//! BLE transport integration tests.
//!
//! Tests that the BLE transport works end-to-end at the node level:
//! handshake, spanning tree convergence, mixed-transport routing.
//! All tests use MockBleIo (in-memory channels, no hardware needed).

use super::*;
use crate::config::BleConfig;
use crate::transport::ble::BleTransport;
use crate::transport::ble::addr::BleAddr;
use crate::transport::ble::io::{MockBleIo, MockBleStream};
use crate::transport::{Transport, TransportHandle, TransportId, packet_channel};
use spanning_tree::{
    TestNode, cleanup_nodes, drain_all_packets, initiate_handshake, verify_tree_convergence,
};
use std::collections::HashMap;
use std::sync::{Arc, Mutex as StdMutex};

/// Generate a deterministic BLE address for test node `n`.
fn ble_addr(n: u8) -> BleAddr {
    BleAddr {
        adapter: "hci0".to_string(),
        device: [0xAA, 0xBB, 0xCC, 0xDD, 0xEE, n],
    }
}

/// A pre-connected stream bank for MockBleIo connect handlers.
///
/// When a connect handler fires, it looks up the target address in this
/// bank and returns the pre-created stream. The peer end should be
/// injected into the target node's acceptor separately.
type StreamBank = Arc<StdMutex<HashMap<String, MockBleStream>>>;

/// Create a test node with a BLE transport backed by MockBleIo.
///
/// Returns the TestNode and its MockBleIo (via Arc inside the transport)
/// for test injection of connections and scan results.
async fn make_test_node_ble(node_num: u8) -> TestNode {
    let mut node = make_node();
    let transport_id = TransportId::new(1);
    let addr = ble_addr(node_num);

    let config = BleConfig {
        adapter: Some("hci0".to_string()),
        mtu: Some(2048),
        accept_connections: Some(true),
        scan: Some(false),      // no auto-scan in tests
        advertise: Some(false), // no advertising in tests
        auto_connect: Some(false),
        ..Default::default()
    };

    let io = MockBleIo::new("hci0", addr.clone());
    let (packet_tx, packet_rx) = packet_channel(256);
    let mut transport = BleTransport::new(transport_id, None, config, io, packet_tx);
    transport.start_async().await.unwrap();

    let ta = addr.to_transport_addr();

    node.transports
        .insert(transport_id, TransportHandle::Ble(transport));

    TestNode {
        node,
        transport_id,
        packet_rx: spanning_tree::bridge_to_unbounded(packet_rx),
        addr: ta,
    }
}

/// Extract the BleAddr from a TestNode's TransportAddr.
fn node_ble_addr(node: &TestNode) -> BleAddr {
    BleAddr::parse(node.addr.as_str().unwrap()).unwrap()
}

/// Wire a unidirectional BLE connection from node `i` to node `j`.
///
/// Creates a MockBleStream pair, deposits one end in a stream bank for
/// node i's connect handler, and injects the other end into node j's
/// accept loop. Must be called after `make_test_node_ble()` and before
/// `initiate_handshake()`.
async fn wire_ble_connection(nodes: &[TestNode], i: usize, j: usize, bank: &StreamBank) {
    let addr_i = node_ble_addr(&nodes[i]);
    let addr_j = node_ble_addr(&nodes[j]);

    let (stream_i, stream_j) = MockBleStream::pair(addr_j.clone(), addr_i.clone(), 2048);

    // Store stream_i in the bank keyed by node j's address string.
    // When node i connects to node j, the handler returns this stream.
    let key = nodes[j].addr.to_string();
    bank.lock().unwrap().insert(key, stream_i);

    // Inject stream_j into node j's accept loop so it sees the inbound.
    let transport_j = nodes[j]
        .node
        .transports
        .get(&nodes[j].transport_id)
        .unwrap();
    match transport_j {
        TransportHandle::Ble(t) => {
            t.io().inject_inbound(stream_j).await;
        }
        _ => panic!("expected BLE transport"),
    }
}

