Merge branch 'master' into issue-337

1 files changed, 716 insertions, 0 deletions

diff --git a/bot/exts/evergreen/snakes/_utils.py b/bot/exts/evergreen/snakes/_utils.py
new file mode 100644
index 00000000..7d6caf04
--- /dev/null
+++ b/bot/exts/evergreen/snakes/_utils.py
@@ -0,0 +1,716 @@
+import asyncio
+import io
+import json
+import logging
+import math
+import random
+from itertools import product
+from pathlib import Path
+from typing import List, Tuple
+
+from PIL import Image
+from PIL.ImageDraw import ImageDraw
+from discord import File, Member, Reaction
+from discord.ext.commands import Cog, Context
+
+from bot.constants import Roles
+
+SNAKE_RESOURCES = Path("bot/resources/snakes").absolute()
+
+h1 = r'''```
+        ----
+       ------
+     /--------\
+     |--------|
+     |--------|
+      \------/
+        ----```'''
+h2 = r'''```
+        ----
+       ------
+     /---\-/--\
+     |-----\--|
+     |--------|
+      \------/
+        ----```'''
+h3 = r'''```
+        ----
+       ------
+     /---\-/--\
+     |-----\--|
+     |-----/--|
+      \----\-/
+        ----```'''
+h4 = r'''```
+        -----
+       -----  \
+     /--|  /---\
+     |--\  -\---|
+     |--\--/--  /
+      \------- /
+        ------```'''
+stages = [h1, h2, h3, h4]
+snakes = {
+    "Baby Python": "https://i.imgur.com/SYOcmSa.png",
+    "Baby Rattle Snake": "https://i.imgur.com/i5jYA8f.png",
+    "Baby Dragon Snake": "https://i.imgur.com/SuMKM4m.png",
+    "Baby Garden Snake": "https://i.imgur.com/5vYx3ah.png",
+    "Baby Cobra": "https://i.imgur.com/jk14ryt.png"
+}
+
+BOARD_TILE_SIZE = 56         # the size of each board tile
+BOARD_PLAYER_SIZE = 20       # the size of each player icon
+BOARD_MARGIN = (10, 0)       # margins, in pixels (for player icons)
+# The size of the image to download
+# Should a power of 2 and higher than BOARD_PLAYER_SIZE
+PLAYER_ICON_IMAGE_SIZE = 32
+MAX_PLAYERS = 4              # depends on the board size/quality, 4 is for the default board
+
+# board definition (from, to)
+BOARD = {
+    # ladders
+    2: 38,
+    7: 14,
+    8: 31,
+    15: 26,
+    21: 42,
+    28: 84,
+    36: 44,
+    51: 67,
+    71: 91,
+    78: 98,
+    87: 94,
+
+    # snakes
+    99: 80,
+    95: 75,
+    92: 88,
+    89: 68,
+    74: 53,
+    64: 60,
+    62: 19,
+    49: 11,
+    46: 25,
+    16: 6
+}
+
+DEFAULT_SNAKE_COLOR: int = 0x15c7ea
+DEFAULT_BACKGROUND_COLOR: int = 0
+DEFAULT_IMAGE_DIMENSIONS: Tuple[int] = (200, 200)
+DEFAULT_SNAKE_LENGTH: int = 22
+DEFAULT_SNAKE_WIDTH: int = 8
+DEFAULT_SEGMENT_LENGTH_RANGE: Tuple[int] = (7, 10)
+DEFAULT_IMAGE_MARGINS: Tuple[int] = (50, 50)
+DEFAULT_TEXT: str = "snek\nit\nup"
+DEFAULT_TEXT_POSITION: Tuple[int] = (
+    10,
+    10
+)
+DEFAULT_TEXT_COLOR: int = 0xf2ea15
+X = 0
+Y = 1
+ANGLE_RANGE = math.pi * 2
+
+
+def get_resource(file: str) -> List[dict]:
+    """Load Snake resources JSON."""
