination, "Ruby installation directory you want to sync up. Ex: /opt/ruby-enterprise", :type => String, :required => false
  opt :disable_sudo, "Disable sudo when installing gems", :default => false
  opt :build_docs, "Build documentation", :default => false
end

# Check if the file or directory exists, if not exit
Trollop::die :source, "\n\t-- Directory or file '#{opts[:source]}' does not exist" unless File.exists?(opts[:source])  

# Check if source is a file or directory.
if File.ftype(opts[:source]) == 'file'
  @source_type = 'file'
else
  @source_type = 'directory'
  Trollop::die :source, "\n\t-- Binary '#{opts[:source]}/bin/gem' does not exist" unless File.exists?("#{opts[:source]}/bin/gem")
end

# Attempt to set default destination based upon location of 'gem' binary
if opts[:destination].nil?
  guessed_destination_path = `which gem`.split('/')[0..-3].join('/')
  Trollop::die :destination, "\n\t-- Destination was not set, and gemsync could not guess it" if (guessed_destination_path == opts[:source] || !File.directory?(guessed_destination_path))
else
  # Die if destination is set incorrectly
  Trollop::die :destination, "\n\t-- Directory '#{opts[:destination]}' does not exist" unless File.directory?(opts[:destination])
  Trollop::die :destination, "\n\t-- Binary '#{opts[:destination]}/bin/gem' does not exist" unless File.exists?("#{opts[:destination]}/bin/gem")
end

# Cleanup main and sync dir, they shouldn't end in a '/' so lets chomp it.
# Couldn't use chomp! since opts are frozen.
@main_dir = opts[:source].chomp('/')
@sync_dir = opts[:destination].nil? ? guessed_destination_path.chomp('/') : opts[:destination].chomp('/')

# Setup additional flags
@docstring = opts[:build_docs] ? '' : '--no-ri --no-rdoc'
@sudostring = opts[:disable_sudo] ? '' : (`which sudo`.strip + ' ') # Just stripping newline

# Gems you don't want to sync
def get_exceptions
  # Setup hash of common gems that certain ruby installs can't support
  # For now this is just rubynode for REE and JRuby, feel free to add more
  # hpricot is not in the jruby list because 0.6.x is supported.
  common_exceptions = {
    :ree => ["rubynode"], 
    :jruby => ["acts_as_ferret", "bleak_house", "bluecloth", "dnssd", "fastthread", "fcgi", "ferret", "fraction", "jk-ferret", "json", "libxml-ruby", "linecache","mysql", "mysql2", "mysqlplus", "passenger", "pauldix-feedzirra", "pcaprub", "rb-appscript", "rmagick", "ruby-debug-base", "ruby-prof", "rubynode", "sqlite3-ruby", "system_timer", "taf2-curb", "termios", "timetrap", "unicorn", "wikitext", "yajl-ruby"]
  }
  mandated_version = {:ruby187 => ["bleak_house"]}
  returned_exceptions = ['']
  sync_version = `#{@sync_dir}/bin/gem --version`
  if @sync_dir.match('enterprise')
    returned_exceptions += common_exceptions[:ree]
  elsif @sync_dir.match('jruby')
    returned_exceptions += common_exceptions[:jruby]
  end
  if sync_version != '1.8.7'
    returned_exceptions += mandated_version[:ruby187]
  end
  return returned_exceptions
end

# Get file as string
def get_file_as_string(filename)
  data = ''
  f = File.open(filename, "r") 
  f.each_line do |line|
    data += line
  end
  return data
end

# Get gem list from source
if @source_type == 'directory'
  gem_list = %x[#{@main_dir}/bin/gem list].split("\n")
else
  gem_list = get_file_as_string(opts[:source]).split("\n")
end

# Get gem list from destination
sync_gem_list = %x[#{@sync_dir}/bin/gem list].split("\n")

# Cleanup gems we know we don't need to update
gems = gem_list - sync_gem_list

# Loop through gems and update them.
for gem in gems
  # Trap regexps in try block incase matches don't work out.
  begin
    gem_name = gem.match(/(.*) \((.*)\)/)[1]
    gem_versions = gem.match(/(.*) \((.*)\)/)[2]
  rescue
    gem_name = nil
    gem_versions = nil
  end
  next if gem_name.nil? || gem_versions.nil?
  
  # If valid gem start checking/updating it.
  puts "## Checking #{gem_name}"
  if get_exceptions().include?(gem_name)
    puts "This gem is known to be incompatible with the sync'd ruby installation"
    next
  end
  current_gem_info = %x[#{@sync_dir}/bin/gem list #{gem_name}]
  current_gem_info_items = current_gem_info.split("\n")
  for curgem in current_gem_info_items
    curgem_name = curgem.match(/(.*) \((.*)\)/)[1]
    if gem_name == curgem_name
      current_gem_details = curgem
    end
  end
  if current_gem_details.nil? || current_gem_details == "\n" || current_gem_details == ""
    current_gem_versions = []
  else
    current_gem_versions = current_gem_details.match(/(.*) \((.*)\)/)[2].split(", ")
  end
  for version in (gem_versions.split(", ") - current_gem_versions)
    if gem_name == "mysql"
      # Also look for mysql5 type binaries that some package managers use
      mysql_config = `which mysql_config` || `which mysql_config5`
      mysql_dir = `which mysql` || `which mysql5`
      mysql_dir = mysql_dir.split('/')[0..-3].join('/')
      system("#{@sudostring}#{@sync_dir}/bin/gem install #{gem_name} -v #{version} -- --with-mysql-dir=#{mysql_dir} --with-mysql-config=#{mysql_config} #{@docstring}")
    else
      system("#{@sudostring}#{@sync_dir}/bin/gem install #{gem_name} -v #{version} #{@docstring}")
    end
  end
end