1 files changed, 356 insertions, 0 deletions
diff --git a/bot/exts/evergreen/duck_game.py b/bot/exts/evergreen/duck_game.py
new file mode 100644
index 00000000..51e7a98a
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+++ b/bot/exts/evergreen/duck_game.py
@@ -0,0 +1,356 @@
+import asyncio
+import random
+import re
+from collections import defaultdict
+from io import BytesIO
+from itertools import product
+from pathlib import Path
+from urllib.parse import urlparse
+
+import discord
+from PIL import Image, ImageDraw, ImageFont
+from discord.ext import commands
+
+from bot.bot import Bot
+from bot.constants import Colours, MODERATION_ROLES
+from bot.utils.decorators import with_role
+
+
+DECK = list(product(*[(0, 1, 2)]*4))
+
+GAME_DURATION = 180
+
+# Scoring
+CORRECT_SOLN = 1
+INCORRECT_SOLN = -1
+CORRECT_GOOSE = 2
+INCORRECT_GOOSE = -1
+
+# Distribution of minimum acceptable solutions at board generation.
+# This is for gameplay reasons, to shift the number of solutions per board up,
+# while still making the end of the game unpredictable.
+# Note: this is *not* the same as the distribution of number of solutions.
+
+SOLN_DISTR = 0, 0.05, 0.05, 0.1, 0.15, 0.25, 0.2, 0.15, .05
+
+IMAGE_PATH = Path("bot", "resources", "evergreen", "all_cards.png")
+FONT_PATH = Path("bot", "resources", "evergreen", "LuckiestGuy-Regular.ttf")
+HELP_IMAGE_PATH = Path("bot", "resources", "evergreen", "ducks_help_ex.png")
+
+ALL_CARDS = Image.open(IMAGE_PATH)
+LABEL_FONT = ImageFont.truetype(str(FONT_PATH), size=16)
+CARD_WIDTH = 155
+CARD_HEIGHT = 97
+
+EMOJI_WRONG = "\u274C"
+
+ANSWER_REGEX = re.compile(r'^\D*(\d+)\D+(\d+)\D+(\d+)\D*$')
+
+HELP_TEXT = """
+**Each card has 4 features**
+Color, Number, Hat, and Accessory
+
+**A valid flight**
+3 cards where each feature is either all the same or all different
+
+**Call "GOOSE"**
+if you think there are no more flights
+
+**+1** for each valid flight
+**+2** for a correct "GOOSE" call
+**-1** for any wrong answer
+
+The first flight below is invalid: the first card has swords while the other two have no accessory.\
+ It would be valid if the first card was empty-handed, or one of the other two had paintbrushes.
+
+The second flight is valid because there are no 2:1 splits; each feature is either all the same or all different.
+"""
+
+
+def assemble_board_image(board: list[tuple[int]], rows: int, columns: int) -> Image:
+    """Cut and paste images representing the given cards into an image representing the board."""
+    new_im = Image.new("RGBA", (CARD_WIDTH*columns, CARD_HEIGHT*rows))
+    draw = ImageDraw.Draw(new_im)
+    for idx, card in enumerate(board):
+        card_image = get_card_image(card)
+        row, col = divmod(idx, columns)
+        top, left = row * CARD_HEIGHT, col * CARD_WIDTH
+        new_im.paste(card_image, (left, top))
+        draw.text(
+            xy=(left+5, top+5),  # magic numbers are buffers for the card labels
+            text=str(idx),
+            fill=(0, 0, 0),
+            font=LABEL_FONT,
+        )
+    return new_im
+
+
+def get_card_image(card: tuple[int]) -> Image:
+    """Slice the image containing all the cards to get just this card."""
+    # The master card image file should have 9x9 cards,
+    # arranged such that their features can be interpreted as ordered trinary.
+    row, col = divmod(as_trinary(card), 9)
+    x1 = col * CARD_WIDTH
+    x2 = x1 + CARD_WIDTH
+    y1 = row * CARD_HEIGHT
+    y2 = y1 + CARD_HEIGHT
+    return ALL_CARDS.crop((x1, y1, x2, y2))
+
+
+def as_trinary(card: tuple[int]) -> int:
+    """Find the card's unique index by interpreting its features as trinary."""
+    return int(''.join(str(x) for x in card), base=3)
+
+
+class DuckGame:
+    """A class for a single game."""
+
+    def __init__(
+        self,
+        rows: int = 4,
+        columns: int = 3,
+        minimum_solutions: int = 1,
+    ) -> None:
+        """
+        Take samples from the deck to generate a board.
+
+        Args:
+            rows (int, optional): Rows in the game board. Defaults to 4.
+            columns (int, optional): Columns in the game board. Defaults to 3.