+    with (SNAKE_RESOURCES / f"{file}.json").open(encoding="utf-8") as snakefile:
+        return json.load(snakefile)
+
+
+def smoothstep(t: float) -> float:
+    """Smooth curve with a zero derivative at 0 and 1, making it useful for interpolating."""
+    return t * t * (3. - 2. * t)
+
+
+def lerp(t: float, a: float, b: float) -> float:
+    """Linear interpolation between a and b, given a fraction t."""
+    return a + t * (b - a)
+
+
+class PerlinNoiseFactory(object):
+    """
+    Callable that produces Perlin noise for an arbitrary point in an arbitrary number of dimensions.
+
+    The underlying grid is aligned with the integers.
+
+    There is no limit to the coordinates used; new gradients are generated on the fly as necessary.
+
+    Taken from: https://gist.github.com/eevee/26f547457522755cb1fb8739d0ea89a1
+    Licensed under ISC
+    """
+
+    def __init__(self, dimension: int, octaves: int = 1, tile: Tuple[int] = (), unbias: bool = False):
+        """
+        Create a new Perlin noise factory in the given number of dimensions.
+
+        dimension should be an integer and at least 1.
+
+        More octaves create a foggier and more-detailed noise pattern.  More than 4 octaves is rather excessive.
+
+        ``tile`` can be used to make a seamlessly tiling pattern.
+        For example:
+            pnf = PerlinNoiseFactory(2, tile=(0, 3))
+
+        This will produce noise that tiles every 3 units vertically, but never tiles horizontally.
+
+        If ``unbias`` is True, the smoothstep function will be applied to the output before returning
+        it, to counteract some of Perlin noise's significant bias towards the center of its output range.
+        """
+        self.dimension = dimension
+        self.octaves = octaves
+        self.tile = tile + (0,) * dimension
+        self.unbias = unbias
+
+        # For n dimensions, the range of Perlin noise is ±sqrt(n)/2; multiply
+        # by this to scale to ±1
+        self.scale_factor = 2 * dimension ** -0.5
+
+        self.gradient = {}
+
+    def _generate_gradient(self) -> Tuple[float, ...]:
+        """
+        Generate a random unit vector at each grid point.
+
+        This is the "gradient" vector, in that the grid tile slopes towards it
+        """
+        # 1 dimension is special, since the only unit vector is trivial;
+        # instead, use a slope between -1 and 1
+        if self.dimension == 1:
+            return (random.uniform(-1, 1),)
+
+        # Generate a random point on the surface of the unit n-hypersphere;
+        # this is the same as a random unit vector in n dimensions.  Thanks
+        # to: http://mathworld.wolfram.com/SpherePointPicking.html
+        # Pick n normal random variables with stddev 1
+        random_point = [random.gauss(0, 1) for _ in range(self.dimension)]
+        # Then scale the result to a unit vector
+        scale = sum(n * n for n in random_point) ** -0.5
+        return tuple(coord * scale for coord in random_point)
+
+    def get_plain_noise(self, *point) -> float:
+        """Get plain noise for a single point, without taking into account either octaves or tiling."""
+        if len(point) != self.dimension:
+            raise ValueError("Expected {0} values, got {1}".format(
+                self.dimension, len(point)))
+
+        # Build a list of the (min, max) bounds in each dimension
+        grid_coords = []
+        for coord in point:
+            min_coord = math.floor(coord)
+            max_coord = min_coord + 1
+            grid_coords.append((min_coord, max_coord))
+
+        # Compute the dot product of each gradient vector and the point's
+        # distance from the corresponding grid point.  This gives you each
+        # gradient's "influence" on the chosen point.
