#![no_std]

mod dns;
pub(crate) mod encoder;
pub mod server;
mod service;
mod state;

extern crate alloc;

use core::net::{Ipv4Addr, SocketAddrV4};

pub use crate::service::Service;
pub use crate::state::MdnsAction;
use crate::{dns::flags::Flags, server::Server, state::MdnsStateMachine};

/// Standard port for mDNS (5353).
pub const MDNS_PORT: u16 = 5353;

/// Standard IPv4 multicast address for mDNS (224.0.0.251).
pub const GROUP_ADDR_V4: Ipv4Addr = Ipv4Addr::new(224, 0, 0, 251);
pub const GROUP_SOCK_V4: SocketAddrV4 = SocketAddrV4::new(GROUP_ADDR_V4, MDNS_PORT);

#[derive(Debug)]
#[cfg_attr(feature = "defmt", derive(defmt::Format))]
pub struct MdnsService {
    server: Server,
    state: MdnsStateMachine,
}

impl MdnsService {
    pub fn new(service: Service) -> Self {
        Self {
            server: Server::new(service),
            state: Default::default(),
        }
    }

    pub fn next_action(&mut self) -> MdnsAction {
        self.state.drive_next_action()
    }

    pub fn send_announcement<'buffer>(&self, outgoing: &'buffer mut [u8]) -> Option<&'buffer [u8]> {
        self.server.broadcast(
            server::ResponseKind::Announcement,
            Flags::standard_response(),
            1,
            alloc::vec::Vec::new(),
            outgoing,
        )
    }

    pub fn listen_for_queries<'buffer>(
        &mut self,
        incoming: &[u8],
        outgoing: &'buffer mut [u8],
    ) -> Option<&'buffer [u8]> {
        self.server.respond(incoming, outgoing)
    }
}