feat: add welcome message cog for new member DMs

bmt_discord_bot/__init__.py

@@ -15,6 +15,7 @@ class Bot(commands.Bot):
         "math",
         "reminders",
         "viraj",
+        "welcome",
     ]
 
     def __init__(self, database: Database):

bmt_discord_bot/cogs/welcome.py

@@ -0,0 +1,122 @@
+import discord
+from discord.ext import commands
+
+from bmt_discord_bot import Bot, Context
+
+
+class EditWelcomeModal(discord.ui.Modal, title="Edit Welcome Message"):
+    message = discord.ui.TextInput(
+        label="Welcome Message",
+        style=discord.TextStyle.paragraph,
+        placeholder="Enter the welcome message to send to new members...",
+        required=False,
+        max_length=2000,
+    )
+
+    def __init__(self, current_message: str | None, cog: "Welcome", guild_id: int):
+        super().__init__()
+        self.cog = cog
+        self.guild_id = guild_id
+        if current_message:
+            self.message.default = current_message
+
+    async def on_submit(self, interaction: discord.Interaction):
+        new_message = self.message.value.strip() if self.message.value else None
+
+        if new_message:
+            await self.cog.bot.database.pool.execute(
+                """
+                    INSERT INTO welcome_settings (guild_id, welcome_message)
+                    VALUES ($1, $2)
+                    ON CONFLICT (guild_id) DO UPDATE SET welcome_message = EXCLUDED.welcome_message
+                """,
+                self.guild_id,
+                new_message,
+            )
+            await interaction.response.send_message(
+                "Welcome message updated successfully.", ephemeral=True
+            )
+        else:
+            await self.cog.bot.database.pool.execute(
+                """
+                    DELETE FROM welcome_settings
+                    WHERE guild_id = $1
+                """,
+                self.guild_id,
+            )
+            await interaction.response.send_message(
+                "Welcome message has been disabled.", ephemeral=True
+            )
+
+
+class WelcomeView(discord.ui.View):
+    def __init__(self, cog: "Welcome", guild_id: int, current_message: str | None):
+        super().__init__(timeout=180)
+        self.cog = cog
+        self.guild_id = guild_id
+        self.current_message = current_message
+
+    @discord.ui.button(label="Edit Message", style=discord.ButtonStyle.primary)
+    async def edit_button(self, interaction: discord.Interaction, button: discord.ui.Button):
+        modal = EditWelcomeModal(self.current_message, self.cog, self.guild_id)
+        await interaction.response.send_modal(modal)
+
+
+class Welcome(commands.Cog):
+    """Welcome new members with a direct message."""
+
+    def __init__(self, bot: Bot):
+        self.bot = bot
+
+    async def get_welcome_message(self, guild_id: int) -> str | None:
+        return await self.bot.database.pool.fetchval(
+            """
+                SELECT welcome_message
+                FROM welcome_settings
+                WHERE guild_id = $1
+            """,
+            guild_id,
+        )
+
+    @commands.Cog.listener()
+    async def on_member_join(self, member: discord.Member):
+        if member.bot:
+            return
+
+        welcome_message = await self.get_welcome_message(member.guild.id)
+        if not welcome_message:
+            return
+
+        try:
+            await member.send(welcome_message)
+        except discord.Forbidden:
+            pass
+
+    @commands.hybrid_command()
+    @commands.guild_only()
+    @commands.has_permissions(manage_guild=True)
+    async def welcome(self, ctx: Context):
+        """View and edit the welcome message for new members."""
+
+        assert ctx.guild is not None
+        current_message = await self.get_welcome_message(ctx.guild.id)
+
+        if current_message:
+            embed = discord.Embed(
+                title="Current Welcome Message",
+                description=current_message,
+                color=discord.Color.blue(),
+            )
+        else:
+            embed = discord.Embed(
+                title="Welcome Message",
+                description="No welcome message is currently set for this server.",
+                color=discord.Color.greyple(),
+            )
+
+        view = WelcomeView(self, ctx.guild.id, current_message)
+        await ctx.send(embed=embed, view=view)
+
+
+async def setup(bot):
+    await bot.add_cog(Welcome(bot))

bmt_discord_bot/database.py

@@ -24,6 +24,7 @@ class Database:
     MIGRATIONS = [
         Migration.from_files("0001_reminders"),
         Migration.from_files("0002_math"),
+        Migration.from_files("0003_welcome"),
     ]
 
     def __init__(self, pool: asyncpg.Pool):

bmt_discord_bot/migrations/0003_welcome.sql

@@ -0,0 +1,4 @@
+CREATE TABLE welcome_settings (
+    guild_id BIGINT PRIMARY KEY,
+    welcome_message TEXT
+);

bmt_discord_bot/migrations/0003_welcome_down.sql

@@ -0,0 +1 @@
+DROP TABLE welcome_settings;