+        dots = []
+        for grid_point in product(*grid_coords):
+            if grid_point not in self.gradient:
+                self.gradient[grid_point] = self._generate_gradient()
+            gradient = self.gradient[grid_point]
+
+            dot = 0
+            for i in range(self.dimension):
+                dot += gradient[i] * (point[i] - grid_point[i])
+            dots.append(dot)
+
+        # Interpolate all those dot products together.  The interpolation is
+        # done with smoothstep to smooth out the slope as you pass from one
+        # grid cell into the next.
+        # Due to the way product() works, dot products are ordered such that
+        # the last dimension alternates: (..., min), (..., max), etc.  So we
+        # can interpolate adjacent pairs to "collapse" that last dimension.  Then
+        # the results will alternate in their second-to-last dimension, and so
+        # forth, until we only have a single value left.
+        dim = self.dimension
+        while len(dots) > 1:
+            dim -= 1
+            s = smoothstep(point[dim] - grid_coords[dim][0])
+
+            next_dots = []
+            while dots:
+                next_dots.append(lerp(s, dots.pop(0), dots.pop(0)))
+
+            dots = next_dots
+
+        return dots[0] * self.scale_factor
+
+    def __call__(self, *point) -> float:
+        """
+        Get the value of this Perlin noise function at the given point.
+
+        The number of values given should match the number of dimensions.
+        """
+        ret = 0
+        for o in range(self.octaves):
+            o2 = 1 << o
+            new_point = []
+            for i, coord in enumerate(point):
+                coord *= o2
+                if self.tile[i]:
+                    coord %= self.tile[i] * o2
+                new_point.append(coord)
+            ret += self.get_plain_noise(*new_point) / o2
+
+        # Need to scale n back down since adding all those extra octaves has
+        # probably expanded it beyond ±1
+        # 1 octave: ±1
+        # 2 octaves: ±1½
+        # 3 octaves: ±1¾
+        ret /= 2 - 2 ** (1 - self.octaves)
+
+        if self.unbias:
+            # The output of the plain Perlin noise algorithm has a fairly
+            # strong bias towards the center due to the central limit theorem
+            # -- in fact the top and bottom 1/8 virtually never happen.  That's
+            # a quarter of our entire output range!  If only we had a function
+            # in [0..1] that could introduce a bias towards the endpoints...
+            r = (ret + 1) / 2
+            # Doing it this many times is a completely made-up heuristic.
+            for _ in range(int(self.octaves / 2 + 0.5)):
+                r = smoothstep(r)
+            ret = r * 2 - 1
+
+        return ret
+
+
+def create_snek_frame(
+        perlin_factory: PerlinNoiseFactory, perlin_lookup_vertical_shift: float = 0,
+        image_dimensions: Tuple[int] = DEFAULT_IMAGE_DIMENSIONS, image_margins: Tuple[int] = DEFAULT_IMAGE_MARGINS,
+        snake_length: int = DEFAULT_SNAKE_LENGTH,
+        snake_color: int = DEFAULT_SNAKE_COLOR, bg_color: int = DEFAULT_BACKGROUND_COLOR,
+        segment_length_range: Tuple[int] = DEFAULT_SEGMENT_LENGTH_RANGE, snake_width: int = DEFAULT_SNAKE_WIDTH,
+        text: str = DEFAULT_TEXT, text_position: Tuple[int] = DEFAULT_TEXT_POSITION,
+        text_color: Tuple[int] = DEFAULT_TEXT_COLOR
+) -> Image:
+    """
+    Creates a single random snek frame using Perlin noise.
+
+    `perlin_lookup_vertical_shift` represents the Perlin noise shift in the Y-dimension for this frame.
+    If `text` is given, display the given text with the snek.
