module MonkeyReloader

# File lib/monkey-reloader.rb, line 65
def blacklist(files = [])
  @@blacklist ||= Set.new

  expand_paths @@blacklist.merge parse_paths files
end

# File lib/monkey-reloader.rb, line 13
def config(opts = {})
  whitelist = opts[:whitelist]
  if !whitelist or whitelist.empty?
    raise ArgumentError.new 'whitelist expected'
  end

  blacklist = opts.key?(:blacklist) ? opts[:blacklist] : [
    # by default, block dangerous Rails behavior
    'bin',
    'config',
    'db',
    'log',
    'script',
    'spec',
  ].select {|dir| Dir.exists? dir}

  @@whitelist = Set.new
  self.whitelist whitelist

  @@blacklist = Set.new
  self.blacklist blacklist

  update_hash

  self
end

# File lib/monkey-reloader.rb, line 40
def load
  # reload all changed files
  wlist = whitelist
  blist = blacklist

  files = changed_files.select do |file|
    wlist.include? file
  end.reject do |file|
    blist.include? file
  end

  update_hash
  pwd = Pathname.new Dir.pwd

  files.each do |file|
    Kernel.load file
  end
end

# File lib/monkey-reloader.rb, line 59
def whitelist(files = [])
  @@whitelist ||= Set.new

  expand_paths @@whitelist.merge parse_paths files
end

# File lib/monkey-reloader.rb, line 112
def changed_files
  # return a list of changed files

  files = Set.new
  # grab last arg, space delemited
  cut = "rev | cut -d' ' -f 1 | rev"

  # find recent changes via git, eg.
  #   ' M path/to/file'
  #   'RM path/to/file -> path/to/renamed/file'
  files.merge `git status -s | #{cut}`.split

  # find committed changes if there was a branch change / rebase
  files.merge `git diff --name-status HEAD..#{@@hash} | #{cut}`.split

  # filter for ruby files and those that dissapeared during
  # a branch change
  files.select do |file|
    /\.rb$/.match file and File.exists? file
  end
end

# File lib/monkey-reloader.rb, line 94
def expand_paths(paths = [])
  # recalculate path expansions, but keep relative paths.
  # note that caching will miss filesystem changes

  pwd = Pathname.new Dir.pwd
  Array(paths).map do |path|
    Dir[path]
  end.flatten.map do |path|
    # map back to relative paths
    Pathname.new(path).relative_path_from(pwd).to_s
  end
end

# File lib/monkey-reloader.rb, line 74
def parse_paths(paths = [])
  Array(paths).map do |path|
    path = File.expand_path path

    if path.include? '*'
      path
    elsif Dir.exists? path
      "#{path}/**/*.rb"
    elsif File.exists? path
      unless /\.rb$/.match path
        raise ArgumentError.new ".rb files only: #{path}"
      end

      path
    else
      raise ArgumentError.new "path not found: #{path}"
    end
  end
end

# File lib/monkey-reloader.rb, line 107
def update_hash
  # get current git branch hash
  @@hash = `git rev-parse HEAD`.strip
end