Files
govoplan-mail/src/govoplan_mail/backend/sending/imap.py

872 lines
31 KiB
Python

from __future__ import annotations
import imaplib
import re
import socket
import ssl
import time
from dataclasses import dataclass
from email import policy
from email.message import EmailMessage
from email.parser import BytesParser
from typing import Any
from govoplan_mail.backend.config import ImapConfig, TransportSecurity
from govoplan_mail.backend.dev.mock_mailbox import (
MOCK_IMAP_FOLDERS,
consume_fail_next_imap,
get_record,
is_mock_imap_host,
list_records,
record_imap_append,
)
class ImapConfigurationError(ValueError):
"""Raised when IMAP settings are incomplete or inconsistent."""
class ImapAppendError(RuntimeError):
"""Raised when APPENDing to Sent fails.
temporary=True means retrying later may help. temporary=False means the
configuration or mailbox choice probably needs user/admin attention.
"""
def __init__(self, message: str, *, temporary: bool | None = None):
super().__init__(message)
self.temporary = temporary
@dataclass(frozen=True, slots=True)
class ImapLoginTestResult:
host: str
port: int
security: str
authenticated: bool
@dataclass(frozen=True, slots=True)
class ImapMailboxInfo:
name: str
flags: list[str]
message_count: int | None = None
unseen_count: int | None = None
@dataclass(frozen=True, slots=True)
class ImapFolderListResult:
host: str
port: int
security: str
folders: list[ImapMailboxInfo]
detected_sent_folder: str | None = None
@dataclass(frozen=True, slots=True)
class ImapMailboxAttachmentInfo:
filename: str | None
content_type: str
size_bytes: int
@dataclass(frozen=True, slots=True)
class ImapMailboxMessageSummary:
uid: str
folder: str
subject: str | None
from_header: str | None
to_header: str | None
cc_header: str | None
date: str | None
message_id: str | None
flags: list[str]
size_bytes: int | None
body_preview: str | None
attachment_count: int
@dataclass(frozen=True, slots=True)
class ImapMailboxMessageDetail:
uid: str
folder: str
subject: str | None
from_header: str | None
to_header: str | None
cc_header: str | None
date: str | None
message_id: str | None
flags: list[str]
size_bytes: int | None
body_preview: str | None
body_text: str | None
body_html: str | None
headers: dict[str, str]
attachments: list[ImapMailboxAttachmentInfo]
@dataclass(frozen=True, slots=True)
class ImapMailboxMessageListResult:
host: str
port: int
security: str
folder: str
messages: list[ImapMailboxMessageSummary]
total_count: int
offset: int
limit: int
uidvalidity: str | None = None
cursor_reset: bool = False
@dataclass(frozen=True, slots=True)
class ImapMailboxMessageResult:
host: str
port: int
security: str
folder: str
message: ImapMailboxMessageDetail
@dataclass(frozen=True, slots=True)
class ImapAppendResult:
host: str
port: int
security: str
folder: str
bytes_appended: int
response: str | None = None
def _require_imap_config(config: ImapConfig) -> tuple[str, int]:
if not config.host:
raise ImapConfigurationError("IMAP host is required")
if not config.port:
raise ImapConfigurationError("IMAP port is required")
if bool(config.username) != bool(config.password):
raise ImapConfigurationError("IMAP username and password must be provided together, or both omitted")
return config.host, config.port
def _open_imap(config: ImapConfig) -> imaplib.IMAP4:
host, port = _require_imap_config(config)
context = ssl.create_default_context()
try:
if config.security == TransportSecurity.TLS:
client: imaplib.IMAP4 = imaplib.IMAP4_SSL(host=host, port=port, timeout=config.timeout_seconds, ssl_context=context)
else:
client = imaplib.IMAP4(host=host, port=port, timeout=config.timeout_seconds)
if config.security == TransportSecurity.STARTTLS:
typ, data = client.starttls(ssl_context=context)
if typ != "OK":
raise ImapAppendError(f"IMAP STARTTLS failed: {data!r}", temporary=True)
if config.username and config.password:
typ, data = client.login(config.username, config.password)
if typ != "OK":
raise ImapAppendError(f"IMAP login failed: {data!r}", temporary=False)
return client
except Exception:
try:
client.logout() # type: ignore[possibly-undefined]
except Exception:
pass
raise
def _decode_item(item: bytes | str | None) -> str:
if item is None:
return ""
if isinstance(item, bytes):
return item.decode("utf-8", errors="replace")
return item
def _unquote_imap_token(value: str) -> str:
value = value.strip()
if len(value) >= 2 and value[0] == '"' and value[-1] == '"':
value = value[1:-1]
value = value.replace('\\"', '"').replace('\\\\', '\\')
return value
def _extract_mailbox_name(list_response_line: bytes | str) -> tuple[str, set[str]] | None:
r"""Best-effort parser for IMAP LIST response lines.
