Initial commit

app/imap_client.py

@@ -0,0 +1,92 @@
+from __future__ import annotations
+
+import email
+import imaplib
+import logging
+from dataclasses import dataclass
+from datetime import date
+from email.message import Message
+
+from app.config import InboxConfig
+
+logger = logging.getLogger(__name__)
+
+
+class IMAPError(Exception):
+    pass
+
+
+@dataclass
+class IMAPMessage:
+    uid: str
+    raw: bytes
+    seen: bool
+    message: Message
+
+
+class IMAPClient:
+    def __init__(self, inbox: InboxConfig):
+        self.inbox = inbox
+        self.conn: imaplib.IMAP4 | imaplib.IMAP4_SSL | None = None
+
+    def __enter__(self) -> "IMAPClient":
+        if not self.inbox.username or not self.inbox.password:
+            raise IMAPError(f"Missing IMAP credentials for inbox {self.inbox.id}")
+        cls = imaplib.IMAP4_SSL if self.inbox.imap_ssl else imaplib.IMAP4
+        self.conn = cls(self.inbox.imap_host, self.inbox.imap_port)
+        typ, _ = self.conn.login(self.inbox.username, self.inbox.password)
+        if typ != "OK":
+            raise IMAPError(f"IMAP login failed for {self.inbox.id}")
+        logger.info("IMAP connection succeeded for inbox %s", self.inbox.id)
+        return self
+
+    def __exit__(self, exc_type, exc, tb) -> None:
+        if self.conn is None:
+            return
+        try:
+            self.conn.logout()
+        except Exception:
+            pass
+
+    def select_folder(self, folder: str) -> None:
+        assert self.conn is not None
+        typ, data = self.conn.select(f'"{folder}"', readonly=False)
+        if typ != "OK":
+            raise IMAPError(f"IMAP folder does not exist or cannot be selected: {folder}")
+
+    def search_uids(self, *, unread_only: bool, since: date | None = None, before: date | None = None, limit: int | None = None) -> list[str]:
+        assert self.conn is not None
+        criteria: list[str] = ["UNSEEN" if unread_only else "ALL"]
+        if since:
+            criteria.extend(["SINCE", since.strftime("%d-%b-%Y")])
+        if before:
+            criteria.extend(["BEFORE", before.strftime("%d-%b-%Y")])
+        typ, data = self.conn.uid("SEARCH", None, *criteria)
+        if typ != "OK":
+            raise IMAPError("IMAP UID search failed")
+        uids = data[0].decode().split() if data and data[0] else []
+        return uids[:limit] if limit else uids
+
+    def fetch_message(self, uid: str) -> IMAPMessage:
+        assert self.conn is not None
+        typ, data = self.conn.uid("FETCH", uid, "(RFC822 FLAGS)")
+        if typ != "OK" or not data:
+            raise IMAPError(f"Could not fetch UID {uid}")
+        raw = b""
+        flags = b""
+        for item in data:
+            if isinstance(item, tuple):
+                flags += item[0]
+                raw = item[1]
+        return IMAPMessage(uid=uid, raw=raw, seen=b"\\Seen" in flags, message=email.message_from_bytes(raw))
+
+    def mark_seen(self, uid: str) -> None:
+        assert self.conn is not None
+        self.conn.uid("STORE", uid, "+FLAGS", "(\\Seen)")
+
+    def move(self, uid: str, folder: str) -> None:
+        assert self.conn is not None
+        typ, _ = self.conn.uid("COPY", uid, f'"{folder}"')
+        if typ == "OK":
+            self.conn.uid("STORE", uid, "+FLAGS", "(\\Deleted)")
+            self.conn.expunge()