class Rubocop::CLI

def self.rip_source(source)
  tokens = Ripper.lex(source.join("\n")).map { |t| Cop::Token.new(*t) }
  sexp = Ripper.sexp(source.join("\n"))
  Cop::Position.make_position_objects(sexp)
  correlations = Cop::Grammar.new(tokens).correlate(sexp)
  [tokens, sexp, correlations]
end

def config_from_dotfile(target_file_dir)
  return unless target_file_dir
  # @configs is a cache that maps directories to
  # configurations. We search for .rubocop.yml only if we haven't
  # already found it for the given directory.
  unless @configs[target_file_dir]
    dir = target_file_dir
    while dir != '/'
      path = File.join(dir, '.rubocop.yml')
      if File.exist?(path)
        @configs[target_file_dir] = YAML.load_file(path)
        break
      end
      dir = File.expand_path('..', dir)
    end
    path = File.join(Dir.home, '.rubocop.yml')
    @configs[target_file_dir] = YAML.load_file(path) if File.exist?(path)
  end
  @configs[target_file_dir]
end

def cops_on_duty(config)
  cops_on_duty = []
  Cop::Cop.all.each do |cop_klass|
    cop_config = config[cop_klass.name.split('::').last] if config
    cops_on_duty << cop_klass if cop_config.nil? || cop_config['Enabled']
  end
  cops_on_duty
end

def get_rid_of_invalid_byte_sequences(line)
  enc = line.encoding.name
  # UTF-16 works better in this algorithm but is not supported in 1.9.2.
  temporary_encoding = (RUBY_VERSION == '1.9.2') ? 'UTF-8' : 'UTF-16'
  line.encode!(temporary_encoding, enc, invalid: :replace, replace: '')
  line.encode!(enc, temporary_encoding)
end

def run(args = ARGV)
  $options = { mode: :default }
  OptionParser.new do |opts|
    opts.banner = 'Usage: rubocop [options] [file1, file2, ...]'
    opts.on('-d', '--[no-]debug', 'Display debug info') do |d|
      $options[:debug] = d
    end
    opts.on('-e', '--emacs', 'Emacs style output') do
      $options[:mode] = :emacs_style
    end
    opts.on('-c FILE', '--config FILE', 'Configuration file') do |f|
      $options[:config] = YAML.load_file(f)
    end
    opts.on('-s', '--silent', 'Silence summary') do |s|
      $options[:silent] = s
    end
    opts.on('-v', '--version', 'Display version') do
      puts Rubocop::VERSION
      exit(0)
    end
  end.parse!(args)
  total_offences = 0
  @configs = {}
  target_files = target_files(args)
  config = $options[:config] || config_from_dotfile(target_files[0])
  cops = cops_on_duty(config)
  show_cops_on_duty(cops) if $options[:debug]
  target_files(args).each do |file|
    report = Report.create(file, $options[:mode])
    source = File.readlines(file).map do |line|
      get_rid_of_invalid_byte_sequences(line)
      line.chomp
    end
    tokens, sexp, correlations = CLI.rip_source(source)
    cops.each do |cop_klass|
      cop_config = config[cop_klass.name.split('::').last] if config
      cop_klass.config = cop_config
      cop = cop_klass.new
      cop.correlations = correlations
      cop.inspect(file, source, tokens, sexp)
      total_offences += cop.offences.count
      report << cop if cop.has_report?
    end
    report.display unless report.empty?
  end
  unless $options[:silent]
    print "\n#{target_files(args).count} files inspected, "
    puts "#{total_offences} offences detected"
      .send(total_offences.zero? ? :green : :red)
  end
  return total_offences == 0 ? 0 : 1
end

def show_cops_on_duty(cops)
  puts '== Reporting for duty =='
  cops.each { |c| puts ' * '.yellow + c.to_s.green }
  puts '========================'
end

def target_files(args)
  return Dir['**/*.rb'] if args.empty?
  files = []
  args.each do |target|
    if File.directory?(target)
      files << Dir["#{target}/**/*.rb"]
    elsif target =~ /\*/
      files << Dir[target]
    else
      files << target
    end
  end
  files.flatten
end