Weighing: Add SchemberEventScale

Elwig/Helpers/Weighing/SchemberEventScale.cs

@@ -1,5 +1,12 @@
-namespace Elwig.Helpers.Weighing {
-    public class SchemberEventScale : Scale, IEventScale {
+using System;
+using System.IO;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Windows;
+
+namespace Elwig.Helpers.Weighing {
+    public class SchemberEventScale : Scale, IEventScale, IDisposable {
 
         public string Manufacturer => "Schember";
         public int InternalScaleNr => 1;
@@ -8,15 +15,74 @@
         public bool IsReady { get; private set; }
         public bool HasFillingClearance { get; private set; }
 
+        public event IEventScale.EventHandler<WeighingEventArgs> WeighingEvent;
+
+        private bool IsRunning = true;
+        private readonly Thread BackgroundThread;
+
         public SchemberEventScale(string id, string model, string cnx, string? empty = null, string? filling = null, int? limit = null, string? log = null) :
             base(cnx, empty, filling, limit, log) {
             ScaleId = id;
             Model = model;
             IsReady = true;
             HasFillingClearance = false;
-            Stream.WriteTimeout = 250;
-            Stream.ReadTimeout = 6000;
+            BackgroundThread = new Thread(new ParameterizedThreadStart(BackgroundLoop));
+            BackgroundThread.Start();
         }
 
+        protected virtual void RaiseWeighingEvent(WeighingEventArgs evt) {
+            App.MainDispatcher.BeginInvoke(() => WeighingEvent?.Invoke(this, evt));
+        }
+
+        public new void Dispose() {
+            IsRunning = false;
+            BackgroundThread.Interrupt();
+            BackgroundThread.Join();
+            base.Dispose();
+            GC.SuppressFinalize(this);
+        }
+
+        protected async void BackgroundLoop(object? parameters) {
+            while (IsRunning) {
+                try {
+                    var data = await Receive();
+                    RaiseWeighingEvent(new WeighingEventArgs(data));
+                } catch (Exception ex) {
+                    MessageBox.Show($"Beim Wiegen ist ein Fehler Aufgetreten:\n\n{ex.Message}", "Waagenfehler",
+                        MessageBoxButton.OK, MessageBoxImage.Error);
+                }
+            }
+        }
+
+        protected async Task<WeighingResult> Receive() {
+            string? line = null;
+            using (var reader = new StreamReader(Stream, Encoding.ASCII, false, -1, true)) {
+                line = await reader.ReadLineAsync();
+                if (LogPath != null) await File.AppendAllTextAsync(LogPath, $"{line}\r\n");
+            }
+            if (line == null || line.Length != 32 || line[0] != ' ' || line[9] != ' ' || line[15] != ' ' || line[20] != ' ') {
+                throw new IOException($"Invalid event from scale: '{line}'");
+            }
+
+            var date    = line[ 1.. 9];
+            var time    = line[10..15];
+            var identNr = line[16..20].Trim();
+            var netto   = line[21..30].Trim();
+            var unit    = line[30..32];
+
+            if (unit != "kg") {
+                throw new IOException($"Unsupported unit in weighing event: '{unit}'");
+            }
+
+            identNr = identNr.Length > 0 && identNr != "0" ? identNr : null;
+            var parsedDate = DateOnly.Parse(date);
+            return new() {
+                Weight = int.Parse(netto),
+                WeighingId = identNr,
+                FullWeighingId = identNr != null ? $"{parsedDate:yyyy-MM-dd}/{identNr}" : null,
+                Date = parsedDate,
+                Time = TimeOnly.Parse(time),
+            };
+        }
     }
 }