+    """
+    start_x = random.randint(image_margins[X], image_dimensions[X] - image_margins[X])
+    start_y = random.randint(image_margins[Y], image_dimensions[Y] - image_margins[Y])
+    points = [(start_x, start_y)]
+
+    for index in range(0, snake_length):
+        angle = perlin_factory.get_plain_noise(
+            ((1 / (snake_length + 1)) * (index + 1)) + perlin_lookup_vertical_shift
+        ) * ANGLE_RANGE
+        current_point = points[index]
+        segment_length = random.randint(segment_length_range[0], segment_length_range[1])
+        points.append((
+            current_point[X] + segment_length * math.cos(angle),
+            current_point[Y] + segment_length * math.sin(angle)
+        ))
+
+    # normalize bounds
+    min_dimensions = [start_x, start_y]
+    max_dimensions = [start_x, start_y]
+    for point in points:
+        min_dimensions[X] = min(point[X], min_dimensions[X])
+        min_dimensions[Y] = min(point[Y], min_dimensions[Y])
+        max_dimensions[X] = max(point[X], max_dimensions[X])
+        max_dimensions[Y] = max(point[Y], max_dimensions[Y])
+
+    # shift towards middle
+    dimension_range = (max_dimensions[X] - min_dimensions[X], max_dimensions[Y] - min_dimensions[Y])
+    shift = (
+        image_dimensions[X] / 2 - (dimension_range[X] / 2 + min_dimensions[X]),
+        image_dimensions[Y] / 2 - (dimension_range[Y] / 2 + min_dimensions[Y])
+    )
+
+    image = Image.new(mode='RGB', size=image_dimensions, color=bg_color)
+    draw = ImageDraw(image)
+    for index in range(1, len(points)):
+        point = points[index]
+        previous = points[index - 1]
+        draw.line(
+            (
+                shift[X] + previous[X],
+                shift[Y] + previous[Y],
+                shift[X] + point[X],
+                shift[Y] + point[Y]
+            ),
+            width=snake_width,
+            fill=snake_color
+        )
+    if text is not None:
+        draw.multiline_text(text_position, text, fill=text_color)
+    del draw
+    return image
+
+
+def frame_to_png_bytes(image: Image) -> io.BytesIO:
+    """Convert image to byte stream."""
+    stream = io.BytesIO()
+    image.save(stream, format='PNG')
+    stream.seek(0)
+    return stream
+
+
+log = logging.getLogger(__name__)
+START_EMOJI = "\u2611"     # :ballot_box_with_check: - Start the game
+CANCEL_EMOJI = "\u274C"    # :x: - Cancel or leave the game
+ROLL_EMOJI = "\U0001F3B2"  # :game_die: - Roll the die!
+JOIN_EMOJI = "\U0001F64B"  # :raising_hand: - Join the game.
+STARTUP_SCREEN_EMOJI = [
+    JOIN_EMOJI,
+    START_EMOJI,
+    CANCEL_EMOJI
+]
+GAME_SCREEN_EMOJI = [
+    ROLL_EMOJI,
+    CANCEL_EMOJI
+]
+
+
+class SnakeAndLaddersGame:
+    """Snakes and Ladders game Cog."""
+
+    def __init__(self, snakes: Cog, context: Context):
+        self.snakes = snakes
+        self.ctx = context
+        self.channel = self.ctx.channel
+        self.state = 'booting'
+        self.started = False
+        self.author = self.ctx.author
+        self.players = []
+        self.player_tiles = {}
+        self.round_has_rolled = {}
+        self.avatar_images = {}
+        self.board = None
+        self.positions = None
+        self.rolls = []
+
+    async def open_game(self) -> None:
+        """
+        Create a new Snakes and Ladders game.
+
+        Listen for reactions until players have joined, and the game has been started.
+        """
+        def startup_event_check(reaction_: Reaction, user_: Member) -> bool:
+            """Make sure that this reaction is what we want to operate on."""
