Import: DXF backend/frontend, report more unsupported features info

Now for unsupported features we report on line numbers and on the entity
handle, in case that unsupported feature is a DXF entity. To avoid
flooding the output, only a maximum of 5 instances are reported with
details. The rest simply add up to the global count and are ellipsized
in the report.

Report output is now in sentence case.

src/Mod/Draft/importDXF.py

@@ -4228,38 +4228,38 @@ class DxfImportReporter:
         Formats the statistics into a human-readable string for console output.
         """
         if not self.stats:
-            return "DXF Import: No statistics were returned from the importer.\n"
+            return "DXF Import: no statistics were returned from the importer.\n"
 
-        lines = ["\n--- DXF Import Summary ---"]
+        lines = ["\n--- DXF import summary ---"]
 
         # General info
-        lines.append(f"DXF Version: {self.stats.get('dxfVersion', 'Unknown')}")
-        lines.append(f"File Encoding: {self.stats.get('dxfEncoding', 'Unknown')}")
+        lines.append(f"DXF version: {self.stats.get('dxfVersion', 'Unknown')}")
+        lines.append(f"File encoding: {self.stats.get('dxfEncoding', 'Unknown')}")
 
         # Scaling info
         file_units = self.stats.get('fileUnits', 'Not specified')
         source = self.stats.get('scalingSource', '')
         if source:
-            lines.append(f"File Units: {file_units} (from {source})")
+            lines.append(f"File units: {file_units} (from {source})")
         else:
-            lines.append(f"File Units: {file_units}")
+            lines.append(f"File units: {file_units}")
 
         manual_scaling = self.stats.get('importSettings', {}).get('Manual scaling factor', '1.0')
-        lines.append(f"Manual Scaling Factor: {manual_scaling}")
+        lines.append(f"Manual scaling factor: {manual_scaling}")
 
         final_scaling = self.stats.get('finalScalingFactor', 1.0)
-        lines.append(f"Final Scaling: 1 DXF unit = {final_scaling:.4f} mm")
+        lines.append(f"Final scaling: 1 DXF unit = {final_scaling:.4f} mm")
         lines.append("")
 
         # Timing
         lines.append("Performance:")
         cpp_time = self.stats.get('importTimeSeconds', 0.0)
-        lines.append(f"  - C++ Import Time: {cpp_time:.4f} seconds")
-        lines.append(f"  - Total Import Time: {self.total_time:.4f} seconds")
+        lines.append(f"  - C++ import time: {cpp_time:.4f} seconds")
+        lines.append(f"  - Total import time: {self.total_time:.4f} seconds")
         lines.append("")
 
         # Settings
-        lines.append("Import Settings:")
+        lines.append("Import settings:")
         settings = self.stats.get('importSettings', {})
         if settings:
             for key, value in sorted(settings.items()):
@@ -4269,7 +4269,7 @@ class DxfImportReporter:
         lines.append("")
 
         # Counts
-        lines.append("Entity Counts:")
+        lines.append("Entity counts:")
         total_read = 0
         entities = self.stats.get('entityCounts', {})
         if entities:
@@ -4283,15 +4283,31 @@ class DxfImportReporter:
         lines.append(f"FreeCAD objects created: {self.stats.get('totalEntitiesCreated', 0)}")
         lines.append("")
 
-        lines.append("Unsupported Features:")
+        lines.append("Import issues and unsupported features:")
         unsupported = self.stats.get('unsupportedFeatures', {})
         if unsupported:
-            for key, value in sorted(unsupported.items()):
-                lines.append(f"  - {key}: {value} time(s)")
-        else:
-            lines.append("  (None)")
+            for key, occurrences in sorted(unsupported.items()):
+                count = len(occurrences)
+                max_details_to_show = 5
 
