Reminders: Refactor all opt-in button related logic into View class

- More resilient handling of API errors.
- Don't rely on string manipulation to disable the button.

bot/exts/utils/reminders.py

@@ -82,12 +82,21 @@ async def cancel(self, interaction: Interaction, button: discord.ui.Button) -> N
 class OptInReminderMentionView(discord.ui.View):
     """A button to opt-in to get notified of someone else's reminder."""
 
-    def __init__(self, cog: "Reminders", reminder: dict):
+    def __init__(self, cog: "Reminders", reminder: dict, expiration: Duration):
         super().__init__()
+
         self.cog = cog
         self.reminder = reminder
 
-    async def get_embed_description(self) -> str:
+        self.timeout = min(
+            (expiration - datetime.now(UTC)).total_seconds(),
+            REMINDER_MENTION_BUTTON_TIMEOUT
+        )
+
+    async def get_embed_description(
+        self,
+        message: str = "Click on the button to add yourself to the list of mentions."
+    ) -> str:
         """Return a string for use in the embed that shows the button."""
 
         description = "The following user(s) will be notified when the reminder arrives:\n"
@@ -96,7 +105,8 @@ async def get_embed_description(self) -> str:
                 [self.reminder["author"]] + self.reminder["mentions"]
             )
         ])
-        description += "\n\nClick on the button to add yourself to the list of mentions."
+        if message:
+            description += f"\n\n{message}"
 
         return description
 
@@ -107,11 +117,13 @@ async def button_callback(self, interaction: discord.Interaction, button: discor
         # This is required in case the reminder was edited/deleted between
         # creation and the opt-in button click.
         try:
-            self.reminder = await self.cog.bot.api_client.get(f"bot/reminders/{self.reminder['id']}")
+            api_response = await self.cog.bot.api_client.get(f"bot/reminders/{self.reminder['id']}")
         except ResponseCodeError as e:
             await self.handle_api_error(interaction, button, e)
             return
 
+        self.reminder = api_response
+
         # Check whether the user should be added.
         if interaction.user.id == self.reminder['author']:
             await interaction.response.send_message(
@@ -139,11 +151,13 @@ async def button_callback(self, interaction: discord.Interaction, button: discor
 
         # Add the user to the list of mentions.
         try:
-            self.reminder = await self.cog.add_mention_opt_in(self.reminder, interaction.user.id)
+            api_response = await self.cog.add_mention_opt_in(self.reminder, interaction.user.id)
         except ResponseCodeError as e:
             await self.handle_api_error(interaction, button, e)
             return
 
+        self.reminder = api_response
+
         # Confirm that it was successful.
         await interaction.response.send_message(
             "You were successfully added to the list of mentions for that reminder.",
@@ -198,7 +212,7 @@ async def disable(
         self,
         interaction: discord.Interaction,
         button: discord.ui.Button,
-        reason: str | None = None,
+        reason: str = "",
     ) -> None:
         """Disable the button and add an optional reason to the original interaction message."""
 
@@ -208,15 +222,11 @@ async def disable(
 
         try:
             embed = embeds[0]
-            embed.description = embed.description.split("\n\n", maxsplit=2)[0]
-            if reason:
-                embed.description += "\n\n" + reason
-
+            embed.description = await self.get_embed_description(reason)
             await interaction.message.edit(embed=embed, view=self)
-
         except:
             log.trace("Unable to disable the reminder notification button.")
-            await interaction.message.edit(embeds=embeds, view=None)
+            await interaction.message.edit(embeds=[], view=None)
 
 
 class Reminders(Cog):
@@ -534,16 +544,12 @@ async def new_reminder(
         )
 
         # Add a button for others to also get notified.
-        view = OptInReminderMentionView(self, reminder)
-
-        button_embed = discord.Embed(
-            description=await view.get_embed_description(),
-        )
-        button_timeout = min(
-            (expiration - datetime.now(UTC)).total_seconds(),
-            REMINDER_MENTION_BUTTON_TIMEOUT
+        view = OptInReminderMentionView(self, reminder, expiration)
+        await ctx.send(
+            view=view,
+            delete_after=view.timeout,
+            embed=discord.Embed(description=await view.get_embed_description())
         )
-        await ctx.send(embed=button_embed, view=view, delete_after=button_timeout)
 
         self.schedule_reminder(reminder)