pub mod discovery;
pub mod error;
pub mod http_server;
pub mod models;
pub mod transfer;

use std::{
    collections::HashMap,
    net::{Ipv4Addr, SocketAddr, SocketAddrV4},
    sync::Arc,
};

use models::device::DeviceInfo;
use serde::{Deserialize, Serialize};
use tokio::{net::UdpSocket, sync::Mutex, task::JoinHandle};
use transfer::Session;

pub const DEFAULT_PORT: u16 = 53317;
pub const MULTICAST_IP: Ipv4Addr = Ipv4Addr::new(224, 0, 0, 167);
pub const LISTENING_SOCKET_ADDR: SocketAddrV4 =
    SocketAddrV4::new(Ipv4Addr::from_bits(0), DEFAULT_PORT);

#[derive(Clone)]
pub struct JoecalState {
    pub device: DeviceInfo,
    pub peers: Arc<Mutex<HashMap<String, (SocketAddr, DeviceInfo)>>>,
    pub sessions: Arc<Mutex<HashMap<String, Session>>>, // Session ID to Session
    pub running_state: Arc<Mutex<RunningState>>,
    pub socket: Arc<UdpSocket>,
    pub client: Arc<reqwest::Client>,
}

impl JoecalState {
    pub async fn new(device: DeviceInfo) -> crate::error::Result<Self> {
        let socket = UdpSocket::bind(LISTENING_SOCKET_ADDR).await?;
        socket.set_multicast_loop_v4(true)?;
        socket.set_multicast_ttl_v4(2)?; // one hop out from localnet
        socket.join_multicast_v4(MULTICAST_IP, Ipv4Addr::from_bits(0))?;

        Ok(Self {
            device,
            peers: Default::default(),
            sessions: Default::default(),
            running_state: Default::default(),
            socket: socket.into(),
            client: reqwest::Client::new().into(),
        })
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum RunningState {
    Running,
    Sending,
    Receiving,
    Stopping,
}

impl Default for RunningState {
    fn default() -> Self {
        Self::Running
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Config {
    pub multicast_addr: SocketAddrV4,
    pub port: u16,
    pub download_dir: String,
}

impl Default for Config {
    fn default() -> Self {
        let home = std::env::home_dir().unwrap_or("/tmp".into());
        let dd = home.join("joecalsend-downloads");
        Self {
            multicast_addr: SocketAddrV4::new(MULTICAST_IP, DEFAULT_PORT),
            port: DEFAULT_PORT,
            download_dir: dd.to_string_lossy().into(),
        }
    }
}

impl JoecalState {
    pub async fn start(
        &self,
        config: &Config,
    ) -> crate::error::Result<(JoinHandle<()>, JoinHandle<()>, JoinHandle<()>)> {
        let state = self.clone();
        let konfig = config.clone();
        let server_handle = {
            tokio::spawn(async move {
                if let Err(e) = state.start_http_server(&konfig).await {
                    eprintln!("HTTP server error: {e}");
                }
            })
        };
        let state = self.clone();
        let konfig = config.clone();
        let udp_handle = {
            tokio::spawn(async move {
                if let Err(e) = state.listen_multicast(&konfig).await {
                    eprintln!("UDP listener error: {e}");
                }
            })
        };

        let state = self.clone();
        let config = config.clone();
        let announcement_handle = {
            tokio::spawn(async move {
                loop {
                    if let Err(e) = state.announce(None, &config).await {
                        eprintln!("Announcement error: {e}");
                    }
                    tokio::time::sleep(std::time::Duration::from_secs(5)).await;
                    if let Ok(lock) = state.running_state.try_lock()
                        && *lock == RunningState::Stopping
                    {
                        break;
                    }
                }
            })
        };

        Ok((server_handle, udp_handle, announcement_handle))
    }

    pub async fn refresh_peers(&self) {
        let mut peers = self.peers.lock().await;
        peers.clear();
    }
}