class Pry::Command::Hist

def check_for_juxtaposed_replay(replay_sequence)
  if replay_sequence =~ /\Ahist(?:ory)?\b/
    # Create *fresh* instance of Options for parsing of "hist" command.
    _slop = self.slop
    _slop.parse replay_sequence.split(' ')[1..-1]
    if _slop.present?(:r)
      replay_sequence = replay_sequence.split("\n").join('; ')
      index = opts[:r]
      index = index.min if index.min == index.max || index.max.nil?
      raise CommandError, "Replay index #{ index } points out to another replay call: `#{ replay_sequence }`"
    end
  else
    false
  end
end

def options(opt)
  opt.on :H, :head,   "Display the first N items", :optional_argument => true, :as => Integer
  opt.on :T, :tail,   "Display the last N items", :optional_argument => true, :as => Integer
  opt.on :s, :show,   "Show the given range of lines", :optional_argument => true, :as => Range
  opt.on :G, :grep,   "Show lines matching the given pattern", :argument => true, :as => String
  opt.on :c, :clear , "Clear the current session's history"
  opt.on :r, :replay, "Replay a line or range of lines", :argument => true, :as => Range
  opt.on     :save,   "Save history to a file", :argument => true, :as => Range
  opt.on :e, :'exclude-pry', "Exclude Pry commands from the history"
  opt.on :n, :'no-numbers',  "Omit line numbers"
  opt.on :f, :flood,         "Do not use a pager to view text longer than one screen"
end

def process
  @history = Pry::Code(Pry.history.to_a)
  if opts.present?(:show)
    @history = @history.between(opts[:show])
  end
  if opts.present?(:grep)
    @history = @history.grep(opts[:grep])
  end
  @history = case
    when opts.present?(:head)
      @history.take_lines(1, opts[:head] || 10)
    when opts.present?(:tail)
      @history.take_lines(-(opts[:tail] || 10), opts[:tail] || 10)
    when opts.present?(:show)
      @history.between(opts[:show])
    else
      @history
    end
  if opts.present?(:'exclude-pry')
    @history = @history.select { |l, ln| !command_set.valid_command?(l) }
  end
  if opts.present?(:save)
    process_save
  elsif opts.present?(:clear)
    process_clear
  elsif opts.present?(:replay)
    process_replay
  else
    process_display
  end
end

def process_clear
  Pry.history.clear
  output.puts "History cleared."
end

def process_display
  unless opts.present?(:'no-numbers')
    @history = @history.with_line_numbers
  end
  render_output(@history, opts)
end

def process_replay
  @history = @history.between(opts[:r])
  replay_sequence = @history.raw
  # If we met follow-up "hist" call, check for the "--replay" option
  # presence. If "hist" command is called with other options, proceed
  # further.
  check_for_juxtaposed_replay(replay_sequence)
  _pry_.input_stack.push _pry_.input
  _pry_.input = StringIO.new(replay_sequence)
  # eval_string << "#{@history.raw}\n"
  # run "show-input" unless _pry_.complete_expression?(eval_string)
end

def process_save
  case opts[:save]
  when Range
    @history = @history.between(opts[:save])
    unless args.first
      raise CommandError, "Must provide a file name."
    end
    file_name = File.expand_path(args.first)
  when String
    file_name = File.expand_path(opts[:save])
  end
  output.puts "Saving history in #{file_name}..."
  File.open(file_name, 'w') { |f| f.write(@history.raw) }
  output.puts "History saved."
end