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lukasandClaude Opus 4.8 a5ec0d21cb Initial commit: webmail client (M0/M1)
Three-pane webmail client.
- Backend: FastAPI + async SQLAlchemy + arq worker (Postgres/Redis), IMAP/SMTP
  sync, threading, search, drafts/outbox with undo, attachments, 2FA.
- Frontend: React 18 + Vite + TypeScript + TanStack Query + Tailwind; three-pane
  UI with rich-text composer, light/dark themes, resizable panels.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-17 23:20:34 +02:00

67 lines
2.1 KiB
Python

"""Message-ID and subject normalization (SPEC §7.1, §7.3)."""
from __future__ import annotations
import hashlib
import re
# Repeated reply/forward prefixes to strip, case-insensitive (incl. Polish Odp:/PD:).
_PREFIX_RE = re.compile(r"^\s*(re|fw|fwd|odp|pd)\s*:\s*", re.IGNORECASE)
_WS_RE = re.compile(r"\s+")
_ANGLE_RE = re.compile(r"<([^>]*)>")
def normalize_message_id(raw: str | None) -> str | None:
"""Normalize a Message-ID per SPEC §7.1.
Strip angle brackets and whitespace, lowercase the domain part only.
Return None for obviously invalid ids (no ``@``).
"""
if raw is None:
return None
text = raw.strip()
m = _ANGLE_RE.search(text)
if m:
text = m.group(1)
text = text.strip().strip("<>").strip()
if "@" not in text:
return None
local, _, domain = text.rpartition("@")
if not local or not domain:
return None
return f"{local}@{domain.lower()}"
def normalize_reference_list(raw: str | None) -> list[str]:
"""Parse a References / In-Reply-To header value into normalized ids, in order."""
if not raw:
return []
out: list[str] = []
for token in _ANGLE_RE.findall(raw) or raw.split():
norm = normalize_message_id(token)
if norm and norm not in out:
out.append(norm)
return out
def synthesize_message_id(raw_message: bytes) -> str:
"""Synthesize a non-authoritative Message-ID for a message that lacks one (§7.1)."""
digest = hashlib.sha256(raw_message).hexdigest()[:32]
return f"{digest}@synthetic.local"
def is_synthetic(message_id: str | None) -> bool:
"""Return True if ``message_id`` is a synthesized (non-authoritative) id."""
return message_id is not None and message_id.endswith("@synthetic.local")
def normalize_subject(subject: str) -> str:
"""Normalize a subject for the §7.3 fallback: strip repeated Re:/Fw:/... prefixes."""
text = subject or ""
while True:
stripped = _PREFIX_RE.sub("", text, count=1)
if stripped == text:
break
text = stripped
return _WS_RE.sub(" ", text).strip()