-        lines.append("--- End of Summary ---\n")
+                details_list = []
+                for i, (line, handle) in enumerate(occurrences):
+                    if i >= max_details_to_show:
+                        break
+                    if handle:
+                        details_list.append(f"line {line} (handle {handle})")
+                    else:
+                        details_list.append(f"line {line} (no handle available)")
+
+                details_str = ", ".join(details_list)
+                if count > max_details_to_show:
+                    lines.append(f"  - {key}: {count} time(s). Examples: {details_str}, ...")
+                else:
+                    lines.append(f"  - {key}: {count} time(s) at {details_str}")
+        else:
+            lines.append("  (none)")
+
+        lines.append("--- End of summary ---\n")
         return "\n".join(lines)
 
     def report_to_console(self):

src/Mod/Import/App/dxf/ImpExpDxf.cpp

@@ -1404,7 +1404,14 @@ Py::Object ImpExpDxfRead::getStatsAsPyObject()
     // Create a nested dictionary for any unsupported DXF features encountered.
     Py::Dict unsupportedFeaturesDict;
     for (const auto& pair : m_stats.unsupportedFeatures) {
-        unsupportedFeaturesDict.setItem(pair.first.c_str(), Py::Long(pair.second));
+        Py::List occurrencesList;
+        for (const auto& occurrence : pair.second) {
+            Py::Tuple infoTuple(2);
+            infoTuple.setItem(0, Py::Long(occurrence.first));
+            infoTuple.setItem(1, Py::String(occurrence.second));
+            occurrencesList.append(infoTuple);
+        }
+        unsupportedFeaturesDict.setItem(pair.first.c_str(), occurrencesList);
     }
     statsDict.setItem("unsupportedFeatures", unsupportedFeaturesDict);
 

src/Mod/Import/App/dxf/dxf.cpp

@@ -2342,8 +2342,8 @@ bool CDxfRead::ReadDimension()
 
 bool CDxfRead::ReadUnknownEntity()
 {
-    UnsupportedFeature("Entity type '%s'", m_record_data);
     ProcessAllEntityAttributes();
+    UnsupportedFeature("Entity type '%s'", m_record_data);
     return true;
 }
 
@@ -2403,7 +2403,7 @@ void CDxfRead::UnsupportedFeature(const char* format, args&&... argValuess)
 {
     // NOLINTNEXTLINE(runtime/printf)
     std::string formattedMessage = fmt::sprintf(format, std::forward<args>(argValuess)...);
-    m_stats.unsupportedFeatures[formattedMessage]++;
+    m_stats.unsupportedFeatures[formattedMessage].emplace_back(m_line, m_current_entity_handle);
 }
 
 bool CDxfRead::get_next_record()
@@ -2798,6 +2798,8 @@ bool CDxfRead::ReadEntity()
 {
     InitializeAttributes();
     m_entityAttributes.SetDefaults();
+    m_current_entity_handle.clear();
+    SetupStringAttribute(eHandle, m_current_entity_handle);
     EntityNormalVector.Set(0, 0, 1);
     Setup3DVectorAttribute(eExtrusionDirection, EntityNormalVector);
     SetupStringAttribute(eLinetypeName, m_entityAttributes.m_LineType);

src/Mod/Import/App/dxf/dxf.h

@@ -187,7 +187,7 @@ struct DxfImportStats
     double finalScalingFactor = 1.0;
     std::map<std::string, int> entityCounts;
     std::map<std::string, std::string> importSettings;
-    std::map<std::string, int> unsupportedFeatures;
+    std::map<std::string, std::vector<std::pair<int, std::string>>> unsupportedFeatures;
     int totalEntitiesCreated = 0;
 };
 
@@ -200,6 +200,7 @@ enum eDXFGroupCode_t
     ePrimaryText = 1,
     eName = 2,
     eExtraText = 3,
+    eHandle = 5,
     eLinetypeName = 6,
     eTextStyleName = 7,
     eLayerName = 8,
@@ -462,6 +463,7 @@ private:
     bool m_not_eof = true;
     int m_line = 0;
     bool m_repeat_last_record = false;
+    std::string m_current_entity_handle;
 
     // The scaling from DXF units to millimetres.
     // This does not include the dxfScaling option