use std::any::Any;
use std::fmt::Debug;
use crate::error::Result;
use crate::io::{ByteStreamReader, ByteStreamWriter};
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum Direction {
    ClientToServer,
    ServerToClient,
    Bidirectional,
}
impl Direction {
    pub const fn accepts_from_client(self) -> bool {
        matches!(self, Direction::ClientToServer | Direction::Bidirectional)
    }
    pub const fn accepts_from_server(self) -> bool {
        matches!(self, Direction::ServerToClient | Direction::Bidirectional)
    }
}
pub trait Payload: Sized {
    fn encode(&self, writer: &mut ByteStreamWriter) -> Result<()>;
    fn decode(reader: &mut ByteStreamReader<'_>) -> Result<Self>;
    fn to_bytes(&self) -> Result<Vec<u8>> {
        let mut writer = ByteStreamWriter::with_capacity(64);
        self.encode(&mut writer)?;
        Ok(writer.into_inner())
    }
    fn from_bytes(bytes: &[u8]) -> Result<Self> {
        let mut reader = ByteStreamReader::new(bytes);
        Self::decode(&mut reader)
    }
}
pub trait MessageMeta: Payload {
    const MESSAGE_TYPE: u16;
    const MESSAGE_VERSION: u16;
    const DIRECTION: Direction;
    const NAME: &'static str;
}
pub trait Message: Debug + Send + Sync + 'static {
    fn message_type(&self) -> u16;
    fn message_version(&self) -> u16;
    fn direction(&self) -> Direction;
    fn name(&self) -> &'static str;
    fn encode_payload(&self, writer: &mut ByteStreamWriter) -> Result<()>;
    fn as_any(&self) -> &dyn Any;
}
impl<T> Message for T
where
    T: MessageMeta + Debug + Send + Sync + 'static,
{
    fn message_type(&self) -> u16 {
        T::MESSAGE_TYPE
    }
    fn message_version(&self) -> u16 {
        T::MESSAGE_VERSION
    }
    fn direction(&self) -> Direction {
        T::DIRECTION
    }
    fn name(&self) -> &'static str {
        T::NAME
    }
    fn encode_payload(&self, writer: &mut ByteStreamWriter) -> Result<()> {
        Payload::encode(self, writer)
    }
    fn as_any(&self) -> &dyn Any {
        self
    }
}