yy.erl

%% -*- coding: utf-8 -*-

-module(yy).
-export([start/0]).

monsters() -> ["焼きたてパン", "強いシャチホコ", "もんじゃ焼き一年生",
  "怪人ホタテ男", "ニセ勇者", "逃げ足の早いアレ", "睡魔", "煩悩",
  "愛らしい子犬の中の人", "恋するスズメバチ", "勇敢なクマンバチ",
  "信じられない物", "勇者の師匠", "浮遊する鎧", "怪盗ドボン", "闇の招き猫",
  "誘惑のカスタードクリーム", "しょっぱすぎる籠手", "カレー味の兜",
  "光沢だけは一流の盾", "若葉マークのモンスター", "新緑の季節",
  "梅雨時の車両のニオイ", "暑すぎる夏", "新宿らしき何か",
  "やたら発達したドーナツ", "育ちすぎたクマー", "なごやかな雰囲気",
  "凍り付いた気配", "忍び寄る恐怖"].

skills() -> ["お豆腐の買い方", "鉛筆の買い方", "消しゴムの使い方",
  "メモの取り方", "攻撃に使えないこともない呪文", "裏町の歩き方", "森林浴",
  "珈琲の味", "しじみのみそ汁の作り方", "回覧板の回し方",
  "郵便物の投函方法", "立ち話のコツ", "猫の呼び方", "犬の呼び方",
  "カラスの呼び方", "鳩専用豆鉄砲", "秘密の趣味", "速く走るコツ",
  "剣の使い方", "斧の使い方", "まきわりで、まっきわりわり", "聖なる祈り",
  "孤独", "涼しく過ごすコツ", "お洒落のコツ", "卵をふわっと焼く方法",
  "ごはんの研ぎ方", "油汚れの対応方法", "大人の振るまい", "Suicaの使い方"].

win_msg() ->      "*-----\n~tsを倒した！\n~pの経験値を得た。\n".
levelup_msg1() -> "勇者は~pにレベルが上がった！\n勇者は、~tsを覚えた。\n\n".
levelup_msg2() -> "そして、\nかくかくしかじかで、"
                  "山あり谷ありの冒険が続いたが割愛。\n\n".
ending_msg() ->   "勇者は、また、レベルが上がった！\n"
                  "勇者は、ふと空しさを覚えた。\n".

max_level() ->    30.
message_wait() -> 500. % milliseconds

start() ->
  System = spawn(fun() -> system() end),
  System ! start.

system() ->
  receive
    start ->
      Hero = spawn(fun() -> hero(1) end),
      register(hero, Hero),
      Rand = spawn(fun() -> rand() end),
      register(rand, Rand),
      register(system, self()),
      self() ! encounter;
    
    encounter ->
      Monster = spawn(fun() -> monster() end),
      Monster ! encounter;
    
    {win, MonsterName, Exp} ->
      io:fwrite(win_msg(), [MonsterName, Exp]);
    
    {levelup, Level, Skill} ->
      MaxLevel = max_level(),
      if
        Level == MaxLevel -> self() ! ending;
        Level /= MaxLevel ->
          io:fwrite(levelup_msg1(), [Level, Skill]),
          timer:sleep(message_wait()),
          io:fwrite(levelup_msg2()),
          timer:sleep(message_wait()),
          self() ! encounter
      end;
    
    ending ->
      io:fwrite(ending_msg()),
      hero ! terminate,
      rand ! terminate,
      exit(normal)
  end,
  system().

hero(Level) ->
  receive
    {attack, MonsterName} ->
      self() ! {win, MonsterName};
    
    {win, MonsterName} ->
      system ! {win, MonsterName, fact(Level)},
      self() ! levelup;
    
    levelup ->
      rand ! {select_one, self(), skills()};
    
    {selected, Skill} ->
      system ! {levelup, Level, Skill},
      hero(Level + 1);
    
    terminate -> exit(normal)
  end,
  hero(Level).

monster() ->
  rand ! {select_one, self(), monsters()},
  receive
    {selected, Name} -> monster(Name)
  end.

monster(Name) ->
  receive
    encounter -> hero ! {attack, Name}
  end.

rand() ->
  {A, B, C} = now(),
  random:seed(A, B, C),
  rand_loop().

rand_loop() ->
  receive
    {select_one, From, List} ->
      N = random:uniform(length(List)),
      From ! {selected, lists:nth(N, List)};
    terminate -> exit(normal)
  end,
  rand_loop().

fact(0) -> 1;
fact(N) -> N * fact(N - 1).