/// Install a connect handler on node `i` that draws from the stream bank.
fn install_connect_handler(nodes: &[TestNode], i: usize, bank: &StreamBank) {
    let bank = Arc::clone(bank);
    let transport_i = nodes[i]
        .node
        .transports
        .get(&nodes[i].transport_id)
        .unwrap();
    match transport_i {
        TransportHandle::Ble(t) => {
            t.io().set_connect_handler(move |addr, _psm| {
                let key = addr.to_transport_addr().to_string();
                let mut map = bank.lock().unwrap();
                match map.remove(&key) {
                    Some(stream) => Ok(stream),
                    None => Err(crate::transport::TransportError::ConnectionRefused),
                }
            });
        }
        _ => panic!("expected BLE transport"),
    }
}

/// Establish a BLE connection from node `i` to node `j` via connect_async.
///
/// Must be called after `wire_ble_connection` and `install_connect_handler`.
/// BLE send_async fails fast if no connection exists, so connections must
/// be pre-established before initiating handshakes.
async fn establish_ble_connection(nodes: &[TestNode], i: usize, j: usize) {
    let transport = nodes[i]
        .node
        .transports
        .get(&nodes[i].transport_id)
        .unwrap();
    transport.connect(&nodes[j].addr).await.unwrap();
    // Let the background connect task complete
    tokio::task::yield_now().await;
}

/// Two BLE nodes complete a Noise handshake and establish bidirectional peering.
#[tokio::test]
async fn test_ble_two_node_handshake() {
    let mut nodes = vec![make_test_node_ble(1).await, make_test_node_ble(2).await];

    // Wire connection: node 0 → node 1
    let bank: StreamBank = Arc::new(StdMutex::new(HashMap::new()));
    wire_ble_connection(&nodes, 0, 1, &bank).await;
    install_connect_handler(&nodes, 0, &bank);
    establish_ble_connection(&nodes, 0, 1).await;

    // Initiate handshake
    initiate_handshake(&mut nodes, 0, 1).await;

    // Drain all packets (handshake + TreeAnnounce exchange)
    let total = drain_all_packets(&mut nodes, false).await;
    assert!(total > 0, "should have processed packets");

    // Verify bidirectional peering
    let addr_0 = *nodes[0].node.node_addr();
    let addr_1 = *nodes[1].node.node_addr();
    assert!(
        nodes[0].node.get_peer(&addr_1).is_some(),
        "node 0 should have node 1 as peer"
    );
    assert!(
        nodes[1].node.get_peer(&addr_0).is_some(),
        "node 1 should have node 0 as peer"
    );

    cleanup_nodes(&mut nodes).await;
}

/// Three BLE nodes in a chain converge to a consistent spanning tree.
#[tokio::test]
async fn test_ble_three_node_chain() {
    let mut nodes = vec![
        make_test_node_ble(1).await,
        make_test_node_ble(2).await,
        make_test_node_ble(3).await,
    ];

    let bank: StreamBank = Arc::new(StdMutex::new(HashMap::new()));

    // Wire: 0 -- 1 -- 2
    wire_ble_connection(&nodes, 0, 1, &bank).await;
    wire_ble_connection(&nodes, 1, 2, &bank).await;
    install_connect_handler(&nodes, 0, &bank);
    install_connect_handler(&nodes, 1, &bank);
    establish_ble_connection(&nodes, 0, 1).await;
    establish_ble_connection(&nodes, 1, 2).await;

    initiate_handshake(&mut nodes, 0, 1).await;
    initiate_handshake(&mut nodes, 1, 2).await;

    let total = drain_all_packets(&mut nodes, false).await;
    assert!(total > 0, "should have processed packets");

    // Verify spanning tree convergence
    verify_tree_convergence(&nodes);

    // Verify correct root
    let expected_root = nodes.iter().map(|tn| *tn.node.node_addr()).min().unwrap();
    for tn in &nodes {
        assert_eq!(*tn.node.tree_state().root(), expected_root);
    }