+            return (
+                all((
+                    reaction_.message.id == startup.id,       # Reaction is on startup message
+                    reaction_.emoji in STARTUP_SCREEN_EMOJI,  # Reaction is one of the startup emotes
+                    user_.id != self.ctx.bot.user.id,         # Reaction was not made by the bot
+                ))
+            )
+
+        # Check to see if the bot can remove reactions
+        if not self.channel.permissions_for(self.ctx.guild.me).manage_messages:
+            log.warning(
+                "Unable to start Snakes and Ladders - "
+                f"Missing manage_messages permissions in {self.channel}"
+            )
+            return
+
+        await self._add_player(self.author)
+        await self.channel.send(
+            "**Snakes and Ladders**: A new game is about to start!",
+            file=File(
+                str(SNAKE_RESOURCES / "snakes_and_ladders" / "banner.jpg"),
+                filename='Snakes and Ladders.jpg'
+            )
+        )
+        startup = await self.channel.send(
+            f"Press {JOIN_EMOJI} to participate, and press "
+            f"{START_EMOJI} to start the game"
+        )
+        for emoji in STARTUP_SCREEN_EMOJI:
+            await startup.add_reaction(emoji)
+
+        self.state = 'waiting'
+
+        while not self.started:
+            try:
+                reaction, user = await self.ctx.bot.wait_for(
+                    "reaction_add",
+                    timeout=300,
+                    check=startup_event_check
+                )
+                if reaction.emoji == JOIN_EMOJI:
+                    await self.player_join(user)
+                elif reaction.emoji == CANCEL_EMOJI:
+                    if user == self.author or (self._is_moderator(user) and user not in self.players):
+                        # Allow game author or non-playing moderation staff to cancel a waiting game
+                        await self.cancel_game()
+                        return
+                    else:
+                        await self.player_leave(user)
+                elif reaction.emoji == START_EMOJI:
+                    if self.ctx.author == user:
+                        self.started = True
+                        await self.start_game(user)
+                        await startup.delete()
+                        break
+
+                await startup.remove_reaction(reaction.emoji, user)
+
+            except asyncio.TimeoutError:
+                log.debug("Snakes and Ladders timed out waiting for a reaction")
+                await self.cancel_game()
+                return  # We're done, no reactions for the last 5 minutes
+
+    async def _add_player(self, user: Member) -> None:
+        """Add player to game."""
+        self.players.append(user)
+        self.player_tiles[user.id] = 1
+
+        avatar_bytes = await user.avatar_url_as(format='jpeg', size=PLAYER_ICON_IMAGE_SIZE).read()
+        im = Image.open(io.BytesIO(avatar_bytes)).resize((BOARD_PLAYER_SIZE, BOARD_PLAYER_SIZE))
+        self.avatar_images[user.id] = im
+
+    async def player_join(self, user: Member) -> None:
+        """
+        Handle players joining the game.
+
+        Prevent player joining if they have already joined, if the game is full, or if the game is
+        in a waiting state.
+        """
+        for p in self.players:
+            if user == p:
+                await self.channel.send(user.mention + " You are already in the game.", delete_after=10)
+                return
+        if self.state != 'waiting':
+            await self.channel.send(user.mention + " You cannot join at this time.", delete_after=10)
+            return
+        if len(self.players) is MAX_PLAYERS:
+            await self.channel.send(user.mention + " The game is full!", delete_after=10)
+            return
+
+        await self._add_player(user)
+
+        await self.channel.send(
+            f"**Snakes and Ladders**: {user.mention} has joined the game.\n"
+            f"There are now {str(len(self.players))} players in the game.",
+            delete_after=10
+        )
+
+    async def player_leave(self, user: Member) -> bool:
+        """
+        Handle players leaving the game.
+
+        Leaving is prevented if the user wasn't part of the game.
+
+        If the number of players reaches 0, the game is terminated. In this case, a sentinel boolean
+        is returned True to prevent a game from continuing after it's destroyed.
+        """
+        is_surrendered = False  # Sentinel value to assist with stopping a surrendered game
+        for p in self.players:
+            if user == p:
+                self.players.remove(p)
+                self.player_tiles.pop(p.id, None)
+                self.round_has_rolled.pop(p.id, None)
+                await self.channel.send(
+                    "**Snakes and Ladders**: " + user.mention + " has left the game.",
+                    delete_after=10
+                )
+
+                if self.state != 'waiting' and len(self.players) == 0:
+                    await self.channel.send("**Snakes and Ladders**: The game has been surrendered!")
