class GitStashout

# File lib/git_stashout.rb, line 82
def checkout(branch_name)
  output = repo.git.checkout({}, branch_name)
  puts "checking out #{branch_name}".yellow

  unless on_branch?(branch_name)
    raise GitError.new("Failed to checkout #{branch_name}", output)
  end
end

# File lib/git_stashout.rb, line 54
def get_repo
  repo_dir = `git rev-parse --show-toplevel`.chomp

  if $? == 0
    Dir.chdir repo_dir
    @repo = Grit::Repo.new(repo_dir)
  else
    raise GitError, "We don't seem to be in a git repository."
  end
end

# File lib/git_stashout.rb, line 91
def on_branch?(branch_name=nil)
  repo.head.respond_to?(:name) and repo.head.name == branch_name
end

# File lib/git_stashout.rb, line 24
  def process_args(argv)
    banner = <<BANNER
Git Stashout takes a single argument, the branch.
    $ git_stashout some_branch
    #{"stashing 5 changes".magenta}
    #{"checking out some_branch".yellow}
    #{"unstashing".magenta}
BANNER

    case argv
    when ["-v"], ["--version"]
      $stdout.puts "git_stashout #{GitStashout::VERSION}"
      exit
    when ["-h"], ["--help"]
      $stderr.puts(banner)
      exit
    else
      if argv.length == 1
        return argv[0]
      else
        $stderr.puts(banner)
        exit 1
      end
    end
  end

# File lib/git_stashout.rb, line 50
def repo
  @repo ||= get_repo
end

# File lib/git_stashout.rb, line 6
def run(argv)
  branch_name = process_args(argv)

  Grit::Git.with_timeout(0) do
    if on_branch?(branch_name)
      puts "already on #{branch_name}".green
    else
      with_stash do
        checkout(branch_name)
        puts "done".green
      end
    end
  end
rescue GitError => e
  puts e.message
  exit 1
end

# File lib/git_stashout.rb, line 65
def with_stash
  stashed = false

  if change_count > 0
    puts "stashing #{change_count} changes".magenta
    repo.git.stash
    stashed = true
  end

  yield

  if stashed
    puts "unstashing".magenta
    repo.git.stash({}, "pop")
  end
end

# File lib/git_stashout.rb, line 113
def change_count
  @change_count ||= begin
    repo.git.status(:porcelain => true, :'untracked-files' => 'no').split("\n").count
  end
end