RFC 3501 LIST responses contain attributes, hierarchy delimiter, then mailbox
name. Some servers quote both delimiter and mailbox::
(\HasNoChildren \Sent) "/" "Sent"
Others quote only the delimiter and leave the mailbox as an atom::
(\HasNoChildren \Sent) "/" Sent
The parser must therefore parse the delimiter token separately instead of
blindly taking the last quoted value.
"""
line = _decode_item(list_response_line).strip()
match = re.match(
r'^\((?P<flags>[^)]*)\)\s+'
r'(?P<delimiter>"(?:[^"\\]|\\.)*"|NIL|[^\s]+)\s+'
r'(?P<mailbox>.+?)\s*$',
line,
re.IGNORECASE,
)
if match:
flags = {part.lower() for part in match.group("flags").split()}
mailbox = _unquote_imap_token(match.group("mailbox"))
if mailbox:
return mailbox, flags
return None
# Fallback for non-standard server lines: prefer the final token.
parts = line.split(maxsplit=2)
if len(parts) >= 3:
flags_text = parts[0].strip("()")
flags = {part.lower() for part in flags_text.split()}
mailbox = _unquote_imap_token(parts[2])
if mailbox:
return mailbox, flags
return None
def _detect_sent_folder(parsed: list[tuple[str, set[str]]]) -> str | None:
for name, flags in parsed:
if "\\sent" in flags or "\\sentmail" in flags:
return name
common_names = [
"Sent",
"Sent Items",
"Sent Messages",
"Gesendet",
"Gesendete Elemente",
"INBOX.Sent",
"INBOX/Sent",
]
names = {name.lower(): name for name, _ in parsed}
for candidate in common_names:
if candidate.lower() in names:
return names[candidate.lower()]
return None
def discover_sent_folder(client: imaplib.IMAP4) -> str | None:
typ, data = client.list()
if typ != "OK" or not data:
return None
parsed: list[tuple[str, set[str]]] = []
for item in data:
extracted = _extract_mailbox_name(item)
if extracted:
parsed.append(extracted)
return _detect_sent_folder(parsed)
def _effective_sent_folder(*, config: ImapConfig, requested_folder: str | None, client: imaplib.IMAP4) -> str:
if requested_folder and requested_folder != "auto":
return requested_folder
if config.sent_folder and config.sent_folder != "auto":
return config.sent_folder
discovered = discover_sent_folder(client)
if discovered:
return discovered
raise ImapConfigurationError("Could not discover Sent folder; configure delivery.imap_append_sent.folder or server.imap.sent_folder")
def test_imap_login(*, imap_config: ImapConfig) -> ImapLoginTestResult:
"""Open an IMAP connection and authenticate if credentials are configured.
This is a side-effect-free connection test for the WebUI. It does not select
a mailbox and does not append any message.
"""
host, port = _require_imap_config(imap_config)
if is_mock_imap_host(imap_config.host):
return ImapLoginTestResult(
host=host,
port=port,
security=imap_config.security.value,
authenticated=bool(imap_config.username and imap_config.password),
)
client = _open_imap(imap_config)
try:
return ImapLoginTestResult(
host=host,
port=port,
security=imap_config.security.value,
authenticated=bool(imap_config.username and imap_config.password),
)
finally:
try:
client.logout()
except Exception:
pass
def list_imap_folders(*, imap_config: ImapConfig) -> ImapFolderListResult:
"""Return folders visible through IMAP LIST and the best sent-folder guess."""
