fix: Add timeout settings and retry logic to MySQL connector

Configuration improvements:
- Set read_timeout=300 (5 minutes) to handle long queries
- Set write_timeout=300 (5 minutes) for writes
- Set max_allowed_packet=64MB to handle larger data transfers

Retry logic:
- Added retry mechanism with max 3 retries on fetch failure
- Auto-reconnect on connection loss before retry
- Better error messages showing retry attempts

This fixes the 'connection is lost' error that occurs during
long-running migrations by:
1. Giving MySQL queries more time to complete
2. Allowing larger packet sizes for bulk data
3. Automatically recovering from connection drops

Fixes: 'Connection is lost' error during full migration

tests/test_setup.py

@@ -1,5 +1,6 @@
 """Test setup and basic functionality."""
 import pytest
+from datetime import timedelta, time
 from config import get_settings, TABLE_CONFIGS, RAWDATACOR_COLUMNS, ELABDATADISP_FIELD_MAPPING
 from src.transformers.data_transformer import DataTransformer
 
@@ -61,6 +62,12 @@ class TestDataTransformation:
         assert pg_row["id"] == 1
         assert pg_row["unit_name"] == "TestUnit"
         assert pg_row["tool_name_id"] == "Tool1"
+        assert pg_row["event_timestamp"] is not None
+        assert pg_row["event_timestamp"].year == 2024
+        assert pg_row["event_timestamp"].month == 1
+        assert pg_row["event_timestamp"].day == 1
+        assert pg_row["event_timestamp"].hour == 12
+        assert pg_row["event_timestamp"].minute == 0
         assert isinstance(pg_row["measurements"], dict)
         assert "0" in pg_row["measurements"]
         assert pg_row["measurements"]["0"]["value"] == "100.5"
@@ -110,6 +117,12 @@ class TestDataTransformation:
         # Verify
         assert pg_row["id_elab_data"] == 5000
         assert pg_row["state"] == "OK"
+        assert pg_row["event_timestamp"] is not None
+        assert pg_row["event_timestamp"].year == 2024
+        assert pg_row["event_timestamp"].month == 1
+        assert pg_row["event_timestamp"].day == 1
+        assert pg_row["event_timestamp"].hour == 12
+        assert pg_row["event_timestamp"].minute == 0
         assert isinstance(pg_row["measurements"], dict)
         assert "shifts" in pg_row["measurements"]
         assert "coordinates" in pg_row["measurements"]
@@ -135,6 +148,105 @@ class TestDataTransformation:
         assert "state" in columns
 
 
+class TestTimeConversion:
+    """Test time conversion utilities."""
+
+    def test_convert_time_from_string(self):
+        """Test converting time from string format."""
+        event_time = "12:30:45"
+        result = DataTransformer._convert_time(event_time)
+        assert isinstance(result, time)
+        assert result.hour == 12
+        assert result.minute == 30
+        assert result.second == 45
+
+    def test_convert_time_from_timedelta(self):
+        """Test converting time from timedelta (MySQL TIME format)."""
+        # MySQL returns TIME columns as timedelta
+        event_time = timedelta(hours=14, minutes=25, seconds=30)
+        result = DataTransformer._convert_time(event_time)
+        assert isinstance(result, time)
+        assert result.hour == 14
+        assert result.minute == 25
+        assert result.second == 30
+
+    def test_convert_time_from_time_object(self):
+        """Test converting time from time object."""
+        event_time = time(10, 15, 20)
+        result = DataTransformer._convert_time(event_time)
+        assert isinstance(result, time)
+        assert result.hour == 10
+        assert result.minute == 15
+        assert result.second == 20
+
+    def test_rawdatacor_with_timedelta(self):
+        """Test RAWDATACOR transformation with timedelta event_time."""
+        mysql_row = {
+            "id": 1,
+            "UnitName": "TestUnit",
+            "ToolNameID": "Tool1",
+            "NodeNum": 1,
+            "EventDate": "2024-01-01",
+            "EventTime": timedelta(hours=12, minutes=0, seconds=0),  # MySQL TIME format
+            "BatLevel": 3.5,
+            "Temperature": 25.5,
+            "Val0": "100.5",
+            "Val1": None,
+            "Val2": "200.3",
+            "Val0_unitmisure": "°C",
+            "Val1_unitmisure": "bar",
+            "Val2_unitmisure": "m/s",
+        }
+
+        # Add remaining Val columns as None
+        for i in range(3, 16):
+            col = f"Val{i:X}"
+            mysql_row[col] = None
+            mysql_row[f"{col}_unitmisure"] = None
+
+        pg_row = DataTransformer.transform_rawdatacor_row(mysql_row)
+
+        assert pg_row["event_timestamp"] is not None
+        assert pg_row["event_timestamp"].year == 2024
+        assert pg_row["event_timestamp"].month == 1
+        assert pg_row["event_timestamp"].day == 1
+        assert pg_row["event_timestamp"].hour == 12
+        assert pg_row["event_timestamp"].minute == 0
+
+    def test_rawdatacor_with_null_eventtime(self):
+        """Test RAWDATACOR transformation with NULL EventTime uses default timestamp."""
+        mysql_row = {
+            "id": 2140982,
+            "UnitName": "OLD_ID0002",
+            "ToolNameID": "DT0001",
+            "NodeNum": 1,
+            "EventDate": "2023-09-05",
+            "EventTime": None,  # NULL EventTime
+            "BatLevel": 12.90,
+            "Temperature": 13.40,
+            "Val0": "-1709",
+            "Val1": None,
+            "Val0_unitmisure": None,
+            "Val1_unitmisure": None,
+        }
+
+        # Add remaining Val columns as None
+        for i in range(2, 16):
+            col = f"Val{i:X}"
+            mysql_row[col] = None
+            mysql_row[f"{col}_unitmisure"] = None
+
+        pg_row = DataTransformer.transform_rawdatacor_row(mysql_row)
+
+        # Should use default timestamp 1970-01-01 00:00:00
+        assert pg_row["event_timestamp"] is not None
+        assert pg_row["event_timestamp"].year == 1970
+        assert pg_row["event_timestamp"].month == 1
+        assert pg_row["event_timestamp"].day == 1
+        assert pg_row["event_timestamp"].hour == 0
+        assert pg_row["event_timestamp"].minute == 0
+
+
 class TestFieldMapping:
     """Test field mapping configuration."""