feat: migrate dashboard live logs to Server-Sent Events (SSE)

decnet/web/api.py

@@ -4,7 +4,8 @@ from datetime import timedelta
 from typing import Any, AsyncGenerator, Optional
 
 import jwt
-from fastapi import Depends, FastAPI, HTTPException, Query, status
+from fastapi import Depends, FastAPI, HTTPException, Query, status, Request
+from fastapi.responses import StreamingResponse
 from fastapi.middleware.cors import CORSMiddleware
 from fastapi.security import OAuth2PasswordBearer
 from pydantic import BaseModel
@@ -70,12 +71,24 @@ app.add_middleware(
 oauth2_scheme: OAuth2PasswordBearer = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")
 
 
-async def get_current_user(token: str = Depends(oauth2_scheme)) -> str:
+async def get_current_user(request: Request) -> str:
     _credentials_exception: HTTPException = HTTPException(
         status_code=status.HTTP_401_UNAUTHORIZED,
         detail="Could not validate credentials",
         headers={"WWW-Authenticate": "Bearer"},
     )
+    
+    # Extract token from header or query param
+    token: str | None = None
+    auth_header = request.headers.get("Authorization")
+    if auth_header and auth_header.startswith("Bearer "):
+        token = auth_header.split(" ")[1]
+    elif request.query_params.get("token"):
+        token = request.query_params.get("token")
+        
+    if not token:
+        raise _credentials_exception
+
     try:
         _payload: dict[str, Any] = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
         _user_uuid: Optional[str] = _payload.get("uuid")
@@ -205,3 +218,50 @@ async def api_update_mutate_interval(decky_name: str, req: MutateIntervalRequest
     decky.mutate_interval = req.mutate_interval
     save_state(config, compose_path)
     return {"message": "Mutation interval updated"}
+
+
+@app.get("/api/v1/stream")
+async def stream_events(
+    request: Request, 
+    last_event_id: int = Query(0, alias="lastEventId"), 
+    search: Optional[str] = None,
+    current_user: str = Depends(get_current_user)
+) -> StreamingResponse:
+    import json
+    import asyncio
+    
+    async def event_generator() -> AsyncGenerator[str, None]:
+        # Start tracking from the provided ID, or current max if 0
+        last_id = last_event_id
+        if last_id == 0:
+            last_id = await repo.get_max_log_id()
+            
+        stats_interval_sec = 10
+        loops_since_stats = 0
+        
+        while True:
+            if await request.is_disconnected():
+                break
+
+            # Poll for new logs
+            new_logs = await repo.get_logs_after_id(last_id, limit=50, search=search)
+            if new_logs:
+                # Update last_id to the max id in the fetched batch
+                last_id = max(log["id"] for log in new_logs)
+                payload = json.dumps({"type": "logs", "data": new_logs})
+                yield f"event: message\ndata: {payload}\n\n"
+                
+                # If we have new logs, stats probably changed, so force a stats update
+                loops_since_stats = stats_interval_sec
+            
+            # Periodically poll for stats
+            if loops_since_stats >= stats_interval_sec:
+                stats = await repo.get_stats_summary()
+                payload = json.dumps({"type": "stats", "data": stats})
+                yield f"event: message\ndata: {payload}\n\n"
+                loops_since_stats = 0
+                
+            loops_since_stats += 1
+            await asyncio.sleep(1)
+
+    return StreamingResponse(event_generator(), media_type="text/event-stream")