    // Verify peer counts
    assert_eq!(nodes[0].node.peer_count(), 1);
    assert_eq!(nodes[1].node.peer_count(), 2);
    assert_eq!(nodes[2].node.peer_count(), 1);

    // Verify bloom filter reachability: node 0 → node 2
    let addr_2 = *nodes[2].node.node_addr();
    let reaches = nodes[0].node.peers().any(|p| p.may_reach(&addr_2));
    assert!(reaches, "node 0 should see node 2 as reachable");

    cleanup_nodes(&mut nodes).await;
}

/// Mixed transport: UDP and BLE nodes coexist in independent components.
#[tokio::test]
async fn test_ble_mixed_transport() {
    use spanning_tree::{make_test_node, verify_tree_convergence_components};

    let udp_0 = make_test_node().await;
    let udp_1 = make_test_node().await;
    let ble_0 = make_test_node_ble(1).await;
    let ble_1 = make_test_node_ble(2).await;

    let mut nodes = vec![udp_0, udp_1, ble_0, ble_1];

    // Wire BLE pair
    let bank: StreamBank = Arc::new(StdMutex::new(HashMap::new()));
    wire_ble_connection(&nodes, 2, 3, &bank).await;
    install_connect_handler(&nodes, 2, &bank);
    establish_ble_connection(&nodes, 2, 3).await;

    // Handshake within each component
    initiate_handshake(&mut nodes, 0, 1).await; // UDP pair
    initiate_handshake(&mut nodes, 2, 3).await; // BLE pair

    let total = drain_all_packets(&mut nodes, false).await;
    assert!(total > 0);

    // Verify each component converges independently
    verify_tree_convergence_components(&nodes, &[vec![0, 1], vec![2, 3]]);

    // BLE component has its own root
    let ble_root = std::cmp::min(*nodes[2].node.node_addr(), *nodes[3].node.node_addr());
    assert_eq!(*nodes[2].node.tree_state().root(), ble_root);
    assert_eq!(*nodes[3].node.tree_state().root(), ble_root);

    cleanup_nodes(&mut nodes).await;
}

/// BLE scan+probe loop discovers peers via adapter scan events.
#[tokio::test(start_paused = true)]
async fn test_ble_discovery() {
    let mut node = make_node();
    let transport_id = TransportId::new(1);
    let addr = ble_addr(1);

    // Enable scanning so the scan+probe loop runs
    let config = BleConfig {
        adapter: Some("hci0".to_string()),
        mtu: Some(2048),
        accept_connections: Some(true),
        scan: Some(true),
        advertise: Some(false),
        auto_connect: Some(false),
        ..Default::default()
    };

    let io = MockBleIo::new("hci0", addr.clone());
    // Probe connect must succeed for peers to reach the discovery buffer
    let local = addr.clone();
    io.set_connect_handler(move |target, _psm| {
        let (stream, _peer) = MockBleStream::pair(local.clone(), target.clone(), 2048);
        Ok(stream)
    });
    let (packet_tx, packet_rx) = packet_channel(256);
    let mut transport = BleTransport::new(transport_id, None, config, io, packet_tx);
    transport.start_async().await.unwrap();

    // Inject scan results via the I/O mock
    transport.io().inject_scan_result(ble_addr(2)).await;
    transport.io().inject_scan_result(ble_addr(3)).await;

    // Let scan_probe_loop pick up results and schedule jitter
    tokio::task::yield_now().await;
    // Advance past max jitter so probes fire
    tokio::time::advance(std::time::Duration::from_secs(6)).await;
    tokio::task::yield_now().await;

    // Peers appear as bare addresses in discovery buffer after probe
    let peers = transport.discover().unwrap();
    assert_eq!(peers.len(), 2);

    let ta = addr.to_transport_addr();
    node.transports
        .insert(transport_id, TransportHandle::Ble(transport));

    let mut nodes = vec![TestNode {
        node,
        transport_id,
        packet_rx: spanning_tree::bridge_to_unbounded(packet_rx),
        addr: ta,
    }];
    cleanup_nodes(&mut nodes).await;
}