feat: add utils module

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/utils.py

@@ -0,0 +1,157 @@
+"""Shared utility functions for ai-chat-exporter."""
+
+import re
+from datetime import datetime, timezone
+from pathlib import Path
+
+from slugify import slugify
+
+
+# Keys whose values should be redacted in log output
+_SENSITIVE_KEYS = frozenset(
+    {"token", "key", "secret", "password", "authorization", "session", "sessionkey"}
+)
+
+
+def generate_filename(title: str, conv_id: str, created_at: str) -> str:
+    """Build the export filename for a conversation.
+
+    Format: YYYY-MM-DD_{slug}_{id[:8]}.md
+
+    Args:
+        title: Conversation title.
+        conv_id: Conversation ID (at least 8 chars recommended).
+        created_at: ISO8601 creation timestamp.
+
+    Returns:
+        Filename string, e.g. "2024-06-10_my-conversation_abc12345.md"
+    """
+    dt = _parse_dt(created_at)
+    date_str = dt.strftime("%Y-%m-%d")
+    slug = slugify(title, max_length=60, word_boundary=True) or "untitled"
+    short_id = conv_id[:8]
+    return f"{date_str}_{slug}_{short_id}.md"
+
+
+def build_export_path(
+    base_dir: Path,
+    provider: str,
+    project: str | None,
+    created_at: str,
+    filename: str,
+    structure: str = "provider/project/year",
+) -> Path:
+    """Build the full output path for an exported file.
+
+    Args:
+        base_dir: Root export directory (e.g. Path("./exports")).
+        provider: "chatgpt" or "claude".
+        project: Project name (will be slugified), or None/empty for no-project.
+        created_at: ISO8601 creation timestamp (used for year folder).
+        filename: Already-generated filename from generate_filename().
+        structure: OUTPUT_STRUCTURE value. One of:
+            "provider/project/year" (default)
+            "provider/project"
+            "provider/year"
+
+    Returns:
+        Full Path to the output file.
+    """
+    dt = _parse_dt(created_at)
+    year = str(dt.year)
+    project_slug = slugify(project, max_length=60, word_boundary=True) if project else "no-project"
+
+    parts: list[str] = [provider]
+
+    if structure == "provider/project/year":
+        parts += [project_slug, year]
+    elif structure == "provider/project":
+        parts += [project_slug]
+    elif structure == "provider/year":
+        parts += [year]
+    else:
+        # Unknown structure — fall back to default
+        parts += [project_slug, year]
+
+    return base_dir.joinpath(*parts) / filename
+
+
+def redact_secrets(data: object) -> object:
+    """Recursively redact sensitive values from a dict/list for safe logging.
+
+    Keys matching _SENSITIVE_KEYS (case-insensitive) have their values
+    replaced with "[REDACTED]".
+
+    Args:
+        data: Any JSON-serializable object.
+
+    Returns:
+        A new object with sensitive values replaced.
+    """
+    if isinstance(data, dict):
+        return {
+            k: "[REDACTED]" if k.lower() in _SENSITIVE_KEYS else redact_secrets(v)
+            for k, v in data.items()
+        }
+    if isinstance(data, list):
+        return [redact_secrets(item) for item in data]
+    return data
+
+
+def format_token_status(token: str | None, expiry_dt: datetime | None = None) -> str:
+    """Format a token for the startup config summary log line.
+
+    Never includes the actual token value.
+
+    Args:
+        token: The token string, or None/empty if not set.
+        expiry_dt: Decoded expiry datetime (for JWTs). None if unknown.
+
+    Returns:
+        Human-readable status, e.g. "[SET - expires in 3 days]" or "[NOT SET]"
+    """
+    if not token:
+        return "[NOT SET]"
+
+    if expiry_dt is None:
+        return "[SET]"
+
+    now = datetime.now(tz=timezone.utc)
+    if expiry_dt.tzinfo is None:
+        expiry_dt = expiry_dt.replace(tzinfo=timezone.utc)
+
+    delta = expiry_dt - now
+    days = delta.days
+
+    if days < 0:
+        return "[SET - EXPIRED]"
+    if days == 0:
+        hours = int(delta.seconds / 3600)
+        return f"[SET - expires in {hours}h]"
+    return f"[SET - expires in {days} day{'s' if days != 1 else ''}]"
+
+
+def _parse_dt(ts: str) -> datetime:
+    """Parse an ISO8601 timestamp to a datetime object.
+
+    Handles both timezone-aware and naive strings.
+    """
+    ts = ts.rstrip("Z")
+    # Remove sub-second precision beyond microseconds
+    ts = re.sub(r"(\.\d{6})\d+", r"\1", ts)
+    try:
+        dt = datetime.fromisoformat(ts)
+    except ValueError:
+        # Fallback: try common formats
+        for fmt in ("%Y-%m-%dT%H:%M:%S", "%Y-%m-%d"):
+            try:
+                dt = datetime.strptime(ts, fmt)
+                break
+            except ValueError:
+                continue
+        else:
+            dt = datetime.now()
+
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=timezone.utc)
+    return dt