Feat/mention handler discord

README.md

@@ -162,11 +162,13 @@ You'll need your own throwaway Discord server and bot to develop against:
 1. In the [Discord Developer Portal](https://discord.com/developers/applications),
    create an application, then under **Bot** click **Reset Token** and copy the
    token. No privileged intents are required — `/ask` uses default intents.
-2. Under **OAuth2 → URL Generator**, select the `bot` and `applications.commands`
+2. Scroll down and check the permissions the bot needs: **Send Messages**,
+   **View Channel** and **Read Message History**.
+3. Under **OAuth2 → URL Generator**, select the `bot` and `applications.commands`
    scopes, open the generated URL, and invite the bot to a server you own.
-3. Enable **Settings → Advanced → Developer Mode**, then right-click your server
+4. Enable **Settings → Advanced → Developer Mode**, then right-click your server
    icon → **Copy Server ID**.
-4. Add both values to your `.env`:
+5. Add both values to your `.env`:
 
    ```
    DISCORD_BOT_TOKEN=your_token_here

src/apps/discord_bot.py

@@ -22,6 +22,38 @@ async def on_ready(self) -> None:
         await self.tree.sync(guild=guild)
         log.info("discord_ready", self_user=self.user, guild=settings.discord_guild_id)
 
+    async def on_message(self, message) -> None:
+        # runs only in servers
+        if message.guild is None:
+            return
+
+        # ignores other bots and itself
+        if message.author.bot:
+            return
+
+        bot_standard_mention = f"<@{self.user.id}>"
+        bot_nickname_mention = f"<@!{self.user.id}>"
+
+        # triggering on explicit mention
+        if bot_standard_mention in message.content or bot_nickname_mention in message.content:
+            question = await question_assembler(message)
+
+            # if question is just empty/non-text
+            if question == "":
+                return
+
+            async with message.channel.typing():
+                answer = await ask(question=question)
+
+            content = await render_answer_content(answer)
+
+            try:
+                await message.reply(content)
+            except Exception as e:
+                await message.reply("❌ I couldn't process this request, please try again later.")
+                log.error("discord_ask_failed", error=str(e))
+                return
+
 
 client = CsAssistantBot()
 
@@ -41,12 +73,62 @@ async def ask_command(interaction: discord.Interaction, question: str) -> None:
         log.error("discord_ask_failed", interaction_id=interaction.id, error=str(e))
         return
 
+    content = await render_answer_content(answer)
+    await interaction.followup.send(content)
+    log.info("discord_ask_completed", interaction_id=interaction.id)
+
+
+async def question_assembler(message) -> str:
+    # if message is reply to a question
+    referenced_text = ""
+    if message.reference and message.reference.message_id:
+        try:
+            referenced_message = await message.channel.fetch_message(message.reference.message_id)
+            referenced_text = referenced_message.content
+        except discord.NotFound:
+            log.info(
+                "No referenced text. Not Found.",
+                channel_id=message.channel.id,
+                channel_name=message.channel.name,
+                guild_id=message.guild.id,
+                target_message_id=message.reference.message_id,
+            )
+        except discord.Forbidden:
+            log.warning(
+                "No referenced text. Forbidden.",
+                channel_id=message.channel.id,
+                channel_name=message.channel.name,
+                guild_id=message.guild.id,
+                target_message_id=message.reference.message_id,
+            )
+
+    return question_assembler_helper(
+        content=message.content,
+        bot_id=message.guild.me.id,
+        referenced_text=referenced_text,
+    )
+
+
+def question_assembler_helper(*, content: str, bot_id: int, referenced_text: str = "") -> str:
+    mention_text = strip_bot_mention(content, bot_id)
+
+    if referenced_text:
+        return referenced_text + "\n\n" + mention_text
+    return mention_text
+
+
+def strip_bot_mention(content: str, bot_id: int) -> str:
+    mention_text = content
+    for x in {f"<@{bot_id}>", f"<@!{bot_id}>"}:
+        mention_text = mention_text.replace(x, "")
+    return mention_text.strip()
+
+
+async def render_answer_content(answer) -> str:
     content = answer.text
     if answer.sources:
         content += "\n\n**Sources:**\n" + "\n".join(f"• {source.url}" for source in answer.sources)
-
-    await interaction.followup.send(content)
-    log.info("discord_ask_completed", interaction_id=interaction.id)
+    return content
 
 
 if __name__ == "__main__":

tests/apps/test_discord_bot.py

@@ -0,0 +1,27 @@
+from src.apps.discord_bot import question_assembler_helper, strip_bot_mention
+
+BOT_ID = 123456789
+
+
+def test_plain_mention():
+    message = f"<@{BOT_ID}> test question"
+    assert (strip_bot_mention(message, BOT_ID)) == "test question"
+
+
+def test_both_mentions():
+    message = f"<@{BOT_ID}> <@!{BOT_ID}> test question"
+    assert (strip_bot_mention(message, BOT_ID)) == "test question"
+
+
+def test_concatenate_reference_and_original():
+    message = f"<@{BOT_ID}> test question"
+    referenced_text = "Original text"
+    assert (
+        question_assembler_helper(content=message, bot_id=BOT_ID, referenced_text=referenced_text)
+        == "Original text\n\ntest question"
+    )
+
+
+def test_empty_response():
+    message = f"<@{BOT_ID}>"
+    assert (question_assembler_helper(content=message, bot_id=BOT_ID)) == ""