1 files changed, 203 insertions, 0 deletions
diff --git a/bot/exts/holidays/halloween/candy_collection.py b/bot/exts/holidays/halloween/candy_collection.py
new file mode 100644
index 00000000..4afd5913
--- /dev/null
+++ b/bot/exts/holidays/halloween/candy_collection.py
@@ -0,0 +1,203 @@
+import logging
+import random
+from typing import Union
+
+import discord
+from async_rediscache import RedisCache
+from discord.ext import commands
+
+from bot.bot import Bot
+from bot.constants import Channels, Month
+from bot.utils.decorators import in_month
+
+log = logging.getLogger(__name__)
+
+# chance is 1 in x range, so 1 in 20 range would give 5% chance (for add candy)
+ADD_CANDY_REACTION_CHANCE = 20  # 5%
+ADD_CANDY_EXISTING_REACTION_CHANCE = 10  # 10%
+ADD_SKULL_REACTION_CHANCE = 50  # 2%
+ADD_SKULL_EXISTING_REACTION_CHANCE = 20  # 5%
+
+EMOJIS = dict(
+    CANDY="\N{CANDY}",
+    SKULL="\N{SKULL}",
+    MEDALS=(
+        "\N{FIRST PLACE MEDAL}",
+        "\N{SECOND PLACE MEDAL}",
+        "\N{THIRD PLACE MEDAL}",
+        "\N{SPORTS MEDAL}",
+        "\N{SPORTS MEDAL}",
+    ),
+)
+
+
+class CandyCollection(commands.Cog):
+    """Candy collection game Cog."""
+
+    # User candy amount records
+    candy_records = RedisCache()
+
+    # Candy and skull messages mapping
+    candy_messages = RedisCache()
+    skull_messages = RedisCache()
+
+    def __init__(self, bot: Bot):
+        self.bot = bot
+
+    @in_month(Month.OCTOBER)
+    @commands.Cog.listener()
+    async def on_message(self, message: discord.Message) -> None:
+        """Randomly adds candy or skull reaction to non-bot messages in the Event channel."""
+        # Ignore messages in DMs
+        if not message.guild:
+            return
+        # make sure its a human message
+        if message.author.bot:
+            return
+        # ensure it's hacktober channel
+        if message.channel.id != Channels.community_bot_commands:
+            return
+
+        # do random check for skull first as it has the lower chance
+        if random.randint(1, ADD_SKULL_REACTION_CHANCE) == 1:
+            await self.skull_messages.set(message.id, "skull")
+            await message.add_reaction(EMOJIS["SKULL"])
+        # check for the candy chance next
+        elif random.randint(1, ADD_CANDY_REACTION_CHANCE) == 1:
+            await self.candy_messages.set(message.id, "candy")
+            await message.add_reaction(EMOJIS["CANDY"])
+
+    @in_month(Month.OCTOBER)
+    @commands.Cog.listener()
+    async def on_reaction_add(self, reaction: discord.Reaction, user: Union[discord.User, discord.Member]) -> None:
+        """Add/remove candies from a person if the reaction satisfies criteria."""