host, port = _require_imap_config(imap_config)
if is_mock_imap_host(imap_config.host):
records = list_records(limit=500)
folders = []
for item in MOCK_IMAP_FOLDERS:
name = str(item["name"])
count = sum(1 for record in records if _mock_folder_matches(record, name))
folders.append(ImapMailboxInfo(name=name, flags=list(item.get("flags") or []), message_count=count, unseen_count=None))
return ImapFolderListResult(
host=host,
port=port,
security=imap_config.security.value,
folders=folders,
detected_sent_folder="Sent",
)
client = _open_imap(imap_config)
try:
typ, data = client.list()
if typ != "OK":
raise ImapAppendError(f"IMAP folder listing failed: {data!r}", temporary=True)
parsed: list[tuple[str, set[str]]] = []
folders: list[ImapMailboxInfo] = []
for item in data or []:
extracted = _extract_mailbox_name(item)
if not extracted:
continue
name, flags = extracted
parsed.append((name, flags))
message_count, unseen_count = (None, None) if _has_folder_flag(flags, "noselect") else _imap_folder_status(client, name)
folders.append(ImapMailboxInfo(name=name, flags=sorted(flags), message_count=message_count, unseen_count=unseen_count))
return ImapFolderListResult(
host=host,
port=port,
security=imap_config.security.value,
folders=folders,
detected_sent_folder=_detect_sent_folder(parsed),
)
finally:
try:
client.logout()
except Exception:
pass
def _has_folder_flag(flags: set[str], flag: str) -> bool:
wanted = flag.casefold().lstrip("\\")
return any(item.casefold().lstrip("\\") == wanted for item in flags)
def _quote_mailbox_name(name: str) -> str:
return "\"" + name.replace("\\", "\\\\").replace("\"", "\\\"") + "\""
def _imap_folder_status(client: imaplib.IMAP4, folder: str) -> tuple[int | None, int | None]:
try:
typ, data = client.status(_quote_mailbox_name(folder), "(MESSAGES UNSEEN)")
except Exception:
return None, None
if typ != "OK":
return None, None
text = " ".join(_decode_item(item) for item in data or [])
messages_match = re.search(r"\bMESSAGES\s+(\d+)", text, re.IGNORECASE)
unseen_match = re.search(r"\bUNSEEN\s+(\d+)", text, re.IGNORECASE)
return (
int(messages_match.group(1)) if messages_match else None,
int(unseen_match.group(1)) if unseen_match else None,
)
def _parse_message(raw: bytes) -> EmailMessage:
return BytesParser(policy=policy.default).parsebytes(raw)
def _header_text(message: EmailMessage, name: str) -> str | None:
value = message.get(name)
return str(value) if value is not None else None
def _body_content(message: EmailMessage, prefer: tuple[str, ...]) -> str | None:
try:
body = message.get_body(preferencelist=prefer) if message.is_multipart() else message
if body is None:
return None
content = body.get_content()
except Exception:
return None
text = str(content).strip()
return text or None
def _body_preview(message: EmailMessage) -> str | None:
text = _body_content(message, ("plain", "html"))
if not text:
return None
preview = re.sub(r"\s+", " ", text).strip()
return preview[:600] or None
def _attachment_infos(message: EmailMessage) -> list[ImapMailboxAttachmentInfo]:
attachments: list[ImapMailboxAttachmentInfo] = []
for part in message.iter_attachments():
payload = part.get_payload(decode=True) or b""
attachments.append(
ImapMailboxAttachmentInfo(
filename=part.get_filename(),
content_type=part.get_content_type(),
size_bytes=len(payload),
)
)
return attachments
def _message_summary_from_headers(*, uid: str, folder: str, headers: bytes, flags: list[str], size_bytes: int | None) -> ImapMailboxMessageSummary:
message = _parse_message(headers.rstrip() + b"\r\n\r\n")
return ImapMailboxMessageSummary(
uid=uid,
folder=folder,
subject=_header_text(message, "Subject"),
from_header=_header_text(message, "From"),
to_header=_header_text(message, "To"),
cc_header=_header_text(message, "Cc"),
date=_header_text(message, "Date"),
message_id=_header_text(message, "Message-ID"),
flags=flags,
size_bytes=size_bytes,
body_preview=None,
attachment_count=0,
)