+            minimum_solutions (int, optional): Minimum acceptable number of solutions in the board. Defaults to 1.
+        """
+        self.rows = rows
+        self.columns = columns
+        size = rows * columns
+
+        self._solutions = None
+        self.claimed_answers = {}
+        self.scores = defaultdict(int)
+        self.editing_embed = asyncio.Lock()
+
+        self.board = random.sample(DECK, size)
+        while len(self.solutions) < minimum_solutions:
+            self.board = random.sample(DECK, size)
+
+    @property
+    def board(self) -> list[tuple[int]]:
+        """Accesses board property."""
+        return self._board
+
+    @board.setter
+    def board(self, val: list[tuple[int]]) -> None:
+        """Erases calculated solutions if the board changes."""
+        self._solutions = None
+        self._board = val
+
+    @property
+    def solutions(self) -> None:
+        """Calculate valid solutions and cache to avoid redoing work."""
+        if self._solutions is None:
+            self._solutions = set()
+            for idx_a, card_a in enumerate(self.board):
+                for idx_b, card_b in enumerate(self.board[idx_a+1:], start=idx_a+1):
+                    # Two points determine a line, and there are exactly 3 points per line in {0,1,2}^4.
+                    # The completion of a line will only be a duplicate point if the other two points are the same,
+                    # which is prevented by the triangle iteration.
+                    completion = tuple(
+                        feat_a if feat_a == feat_b else 3-feat_a-feat_b
+                        for feat_a, feat_b in zip(card_a, card_b)
+                    )
+                    try:
+                        idx_c = self.board.index(completion)
+                    except ValueError:
+                        continue
+
+                    # Indices within the solution are sorted to detect duplicate solutions modulo order.
+                    solution = tuple(sorted((idx_a, idx_b, idx_c)))
+                    self._solutions.add(solution)
+
+        return self._solutions
+
+
+class DuckGamesDirector(commands.Cog):
+    """A cog for running Duck Duck Duck Goose games."""
+
+    def __init__(self, bot: Bot) -> None:
+        self.bot = bot
+        self.current_games = {}
+
+    @commands.group(
+        name='duckduckduckgoose',
+        aliases=['dddg', 'ddg', 'duckduckgoose', 'duckgoose'],
+        invoke_without_command=True
+    )
+    @commands.cooldown(rate=1, per=2, type=commands.BucketType.channel)
+    async def start_game(self, ctx: commands.Context) -> None:
+        """Generate a board, send the game embed, and end the game after a time limit."""
+        if ctx.channel.id in self.current_games:
+            await ctx.send("There's already a game running!")
+            return
+
+        minimum_solutions, = random.choices(range(len(SOLN_DISTR)), weights=SOLN_DISTR)
+        game = DuckGame(minimum_solutions=minimum_solutions)
+        game.running = True
+        self.current_games[ctx.channel.id] = game
+
+        game.embed_msg = await self.send_board_embed(ctx, game)
+        await asyncio.sleep(GAME_DURATION)
+
+        # Checking for the channel ID in the currently running games is not sufficient.
+        # The game could have been ended by a player, and a new game already started in the same channel.
+        if game.running:
+            try:
+                del self.current_games[ctx.channel.id]
+                await self.end_game(ctx.channel, game, end_message="Time's up!")
+            except KeyError:
+                pass
+
+    @commands.Cog.listener()
+    async def on_message(self, msg: discord.Message) -> None:
+        """Listen for messages and process them as answers if appropriate."""
+        if msg.author.bot:
+            return
+
+        channel = msg.channel
+        if channel.id not in self.current_games:
+            return
+
+        game = self.current_games[channel.id]
+        if msg.content.strip().lower() == 'goose':
+            # If all of the solutions have been claimed, i.e. the "goose" call is correct.
+            if len(game.solutions) == len(game.claimed_answers):
+                try:
+                    del self.current_games[channel.id]
+                    game.scores[msg.author] += CORRECT_GOOSE
+                    await self.end_game(channel, game, end_message=f"{msg.author.display_name} GOOSED!")
+                except KeyError:
+                    pass
+            else:
+                await msg.add_reaction(EMOJI_WRONG)
+                game.scores[msg.author] += INCORRECT_GOOSE
+            return
+
+        # Valid answers contain 3 numbers.
+        if not (match := re.match(ANSWER_REGEX, msg.content)):
+            return
+        answer = tuple(sorted(int(m) for m in match.groups()))
+
+        # Be forgiving for answers that use indices not on the board.
+        if not all(0 <= n < len(game.board) for n in answer):
+            return
+
+        # Also be forgiving for answers that have already been claimed (and avoid penalizing for racing conditions).
