From b1fdd2205867870733c39c63c9bea05b26197ebe Mon Sep 17 00:00:00 2001
From: Stijn De Clercq <declercq.stijn@outlook.com>
Date: Fri, 11 Feb 2022 23:08:28 +0100
Subject: [PATCH] Reply to original message if command invocation was a reply

---
 cogs/other.py      |  5 +++--
 cogs/school.py     |  5 ++++-
 files/courses.json |  2 +-
 functions/utils.py | 22 +++++++++++++++++++++-
 4 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/cogs/other.py b/cogs/other.py
index 83c5ed4..819ab72 100644
--- a/cogs/other.py
+++ b/cogs/other.py
@@ -7,6 +7,7 @@ from data.menus import custom_commands
 from data.snipe import Action, Snipe
 from decorators import help
 from enums.help_categories import Category
+from functions.utils import reply_to_reference
 from startup.didier import Didier
 
 
@@ -20,7 +21,7 @@ class Other(commands.Cog):
 
     @commands.command(name="Link", usage="[Naam]")
     @help.Category(category=Category.Other)
-    async def link(self, ctx, name: str):
+    async def link(self, ctx: commands.Context, name: str):
         """
         Send commonly used links
         """
@@ -29,7 +30,7 @@ class Other(commands.Cog):
         if match is None:
             return await ctx.reply(f"Geen match gevonden voor \"{name}\".", mention_author=False, delete_after=15)
 
-        return await ctx.reply(match, mention_author=False)
+        await reply_to_reference(ctx, content=match)
 
     @commands.command(name="Custom")
     @help.Category(category=Category.Didier)
diff --git a/cogs/school.py b/cogs/school.py
index e2fc347..4e6d484 100644
--- a/cogs/school.py
+++ b/cogs/school.py
@@ -9,6 +9,7 @@ from enums.help_categories import Category
 from functions import config, les
 from functions.stringFormatters import capitalize
 from functions.timeFormatters import skip_weekends
+from functions.utils import reply_to_reference
 
 
 class School(commands.Cog):
@@ -101,7 +102,9 @@ class School(commands.Cog):
 
         # Get the guide for the current year
         year = 2018 + int(config.get("year"))
-        return await ctx.reply(f"https://studiekiezer.ugent.be/studiefiche/nl/{course.code}/{year}", mention_author=False)
+        link = f"https://studiekiezer.ugent.be/studiefiche/nl/{course.code}/{year}"
+
+        return await reply_to_reference(ctx, content=link)
 
     @commands.command(name="Deadlines", aliases=["dl"])
     @help.Category(category=Category.School)
diff --git a/files/courses.json b/files/courses.json
index 005ea83..d7ec000 100644
--- a/files/courses.json
+++ b/files/courses.json
@@ -77,7 +77,7 @@
     "year": 2
   },
   "Parallelle Computersystemen": {
-    "abbreviations": ["PCS"],
+    "abbreviations": ["Paracomp", "Parallelle", "PCS"],
     "alt": "Parallel Computer Systems",
     "code": "E034140",
     "year": 3
diff --git a/functions/utils.py b/functions/utils.py
index b1a692a..a56865c 100644
--- a/functions/utils.py
+++ b/functions/utils.py
@@ -1,5 +1,6 @@
-from typing import Union
+from typing import Union, Optional
 
+import discord
 from discord import ApplicationContext
 from discord.ext.commands import Context
 
@@ -31,3 +32,22 @@ def get_display_name(ctx: Union[ApplicationContext, Context], user_id: int) -> s
 
     mem = ctx.guild.get_member(user_id)
     return mem.display_name
+
+
+async def reply_to_reference(ctx: Context, content: Optional[str] = None, embed: Optional[discord.Embed] = None, always_mention=False):
+    """Reply to a message
+    In case the message is a reply to another message, try to reply to that one instead and ping the author
+    otherwise, reply to the message that invoked the command & only mention the author if necessary
+    """
+    # Message is a reply
+    if ctx.message.reference is not None:
+        cached = ctx.message.reference.cached_message
+
+        # Reference is not cached anymore: fetch it
+        if cached is None:
+            # Message is in the same channel, otherwise no way to reply to it
+            cached = await ctx.channel.fetch_message(ctx.message.reference.message_id)
+
+        return await cached.reply(content, embed=embed, mention_author=cached.author != ctx.author)
+
+    return await ctx.reply(content, embed=embed, mention_author=always_mention)