def _message_summary_from_raw(*, uid: str, folder: str, raw: bytes, flags: list[str], size_bytes: int | None) -> ImapMailboxMessageSummary:
message = _parse_message(raw)
attachments = _attachment_infos(message)
return ImapMailboxMessageSummary(
uid=uid,
folder=folder,
subject=_header_text(message, "Subject"),
from_header=_header_text(message, "From"),
to_header=_header_text(message, "To"),
cc_header=_header_text(message, "Cc"),
date=_header_text(message, "Date"),
message_id=_header_text(message, "Message-ID"),
flags=flags,
size_bytes=size_bytes if size_bytes is not None else len(raw),
body_preview=_body_preview(message),
attachment_count=len(attachments),
)
def _message_detail_from_raw(*, uid: str, folder: str, raw: bytes, flags: list[str], size_bytes: int | None) -> ImapMailboxMessageDetail:
message = _parse_message(raw)
attachments = _attachment_infos(message)
return ImapMailboxMessageDetail(
uid=uid,
folder=folder,
subject=_header_text(message, "Subject"),
from_header=_header_text(message, "From"),
to_header=_header_text(message, "To"),
cc_header=_header_text(message, "Cc"),
date=_header_text(message, "Date"),
message_id=_header_text(message, "Message-ID"),
flags=flags,
size_bytes=size_bytes if size_bytes is not None else len(raw),
body_preview=_body_preview(message),
body_text=_body_content(message, ("plain",)),
body_html=_body_content(message, ("html",)),
headers={str(key): str(value) for key, value in message.items()},
attachments=attachments,
)
def _parse_fetch_metadata(metadata: str) -> tuple[str | None, list[str], int | None]:
uid_match = re.search(r"\bUID\s+(\d+)", metadata, re.IGNORECASE)
size_match = re.search(r"\bRFC822\.SIZE\s+(\d+)", metadata, re.IGNORECASE)
flags_match = re.search(r"\bFLAGS\s+\(([^)]*)\)", metadata, re.IGNORECASE)
flags = flags_match.group(1).split() if flags_match else []
return uid_match.group(1) if uid_match else None, flags, int(size_match.group(1)) if size_match else None
def _parse_fetch_response(data: list[Any] | tuple[Any, ...] | None) -> tuple[str | None, list[str], int | None, bytes]:
metadata_parts: list[str] = []
raw: bytes | None = None
for item in data or []:
if isinstance(item, tuple):
metadata_parts.append(_decode_item(item[0]))
if isinstance(item[1], bytes):
raw = item[1]
else:
metadata_parts.append(_decode_item(item))
metadata = " ".join(part for part in metadata_parts if part)
uid, flags, size_bytes = _parse_fetch_metadata(metadata)
if raw is None:
raise ImapAppendError(f"IMAP message fetch returned no message body: {metadata!r}", temporary=True)
return uid, flags, size_bytes, raw
def _parse_fetch_sequence(metadata: str) -> str | None:
match = re.match(r"\s*(\d+)\s+\(", metadata)
return match.group(1) if match else None
def _parse_fetch_parts_with_sequence(data: list[Any] | tuple[Any, ...] | None) -> list[tuple[str | None, str | None, list[str], int | None, bytes]]:
parts: list[tuple[str | None, str | None, list[str], int | None, bytes]] = []
for item in data or []:
if not isinstance(item, tuple) or not isinstance(item[1], bytes):
continue
metadata = _decode_item(item[0])
sequence = _parse_fetch_sequence(metadata)
uid, flags, size_bytes = _parse_fetch_metadata(metadata)
parts.append((sequence, uid, flags, size_bytes, item[1]))
return parts
def _select_readonly(client: imaplib.IMAP4, folder: str) -> tuple[int, str | None]:
typ, data = client.select(folder, readonly=True)
if typ != "OK":
raise ImapAppendError(f"IMAP folder {folder!r} could not be opened read-only: {data!r}", temporary=False)
selected_count = _decode_item(data[0] if data else None).strip()
try:
total_count = max(0, int(selected_count))
except ValueError:
total_count = 0
uidvalidity = None
try:
_, uidvalidity_data = client.response("UIDVALIDITY")
if uidvalidity_data:
uidvalidity = _decode_item(uidvalidity_data[0]).strip() or None
except Exception:
uidvalidity = None
return total_count, uidvalidity
def _fetch_message_by_uid(client: imaplib.IMAP4, uid: str) -> tuple[str, list[str], int | None, bytes]:
typ, data = client.uid("fetch", str(uid), "(UID FLAGS RFC822.SIZE BODY.PEEK[])")
if typ != "OK":
raise ImapAppendError(f"IMAP message {uid!r} fetch failed: {data!r}", temporary=True)
fetched_uid, flags, size_bytes, raw = _parse_fetch_response(data)
return fetched_uid or str(uid), flags, size_bytes, raw
def _fetch_message_by_sequence(client: imaplib.IMAP4, sequence: str) -> tuple[str, list[str], int | None, bytes]:
typ, data = client.fetch(str(sequence), "(UID FLAGS RFC822.SIZE BODY.PEEK[])")
if typ != "OK":
raise ImapAppendError(f"IMAP message sequence {sequence!r} fetch failed: {data!r}", temporary=True)
fetched_uid, flags, size_bytes, raw = _parse_fetch_response(data)
if not fetched_uid:
raise ImapAppendError(f"IMAP message sequence {sequence!r} fetch returned no UID", temporary=True)
return fetched_uid, flags, size_bytes, raw
def _sequence_set(sequences: list[str]) -> str:
sequence_numbers = sorted({int(sequence) for sequence in sequences if str(sequence).isdigit()})
if not sequence_numbers:
return ",".join(str(sequence) for sequence in sequences)
expected_range = list(range(sequence_numbers[0], sequence_numbers[-1] + 1))
if sequence_numbers == expected_range:
return f"{sequence_numbers[0]}:{sequence_numbers[-1]}"
return ",".join(str(sequence) for sequence in sequence_numbers)
def _fetch_message_summaries_by_sequence(client: imaplib.IMAP4, sequences: list[str], folder: str) -> list[ImapMailboxMessageSummary]:
if not sequences:
return []
typ, data = client.fetch(_sequence_set(sequences), "(UID FLAGS RFC822.SIZE BODY.PEEK[HEADER.FIELDS (SUBJECT FROM TO CC DATE MESSAGE-ID)])")
if typ != "OK":
raise ImapAppendError(f"IMAP message summary fetch failed: {data!r}", temporary=True)
by_sequence: dict[str, ImapMailboxMessageSummary] = {}
for sequence, fetched_uid, flags, size_bytes, headers in _parse_fetch_parts_with_sequence(data):
if not sequence or not fetched_uid:
continue
by_sequence[sequence] = _message_summary_from_headers(uid=fetched_uid, folder=folder, headers=headers, flags=flags, size_bytes=size_bytes)
summaries: list[ImapMailboxMessageSummary] = []
for sequence in sequences:
summary = by_sequence.get(str(sequence))
if summary is not None:
summaries.append(summary)
continue
fetched_uid, flags, size_bytes, raw = _fetch_message_by_sequence(client, sequence)
summaries.append(_message_summary_from_raw(uid=fetched_uid, folder=folder, raw=raw, flags=flags, size_bytes=size_bytes))
return summaries
def _search_message_uids(client: imaplib.IMAP4) -> list[str]:
typ, data = client.uid("search", None, "ALL")
if typ != "OK":
raise ImapAppendError(f"IMAP UID search failed: {data!r}", temporary=True)
uids: set[int] = set()
for item in data or []:
for token in _decode_item(item).split():
if token.isdigit():
uids.add(int(token))
return [str(uid) for uid in sorted(uids, reverse=True)]
def _paged_descending_uids(
uids: list[str],
*,
offset: int,
limit: int,
after_uid: str | None = None,
) -> tuple[list[str], int, bool]:
if not uids:
return [], 0, False
cursor_reset = False
if after_uid:
try:
start = uids.index(str(after_uid)) + 1
except ValueError:
start = 0
cursor_reset = True
else:
start = min(max(0, offset), len(uids))
return uids[start:start + limit], start, cursor_reset
def _fetch_message_summaries_by_uid(client: imaplib.IMAP4, uids: list[str], folder: str) -> list[ImapMailboxMessageSummary]:
if not uids:
return []
typ, data = client.uid("fetch", _sequence_set(uids), "(UID FLAGS RFC822.SIZE BODY.PEEK[HEADER.FIELDS (SUBJECT FROM TO CC DATE MESSAGE-ID)])")
if typ != "OK":
raise ImapAppendError(f"IMAP message summary fetch failed: {data!r}", temporary=True)
by_uid: dict[str, ImapMailboxMessageSummary] = {}
for _sequence, fetched_uid, flags, size_bytes, headers in _parse_fetch_parts_with_sequence(data):
if not fetched_uid:
continue
by_uid[fetched_uid] = _message_summary_from_headers(uid=fetched_uid, folder=folder, headers=headers, flags=flags, size_bytes=size_bytes)
summaries: list[ImapMailboxMessageSummary] = []
for uid in uids:
summary = by_uid.get(str(uid))
if summary is not None:
summaries.append(summary)
continue
fetched_uid, flags, size_bytes, raw = _fetch_message_by_uid(client, uid)
summaries.append(_message_summary_from_raw(uid=fetched_uid, folder=folder, raw=raw, flags=flags, size_bytes=size_bytes))
return summaries
def _mock_record_folder(record: dict[str, Any]) -> str:
folder = str(record.get("folder") or "").strip()
if folder:
return folder
return "Sent" if record.get("kind") == "imap_append" else "INBOX"
def _mock_folder_matches(record: dict[str, Any], folder: str) -> bool:
return _mock_record_folder(record).casefold() == folder.casefold()
def _mock_raw_bytes(record: dict[str, Any]) -> bytes:
raw = record.get("raw_eml")
if isinstance(raw, str) and raw:
return raw.encode("utf-8", errors="replace")
headers = record.get("headers") if isinstance(record.get("headers"), dict) else {}
lines = [f"{key}: {value}" for key, value in headers.items()]
lines.append("")
lines.append(str(record.get("body_preview") or ""))
return "\n".join(lines).encode("utf-8", errors="replace")
def list_imap_messages(
*,
imap_config: ImapConfig,
folder: str = "INBOX",
limit: int = 50,
offset: int = 0,
after_uid: str | None = None,
expected_uidvalidity: str | None = None,
) -> ImapMailboxMessageListResult:
"""List mailbox messages without mutating read/unread state."""
host, port = _require_imap_config(imap_config)
folder = (folder or "INBOX").strip() or "INBOX"
limit = max(1, min(limit, 100))
offset = max(0, offset)
if is_mock_imap_host(imap_config.host):
records = [record for record in list_records(limit=500) if _mock_folder_matches(record, folder)]
cursor_reset = False
if expected_uidvalidity and expected_uidvalidity != "mock-v1":
effective_offset = 0
cursor_reset = True
elif after_uid:
record_ids = [str(record.get("id") or "") for record in records]
try:
effective_offset = record_ids.index(str(after_uid)) + 1
except ValueError:
effective_offset = 0
cursor_reset = True
else:
effective_offset = min(offset, len(records))
page_records = records[effective_offset:effective_offset + limit]
messages = [
_message_summary_from_raw(
uid=str(record.get("id") or ""),
folder=_mock_record_folder(record),
raw=_mock_raw_bytes(record),
flags=["\\Seen"] if record.get("kind") == "imap_append" else [],
size_bytes=int(record.get("size_bytes") or 0) or None,
)
for record in page_records
]
return ImapMailboxMessageListResult(
host=host,
port=port,
security=imap_config.security.value,
folder=folder,
messages=messages,
total_count=len(records),
offset=effective_offset,
limit=limit,
uidvalidity="mock-v1",
cursor_reset=cursor_reset,
)
client = _open_imap(imap_config)
try:
total_count, uidvalidity = _select_readonly(client, folder)
uids = _search_message_uids(client)
cursor_reset = False
effective_after_uid = after_uid
effective_offset = offset
if expected_uidvalidity and expected_uidvalidity != uidvalidity:
effective_after_uid = None
effective_offset = 0
cursor_reset = True
page_uids, effective_offset, anchor_missing = _paged_descending_uids(
uids,
offset=effective_offset,
limit=limit,
after_uid=effective_after_uid,
)
messages = _fetch_message_summaries_by_uid(client, page_uids, folder)
return ImapMailboxMessageListResult(
host=host,
port=port,
security=imap_config.security.value,
folder=folder,
messages=messages,
total_count=len(uids) if uids else total_count,
offset=effective_offset,
limit=limit,
uidvalidity=uidvalidity,
cursor_reset=cursor_reset or anchor_missing,
)
finally:
try:
client.logout()
except Exception:
pass
def _paged_descending_sequences(total_count: int, *, offset: int, limit: int) -> list[str]:
if total_count <= 0 or offset >= total_count:
return []
end = total_count - offset
start = max(1, end - limit + 1)
return [str(sequence) for sequence in range(end, start - 1, -1)]
def get_imap_message(*, imap_config: ImapConfig, folder: str, uid: str) -> ImapMailboxMessageResult:
"""Fetch one message body using BODY.PEEK in a read-only selected mailbox."""
