feat(gateway): add Discord platform adapter

surfsense_backend/tests/unit/gateway/test_discord_adapter.py

@@ -0,0 +1,92 @@
+from __future__ import annotations
+
+import pytest
+
+from app.gateway.base.adapter import PlatformSendResult
+from app.gateway.discord.adapter import DiscordAdapter
+
+
+def _discord_payload(content: str = "<@999> summarize this channel"):
+    return {
+        "type": "message",
+        "bot_user_id": "999",
+        "event": {
+            "type": "message",
+            "id": "111",
+            "guild_id": "222",
+            "guild_name": "SurfSense Guild",
+            "channel_id": "333",
+            "channel_name": "general",
+            "content": content,
+            "author": {"id": "444", "username": "anish", "bot": False},
+            "mentions": [{"id": "999", "username": "SurfSense"}],
+        },
+    }
+
+
+def test_discord_adapter_parses_mention_and_strips_bot_mention():
+    adapter = DiscordAdapter("discord-token", bot_user_id="999")
+
+    parsed = adapter.parse_inbound(_discord_payload())
+
+    assert parsed.platform == "discord"
+    assert parsed.text == "summarize this channel"
+    assert parsed.external_peer_id == "discord_thread:222:333:111"
+    assert parsed.metadata["discord_user_peer_id"] == "discord_user:222:444"
+    assert parsed.metadata["discord_thread_peer_id"] == "discord_thread:222:333:111"
+    assert parsed.metadata["mentions_bot"] is True
+
+
+def test_discord_adapter_strips_nickname_mention():
+    adapter = DiscordAdapter("discord-token", bot_user_id="999")
+
+    parsed = adapter.parse_inbound(_discord_payload("<@!999> continue"))
+
+    assert parsed.text == "continue"
+
+
+def test_discord_adapter_uses_message_reference_as_thread_key():
+    adapter = DiscordAdapter("discord-token", bot_user_id="999")
+    payload = _discord_payload("<@999> continue")
+    payload["event"]["id"] = "112"
+    payload["event"]["message_reference"] = {
+        "message_id": "111",
+        "channel_id": "333",
+        "guild_id": "222",
+    }
+
+    parsed = adapter.parse_inbound(payload)
+
+    assert parsed.external_peer_id == "discord_thread:222:333:111"
+    assert parsed.metadata["message_id"] == "112"
+    assert parsed.metadata["thread_key"] == "111"
+
+
+def test_discord_adapter_returns_missing_peer_for_incomplete_payload():
+    adapter = DiscordAdapter("discord-token", bot_user_id="999")
+
+    parsed = adapter.parse_inbound({"event": {"id": "111"}})
+
+    assert parsed.external_peer_id is None
+    assert parsed.external_peer_kind == "unknown"
+
+
+@pytest.mark.asyncio
+async def test_discord_adapter_sends_message(mocker):
+    adapter = DiscordAdapter("discord-token", bot_user_id="999")
+    adapter.client.send_message = mocker.AsyncMock(
+        return_value=PlatformSendResult(external_message_id="555")
+    )
+
+    result = await adapter.send_message(
+        external_peer_id="333",
+        text="hello",
+        reply_to_message_id="111",
+    )
+
+    assert result.external_message_id == "555"
+    adapter.client.send_message.assert_awaited_once_with(
+        channel_id="333",
+        content="hello",
+        reply_to_message_id="111",
+    )