+                    is_surrendered = True
+                    self._destruct()
+
+                return is_surrendered
+        else:
+            await self.channel.send(user.mention + " You are not in the match.", delete_after=10)
+            return is_surrendered
+
+    async def cancel_game(self) -> None:
+        """Cancel the running game."""
+        await self.channel.send("**Snakes and Ladders**: Game has been canceled.")
+        self._destruct()
+
+    async def start_game(self, user: Member) -> None:
+        """
+        Allow the game author to begin the game.
+
+        The game cannot be started if the game is in a waiting state.
+        """
+        if not user == self.author:
+            await self.channel.send(user.mention + " Only the author of the game can start it.", delete_after=10)
+            return
+
+        if not self.state == 'waiting':
+            await self.channel.send(user.mention + " The game cannot be started at this time.", delete_after=10)
+            return
+
+        self.state = 'starting'
+        player_list = ', '.join(user.mention for user in self.players)
+        await self.channel.send("**Snakes and Ladders**: The game is starting!\nPlayers: " + player_list)
+        await self.start_round()
+
+    async def start_round(self) -> None:
+        """Begin the round."""
+        def game_event_check(reaction_: Reaction, user_: Member) -> bool:
+            """Make sure that this reaction is what we want to operate on."""
+            return (
+                all((
+                    reaction_.message.id == self.positions.id,  # Reaction is on positions message
+                    reaction_.emoji in GAME_SCREEN_EMOJI,       # Reaction is one of the game emotes
+                    user_.id != self.ctx.bot.user.id,           # Reaction was not made by the bot
+                ))
+            )
+
+        self.state = 'roll'
+        for user in self.players:
+            self.round_has_rolled[user.id] = False
+        board_img = Image.open(str(SNAKE_RESOURCES / "snakes_and_ladders" / "board.jpg"))
+        player_row_size = math.ceil(MAX_PLAYERS / 2)
+
+        for i, player in enumerate(self.players):
+            tile = self.player_tiles[player.id]
+            tile_coordinates = self._board_coordinate_from_index(tile)
+            x_offset = BOARD_MARGIN[0] + tile_coordinates[0] * BOARD_TILE_SIZE
+            y_offset = \
+                BOARD_MARGIN[1] + (
+                    (10 * BOARD_TILE_SIZE) - (9 - tile_coordinates[1]) * BOARD_TILE_SIZE - BOARD_PLAYER_SIZE)
+            x_offset += BOARD_PLAYER_SIZE * (i % player_row_size)
+            y_offset -= BOARD_PLAYER_SIZE * math.floor(i / player_row_size)
+            board_img.paste(self.avatar_images[player.id],
+                            box=(x_offset, y_offset))
+
+        board_file = File(frame_to_png_bytes(board_img), filename='Board.jpg')
+        player_list = '\n'.join((user.mention + ": Tile " + str(self.player_tiles[user.id])) for user in self.players)
+
+        # Store and send new messages
+        temp_board = await self.channel.send(
+            "**Snakes and Ladders**: A new round has started! Current board:",
+            file=board_file
+        )
+        temp_positions = await self.channel.send(
+            f"**Current positions**:\n{player_list}\n\nUse {ROLL_EMOJI} to roll the dice!"
