//! OPLOCK_BREAK handler — acknowledge breaks and update oplock state.

use std::sync::Arc;

use crate::proto::header::Smb2Header;
use crate::proto::messages::{FileId, OplockBreakAck};

use crate::conn::state::Connection;
use crate::dispatch::HandlerResponse;
use crate::handlers::shared::lookup_session_tree;
use crate::ntstatus;
use crate::server::ServerState;

pub async fn handle(
    server: &Arc<ServerState>,
    conn: &Arc<Connection>,
    hdr: &Smb2Header,
    body: &[u8],
) -> HandlerResponse {
    // Parse client's ACK (MS-SMB2 §2.2.24)
    let ack = match OplockBreakAck::parse(body) {
        Ok(a) => a,
        Err(_) => return HandlerResponse::err(ntstatus::STATUS_INVALID_PARAMETER),
    };
    
    // Lookup tree to get path for oplock manager
    let tree_arc = match lookup_session_tree(conn, hdr).await {
        Ok(t) => t,
        Err(s) => return HandlerResponse::err(s),
    };
    
    // Update oplock level in the open
    let path = {
        // Find the open by file_id
        let tree = tree_arc.read().await;
        let opens = tree.opens.read().await;
        if let Some(open_arc) = opens.get(&ack.file_id) {
            let mut open = open_arc.write().await;
            open.oplock_level = ack.oplock_level;
            open.last_path.clone()
        } else {
            return HandlerResponse::err(ntstatus::STATUS_FILE_CLOSED);
        }
    };
    
    // Update OplockManager entry
    server.oplock_manager.update_oplock_level(
        &path,
        ack.file_id,
        ack.oplock_level,
    ).await;
    
    // Echo back the ACK as confirmation (MS-SMB2 §2.2.24)
    let mut buf = Vec::new();
    ack.write_to(&mut buf).expect("encode ack response");
    HandlerResponse::ok(buf)
}