Insert copyright headers

copyright

#!/usr/bin/env ruby

# The MIT License (MIT)
# 
# Copyright (c) 2016 Gregory Higley (Prosumma)
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# Usage is pretty straightforward. However, one word of warning:
# This utility will DESTRUCTIVELY REMOVE the very first comment
# that occurs before the start of any code. This is so that any
# existing header can be replaced. If that doesn't work for you,
# you'll have to edit your files manually. You can always try it
# out and, since I know you're one of those smart people, undo
# the change with your preferred version control system.
#
# If called without argument, this utility searches for a file called
# LICENSE in the current directory. If it does not find that, it searches
# for a file called COPYRIGHT in the current directory. If it does not
# find that, it assumes a file called COPYRIGHT exists in ~/bin. The
# contents of this file will be the header.
#
# To manually specify a header file, use -c or --copyright. Any other
# argument passed is assumed to be the directory whose files are to be
# searched.
#
# Currently, this utility only supports file types that use c-style comments
# with the extensions .swift, .h, .c, .cpp, and .m. It's easy enough
# to add others.

require 'ostruct'
require 'optparse'
require 'io/console'

$options = OpenStruct::new
$options.copyright = nil
$options.path = nil

option_parser = OptionParser::new do |opts|
  opts.on('-c', '--copyright=PATH', 'Path to the copyright file') do |opt|
    $options.copyright = File::expand_path(opt)
  end
end
$options.path = File::expand_path(option_parser.parse(ARGV)[0] || '.')

unless $options.copyright
  if File::exists? 'COPYRIGHT'
    $options.copyright = File::expand_path('COPYRIGHT')
  elsif File::exists? 'LICENSE'
    $options.copyright = File::expand_path('LICENSE')
  else
    $options.copyright = File::join(File::dirname(__FILE__), 'COPYRIGHT')
  end
end

class CStyleCommentHandler
  def initialize(path_regex)
    @path_regex = path_regex
  end
  def process(path)
    return false unless path =~ @path_regex
    contents = nil
    File::open path do |fd|
      contents = fd.read
    end
    # Look for the first comment block
    code = []
    state = nil # :in_group, :in_single, :after
    contents.each_line do |line|
      if code.length > 0
        code << line
      elsif state == :after 
        code << line if line.strip.length > 0
      elsif state == :in_group
        state = :after if line =~ /^\s*\*\//
      elsif state == :in_single
        state = :after if line.strip.length == 0
      elsif line =~ /^\s*\/\*/
        state = :in_group
      elsif line =~ /^\s*\/\//
        state = :in_single
      end
    end
    code.insert 0, ''
    code.insert 0, '*/'
    code.insert 0, COPYRIGHT
    code.insert 0, '/*'
    File::open path, 'w' do |fd|
      fd.puts code 
    end
    true
  end
end

HANDLERS = [CStyleCommentHandler::new(/\.(?:swift|h|c|cpp|m)$/i)]

puts "The path '#{$options.path}' and all of its subdirectories will be searched for files to which to add the copyright header found at #{$options.copyright}."

input = [(print 'Proceed? [yN] '), STDIN.getch][1]
exit unless input =~ /^y$/i

File::open($options.copyright, 'r') do |fd|
  COPYRIGHT = fd.read
end

Dir::chdir $options.path
Dir::glob '**/*' do |path|
  HANDLERS.each do |handler|
    next if handler.process path
  end
end