+        message = reaction.message
+        # check to ensure the reactor is human
+        if user.bot:
+            return
+
+        # check to ensure it is in correct channel
+        if message.channel.id != Channels.community_bot_commands:
+            return
+
+        # if its not a candy or skull, and it is one of 10 most recent messages,
+        # proceed to add a skull/candy with higher chance
+        if str(reaction.emoji) not in (EMOJIS["SKULL"], EMOJIS["CANDY"]):
+            recent_message_ids = map(
+                lambda m: m.id,
+                await self.hacktober_channel.history(limit=10).flatten()
+            )
+            if message.id in recent_message_ids:
+                await self.reacted_msg_chance(message)
+            return
+
+        if await self.candy_messages.get(message.id) == "candy" and str(reaction.emoji) == EMOJIS["CANDY"]:
+            await self.candy_messages.delete(message.id)
+            if await self.candy_records.contains(user.id):
+                await self.candy_records.increment(user.id)
+            else:
+                await self.candy_records.set(user.id, 1)
+
+        elif await self.skull_messages.get(message.id) == "skull" and str(reaction.emoji) == EMOJIS["SKULL"]:
+            await self.skull_messages.delete(message.id)
+
+            if prev_record := await self.candy_records.get(user.id):
+                lost = min(random.randint(1, 3), prev_record)
+                await self.candy_records.decrement(user.id, lost)
+
+                if lost == prev_record:
+                    await CandyCollection.send_spook_msg(user, message.channel, "all of your")
+                else:
+                    await CandyCollection.send_spook_msg(user, message.channel, lost)
+            else:
+                await CandyCollection.send_no_candy_spook_message(user, message.channel)
+        else:
+            return  # Skip saving
+
+        await reaction.clear()
+
+    async def reacted_msg_chance(self, message: discord.Message) -> None:
+        """
+        Randomly add a skull or candy reaction to a message if there is a reaction there already.
+
+        This event has a higher probability of occurring than a reaction add to a message without an
+        existing reaction.
+        """
+        if random.randint(1, ADD_SKULL_EXISTING_REACTION_CHANCE) == 1:
+            await self.skull_messages.set(message.id, "skull")
+            await message.add_reaction(EMOJIS["SKULL"])
+
+        elif random.randint(1, ADD_CANDY_EXISTING_REACTION_CHANCE) == 1:
+            await self.candy_messages.set(message.id, "candy")
+            await message.add_reaction(EMOJIS["CANDY"])
+
+    @property
+    def hacktober_channel(self) -> discord.TextChannel:
+        """Get #hacktoberbot channel from its ID."""
+        return self.bot.get_channel(id=Channels.community_bot_commands)
+
+    @staticmethod
+    async def send_spook_msg(
+        author: discord.Member, channel: discord.TextChannel, candies: Union[str, int]
+    ) -> None:
+        """Send a spooky message."""
+        e = discord.Embed(colour=author.colour)
+        e.set_author(
+            name="Ghosts and Ghouls and Jack o' lanterns at night; "
+            f"I took {candies} candies and quickly took flight."
+        )
+        await channel.send(embed=e)
+
+    @staticmethod
+    async def send_no_candy_spook_message(
+        author: discord.Member,
+        channel: discord.TextChannel
+    ) -> None:
+        """An alternative spooky message sent when user has no candies in the collection."""
+        embed = discord.Embed(color=author.color)
+        embed.set_author(
+            name=(
+                "Ghosts and Ghouls and Jack o' lanterns at night; "
+                "I tried to take your candies but you had none to begin with!"
+            )
+        )
+        await channel.send(embed=embed)
+
+    @in_month(Month.OCTOBER)
+    @commands.command()
+    async def candy(self, ctx: commands.Context) -> None:
+        """Get the candy leaderboard and save to JSON."""
+        records = await self.candy_records.items()
+
+        def generate_leaderboard() -> str:
+            top_sorted = sorted(
+                ((user_id, score) for user_id, score in records if score > 0),
+                key=lambda x: x[1],
+                reverse=True
+            )
+            top_five = top_sorted[:5]
+
+            return "\n".join(
+                f"{EMOJIS['MEDALS'][index]} <@{record[0]}>: {record[1]}"
+                for index, record in enumerate(top_five)
+            ) if top_five else "No Candies"
+
+        e = discord.Embed(colour=discord.Colour.blurple())
+        e.add_field(
+            name="Top Candy Records",
+            value=generate_leaderboard(),
+            inline=False
+        )
+        e.add_field(
+            name="\u200b",
+            value="Candies will randomly appear on messages sent. "
+                  "\nHit the candy when it appears as fast as possible to get the candy! "
+                  "\nBut beware the ghosts...",
+            inline=False
+        )
+        await ctx.send(embed=e)
+
+
+def setup(bot: Bot) -> None:
+    """Load the Candy Collection Cog."""
+    bot.add_cog(CandyCollection(bot))