module MakeGem

# File lib/make_gem.rb, line 10
def self.make_gem(args)
  puts "make gem utility version: #{::MakeGem::VERSION}"

  # Check parameter and extract data.
  if args.empty? || args[0] == "--help"
    puts "Usage:",
         "    make_gem your_gem_name {-d}",
         "        -d adds debug info.",
         "    make_gem --help",
         ""
    exit
  end

  gem_name = args[0]

  if gem_name !~ /\A[a-z][a-z0-9_]*\z/
    puts "ERROR: Invalid gem name: #{gem_name.inspect}", ""
    exit
  end

  $debug = (args[1] == "-d")

  class_name = gem_name.split("_").map(&:capitalize).join
  user_name  = (%x{git config --global user.name}).chomp
  user_email = (%x{git config --global user.email}).chomp
  here       = Dir.pwd + "/"
  there      = here + gem_name + "/"
  make_gem   = File.expand_path(File.dirname(__FILE__)) + "/"
  template   = make_gem + "template/"
  bundler    = Bundler::VERSION.partition(/\d\.\d+/)[1]

  if File.exists?(there)
    puts "ERROR: The folder #{there} already exists."
    exit
  end

  evaluator = binding

  puts "Creating gem    = #{gem_name}"
  puts "Module name     = #{class_name}" if $debug
  puts "User name       = #{user_name.inspect}"
  puts "User email      = #{user_email.inspect}"
  puts "Current folder  = #{here}" if $debug
  puts "Target folder   = #{there}"
  puts "Gem folder      = #{make_gem}" if $debug
  puts "Template folder = #{template}" if $debug
  puts "Bundler version = #{bundler}" if $debug
  puts

  # Verify that we may proceed.
  print "Proceed? (y/n): "
  exit unless STDIN.gets[0] == "y"

  # Process the request.

  puts "0. Establishing starting point."
  %x{bundle gem #{gem_name}}
  Dir.chdir(gem_name)
  %x{git commit -m "Initial commit from bundler."}

  puts "1. Removing extraneous files."
  %x{git rm .travis.yml}
  %x{git rm bin/console}
  %x{git rm bin/setup}
  %x{git commit -m "Fix phase 1"}

  puts "2. Rename the rake file."
  %x{git mv Rakefile rakefile.rb\n}
  %x{git commit -m "Fix phase 2"}

  puts "3. Fix up the code files."
  MakeGem.process(template + "version.erb",
                  there + "lib/" + gem_name + "/version.rb",
                  evaluator)

  MakeGem.process(template + "gem_main.erb",
                  there + "lib/" + gem_name + ".rb",
                  evaluator)

  %x{git add .}
  %x{git commit -m "Fix phase 3"}

  puts "4. Fix up the test files."
  %x{git rm test/test_helper.rb}

  MakeGem.process(template + "gem_test.erb",
                  there + "test/" + gem_name + "_test.rb",
                  evaluator)

  %x{git add .}
  %x{git commit -m "Fix phase 4"}

  puts "5. Fix up the readme file."

  MakeGem.process(template + "README.erb",
                  there + "README.md",
                  evaluator)

  %x{git add .}
  %x{git commit -m "Fix phase 5"}

  puts "6. Fix up the gem specification file."

  MakeGem.process(template + "gem_spec.erb",
                  there + gem_name + ".gemspec",
                  evaluator)

  %x{git add .}
  %x{git commit -m "Fix phase 6"}

  puts "7. Fix up the rake file."

  MakeGem.process(template + "rakefile.erb",
                  there + "rakefile.rb",
                  evaluator)

  %x{git add .}
  %x{git commit -m "Fix phase 7"}

  puts
  puts "To connect to github, use:"
  puts "git remote add origin https://github.com/#{user_name}/#{gem_name}.git"
  puts "git push -u origin master"
  puts

  puts "** Done. **"
end

# File lib/make_gem/process.rb, line 4
def self.process(src, dst, evaluator)
  puts "   #{File.basename(src)} => #{dst}" if $debug
  IO.binwrite(dst, ERB.new(IO.read(src)).result(evaluator))
end