+        )
+
+        # Delete the previous messages
+        if self.board and self.positions:
+            await self.board.delete()
+            await self.positions.delete()
+
+        # remove the roll messages
+        for roll in self.rolls:
+            await roll.delete()
+        self.rolls = []
+
+        # Save new messages
+        self.board = temp_board
+        self.positions = temp_positions
+
+        # Wait for rolls
+        for emoji in GAME_SCREEN_EMOJI:
+            await self.positions.add_reaction(emoji)
+
+        is_surrendered = False
+        while True:
+            try:
+                reaction, user = await self.ctx.bot.wait_for(
+                    "reaction_add",
+                    timeout=300,
+                    check=game_event_check
+                )
+
+                if reaction.emoji == ROLL_EMOJI:
+                    await self.player_roll(user)
+                elif reaction.emoji == CANCEL_EMOJI:
+                    if self._is_moderator(user) and user not in self.players:
+                        # Only allow non-playing moderation staff to cancel a running game
+                        await self.cancel_game()
+                        return
+                    else:
+                        is_surrendered = await self.player_leave(user)
+
+                await self.positions.remove_reaction(reaction.emoji, user)
+
+                if self._check_all_rolled():
+                    break
+
+            except asyncio.TimeoutError:
+                log.debug("Snakes and Ladders timed out waiting for a reaction")
+                await self.cancel_game()
+                return  # We're done, no reactions for the last 5 minutes
+
+        # Round completed
+        # Check to see if the game was surrendered before completing the round, without this
+        # sentinel, the game object would be deleted but the next round still posted into purgatory
+        if not is_surrendered:
+            await self._complete_round()
+
+    async def player_roll(self, user: Member) -> None:
+        """Handle the player's roll."""
+        if user.id not in self.player_tiles:
+            await self.channel.send(user.mention + " You are not in the match.", delete_after=10)
+            return
+        if self.state != 'roll':
+            await self.channel.send(user.mention + " You may not roll at this time.", delete_after=10)
+            return
+        if self.round_has_rolled[user.id]:
+            return
+        roll = random.randint(1, 6)
+        self.rolls.append(await self.channel.send(f"{user.mention} rolled a **{roll}**!"))
+        next_tile = self.player_tiles[user.id] + roll
+
+        # apply snakes and ladders
+        if next_tile in BOARD:
+            target = BOARD[next_tile]
+            if target < next_tile:
+                await self.channel.send(
+                    f"{user.mention} slips on a snake and falls back to **{target}**",
+                    delete_after=15
+                )
+            else:
+                await self.channel.send(
+                    f"{user.mention} climbs a ladder to **{target}**",
+                    delete_after=15
+                )
+            next_tile = target
+
+        self.player_tiles[user.id] = min(100, next_tile)
+        self.round_has_rolled[user.id] = True
+
+    async def _complete_round(self) -> None:
+        """At the conclusion of a round check to see if there's been a winner."""
+        self.state = 'post_round'
+
+        # check for winner
+        winner = self._check_winner()
+        if winner is None:
+            # there is no winner, start the next round
+            await self.start_round()
+            return
+
+        # announce winner and exit
+        await self.channel.send("**Snakes and Ladders**: " + winner.mention + " has won the game! :tada:")
+        self._destruct()
+
+    def _check_winner(self) -> Member:
+        """Return a winning member if we're in the post-round state and there's a winner."""
+        if self.state != 'post_round':
+            return None
+        return next((player for player in self.players if self.player_tiles[player.id] == 100),
+                    None)
+
+    def _check_all_rolled(self) -> bool:
+        """Check if all members have made their roll."""
+        return all(rolled for rolled in self.round_has_rolled.values())
+
+    def _destruct(self) -> None:
+        """Clean up the finished game object."""
+        del self.snakes.active_sal[self.channel]
+
+    def _board_coordinate_from_index(self, index: int) -> Tuple[int, int]:
+        """Convert the tile number to the x/y coordinates for graphical purposes."""
+        y_level = 9 - math.floor((index - 1) / 10)
+        is_reversed = math.floor((index - 1) / 10) % 2 != 0
+        x_level = (index - 1) % 10
+        if is_reversed:
+            x_level = 9 - x_level
+        return x_level, y_level
+
+    @staticmethod
+    def _is_moderator(user: Member) -> bool:
+        """Return True if the user is a Moderator."""
+        return any(Roles.moderator == role.id for role in user.roles)