from datetime import datetime, timezone

from bson import ObjectId

from app.routers.emails import decode_cursor, encode_cursor, summarize


def test_cursor_round_trip_preserves_sort_key():
    entry = {
        "_id": ObjectId(),
        "created_at": datetime(2026, 8, 9, 12, 30, tzinfo=timezone.utc),
    }

    created_at, entry_id = decode_cursor(encode_cursor(entry))

    assert created_at == entry["created_at"]
    assert entry_id == entry["_id"]


def test_naive_cursor_timestamp_is_treated_as_utc():
    naive = datetime(2026, 8, 9, 12, 30)
    created_at, _entry_id = decode_cursor(
        encode_cursor({"_id": ObjectId(), "created_at": naive})
    )
    assert created_at.tzinfo is not None
    assert created_at == datetime(2026, 8, 9, 12, 30, tzinfo=timezone.utc)


def test_summary_uses_account_mailbox_read_state():
    now = datetime(2026, 8, 9, 12, 30, tzinfo=timezone.utc)
    message_id = ObjectId()
    message = {
        "_id": message_id,
        "direction": "inbound",
        "sender": {"name": "Sender", "address": "sender@example.com"},
        "to": [{"name": "user", "address": "user@gentic.email"}],
        "subject": "Hello",
        "snippet": "A short preview",
        "status": "received",
        "created_at": now,
        "received_at": now,
        "attachments": [],
    }
    entry = {
        "_id": ObjectId(),
        "message_id": message_id,
        "mailbox": "inbox",
        "is_read": False,
        "trashed_at": None,
        "created_at": now,
    }

    result = summarize(message, entry)

    assert result.id == str(message_id)
    assert result.is_read is False
    assert result.mailbox == "inbox"
    assert result.snippet == "A short preview"