// Copyright 2023 Protocol Labs.
//
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// copy of this software and associated documentation files (the "Software"),
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// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
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//
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// DEALINGS IN THE SOFTWARE.

mod util;

use libp2p_core::Multiaddr;
use libp2p_identity::PeerId;
use libp2p_memory_connection_limits::*;
use std::time::Duration;
use util::*;

use libp2p_swarm::{dial_opts::DialOpts, DialError, Swarm};
use libp2p_swarm_test::SwarmExt;

#[test]
fn max_bytes() {
    const CONNECTION_LIMIT: usize = 20;
    let max_allowed_bytes = CONNECTION_LIMIT * 1024 * 1024;

    let mut network = Swarm::new_ephemeral(|_| TestBehaviour {
        connection_limits: Behaviour::with_max_bytes(max_allowed_bytes),
        mem_consumer: ConsumeMemoryBehaviour1MBPending0Established::default(),
    });

    let addr: Multiaddr = "/memory/1234".parse().unwrap();
    let target = PeerId::random();

    // Exercise `dial` function to get more stable memory stats later
    network
        .dial(
            DialOpts::peer_id(target)
                .addresses(vec![addr.clone()])
                .build(),
        )
        .expect("Unexpected connection limit.");

    // Adds current mem usage to the limit and update
    let max_allowed_bytes_plus_base_usage =
        max_allowed_bytes + memory_stats::memory_stats().unwrap().physical_mem;
    network.behaviour_mut().connection_limits =
        Behaviour::with_max_bytes(max_allowed_bytes_plus_base_usage);

    for _ in 0..CONNECTION_LIMIT {
        network
            .dial(
                DialOpts::peer_id(target)
                    // Always dial, even if connected or already dialing.
                    .condition(libp2p_swarm::dial_opts::PeerCondition::Always)
                    .addresses(vec![addr.clone()])
                    .build(),
            )
            .expect("Unexpected connection limit.");
    }

    std::thread::sleep(Duration::from_millis(100)); // Memory stats are only updated every 100ms internally, ensure they are up-to-date when we try to exceed it.

    match network
        .dial(
            DialOpts::peer_id(target)
                .condition(libp2p_swarm::dial_opts::PeerCondition::Always)
                .addresses(vec![addr])
                .build(),
        )
        .expect_err("Unexpected dialing success.")
    {
        DialError::Denied { cause } => {
            let exceeded = cause
                .downcast::<MemoryUsageLimitExceeded>()
                .expect("connection denied because of limit");

            assert_eq!(
                exceeded.max_allowed_bytes(),
                max_allowed_bytes_plus_base_usage
            );
            assert!(exceeded.process_physical_memory_bytes() >= exceeded.max_allowed_bytes());
        }
        e => panic!("Unexpected error: {e:?}"),
    }
}