feat(chat): implement native hub chat with sqlite conversations store, SSE streaming and DSH 5th universe integration

app/routers/chat.py

@@ -0,0 +1,76 @@
+from fastapi import APIRouter, HTTPException, Query, Body, Request
+from fastapi.responses import StreamingResponse
+from typing import Optional, Dict, Any, List
+from pydantic import BaseModel
+
+from app.chat_service import (
+    list_universe_conversations,
+    create_universe_conversation,
+    get_conversation_messages,
+    stream_chat_messages,
+    rename_universe_conversation,
+    pin_universe_conversation,
+    delete_universe_conversation
+)
+
+router = APIRouter(prefix="/api/chat", tags=["Chat"])
+
+class CreateConversationRequest(BaseModel):
+    title: Optional[str] = "Nouvelle conversation"
+
+class UpdateConversationRequest(BaseModel):
+    title: Optional[str] = None
+    pinned: Optional[bool] = None
+
+class SendMessageRequest(BaseModel):
+    message: str
+
+@router.get("/{universe_id}/conversations")
+async def get_conversations(universe_id: str):
+    """Returns the list of conversations for a universe."""
+    convs = await list_universe_conversations(universe_id)
+    return {"ok": True, "universe_id": universe_id, "conversations": convs}
+
+@router.post("/{universe_id}/conversations")
+async def create_conversation(universe_id: str, body: CreateConversationRequest = Body(default_factory=CreateConversationRequest)):
+    """Creates a new conversation in a universe."""
+    conv = await create_universe_conversation(universe_id, title=body.title)
+    return {"ok": True, "conversation": conv}
+
+@router.get("/{universe_id}/conversations/{session_key}/messages")
+async def get_messages(universe_id: str, session_key: str):
+    """Retrieves full message history for a conversation."""
+    messages = await get_conversation_messages(universe_id, session_key)
+    return {"ok": True, "session_key": session_key, "messages": messages}
+
+@router.post("/{universe_id}/conversations/{session_key}/send")
+async def send_message(universe_id: str, session_key: str, body: SendMessageRequest):
+    """Sends a message and streams SSE chunks back."""
+    if not body.message or not body.message.strip():
+        raise HTTPException(status_code=400, detail="Message cannot be empty")
+    
+    stream = stream_chat_messages(universe_id, session_key, body.message.strip())
+    return StreamingResponse(
+        stream,
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no"
+        }
+    )
+
+@router.patch("/{universe_id}/conversations/{session_key}")
+async def update_conv(universe_id: str, session_key: str, body: UpdateConversationRequest):
+    """Updates conversation title or pinned status."""
+    if body.title is not None:
+        await rename_universe_conversation(universe_id, session_key, body.title)
+    if body.pinned is not None:
+        await pin_universe_conversation(universe_id, session_key, body.pinned)
+    return {"ok": True}
+
+@router.delete("/{universe_id}/conversations/{session_key}")
+async def delete_conv(universe_id: str, session_key: str):
+    """Deletes a conversation."""
+    await delete_universe_conversation(universe_id, session_key)
+    return {"ok": True}