module Rooms
  class Room
    def initialize engine
      @engine = engine
    end

    def damage_with_bonus damage, bonus
      [damage - bonus, 0].max
    end

    def health_damage damage
      damage_with_bonus damage, @engine.magic_armor
    end

    def endurance_damage damage
      damage_with_bonus damage, @engine.magic_weapon
    end

    def resolve command
      @command = command
      if @engine.state == 'invalid'
        @engine.state = 'play'
      end

      if @engine.state == 'play'
        _do_resolve
      end
    end

    def check_death
      if @engine.health <= 0
        @engine.state = 'dead'
      elsif @engine.endurance <= 0
        @engine.state = 'dead'
      end
    end

    def _do_resolve
      do_resolve
      check_death
      if !instant_resolve
        @engine.add_message resolve_message
      end
    end

    # TODO: limit weapon/armor levels
    def do_resolve
      case @command
      when 'c'
      else
        do_invalid
      end
    end

    def do_invalid
      @engine.state = 'invalid'
      @engine.add_message "Invalid command: #{@command}"

      if !instant_resolve
        enter
      else
        list_options
      end
    end

    def resolve_message
      if @engine.state == 'dead'
        if @engine.health <= 0
          death_message
        elsif @engine.endurance <= 0
          exhaust_message
        end
      else
        success_message
      end
    end

    def enter_message
      ''
    end

    def death_message
      'You die'
    end

    def exhaust_message
      'You fall over exhausted'
    end

    def success_message
      ''
    end

    def options
      [
        'continue',
      ]
    end

    def list_options
      options.each do |option|
        @engine.add_message ">[#{option[0]}]#{option[1..]}"
      end
    end

    def enter
      @engine.add_message enter_message
      if instant_resolve
        do_instant_resolve
        check_death
        @engine.add_message resolve_message
      end

      list_options
    end
  end

  class Welcome < Room
    def instant_resolve
      false
    end

    def do_resolve
    end

    def success_message
      <<~MSG.chomp
        A curse has infested an ancient keep near your town.
        The evil magic has filled the keep with monsters.
        Can you save your home from this Hex?
      MSG
    end

    def to_s
      'welcome'
    end
  end

  class Store < Room
    def instant_resolve
      false
    end

    def enter_message
      'You have enough XP to upgrade your equipment!'
    end

    def options
      [
        'weapon upgrade (-50 X)',
        'armor upgrade (-50 X)'
      ]
    end

    def do_resolve
      case @command
      when 'a'
        @engine.xp -= 50
        @engine.magic_armor += 1
        @message = "You've upgraded your magic armor!"
      when 'w'
        @engine.xp -= 50
        @engine.magic_weapon += 1
        @message = "You've upgraded your magic weapon!"
      else
        do_invalid
      end
    end

    def to_s
      'store'
    end
  end

  class Empty < Room
    def initialize engine
      super engine
      @endurance_damage = endurance_damage 1
    end

    def instant_resolve
      false
    end

    def do_resolve
      case @command
      when 'r'
        @engine.update_hex 1, 3, 0
      when 's'
        @engine.update_hex 3, -@endurance_damage, 0
      when 'm'
      else
        do_invalid
      end
    end

    def enter_message
      'You enter an empty room. Nothing dangerous or interesting happening here.'
    end

    def success_message
      case @command
      when 'r'
        'You rest for a bit. You feel refreshed!'
      when 's'
        'After a while, you find some dried meat. It looks good to eat'
      when 'm'
        "You decide there's no time to waste. You continue down the corridor."
      end
    end

    def options
      [
        'rest (+1 H, +3 E)',
        "scavenge for food (+3 H, #{-@endurance_damage} E)"
      ]
    end

    def to_s
      'empty'
    end
  end

  class Trap < Room
    def initialize engine
      super engine
      @health_damage = health_damage @engine.level
      @endurance_damage = endurance_damage @engine.level
    end

    def instant_resolve
      false
    end

    def do_resolve
      case @command
      when 't'
        @engine.update_hex -@health_damage, 0, 0
      when 'd'
        @engine.update_hex 0, -@endurance_damage, 0
      else
        do_invalid
      end
    end

    def success_message
      case @command
      when 't'
        'Ouch!'
      when 'd'
        'Very carefully, you manage to disable the trap.'
      end
    end

    def enter_message
      'You stop yourself short. Your foot was about to brush a tripwire!'
    end

    def options
      [
        "trigger trap (#{-@health_damage} H)",
        "disable trap (#{-@endurance_damage} E)"
      ]
    end

    def to_s
      'trap'
    end
  end

  class Monster < Room
    def initialize engine
      super engine
      @health_damage = health_damage @engine.level
      @endurance_damage = endurance_damage @engine.level
    end

    def instant_resolve
      false
    end

    def do_resolve
      case @command
      when 'r'
      when 'f'
        @engine.update_hex -@health_damage, -@endurance_damage, @engine.level
      else
        do_invalid
      end
    end

    def enter_message
      'You turn the corner and see an ugly monster!'
    end

    def success_message
      case @command
      when 'r'
        'You book it from there, heart beating fast. But you manage to lose the monster.'
      when 'f'
        'The monster is defeated, your clothes still wet with blood, its and yours.'
      end
    end

    def options
      [
        "run away",
        "fight (#{-@health_damage} H, #{-@endurance_damage} E, #{@engine.level} X)"
      ]
    end

    def to_s
      'monster'
    end
  end

  class Treasure < Room
    def instant_resolve
      true
    end

    def do_instant_resolve
      roll = 1 + rand(6)
      case roll + @engine.level
      when 1..3
        @found = 'key'
        @engine.keys += 1
      else
        @found = 'gold'
        @engine.update_hex 0, 0, @engine.level
      end
    end

    def enter_message
      'You enter a dusty room. Something shiny on the ground catches your eye.'
    end

    def success_message
      case @found
      when 'key'
        'You find a key!'
      when 'gold'
        "You found some gold! (+#{@engine.level} X)"
      end
    end

    def to_s
      'treasure'
    end
  end

  class Stairs < Room
    def instant_resolve
      true
    end

    def do_instant_resolve
      @engine.level += 1
    end

    def enter_message
      'You come across a set of cracked stairs.'
    end

    def success_message
      'You journey downwards.'
    end

    def to_s
      'stairs'
    end
  end

  class Boss < Room
    def initialize engine
      super engine
      @health_damage = health_damage(2 * @engine.level)
      @endurance_damage = endurance_damage(2 * @engine.level)
    end

    def instant_resolve
      true
    end

    def do_instant_resolve
      @engine.update_hex -@health_damage, -@endurance_damage, 2 * @engine.level
    end

    def enter_message
      "You encounter a giant boss monster. There's no escape routes, it's live or die!"
    end

    def success_message
      'You defeat the fiend!'
    end

    def to_s
      'boss'
    end
  end

  class Exit < Room
    def instant_resolve
      true
    end

    def do_instant_resolve
      @engine.state = 'win'
    end

    def success_message
      'You won! Congratulations!'
    end

    def to_s
      'exit'
    end
  end
end