[Bug][SubscriptionBilling]: Performance: Billing document creation does not scale to large datasets (4M+ subscription lines)

src/Apps/W1/Subscription Billing/App/Base/Codeunits/ProgressTracker.Codeunit.al

@@ -0,0 +1,143 @@
+namespace Microsoft.SubscriptionBilling;
+
+/// <summary>
+/// Reusable progress dialog helper for long-running batch processes.
+/// Shows elapsed time, progress (processed/total), estimated time remaining (ETA) and throughput.
+/// All dialog interaction is guarded by GuiAllowed, so callers are safe to use it from background
+/// Job Queue sessions without additional guards.
+/// </summary>
+codeunit 8035 "Progress Tracker"
+{
+    var
+        Window: Dialog;
+        StartTime: DateTime;
+        LastUpdateTime: DateTime;
+        TotalCount: Integer;
+        LastDetail: Text;
+        IsOpen: Boolean;
+        UpdateIntervalMs: Integer;
+        DialogTxt: Label '#1#################################\Processing  #2###############################\Progress    #3###############################\Elapsed     #4###############################\Est. remaining #5############################\Throughput  #6###############################', Comment = '%1 = activity caption, %2 = current item detail, %3 = progress (processed of total), %4 = elapsed time, %5 = estimated time remaining, %6 = throughput';
+        ProgressLbl: Label '%1 of %2 (%3%)', Comment = '%1 = processed count, %2 = total count, %3 = percentage';
+        PerMinuteLbl: Label '%1 / min', Comment = '%1 = number of items processed per minute';
+
+    /// <summary>
+    /// Opens the progress dialog (only when GuiAllowed) and starts the elapsed-time clock.
+    /// </summary>
+    /// <param name="ActivityText">Caption describing the running activity.</param>
+    /// <param name="NewTotalCount">Total number of items to process; used for ETA and percentage. Pass 0 if unknown.</param>
+    procedure StartActivity(ActivityText: Text; NewTotalCount: Integer)
+    begin
+        StartTime := CurrentDateTime();
+        LastUpdateTime := StartTime;
+        TotalCount := NewTotalCount;
+        LastDetail := '';
+        UpdateIntervalMs := 1000; // Redraw the dialog at most once per second.
+        if not GuiAllowed() then
+            exit;
+        Window.Open(DialogTxt);
+        Window.Update(1, ActivityText);
+        IsOpen := true;
+    end;
+
+    /// <summary>
+    /// Updates the dialog. Redraws are throttled (at most once per second, plus whenever the detail
+    /// text changes or the last item is reached) to avoid excessive flicker.
+    /// </summary>
+    /// <param name="ProcessedCount">Number of items processed so far.</param>
+    /// <param name="DetailText">Detail about the current item (e.g. contract no., partner, step).</param>
+    procedure UpdateProgress(ProcessedCount: Integer; DetailText: Text)
+    begin
+        if not IsOpen then
+            exit;
+        if not ShouldUpdate(ProcessedCount, DetailText) then
+            exit;
+        LastDetail := DetailText;
+        LastUpdateTime := CurrentDateTime();
+        Window.Update(2, DetailText);
+        Window.Update(3, FormatProgress(ProcessedCount));
+        Window.Update(4, FormatDurationText(CurrentDateTime() - StartTime));
+        Window.Update(5, FormatEta(ProcessedCount));
+        Window.Update(6, FormatThroughput(ProcessedCount));
+    end;
+
+    /// <summary>
+    /// Closes the progress dialog if it is open.
+    /// </summary>
+    procedure Finish()
+    begin
+        if IsOpen then
+            Window.Close();
+        IsOpen := false;
+    end;
+
+    local procedure ShouldUpdate(ProcessedCount: Integer; DetailText: Text): Boolean
+    begin
+        if DetailText <> LastDetail then
+            exit(true);
+        if (TotalCount > 0) and (ProcessedCount >= TotalCount) then
+            exit(true);
+        exit((CurrentDateTime() - LastUpdateTime) >= UpdateIntervalMs);
+    end;
+
+    local procedure FormatProgress(ProcessedCount: Integer): Text
+    var
+        Percentage: Integer;
+    begin
+        if TotalCount <= 0 then
+            exit(Format(ProcessedCount));
+        Percentage := Round(ProcessedCount / TotalCount * 100, 1);
+        exit(StrSubstNo(ProgressLbl, ProcessedCount, TotalCount, Percentage));
+    end;
+
+    local procedure FormatEta(ProcessedCount: Integer): Text
+    var
+        Elapsed: Duration;
+    begin
+        if (ProcessedCount <= 0) or (TotalCount <= 0) or (ProcessedCount >= TotalCount) then
+            exit('-');
+        Elapsed := CurrentDateTime() - StartTime;
+        exit(FormatDurationText(Round(Elapsed / ProcessedCount * (TotalCount - ProcessedCount), 1)));
+    end;
+
+    local procedure FormatThroughput(ProcessedCount: Integer): Text
+    var
+        Elapsed: Duration;
+        PerMinute: Decimal;
+    begin
+        Elapsed := CurrentDateTime() - StartTime;
+        if Elapsed <= 0 then
+            exit('-');
+        PerMinute := Round(ProcessedCount / (Elapsed / 60000), 0.1);
+        exit(StrSubstNo(PerMinuteLbl, Format(PerMinute, 0, '<Precision,1:1><Standard Format,0>')));
+    end;
+
+    local procedure FormatDurationText(DurationValue: Duration): Text
+    var
+        TotalSeconds: Integer;
+        Days: Integer;
+        Hours: Integer;
+        Minutes: Integer;
+        Seconds: Integer;
+        HH: Text;
+        MM: Text;
+        SS: Text;
+    begin
+        if DurationValue <= 0 then
+            exit('0s');
+        if DurationValue < 1000 then
+            exit('<1s');
+        TotalSeconds := Round(DurationValue / 1000, 1);
+        Days := TotalSeconds div 86400;
+        TotalSeconds := TotalSeconds mod 86400;
+        Hours := TotalSeconds div 3600;
+        TotalSeconds := TotalSeconds mod 3600;
+        Minutes := TotalSeconds div 60;
+        Seconds := TotalSeconds mod 60;
+        HH := PadStr('', 2 - StrLen(Format(Hours)), '0') + Format(Hours);
+        MM := PadStr('', 2 - StrLen(Format(Minutes)), '0') + Format(Minutes);
+        SS := PadStr('', 2 - StrLen(Format(Seconds)), '0') + Format(Seconds);
+        if Days > 0 then
+            exit(Format(Days) + 'd ' + HH + ':' + MM + ':' + SS);
+        exit(HH + ':' + MM + ':' + SS);
+    end;
+}