feat: add backtest progress tracking and fix stop functionality

src/backend/app/api/backtest.py

@@ -169,6 +169,11 @@ def get_backtest(
             status_code=status.HTTP_404_NOT_FOUND, detail="Backtest not found"
         )
 
+    # Add progress from running engine if available
+    if backtest.status == "running" and run_id in running_backtests:
+        engine = running_backtests[run_id]
+        backtest.progress = engine.progress
+    
     return backtest
 
 
@@ -226,7 +231,12 @@ def stop_backtest(
 
     if run_id in running_backtests:
         engine = running_backtests[run_id]
-        asyncio.create_task(engine.stop())
+        engine.running = False  # Direct sync access to running flag
+        backtest.status = "stopped"
+        backtest.ended_at = datetime.utcnow()
+        db.commit()
+    elif backtest.status == "running":
+        # Engine already finished but status not updated
         backtest.status = "stopped"
         backtest.ended_at = datetime.utcnow()
         db.commit()

src/backend/app/db/schemas.py

@@ -90,6 +90,7 @@ class BacktestResponse(BaseModel):
     status: str
     config: dict
     result: Optional[dict]
+    progress: Optional[int] = None
 
     class Config:
         from_attributes = True

src/backend/app/services/backtest/engine.py

@@ -31,6 +31,8 @@ class BacktestEngine:
         self.entry_time: Optional[int] = None
         self.trades: List[Dict[str, Any]] = []
         self.running = False
+        self.progress = 0
+        self.total_klines = 0
 
     async def run(self) -> Dict[str, Any]:
         self.running = True
@@ -98,10 +100,13 @@ class BacktestEngine:
         return self.results
 
     async def _process_klines(self, klines: List[Dict[str, Any]]):
+        self.total_klines = len(klines)
         for i, kline in enumerate(klines):
             if not self.running:
                 break
 
+            self.progress = int((i / self.total_klines) * 100) if self.total_klines > 0 else 0
+
             price = float(kline.get("close", 0))
             if price <= 0:
                 continue
@@ -384,6 +389,8 @@ class BacktestEngine:
 
     async def stop(self):
         self.running = False
+        self.progress = 0
+        self.total_klines = 0
         self.status = "stopped"
         self._calculate_metrics()
 
@@ -393,4 +400,13 @@ class BacktestEngine:
             "status": self.status,
             "results": self.results,
             "signals": self.signals,
+            "progress": self.progress,
+            "total_klines": self.total_klines,
+        }
+
+    def get_status(self) -> Dict[str, Any]:
+        return {
+            "status": self.status,
+            "progress": self.progress,
+            "total_klines": self.total_klines,
         }

src/frontend/src/lib/api/types.ts

@@ -62,9 +62,10 @@ export interface Backtest {
 	bot_id: string;
 	started_at: string;
 	ended_at: string | null;
-	status: 'running' | 'completed' | 'failed';
+	status: 'running' | 'completed' | 'failed' | 'stopped';
 	config: BacktestConfig;
 	result: BacktestResult | null;
+	progress?: number;
 }
 
 export interface BacktestConfig {

src/frontend/src/routes/bot/[id]/backtest/+page.svelte

@@ -33,12 +33,12 @@
 			await loadBot();
 			await loadBacktests();
 			
-			// Poll for backtest updates every 5 seconds if any are running
+			// Poll for backtest updates every 2 seconds if any are running
 			const pollInterval = setInterval(async () => {
 				if ($backtestStore.backtestHistory.some(b => b.status === 'running')) {
 					await loadBacktests();
 				}
-			}, 5000);
+			}, 2000);
 			
 			return () => clearInterval(pollInterval);
 		}
@@ -201,6 +201,12 @@
 								</div>
 							{/if}
 							{#if backtest.status === 'running'}
+								<div class="progress-container">
+									<div class="progress-bar">
+										<div class="progress-fill" style="width: {backtest.progress ?? 0}%"></div>
+									</div>
+									<span class="progress-text">{backtest.progress ?? 0}%</span>
+								</div>
 								<button onclick={() => stopBacktest(backtest.id)} class="btn btn-danger">Stop</button>
 							{/if}
 						</div>
@@ -400,6 +406,11 @@
 		color: #fca5a5;
 	}
 
+	.status-stopped {
+		background: rgba(251, 191, 36, 0.2);
+		color: #fbbf24;
+	}
+
 	.backtest-date {
 		color: #888;
 		font-size: 0.85rem;
@@ -435,6 +446,33 @@
 		color: #ef4444;
 	}
 
+	.progress-container {
+		display: flex;
+		align-items: center;
+		gap: 0.75rem;
+		margin-bottom: 0.75rem;
+	}
+
+	.progress-bar {
+		flex: 1;
+		height: 8px;
+		background: rgba(255, 255, 255, 0.1);
+		border-radius: 4px;
+		overflow: hidden;
+	}
+
+	.progress-fill {
+		height: 100%;
+		background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+		transition: width 0.3s ease;
+	}
+
+	.progress-text {
+		font-size: 0.85rem;
+		color: #888;
+		min-width: 40px;
+	}
+
 	.btn-danger {
 		margin-top: 0.75rem;
 		width: auto;