df_displmgr 0.1.0

use wayland_client::{Connection, EventQueue, Dispatch};
use crate::error::{DisplayError, DisplayResult};
use super::displmgr_wlr_sys::*;

/// Synchronously performs a "Roundtrip" to the Wayland server to collect all monitor data.
pub fn fetch_wlr_topology() -> DisplayResult<WlrGlobalState> {
    let conn = Connection::connect_to_env()
        .map_err(|e| DisplayError::ConnectionFailed)?;
    
    let display = conn.display();
    let mut event_queue = conn.new_event_queue();
    let qh = event_queue.handle();

    // In a real implementation, we would register a 'RegistryState' here
    // to bind to "zwlr_output_manager_v1".
    
    // For the sake of the architectural flow, we assume the manager is bound:
    let state = WlrGlobalState {
        manager: None, // Bound via registry global
        heads: Vec::new(),
    };

    // Blocks until the compositor sends the 'finished' event for the current configuration.
    event_queue.roundtrip(&mut state)
        .map_err(|e| DisplayError::BackendError(e.to_string()))?;

    Ok(state)
}