1 files changed, 99 insertions, 0 deletions
diff --git a/bot/exts/holidays/valentines/lovecalculator.py b/bot/exts/holidays/valentines/lovecalculator.py
new file mode 100644
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+++ b/bot/exts/holidays/valentines/lovecalculator.py
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+import bisect
+import hashlib
+import json
+import logging
+import random
+from pathlib import Path
+from typing import Coroutine, Optional
+
+import discord
+from discord import Member
+from discord.ext import commands
+from discord.ext.commands import BadArgument, Cog, clean_content
+
+from bot.bot import Bot
+from bot.constants import Channels, Client, Lovefest, Month
+from bot.utils.decorators import in_month
+
+log = logging.getLogger(__name__)
+
+LOVE_DATA = json.loads(Path("bot/resources/holidays/valentines/love_matches.json").read_text("utf8"))
+LOVE_DATA = sorted((int(key), value) for key, value in LOVE_DATA.items())
+
+
+class LoveCalculator(Cog):
+    """A cog for calculating the love between two people."""
+
+    @in_month(Month.FEBRUARY)
+    @commands.command(aliases=("love_calculator", "love_calc"))
+    @commands.cooldown(rate=1, per=5, type=commands.BucketType.user)
+    async def love(self, ctx: commands.Context, who: Member, whom: Optional[Member] = None) -> None:
+        """
+        Tells you how much the two love each other.
+
+        This command requires at least one member as input, if two are given love will be calculated between
+        those two users, if only one is given, the second member is asusmed to be the invoker.
+        Members are converted from:
+          - User ID
+          - Mention
+          - name#discrim
+          - name
+          - nickname
+
+        Any two arguments will always yield the same result, regardless of the order of arguments:
+          Running .love @joe#6000 @chrisjl#2655 will always yield the same result.
+          Running .love @chrisjl#2655 @joe#6000 will yield the same result as before.
+        """
+        if (
+            Lovefest.role_id not in [role.id for role in who.roles]
+            or (whom is not None and Lovefest.role_id not in [role.id for role in whom.roles])
+        ):
+            raise BadArgument(
+                "This command can only be ran against members with the lovefest role! "
+                "This role be can assigned by running "
+                f"`{Client.prefix}lovefest sub` in <#{Channels.community_bot_commands}>."
+            )
+
+        if whom is None:
+            whom = ctx.author
+
+        def normalize(arg: Member) -> Coroutine:
+            # This has to be done manually to be applied to usernames
+            return clean_content(escape_markdown=True).convert(ctx, str(arg))
+
+        # Sort to ensure same result for same input, regardless of order
+        who, whom = sorted([await normalize(arg) for arg in (who, whom)])
+
+        # Hash inputs to guarantee consistent results (hashing algorithm choice arbitrary)
+        #
+        # hashlib is used over the builtin hash() to guarantee same result over multiple runtimes
+        m = hashlib.sha256(who.encode() + whom.encode())
+        # Mod 101 for [0, 100]
+        love_percent = sum(m.digest()) % 101
+
+        # We need the -1 due to how bisect returns the point
+        # see the documentation for further detail
+        # https://docs.python.org/3/library/bisect.html#bisect.bisect
+        index = bisect.bisect(LOVE_DATA, (love_percent,)) - 1
+        # We already have the nearest "fit" love level
+        # We only need the dict, so we can ditch the first element
+        _, data = LOVE_DATA[index]
+
+        status = random.choice(data["titles"])
+        embed = discord.Embed(
+            title=status,
+            description=f"{who} \N{HEAVY BLACK HEART} {whom} scored {love_percent}%!\n\u200b",
+            color=discord.Color.dark_magenta()
+        )
+        embed.add_field(
+            name="A letter from Dr. Love:",
+            value=data["text"]
+        )
+        embed.set_footer(text=f"You can unsubscribe from lovefest by using {Client.prefix}lovefest unsub")
+
+        await ctx.send(embed=embed)
+
+
+def setup(bot: Bot) -> None:
+    """Load the Love calculator Cog."""
+    bot.add_cog(LoveCalculator())