feat(bot): switch to in-memory conversation history

- Replaced Nextcloud chat history fetching with in-memory storage for conversation history.
- Added limits to history length based on an environment variable (`CONTEXT_MESSAGES`).
- Simplified prompt-building logic by removing async history fetching.

systems/x86_64-linux/mx/nextcloud-claude-bot/bot.py

@@ -49,8 +49,10 @@ log = logging.getLogger(__name__)
 
 app = FastAPI(title="Nextcloud Claude Bot")
 
-# Number of recent messages to fetch for context
-CONTEXT_MESSAGES = int(os.environ.get("CONTEXT_MESSAGES", "6"))
+# In-memory conversation history per conversation token
+# Format: {token: [(user, message), ...]}
+conversations: dict[str, list[tuple[str, str]]] = {}
+MAX_HISTORY = int(os.environ.get("CONTEXT_MESSAGES", "6"))
 
 
 def generate_bot_auth_headers(body: str = "") -> dict:
@@ -68,35 +70,6 @@ def generate_bot_auth_headers(body: str = "") -> dict:
     }
 
 
-async def fetch_chat_history(conversation_token: str, limit: int = CONTEXT_MESSAGES) -> list[dict]:
-    """Fetch recent messages from Nextcloud Talk conversation."""
-    if not NEXTCLOUD_URL:
-        log.warning("NEXTCLOUD_URL not configured, cannot fetch history")
-        return []
-
-    url = f"{NEXTCLOUD_URL}/ocs/v2.php/apps/spreed/api/v1/chat/{conversation_token}"
-    params = {
-        "limit": limit,
-        "lookIntoFuture": 0,
-    }
-
-    headers = generate_bot_auth_headers()
-    headers["Accept"] = "application/json"
-
-    async with httpx.AsyncClient() as client:
-        try:
-            resp = await client.get(url, params=params, headers=headers)
-            if resp.status_code == 200:
-                data = resp.json()
-                messages = data.get("ocs", {}).get("data", [])
-                # Messages come newest first, reverse for chronological order
-                return list(reversed(messages))
-            else:
-                log.warning(f"Failed to fetch chat history: {resp.status_code} {resp.text[:200]}")
-                return []
-        except Exception as e:
-            log.exception("Error fetching chat history")
-            return []
 
 
 def verify_signature(body: bytes, signature: str, random: Optional[str] = None) -> bool:
@@ -128,32 +101,17 @@ def verify_signature(body: bytes, signature: str, random: Optional[str] = None)
     return False
 
 
-async def build_prompt(conversation_token: str, current_message: str, current_user: str) -> str:
-    """Build prompt with conversation history from Nextcloud."""
+def build_prompt(conversation_token: str, current_message: str, current_user: str) -> str:
+    """Build prompt with in-memory conversation history."""
     parts = []
 
     if SYSTEM_PROMPT:
         parts.append(f"System: {SYSTEM_PROMPT}\n")
 
-    # Fetch recent history from Nextcloud
-    history = await fetch_chat_history(conversation_token)
-
-    # Add recent history (excluding the current message which triggered this)
-    for msg in history:
-        actor_type = msg.get("actorType", "")
-        actor_id = msg.get("actorId", "")
-        message_text = msg.get("message", "")
-        msg_type = msg.get("messageType", "")
-
-        # Skip system messages
-        if msg_type == "system":
-            continue
-
-        # Determine if this is a user or the bot
-        if actor_type == "bots":
-            parts.append(f"Assistant: {message_text}")
-        elif actor_type == "users":
-            parts.append(f"User ({actor_id}): {message_text}")
+    # Add recent history from memory
+    history = conversations.get(conversation_token, [])
+    for role, msg in history[-MAX_HISTORY:]:
+        parts.append(f"{role}: {msg}")
 
     # Add current message
     parts.append(f"User ({current_user}): {current_message}")
@@ -331,17 +289,27 @@ Schreib mir einfach eine Nachricht und ich antworte dir.
 **Befehle:**
 • `/help` oder `/hilfe` – Diese Hilfe anzeigen
 
-Der Bot nutzt die letzten Nachrichten aus dem Chat als Kontext."""
+Der Bot merkt sich die letzten Nachrichten pro Raum (bis zum Neustart)."""
         await send_reply(conversation_token, help_text, reply_to=message_id)
         return JSONResponse({"status": "ok", "action": "help"})
 
     # Build prompt with chat history and call Claude
-    prompt = await build_prompt(conversation_token, message_text, actor_id)
+    prompt = build_prompt(conversation_token, message_text, actor_id)
     response = await call_claude(prompt)
 
+    # Store in history
+    if conversation_token not in conversations:
+        conversations[conversation_token] = []
+    conversations[conversation_token].append((f"User ({actor_id})", message_text))
+    conversations[conversation_token].append(("Assistant", response))
+
+    # Trim history
+    if len(conversations[conversation_token]) > MAX_HISTORY * 2:
+        conversations[conversation_token] = conversations[conversation_token][-MAX_HISTORY * 2:]
+
     # Send response
     await send_reply(conversation_token, response, reply_to=message_id)
-    
+
     return JSONResponse({"status": "ok"})
 
 
@@ -353,7 +321,7 @@ async def health():
         "nextcloud_url": NEXTCLOUD_URL,
         "claude_path": CLAUDE_PATH,
         "allowed_users": ALLOWED_USERS if ALLOWED_USERS else "all",
-        "context_messages": CONTEXT_MESSAGES,
+        "max_history": MAX_HISTORY,
     }