require 'active_support/core_ext/string/inflections'
require 'fileutils'

require_relative 'refactor/version'

module Refactor
  def run(from, to)
    from_camelized = from.camelize
    from_dashed = from.dasherize
    from_humanized = from.humanize
    from_underscored = from.underscore
    to_camelized = to.camelize
    to_dashed = to.dasherize
    to_underscored = to.underscore

    camelized_regex = /(?<=\b|_)#{Regexp.quote(from_camelized)}(?=\b|_)/
    dashed_regex = /(?<=\b|_)#{Regexp.quote(from_dashed)}(?=\b|_)/
    underscored_regex = /(?<=\b|_)#{Regexp.quote(from_underscored)}(?=\b|_)/

    # all files in current directory
    Dir.glob('**/*') do |old_path|
      # ignore certain directories
      unless old_path =~ %r{\A(coverage|pkg|tmp|vendor)(\z|/)}
        # only check the basename so that the directory doesn't get renamed twice
        old_basename = File.basename(old_path)
        new_basename = old_basename.dup
        new_basename.gsub!(dashed_regex, to_dashed)
        new_basename.gsub!(underscored_regex, to_underscored)

        if new_basename == old_basename
          # no change
          new_path = old_path
        else
          # rename file
          new_path = File.join(File.dirname(old_path), new_basename)
          puts "#{old_path} –> #{new_path}"
          FileUtils.mv(old_path, new_path)
        end

        if File.file?(new_path)
          # replace within file
          old_text = File.read(new_path)

          new_text = old_text.dup
          new_text.gsub!(camelized_regex, to_camelized)
          new_text.gsub!(dashed_regex, to_dashed)
          new_text.gsub!(underscored_regex, to_underscored)

          unless new_text == old_text
            # rewrite existing file
            File.write(new_path, new_text)
          end

          # show possible matches in body
          line_num = 0
          new_text.each_line do |old_line|
            new_line = old_line.gsub(/#{Regexp.quote(from_humanized)}/i, "\e[33m\\0\e[0m")
            unless new_line == old_line
              puts "\e[36m#{new_path}:#{line_num}\e[0m #{new_line}"
            end
            line_num += 1
          end
        end
      end
    end
  end
  module_function :run
end