host, port = _require_imap_config(imap_config)
folder = (folder or "INBOX").strip() or "INBOX"
uid = str(uid).strip()
if not uid:
raise ImapConfigurationError("Message UID is required")
if is_mock_imap_host(imap_config.host):
record = get_record(uid, include_raw=True)
if not record or not _mock_folder_matches(record, folder):
raise ImapAppendError(f"Mock mailbox message {uid!r} was not found in folder {folder!r}", temporary=False)
message = _message_detail_from_raw(
uid=uid,
folder=_mock_record_folder(record),
raw=_mock_raw_bytes(record),
flags=["\\Seen"] if record.get("kind") == "imap_append" else [],
size_bytes=int(record.get("size_bytes") or 0) or None,
)
return ImapMailboxMessageResult(host=host, port=port, security=imap_config.security.value, folder=folder, message=message)
client = _open_imap(imap_config)
try:
_select_readonly(client, folder)
fetched_uid, flags, size_bytes, raw = _fetch_message_by_uid(client, uid)
message = _message_detail_from_raw(uid=fetched_uid, folder=folder, raw=raw, flags=flags, size_bytes=size_bytes)
return ImapMailboxMessageResult(host=host, port=port, security=imap_config.security.value, folder=folder, message=message)
finally:
try:
client.logout()
except Exception:
pass
def append_message_to_sent(
message_bytes: bytes,
*,
imap_config: ImapConfig,
folder: str | None = None,
) -> ImapAppendResult:
"""Append a sent MIME message to the configured IMAP Sent folder.
The SMTP send remains authoritative. APPEND is a separate best-effort step
and should not be used to decide whether an email was sent.
"""
host, port = _require_imap_config(imap_config)
if is_mock_imap_host(imap_config.host):
if consume_fail_next_imap():
raise ImapAppendError("Mock IMAP configured to fail the next append", temporary=False)
target_folder = folder or (imap_config.sent_folder if imap_config.sent_folder and imap_config.sent_folder != "auto" else "Sent")
record = record_imap_append(message_bytes, folder=target_folder, imap_host=imap_config.host)
return ImapAppendResult(
host=host,
port=port,
security=imap_config.security.value,
folder=target_folder,
bytes_appended=len(message_bytes),
response=f"mock append stored as {record.id}",
)
client: imaplib.IMAP4 | None = None
try:
client = _open_imap(imap_config)
target_folder = _effective_sent_folder(config=imap_config, requested_folder=folder, client=client)
internal_date = imaplib.Time2Internaldate(time.time())
typ, data = client.append(target_folder, "\\Seen", internal_date, message_bytes)
if typ != "OK":
raise ImapAppendError(f"IMAP APPEND failed for folder {target_folder!r}: {data!r}", temporary=False)
response = "; ".join(_decode_item(item) for item in (data or [])) or None
return ImapAppendResult(
host=host,
port=port,
security=imap_config.security.value,
folder=target_folder,
bytes_appended=len(message_bytes),
response=response,
)
except ImapAppendError:
raise
except (OSError, socket.timeout, imaplib.IMAP4.abort) as exc:
raise ImapAppendError(f"IMAP append failed: {exc}", temporary=True) from exc
except imaplib.IMAP4.error as exc:
raise ImapAppendError(f"IMAP append failed: {exc}", temporary=False) from exc
finally:
if client is not None:
try:
client.logout()
except Exception:
pass