+        if answer in game.claimed_answers:
+            return
+
+        if answer in game.solutions:
+            game.claimed_answers[answer] = msg.author
+            game.scores[msg.author] += CORRECT_SOLN
+            await self.display_claimed_answer(game, msg.author, answer)
+        else:
+            await msg.add_reaction(EMOJI_WRONG)
+            game.scores[msg.author] += INCORRECT_SOLN
+
+    async def send_board_embed(self, ctx: commands.Context, game: DuckGame) -> discord.Message:
+        """Create and send the initial game embed. This will be edited as the game goes on."""
+        image = assemble_board_image(game.board, game.rows, game.columns)
+        with BytesIO() as image_stream:
+            image.save(image_stream, format="png")
+            image_stream.seek(0)
+            file = discord.File(fp=image_stream, filename="board.png")
+        embed = discord.Embed(
+            title="Duck Duck Duck Goose!",
+            color=Colours.bright_green,
+            footer=""
+        )
+        embed.set_image(url="attachment://board.png")
+        return await ctx.send(embed=embed, file=file)
+
+    async def display_claimed_answer(self, game: DuckGame, author: discord.Member, answer: tuple[int]) -> None:
+        """Add a claimed answer to the game embed."""
+        async with game.editing_embed:
+            game_embed, = game.embed_msg.embeds
+            old_footer = game_embed.footer.text
+            if old_footer == discord.Embed.Empty:
+                old_footer = ""
+            game_embed.set_footer(text=f"{old_footer}\n{str(answer):12s}  -  {author.display_name}")
+            await self.edit_embed_with_image(game.embed_msg, game_embed)
+
+    async def end_game(self, channel: discord.TextChannel, game: DuckGame, end_message: str) -> None:
+        """Edit the game embed to reflect the end of the game and mark the game as not running."""
+        game.running = False
+
+        scoreboard_embed = discord.Embed(
+            title=end_message,
+            color=discord.Color.dark_purple(),
+        )
+        scores = sorted(
+            game.scores.items(),
+            key=lambda item: item[1],
+            reverse=True,
+        )
+        scoreboard = "Final scores:\n\n"
+        scoreboard += "\n".join(f"{member.display_name}: {score}" for member, score in scores)
+        scoreboard_embed.description = scoreboard
+        await channel.send(embed=scoreboard_embed)
+
+        missed = [ans for ans in game.solutions if ans not in game.claimed_answers]
+        if missed:
+            missed_text = "Flights everyone missed:\n" + "\n".join(f"{ans}" for ans in missed)
+        else:
+            missed_text = "All the flights were found!"
+
+        game_embed, = game.embed_msg.embeds
+        old_footer = game_embed.footer.text
+        if old_footer == discord.Embed.Empty:
+            old_footer = ""
+        embed_as_dict = game_embed.to_dict()  # Cannot set embed color after initialization
+        embed_as_dict["color"] = discord.Color.red().value
+        game_embed = discord.Embed.from_dict(embed_as_dict)
+        game_embed.set_footer(
+            text=f"{old_footer.rstrip()}\n\n{missed_text}"
+        )
+        await self.edit_embed_with_image(game.embed_msg, game_embed)
+
+    @start_game.command(name="help")
+    async def show_rules(self, ctx: commands.Context) -> None:
+        """Explain the rules of the game."""
+        await self.send_help_embed(ctx)
+
+    @start_game.command(name="stop")
+    @with_role(*MODERATION_ROLES)
+    async def stop_game(self, ctx: commands.Context) -> None:
+        """Stop a currently running game. Only available to mods."""
+        try:
+            game = self.current_games.pop(ctx.channel.id)
+        except KeyError:
+            await ctx.send("No game currently running in this channel")
+            return
+        await self.end_game(ctx.channel, game, end_message="Game canceled.")
+
+    @staticmethod
+    async def send_help_embed(ctx: commands.Context) -> discord.Message:
+        """Send rules embed."""
+        embed = discord.Embed(
+            title="Compete against other players to find valid flights!",
+            color=discord.Color.dark_purple(),
+        )
+        embed.description = HELP_TEXT
+        file = discord.File(HELP_IMAGE_PATH, filename="help.png")
+        embed.set_image(url="attachment://help.png")
+        embed.set_footer(
+            text="Tip: using Discord's compact message display mode can help keep the board on the screen"
+        )
+        return await ctx.send(file=file, embed=embed)
+
+    @staticmethod
+    async def edit_embed_with_image(msg: discord.Message, embed: discord.Embed) -> None:
+        """Edit an embed without the attached image going wonky."""
+        attach_name = urlparse(embed.image.url).path.split("/")[-1]
+        embed.set_image(url=f"attachment://{attach_name}")
+        await msg.edit(embed=embed)
+
+
+def setup(bot: Bot) -> None:
+    """Load the DuckGamesDirector cog."""
+    bot.add_cog(DuckGamesDirector(bot))