"""ClientMessage — container for client-originated messages.

Ported from net.i2p.data.i2cp.ClientMessage.
Used by the message routing system to track outbound messages.
"""

from __future__ import annotations

import hashlib
from dataclasses import dataclass


class SendFlags:
    """Send flags for outbound messages."""

    NONE = 0
    TAG_THRESHOLD_LOW = 1
    TAG_THRESHOLD_HIGH = 2


@dataclass
class ClientMessage:
    """A client-originated message with routing metadata."""

    from_dest: bytes
    to_dest: bytes
    payload: bytes
    message_id: int
    message_nonce: int
    expiration: int | None = None
    flags: int = 0

    @property
    def from_hash(self) -> bytes:
        """SHA-256 hash of the source destination."""
        return hashlib.sha256(self.from_dest).digest()

    @property
    def to_hash(self) -> bytes:
        """SHA-256 hash of the target destination."""
        return hashlib.sha256(self.to_dest).digest()

    @property
    def payload_size(self) -> int:
        return len(self.payload)