use crate::error::TcpServerError;
use domain::{BroadcastPort, Layout, WidgetId, WidgetState};
use protocol::{ServerMessage, WidgetDescriptor, WireDisplayHint, WireLayoutNode, encode};
use tokio::sync::broadcast;

pub struct TcpBroadcaster {
    tx: broadcast::Sender<Vec<u8>>,
}

impl TcpBroadcaster {
    pub fn new(capacity: usize) -> Self {
        let (tx, _) = broadcast::channel(capacity);
        Self { tx }
    }

    pub fn subscribe(&self) -> broadcast::Receiver<Vec<u8>> {
        self.tx.subscribe()
    }

    fn send_frame(&self, frame: Vec<u8>) -> Result<(), TcpServerError> {
        let _ = self.tx.send(frame);
        Ok(())
    }
}

impl BroadcastPort for TcpBroadcaster {
    type Error = TcpServerError;

    async fn push_screen_update(
        &self,
        layout: &Layout,
        widgets: &[(WidgetId, WidgetState)],
    ) -> Result<(), Self::Error> {
        let wire_layout: WireLayoutNode = (&layout.root).into();
        let wire_widgets: Vec<WidgetDescriptor> = widgets
            .iter()
            .map(|(id, state)| WidgetDescriptor {
                id: *id,
                display_hint: WireDisplayHint::IconValue,
                state: state.into(),
            })
            .collect();

        let msg = ServerMessage::ScreenUpdate {
            layout: wire_layout,
            widgets: wire_widgets,
        };

        let frame = encode(&msg).map_err(TcpServerError::Encode)?;
        self.send_frame(frame)
    }

    async fn push_data_update(
        &self,
        updates: &[(WidgetId, WidgetState)],
    ) -> Result<(), Self::Error> {
        let wire_widgets: Vec<WidgetDescriptor> = updates
            .iter()
            .map(|(id, state)| WidgetDescriptor {
                id: *id,
                display_hint: WireDisplayHint::IconValue,
                state: state.into(),
            })
            .collect();

        let msg = ServerMessage::DataUpdate {
            widgets: wire_widgets,
        };

        let frame = encode(&msg).map_err(TcpServerError::Encode)?;
        self.send_frame(frame)
    }
}