From 891322e7a000c2898f44a2b5def5716ca41557de Mon Sep 17 00:00:00 2001
From: Mika <kontakt@donau2space.de>
Date: Sun, 5 Apr 2026 13:56:50 +0000
Subject: [PATCH] Add logging_tool/src/logging_tool/core.py

---
 logging_tool/src/logging_tool/core.py | 85 +++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 logging_tool/src/logging_tool/core.py

diff --git a/logging_tool/src/logging_tool/core.py b/logging_tool/src/logging_tool/core.py
new file mode 100644
index 0000000..8bc935f
--- /dev/null
+++ b/logging_tool/src/logging_tool/core.py
@@ -0,0 +1,85 @@
+from __future__ import annotations
+
+import json
+from dataclasses import dataclass, asdict
+from datetime import datetime
+from pathlib import Path
+from typing import Any, Dict
+
+
+class LogValidationError(Exception):
+    """Custom exception for invalid log entries."""
+
+
+@dataclass
+class LogEntry:
+    """Repräsentiert einen einzelnen Preflight-Versuch."""
+
+    timestamp: datetime
+    measured_p: float
+    freeze_ok: bool
+    setup_fingerprint: str
+    policy_hash: str
+
+    def to_dict(self) -> Dict[str, Any]:
+        """Konvertiert den Eintrag in ein JSON-kompatibles Dictionary."""
+        d = asdict(self)
+        d["timestamp"] = self.timestamp.isoformat()
+        return d
+
+
+def _validate_log_entry(entry: LogEntry) -> None:
+    """Validiert die Felder des LogEntry streng nach Typen."""
+    assert isinstance(entry.timestamp, datetime), "timestamp must be datetime"
+    assert isinstance(entry.measured_p, (float, int)), "measured_p must be a number"
+    assert isinstance(entry.freeze_ok, bool), "freeze_ok must be bool"
+    assert isinstance(entry.setup_fingerprint, str) and entry.setup_fingerprint, (
+        "setup_fingerprint must be non-empty string"
+    )
+    assert isinstance(entry.policy_hash, str) and entry.policy_hash, (
+        "policy_hash must be non-empty string"
+    )
+
+
+def log_preflight_attempt(
+    timestamp: datetime,
+    measured_p: float,
+    freeze_ok: bool,
+    setup_fingerprint: str,
+    policy_hash: str,
+) -> None:
+    """Protokolliert einen Preflight-Versuch als JSON-Eintrag."""
+
+    entry = LogEntry(
+        timestamp=timestamp,
+        measured_p=float(measured_p),
+        freeze_ok=bool(freeze_ok),
+        setup_fingerprint=str(setup_fingerprint),
+        policy_hash=str(policy_hash),
+    )
+
+    _validate_log_entry(entry)
+
+    log_dir = Path("output")
+    log_dir.mkdir(parents=True, exist_ok=True)
+    log_file = log_dir / "preflight_log.json"
+
+    try:
+        if log_file.exists():
+            with log_file.open("r", encoding="utf-8") as f:
+                try:
+                    existing_logs = json.load(f)
+                    if not isinstance(existing_logs, list):
+                        existing_logs = []
+                except json.JSONDecodeError:
+                    existing_logs = []
+        else:
+            existing_logs = []
+
+        existing_logs.append(entry.to_dict())
+
+        with log_file.open("w", encoding="utf-8") as f:
+            json.dump(existing_logs, f, indent=2)
+
+    except (OSError, json.JSONDecodeError) as e:
+        raise LogValidationError(f"Failed to log preflight attempt: {e}") from e