#!/usr/bin/env ruby

$LOAD_PATH << File.expand_path(File.dirname(__FILE__))

require 'loader'
require 'world'

class Game
  include Loader

  attr_accessor :world

  def initialize(story_path, options={})
    @input  = options.fetch(:input)  { $stdin  }
    @output = options.fetch(:output) { $stdout }
    @world  = World.new load(story_path)
  end

  def play!
    start!
    execute_one_command! until ended?
  end

  def start!
    @output.puts @world.start
    @output.print "> "
  end

  def execute_one_command!
    input = @input.gets
    output = @world.execute!(input)

    @output.puts output unless output.empty?
    @output.print "> " unless ended?
  end

  def ended?
    @world.ended?
  end
end

if $PROGRAM_NAME == __FILE__
  story_path = ARGV[0]
  unless story_path
    warn "Usage: #{$PROGRAM_NAME} STORY_FILE"
    exit 1
  end
  game = Game.new(story_path)
  game.play!
end