From 58790fbfd10fad7af4e6f97bb7f7a21c253548ad Mon Sep 17 00:00:00 2001
From: Mika <kontakt@donau2space.de>
Date: Thu, 5 Mar 2026 15:48:03 +0000
Subject: [PATCH] Add data_logging/src/data_logging/core.py

---
 data_logging/src/data_logging/core.py | 75 +++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 data_logging/src/data_logging/core.py

diff --git a/data_logging/src/data_logging/core.py b/data_logging/src/data_logging/core.py
new file mode 100644
index 0000000..ef70849
--- /dev/null
+++ b/data_logging/src/data_logging/core.py
@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+import csv
+import os
+from datetime import datetime
+from pathlib import Path
+from typing import List
+from pydantic import BaseModel, ValidationError, validator
+
+
+class LogEntry(BaseModel):
+    """Repräsentiert einen einzelnen Logeintrag für ein Δt<0-Ereignis."""
+
+    timestamp: datetime
+    value: float
+    status: str
+
+    @validator("status")
+    def validate_status(cls, v: str) -> str:
+        if not v:
+            raise ValueError("status darf nicht leer sein")
+        return v
+
+    def to_dict(self) -> dict:
+        return {
+            "timestamp": self.timestamp.isoformat(),
+            "value": self.value,
+            "status": self.status,
+        }
+
+
+def log_data(data: List[LogEntry], filename: str) -> bool:
+    """Protokolliert eine Liste von Datenereignissen in eine CSV-Datei."""
+    assert isinstance(filename, str), "filename muss ein String sein"
+    assert isinstance(data, list), "data muss eine Liste sein"
+
+    path = Path(filename)
+    try:
+        # Sicherstellen, dass die Zieldirectory existiert
+        if not path.parent.exists():
+            path.parent.mkdir(parents=True, exist_ok=True)
+
+        # Validierung jedes Elements
+        valid_entries = []
+        for entry in data:
+            if isinstance(entry, dict):
+                try:
+                    entry_obj = LogEntry(**entry)
+                except ValidationError as e:
+                    continue  # ungültigen Eintrag überspringen
+                valid_entries.append(entry_obj)
+            elif isinstance(entry, LogEntry):
+                valid_entries.append(entry)
+            else:
+                continue
+
+        if not valid_entries:
+            return False
+
+        file_exists = path.exists()
+
+        with open(path, mode="a", newline="", encoding="utf-8") as csvfile:
+            fieldnames = ["timestamp", "value", "status"]
+            writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
+
+            if not file_exists:
+                writer.writeheader()
+
+            for entry in valid_entries:
+                writer.writerow(entry.to_dict())
+
+        return True
+
+    except (OSError, IOError):
+        return False