Migliora robustezza Dockerfile e controlli TradingBotService

- Installa wget e aggiorna healthcheck in Dockerfile (usa wget invece di curl, UID 1001 per utente non-root)
- Aggiunti controlli di nullità e validità su simboli, prezzi e segnali in TradingBotService
- Migliorata gestione delle eccezioni con stampa dello stack trace
- Filtrati dati non validi prima del calcolo degli indicatori
- Aumentata la sicurezza e la resilienza contro dati corrotti o incompleti

TradingBot/Services/TradingBotService.cs

@@ -162,17 +162,23 @@ public class TradingBotService
         try
         {
             var enabledSymbols = _assetConfigs.Values
-                .Where(c => c.IsEnabled)
+                .Where(c => c != null && c.IsEnabled)
                 .Select(c => c.Symbol)
+                .Where(s => !string.IsNullOrWhiteSpace(s))
                 .ToList();
 
             if (enabledSymbols.Count == 0) return;
 
             var prices = await _marketDataService.GetMarketPricesAsync(enabledSymbols);
             
+            if (prices == null) return;
+
             foreach (var price in prices)
             {
-                await ProcessAssetUpdate(price);
+                if (price != null)
+                {
+                    await ProcessAssetUpdate(price);
+                }
             }
 
             UpdateGlobalStatistics();
@@ -180,11 +186,16 @@ public class TradingBotService
         catch (Exception ex)
         {
             Console.WriteLine($"Error in UpdateAsync: {ex.Message}");
+            Console.WriteLine($"Stack trace: {ex.StackTrace}");
         }
     }
 
     private async Task ProcessAssetUpdate(MarketPrice price)
     {
+        // Add null check for price
+        if (price == null || price.Price <= 0)
+            return;
+
         if (!_assetConfigs.TryGetValue(price.Symbol, out var config) || !config.IsEnabled)
             return;
 
@@ -216,10 +227,15 @@ public class TradingBotService
 
             // Generate trading signal
             var signal = await _strategy.AnalyzeAsync(price.Symbol, _priceHistory[price.Symbol]);
-            OnSignalGenerated?.Invoke(signal);
+            
+            // Add null check for signal
+            if (signal != null)
+            {
+                OnSignalGenerated?.Invoke(signal);
 
-            // Execute trades based on strategy and configuration
-            await EvaluateAndExecuteTrade(price.Symbol, signal, price, config);
+                // Execute trades based on strategy and configuration
+                await EvaluateAndExecuteTrade(price.Symbol, signal, price, config);
+            }
         }
     }
 
@@ -339,10 +355,18 @@ public class TradingBotService
 
     private void UpdateIndicators(string symbol)
     {
-        var history = _priceHistory[symbol];
-        if (history.Count < 26) return;
+        if (!_priceHistory.TryGetValue(symbol, out var history) || history == null || history.Count < 26)
+            return;
 
-        var prices = history.Select(p => p.Price).ToList();
+        // Filter out null prices and extract valid price values
+        var prices = history
+            .Where(p => p != null && p.Price > 0)
+            .Select(p => p.Price)
+            .ToList();
+        
+        // Ensure we still have enough data after filtering
+        if (prices.Count < 26)
+            return;
         
         var rsi = TechnicalAnalysis.CalculateRSI(prices);
         var (macd, signal, histogram) = TechnicalAnalysis.CalculateMACD(prices);
@@ -482,6 +506,9 @@ public class TradingBotService
 
     public MarketPrice? GetLatestPrice(string symbol)
     {
+        if (string.IsNullOrWhiteSpace(symbol))
+            return null;
+
         var history = GetPriceHistory(symbol);
         return history?.LastOrDefault();
     }